International Journal of Cardiology 174 (2014) 348–354
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
A case series of patients with poorly-tolerated arrhythmias related to a preexcitation syndrome and presenting with atypical ECG Béatrice Brembilla-Perrot 1, Jean Marc Sellal, Arnaud Olivier, Vladimir Manenti, Daniel Beurrier, Bassam Al Jouma, Marius Andronache, Christian de Chillou, Nicolas Girerd, Thibaut Villemin Department of Cardiology, University Hospital of Brabois, Vandoeuvre Les Nancy, France
a r t i c l e
i n f o
Article history: Received 18 February 2014 Received in revised form 25 March 2014 Accepted 9 April 2014 Available online 18 April 2014 Keywords: Wolff–Parkinson–White syndrome ECG Electrophysiologic study
a b s t r a c t The aim of study was to report different and unusual patterns of preexcitation syndrome (PS) noted in patients referred for studied for poorly-tolerated arrhythmias and their frequency. Electrophysiologic study (EPS) is an easy means to identify a patient with PS at risk of serious events. However the main basis for this diagnosis is the ECG which associates short PR interval and widening of QRS complex with a delta wave. Methods: ECGs of 861 patients in whom PS related to an atrioventricular accessory pathway (AP) was identified at electrophysiological study (EPS), were studied. Results: The most frequent unusual presentation (9.6%) was the PS presenting with a normal or near normal ECG, noted preferentially for left lateral AP and rarely for posteroseptal or right lateral location. More exceptional (0.1%) was the presence of a long PR interval, which did not exclude a rapid conduction over AP. The association of a complete AV block with symptomatic tachycardias was exceptional (0.3%) and was shown related to a rapid conduction over AP after isoproterenol. Most of the presented patients were at high-risk at EPS. Conclusion: The diagnosis of PS is not always evident and symptoms should draw attention to minor abnormalities and lead to enlarge indications of EPS, only means to confirm or not PS. © 2014 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Wolff–Parkinson–White syndrome (WPW) is diagnosed by the surface ECG in sinus rhythm with a typical pattern associating a short PR interval (b 0.12 s in adults) and a widening of QRS complex with a delta wave [1], called the preexcitation syndrome (PS). The pattern is associated with history of tachycardia. Patients with a PS can be asymptomatic. Some of these patients and patients with a WPW syndrome are known to be at risk of sudden death. The risk is low [2–6] and estimated to be of 0.02% per patient per year [4]. These studies have shown that ventricular fibrillation may be the first event. This low risk of arrhythmias associated with adverse presentation needs to be detected because the events frequently occur in young people without heart disease and a preventive treatment is possible. The main means of diagnosis is the initial ECG. A pattern of PS is noted among 0.1 to 0.5% of the population [7]. The pattern is dependent on the location of accessory pathway (AP), but also on the properties of atrioventricular (AV) node and His Purkinje system and there is a wide spectrum of ECG types encountered. Spontaneous normalization of ECG with intermittent preexcitation is reported in 20
E-mail address: [email protected] (B. Brembilla-Perrot). Cardiology, University Hospital of Brabois, 54500 Vandoeuvre Les Nancy, France. Tel.: +33 3 83 15 32 56; fax: +33 3 83 15 42 26. 1
http://dx.doi.org/10.1016/j.ijcard.2014.04.114 0167-5273/© 2014 Elsevier Ireland Ltd. All rights reserved.
to 30% of WPW [8,9]; dynamic QRS variations in WPW syndrome were noted several years ago [10,11]. The purpose of study was to report unusual patterns of PS, the electrophysiological data of these patients and the prevalence of these atypical patterns in subjects with antegrade conduction through an AP. 2. Methods 2.1. Population The present cases were issued from a consecutive series of 861 patients in whom a PS related to an atrioventricular AP was identified at EPS. There were 528 males and 333 females, aged from 5 to 85 years (mean 34 ± 17). The subjects were consecutively examined in our department between 1990 and May 2013. The initial clinical presentation of the total population was as follows: Three hundred fifty nine patients had a known history of orthodromic AV reciprocating tachycardia. Three hundred five patients were asymptomatic: ventricular PS was discovered during a systematic assessment before anesthesia, before sporting license, prior to employment in certain occupations at risk or on an ECG performed in the preventive medicine. One hundred five patients presented with unexplained syncope without documentation of any arrhythmia, event that was generally the initial cause leading to indicate EPS. Twenty eight patients presented with a documented well-tolerated spontaneous atrial fibrillation (AF). Sixty four patients had an adverse presentation defined as a documented lifethreatening hemodynamically poorly-tolerated arrhythmia.
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354 2.2. Methods The data of ECG at the time of EPS and the data of EPS were retrospectively collected and studied. 1. 2.
3.
Clinical data and the ECG in sinus rhythm were collected. EPS was performed either by intracardiac route in symptomatic patients or first by the transesophageal route in out-patient clinic when these patients were asymptomatic or had unexplained syncope. Our protocol was previously reported [12]. Atrial pacing and programmed atrial stimulation were performed in the basal state and generally after isoproterenol. Definitions. AP location was determined with the 12-lead ECG recorded in maximal preexcitation. The diagnosis of multiple pathways was retained only if ECGs in maximal preexcitation were clearly different or if the sites of ablation were also clearly different. The exact location generally was confirmed by the disappearance of AP at the presumed site during ablation. Unapparent preexcitation syndrome was defined as a normal ECG at the time at electrophysiology which can be related to a masked preexcitation or an intermittent preexcitation. Masked preexcitation was defined as overt antegrade conduction over AP masked by the normal AV conduction. These patients have a minimal preexcitation on the ECG. The signs of the conduction over an AP could be retrospectively detected by the appearance of minor changes of ECG after AP ablation. Intermittent preexcitation was defined as a normal ECG related to a normal AV conduction recorded among patients who presented overt preexcitation on another ECG. PS was considered as at high-risk at EPS when the following association was observed: the maximal heart rate with a 1 to 1 conduction over the AP was more than 240 bpm in control state or more than 290 bpm after isoproterenol infusion [13] during induced sustained AF.
3. Results Seven unusual ECGs are presented. The data are summarized in Table 1. 3.1. Masked PS associated with poorly-tolerated arrhythmias was the most frequent unusual presentation The ECGs were recorded in patients complaining of tachycardia or syncope. Atrial pacing and EPS revealed the presence of a malignant form of PS. The AP conducted in the anterograde conduction was frequently left-lateral sided. Minor changes of ECG were noted after AP successful ablation, but were variable: In case 1, a man aged 46 years (Fig. 1), only r′ in V1 disappeared after ablation.
349
In case 2, a man aged 43 years (Fig. 2), the size of R wave decreased in precordial leads from V1 to V5 after ablation with a change of a pattern R/s to r/S in leads V2 and V3. In case 3, a man aged 25 years (Figs. 3 and 4), the size of R wave in lead V2 decreased after ablation. Less frequently, PS was related to a posteroseptal AP (Fig. 5). The man aged of 57 years had presented a poorly-tolerated AF requiring emergent electrical shock. ECG in sinus rhythm was normal. After ablation of the left posteroseptal AP, a small decrease of the size of ventriculograms in frontal leads was noted. Precordial leads were unchanged. Rarely preexcitation syndrome can be related to a right lateral AP (Fig. 6). In this last case, patient of 25 years complaining of tachycardias, the ECG was normal. At EPS, antidromic tachycardia and then atrial fibrillation using a right lateral AP were induced. Ablation was performed in sinus rhythm because at the site of right lateral AP there was a direct activation of ventricles by atrial activity despite a normal ECG. After ablation, ECG was unchanged despite increasing delay between atrial electrogram and ventriculogram at the site of ablation. These unapparent PSs were noted in 83 patients of our population (9.6%) and 12% of them had a high-risk PS; 46 other patients had intermittent PS. 3.2. Delta waves and long PR interval Fig. 7 was recorded in a man aged 64 years, who had presented a poorly-tolerated AF requiring electrical chock in emergency. There was a delta wave but PR interval was prolonged (220 ms). After ablation of a left lateral sided AP, PR interval was 240 ms in relationship with AV node conduction abnormalities (AH interval 140 ms). Despite poor conduction in normal AV system, the rate in AF conducted by AP was rapid. This ECG remains exceptional and was noted only in one patient of our population (0.1%). 3.3. Complete AV block and preexcitation syndrome Fig. 8 reports the case of a 58 year old man complaining of poorlytolerated tachycardias associated with supraventricular tachycardiarelated tachycardiomyopathy and heart failure. This last complication was facilitated by the presence of left ventricular noncompaction. Three years earlier, ablation of a right posteroseptal sided AP responsible for orthodromic re-entrant tachycardia was complicated by the occurrence of a complete AV block. A pace-maker was implanted. Left ventricular ejection fraction was preserved. Later the patient still complained of tachycardia and was admitted for heart failure. Frequent episodes of tachycardias with wide QRS complexes were recorded on a Holter monitor. Therefore a second EPS was performed. At control state, there were no anterograde and retrograde conductions over normal AV conduction system or over AP. After isoproterenol infusion, the
Table 1 Presentation of the case series. Gender: M = male, ECG: N = normal; 1 AVB = first d AV block, PS: preexcitation syndrome, 3rd D AVB: 3rd degree AV; symptoms: S syncope, PT T: poorly-tolerated documented tachycardia, PT AF = poorly-tolerated AF, HF: stage 3 or 4 heart failure; AP loc = AP location, LL left lateral, LPS left posteroseptal, R PS right posteroseptal, AS anteroseptal, RL right lateral; rate base: maximal heat rate conducted over AP in basal state (bpm); rate iso = maximal heat rate conducted over AP during isoproterenol infusion (bpm); ind T = induced tachycardia: ATD antidromic tachycardia, AVRT: AV re-entrant tachycardia, AF: atrial fibrillation. Case
Age
Gender
ECG
Symptoms
AP loc
Rate base
Rate iso
Ind T
1 2 3 4 5 6 7
46 43 25 57 25 64 58
M M M M M M M
N N N N N 1AVB 3rd d AVB
PT T PT AF PT AF PT AF PT AF PT AF HF
LL LL LL LPS RL LL RPS
220 240 230 260 220 220 0
280 290 300
AF AF AF AF AF AF AF
290 290 280
+ AVRT + ATD + AVRT + AVRT + ATD
350
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
Fig. 1. (Patient no. 1): On the left panel: induced sustained AF; AF was conducted over AP at high rate (N240 bpm). On the right panel: ECG recorded during AP ablation (arrow); before ablation the ECG was near normal. We note a transitory maximal conduction over AP (or radiofrequency-induced automaticity at AP) and then a disappearance of the r′ wave in V1 probably related to the conduction over AP.
right posteroseptal AP was capable of rapid anterograde AV conduction until 280 bpm reproducing the symptoms. After AP ablation, the patient was in complete AV block with QRS complexes of normal duration (0.10 s) (suprahisian AV block) and was dependent on its pacemaker. He became asymptomatic. Two other cases of complete AV block associated with PS were noted in our population: another iatrogenic AV block occurred in a patient with a concealed conduction over a left posteroseptal AP during the attempt of AP ablation; it was related to an inadvertent normal AV conduction ablation; an anterograde conduction over the AP reappeared later and the patient still presented reentrant tachycardias despite the complete AV block. A second procedure was required to ablate the AP. One natural paroxysmal AV block was noted in a patient complaining of syncope (0.3%). Pacemaker implantation suppressed syncope and ablation of the AP was not required. 4. Discussion We have reported some ECGs considered as normal, or with atypical presentation, that are considered as rare in PS. These patients were
studied because they complained of tachycardia or unexplained dizziness/syncope. Similar findings could be expected in apparently asymptomatic subjects; systematic ECG in subjects at risk of arrhythmias as athletes is probably not sufficient to eliminate the presence of a masked electrical abnormality as a PS sometimes at risk of serious events. The interpretation of symptoms by patient is variable and some patients with overt PS are presented as asymptomatic but after interrogatory, dyspnea, chest pain or transitory anxiousness are frequently noted in patients with induced tachycardia. The most frequent unusual ECG of PS was the masked pattern of PS, associated with minor signs of preexcitation retrospectively visible when ECG became slightly different after AP ablation. The reported cases had a masked preexcitation, defined as overt anterograde conduction through the AP masked by the normal AV conduction. These patients have a minimal preexcitation on the ECG that may become apparent when this ECG differed after ablation. These cases differed from patients with intermittent preexcitation defined as a normal ECG related to a normal AV conduction recorded among patients who presented overt preexcitation on another ECG.
Fig. 2. (Patient no. 2): On the left panel: spontaneous malignant form in a patient with a left lateral AP; On the middle panel: ECG before ablation. On the right panel: ECG after ablation: The size of R wave decreased in precordial leads from V1 to V5 after ablation (right ECG). There was a new appearance of T wave inversion in III and aVF just after ablation not explained by the site of ablation (left lateral). This figure was previously reported [14].
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
351
Fig. 3. (Patient no. 3): On the left panel: induced atrial fibrillation conducted at 300 bpm over AP in a patient with a left-lateral sided AP complaining of tachycardia. On the right panel: disappearance of conduction over AP only visible on the distal coronary sinus recording with an abrupt increase of AV interval.
We previously reported that the frequency of a normal or near normal ECG in patients who had a preexcitation syndrome proved by electrophysiologic study represented 11% of our population with anterograde conduction through an AP; this prevalence could be underestimated [14,15]. This prevalence included the patients with intermittent PS and the patients with masked PS. The risk to have an electrophysiological malignant form was reported as similar to patients with permanently overt preexcitation syndrome in sinus rhythm. The importance of ventricular preexcitation on ECG in sinus rhythm depends on the quality of the nodohisian conduction and the distance between the AP and the normal conduction system [9]. More AP is located away from the sinus node and the normal atrioventricular system, less ventricular preexcitation is visible. Concealed conduction in
anomalous AV bypass tracts can be demonstrated in both anterograde and retrograde directions in most patients with WPW syndrome and is an important factor in the clinical expression of their arrhythmias [16,17]. Changes in atrioventricular conduction may account for the variability of the QRS pattern in patients with a PS [18–20]. Most of our patients had a left lateral AP, but some of them had septal or right APs and we have no explanation for the absence of clear sign of preexcitation in sinus rhythm, except a preferential conduction over normal AV system. Exceptionally, the PR interval is greater than 0.12 s [16], the QRS complex is more or less wide and there is a delta wave. This form of pre-excitation is more common in left AP than in right APs. It is due to a disorder of intra-atrial conduction or a first degree block in the AP
Fig. 4. (Patient no. 3): ECGs recorded just before ablation and after successful ablation (patient of Fig. 3). On the left panel: ECG before ablation; On the right panel: ECG after ablation; the surface ECG is near similar before and after ablation. Only the size of R wave in leads V2 and V3 decreased after ablation (right ECG) with a change of a pattern of R/s to r/S after ablation.
352
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
Fig. 5. (Patient no. 4): On the left panel: poorly-tolerated atrial fibrillation conducted over a septal AP (QS pattern in leads II, III, VF) requiring emergent electrical shock and occurring in a patient with a preexcitation syndrome related to a left posteroseptal AP. On the right panel: ECG during ablation of the left posteroseptal AP indicated by the arrow; a small decrease of the size of ventriculograms in frontal leads was noted corresponding to the disappearance of anterograde conduction over AP. Precordial leads were unchanged.
[21]. In our case nodal AV conduction was abnormal. It was reported in less than 1/1000 patients with a PS. The long PR interval does not exclude a rapid conduction over AP in the case of AF as in our patient.
At least, disorders of conduction occurring simultaneously in both normal and AP's of patients with a PS have only rarely been observed [22]. Impaired conduction in both pathways in PS has been noted in
Fig. 6. (Patient no. 5): On the left panel: only short PR interval on the ECG before ablation. On the middle panel: AF using initially normal AV conduction system and a right lateral AP. On the right panel: ECG during ablation; on the right lateral atrium there was a site with a fusion of atrial and ventricular electrograms. The arrow on the lead of ablation indicated that application of radiofrequency energy at this site increased immediately the interval between atrial and ventricular electrograms. After ablation, ECG was unchanged (leads D1, D2, VF, V1, V6) with the same short PR interval despite increasing delay between atrial electrogram and ventriculogram at the site of ablation visible on the third beat of the right panel.
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
353
Fig. 7. (Patient no. 6): On the left panel: spontaneous malignant form in a patient with a left lateral AP. On the right panel: ECG during ablation; there is a long PR interval before ablation despite a presentation with a malignant form. After AP ablation, the PR interval was slightly longer.
patient with mitral annulus calcification [23]. Infrahisian conduction abnormalities were previously reported by our group in one patient with syncope [24]. One-to-one conduction through the AP occurred only at a distinct range of cycle lengths, at lower frequencies the accessory tracts were refractory and a 2nd or a 3rd degree A-V block occurred. In our case, the patient had adrenergic tachycardia rapidly conducted over AP and developed tachycardia-induced cardiomyopathy. Isoproterenol infusion frequently used to enhance conduction over AP is capable to demonstrate an anterograde rapid conduction over AP [25, 26]. Vagal stimulation was used several years ago to provoke the reappearance of ventricular preexcitation [27]. The clinical implications are important. Apparently normal ECG does not exclude the presence of an accessory pathway. Therefore systematic
ECG is probably not sufficient in asymptomatic subjects at high of arrhythmias as competitive athletes or military or police to exclude the diagnosis. We must be especially vigilant in symptomatic patients complaining of tachycardia associated or not with syncope. ECG should be repeated and non-invasive studies as exercise testing and ECG Holter monitoring are indicated to look for small variations of QRS morphology. If it is done locally, transesophageal atrial pacing is an easy way to reveal a preexcitation syndrome. The limitation of the study is the lack of repetition of ECG in sinus rhythm, of systematic exercise testing and vagal maneuvers to evaluate possible changes of ECG that have oriented the diagnosis. In conclusion preexcitation syndromes may present with several unusual patterns on ECG. Classical pattern of PS is not always present
Fig. 8. (Patient no. 7): On the left panel: intermittent conduction over a right posteroseptal AP (first and last complexes) in a patient with complete AV block; the other enlarged QRS complexes are stimulated electrograms. On the middle panel: after isoproterenol infusion, 1/1 conduction over AP. On the right panel: after AP ablation, complete AV block and QRS with a normal duration.
354
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
and in symptomatic patients minor signs of PS should be sought. All locations of AP's can be encountered, but left lateral location is the more frequent location presenting with a near normal ECG. References [1] Anderson RH, Becker AE, Brechenmacher C, Davies MJ, Rossi L. Ventricular preexcitation. A proposed nomenclature for its substrates. Eur J Cardiol 1975;3:27–36. [2] Klein GJ, Bashore TM, Sellers TD, Pritchett ELC, Smith WM, Gallagher JS. Ventricular fibrillation in the Wolff–Parkinson–White syndrome. N Engl J Med 1979;301:1080–5. [3] Brembilla-Perrot B, Aliot E, Louis P, et al. Devenir de 195 patients atteints de syndrome de Wolff–Parkinson–White. Arch Mal Coeur 1987;80:271–7. [4] Fitzsimmons PJ, Mc Whirter PD, Peterson DW, Kruyer WB. The natural history of Wolff–Parkinson–White syndrome in 228 military aviators: a long-term follow-up of 22 years. Am Heart J 2001;142:530–6. [5] Timmermanns C, Smeets JL, Rodriguez LM, Vrouchos G, Van den Dool A, Wellens HJ. Aborted sudden death in the Wolff–Parkinson–White syndrome. Am J Cardiol 1995;76:492–4. [6] Montoya P, Brugada P, Smeets J, et al. Ventricular fibrillation in the Wolff– Parkinson–White syndrome. Eur Heart J 1991;12:144–50. [7] Pelliccia A, Culasso F, Di Paolo FM, et al. Prevalence of abnormal electrocardiograms in a large, unselected population undergoing pre-participation cardiovascular screening. Eur Heart J 2007;28:2006–10. [8] Klein GJ, Gulamhusein SS. Intermittent preexcitation in the Wolff–Parkinson–White syndrome. Am J Cardiol 1983;52:292–6. [9] Garcia OL, Castellanos A, Vagueiro MC, Myerburg RJ, Gelband H. Arrival of excitation at the left ventricular apical endocardium in W.P.W. syndrome type B. J Electrocardiol 1982;15:165–72. [10] Hindman MC, Last JH, Rosen KM. W.P.W. syndrome observed by portable monitoring. Ann Intern Med 1973;79:654–63. [11] Khair GZ, Tristami FE, Bamrath VS. Dynamic QRS variations in Wolff–Parkinson– White syndrome: electrocardiographic and clinical observations. Am Heart J 1983;105:878–82. [12] Brembilla-Perrot B, Chometon F, Groben L, et al. Interest of non-invasive and semiinvasive testings in asymptomatic children with pre-excitation syndrome. Europace 2007;9:837–43. [13] Brembilla-Perrot B, Tatar C, Suty-Selton C. Risk factors of adverse presentation as the first arrhythmia in Wolff–Parkinson–White syndrome. Pacing Clin Electrophysiol 2010;33:1074–81.
[14] Brembilla-Perrot B, Brembilla-Perrot B, Valizadeh Moejezi R, et al. Missing diagnosis of preexcitation syndrome on ECG. Clinical and electrophysiological significance. Int J Cardiol 2013;163:288–93. [15] Brembilla-Perrot B, Moulin-Zinsch A, Sellal JM, et al. Impact of transesophageal EP study to elucidate the mechanism of arrhythmia in children with SVT and no preexcitation. Pediatr Cardiol 2013;34:1695–702. [16] Klein GJ, Yee R, Sharma AD. Concealed conduction in accessory atrioventricular pathways: an important determinant of the expression of arrhythmias in patients with Wolff–Parkinson–White syndrome. Circulation 1984;70:402–11. [17] Svinarich JT, Tai DY, Mickelson J, Keung EC, Sung RJ. Electrophysiologic demonstration of concealed conduction in anomalous atrioventricular bypass tracts. J Am Coll Cardiol 1985;5:898–903. [18] Parameswaran R, Ohe T, Nakhjavan FK, Goldberg H. Spontaneous variations in atrioventricular conduction in pre-excitation. Br Heart J 1976;38:427–30. [19] Teo WS, Klein GJ, Yee R, Leitch JW, Murdock CJ. Significance of minimal preexcitation in W.P.W. syndrome. Am J Cardiol 1991;67:205–7. [20] Fujiki A, Yoshida S, Tani M, Mizumaki K, Tsuji H, Sasayama S. Phase 3 and phase 4 block in the accessory pathway. J Cardiol 1990;20:217–25. [21] Guérot C, Valere P-E, Castillo-Fenoy A, Rl Tricot. Syndrome de W.P.W. et espace P R long. A propos d'une observation associant une double voie de préexcitation et un trouble de conduction intra-auriculaire. Ann Cardiol Angeiol 1975;24:51–7. [22] Seipel L, Mäurer W, Zebe H. Severe atrioventricular block in 2 cases with preexcitation syndrome. Z Kardiol 1976;65:616–23. [23] Kriwisky M, Goldstein J, Gotsman MS. Accessory atrioventricular pathway, supra-, and infrahisian conduction impaired due to mitral annulus calcification. Clin Cardiol 1987;10:818–20. [24] Brembilla-Perrot B, Chometon F, Groben L, et al. Are the results of electrophysiological study different in patients with a pre-excitation syndrome, with and without syncope? Europace 2008;10:175–80. [25] Easley Jr AR, Sensecqua JE, Mann DE, Reiter MJ. Intermittent preexcitation: marked enhancement of anterograde conduction in the atrioventricular accessory pathway with isoproterenol. Pacing Clin Electrophysiol 1988;11:349–54. [26] Yamamoto T, Yeh SJ, Lin FC, Wu DL. Effects of isoproterenol on accessory pathway conduction in intermittent or concealed Wolff–Parkinson–White syndrome. Am J Cardiol 1990;65:1438–42. [27] Przybylski J, Chiale PA, Halpern MS, Nau GJ, Elizari MV, Rosenbaum MB. Unmasking of ventricular preexcitation by vagal stimulation or isoproterenol administration. Circulation 1980;61:1030–7.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
A case series of patients with poorly-tolerated arrhythmias related to a preexcitation syndrome and presenting with atypical ECG Béatrice Brembilla-Perrot 1, Jean Marc Sellal, Arnaud Olivier, Vladimir Manenti, Daniel Beurrier, Bassam Al Jouma, Marius Andronache, Christian de Chillou, Nicolas Girerd, Thibaut Villemin Department of Cardiology, University Hospital of Brabois, Vandoeuvre Les Nancy, France
a r t i c l e
i n f o
Article history: Received 18 February 2014 Received in revised form 25 March 2014 Accepted 9 April 2014 Available online 18 April 2014 Keywords: Wolff–Parkinson–White syndrome ECG Electrophysiologic study
a b s t r a c t The aim of study was to report different and unusual patterns of preexcitation syndrome (PS) noted in patients referred for studied for poorly-tolerated arrhythmias and their frequency. Electrophysiologic study (EPS) is an easy means to identify a patient with PS at risk of serious events. However the main basis for this diagnosis is the ECG which associates short PR interval and widening of QRS complex with a delta wave. Methods: ECGs of 861 patients in whom PS related to an atrioventricular accessory pathway (AP) was identified at electrophysiological study (EPS), were studied. Results: The most frequent unusual presentation (9.6%) was the PS presenting with a normal or near normal ECG, noted preferentially for left lateral AP and rarely for posteroseptal or right lateral location. More exceptional (0.1%) was the presence of a long PR interval, which did not exclude a rapid conduction over AP. The association of a complete AV block with symptomatic tachycardias was exceptional (0.3%) and was shown related to a rapid conduction over AP after isoproterenol. Most of the presented patients were at high-risk at EPS. Conclusion: The diagnosis of PS is not always evident and symptoms should draw attention to minor abnormalities and lead to enlarge indications of EPS, only means to confirm or not PS. © 2014 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Wolff–Parkinson–White syndrome (WPW) is diagnosed by the surface ECG in sinus rhythm with a typical pattern associating a short PR interval (b 0.12 s in adults) and a widening of QRS complex with a delta wave [1], called the preexcitation syndrome (PS). The pattern is associated with history of tachycardia. Patients with a PS can be asymptomatic. Some of these patients and patients with a WPW syndrome are known to be at risk of sudden death. The risk is low [2–6] and estimated to be of 0.02% per patient per year [4]. These studies have shown that ventricular fibrillation may be the first event. This low risk of arrhythmias associated with adverse presentation needs to be detected because the events frequently occur in young people without heart disease and a preventive treatment is possible. The main means of diagnosis is the initial ECG. A pattern of PS is noted among 0.1 to 0.5% of the population [7]. The pattern is dependent on the location of accessory pathway (AP), but also on the properties of atrioventricular (AV) node and His Purkinje system and there is a wide spectrum of ECG types encountered. Spontaneous normalization of ECG with intermittent preexcitation is reported in 20
E-mail address: [email protected] (B. Brembilla-Perrot). Cardiology, University Hospital of Brabois, 54500 Vandoeuvre Les Nancy, France. Tel.: +33 3 83 15 32 56; fax: +33 3 83 15 42 26. 1
http://dx.doi.org/10.1016/j.ijcard.2014.04.114 0167-5273/© 2014 Elsevier Ireland Ltd. All rights reserved.
to 30% of WPW [8,9]; dynamic QRS variations in WPW syndrome were noted several years ago [10,11]. The purpose of study was to report unusual patterns of PS, the electrophysiological data of these patients and the prevalence of these atypical patterns in subjects with antegrade conduction through an AP. 2. Methods 2.1. Population The present cases were issued from a consecutive series of 861 patients in whom a PS related to an atrioventricular AP was identified at EPS. There were 528 males and 333 females, aged from 5 to 85 years (mean 34 ± 17). The subjects were consecutively examined in our department between 1990 and May 2013. The initial clinical presentation of the total population was as follows: Three hundred fifty nine patients had a known history of orthodromic AV reciprocating tachycardia. Three hundred five patients were asymptomatic: ventricular PS was discovered during a systematic assessment before anesthesia, before sporting license, prior to employment in certain occupations at risk or on an ECG performed in the preventive medicine. One hundred five patients presented with unexplained syncope without documentation of any arrhythmia, event that was generally the initial cause leading to indicate EPS. Twenty eight patients presented with a documented well-tolerated spontaneous atrial fibrillation (AF). Sixty four patients had an adverse presentation defined as a documented lifethreatening hemodynamically poorly-tolerated arrhythmia.
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354 2.2. Methods The data of ECG at the time of EPS and the data of EPS were retrospectively collected and studied. 1. 2.
3.
Clinical data and the ECG in sinus rhythm were collected. EPS was performed either by intracardiac route in symptomatic patients or first by the transesophageal route in out-patient clinic when these patients were asymptomatic or had unexplained syncope. Our protocol was previously reported [12]. Atrial pacing and programmed atrial stimulation were performed in the basal state and generally after isoproterenol. Definitions. AP location was determined with the 12-lead ECG recorded in maximal preexcitation. The diagnosis of multiple pathways was retained only if ECGs in maximal preexcitation were clearly different or if the sites of ablation were also clearly different. The exact location generally was confirmed by the disappearance of AP at the presumed site during ablation. Unapparent preexcitation syndrome was defined as a normal ECG at the time at electrophysiology which can be related to a masked preexcitation or an intermittent preexcitation. Masked preexcitation was defined as overt antegrade conduction over AP masked by the normal AV conduction. These patients have a minimal preexcitation on the ECG. The signs of the conduction over an AP could be retrospectively detected by the appearance of minor changes of ECG after AP ablation. Intermittent preexcitation was defined as a normal ECG related to a normal AV conduction recorded among patients who presented overt preexcitation on another ECG. PS was considered as at high-risk at EPS when the following association was observed: the maximal heart rate with a 1 to 1 conduction over the AP was more than 240 bpm in control state or more than 290 bpm after isoproterenol infusion [13] during induced sustained AF.
3. Results Seven unusual ECGs are presented. The data are summarized in Table 1. 3.1. Masked PS associated with poorly-tolerated arrhythmias was the most frequent unusual presentation The ECGs were recorded in patients complaining of tachycardia or syncope. Atrial pacing and EPS revealed the presence of a malignant form of PS. The AP conducted in the anterograde conduction was frequently left-lateral sided. Minor changes of ECG were noted after AP successful ablation, but were variable: In case 1, a man aged 46 years (Fig. 1), only r′ in V1 disappeared after ablation.
349
In case 2, a man aged 43 years (Fig. 2), the size of R wave decreased in precordial leads from V1 to V5 after ablation with a change of a pattern R/s to r/S in leads V2 and V3. In case 3, a man aged 25 years (Figs. 3 and 4), the size of R wave in lead V2 decreased after ablation. Less frequently, PS was related to a posteroseptal AP (Fig. 5). The man aged of 57 years had presented a poorly-tolerated AF requiring emergent electrical shock. ECG in sinus rhythm was normal. After ablation of the left posteroseptal AP, a small decrease of the size of ventriculograms in frontal leads was noted. Precordial leads were unchanged. Rarely preexcitation syndrome can be related to a right lateral AP (Fig. 6). In this last case, patient of 25 years complaining of tachycardias, the ECG was normal. At EPS, antidromic tachycardia and then atrial fibrillation using a right lateral AP were induced. Ablation was performed in sinus rhythm because at the site of right lateral AP there was a direct activation of ventricles by atrial activity despite a normal ECG. After ablation, ECG was unchanged despite increasing delay between atrial electrogram and ventriculogram at the site of ablation. These unapparent PSs were noted in 83 patients of our population (9.6%) and 12% of them had a high-risk PS; 46 other patients had intermittent PS. 3.2. Delta waves and long PR interval Fig. 7 was recorded in a man aged 64 years, who had presented a poorly-tolerated AF requiring electrical chock in emergency. There was a delta wave but PR interval was prolonged (220 ms). After ablation of a left lateral sided AP, PR interval was 240 ms in relationship with AV node conduction abnormalities (AH interval 140 ms). Despite poor conduction in normal AV system, the rate in AF conducted by AP was rapid. This ECG remains exceptional and was noted only in one patient of our population (0.1%). 3.3. Complete AV block and preexcitation syndrome Fig. 8 reports the case of a 58 year old man complaining of poorlytolerated tachycardias associated with supraventricular tachycardiarelated tachycardiomyopathy and heart failure. This last complication was facilitated by the presence of left ventricular noncompaction. Three years earlier, ablation of a right posteroseptal sided AP responsible for orthodromic re-entrant tachycardia was complicated by the occurrence of a complete AV block. A pace-maker was implanted. Left ventricular ejection fraction was preserved. Later the patient still complained of tachycardia and was admitted for heart failure. Frequent episodes of tachycardias with wide QRS complexes were recorded on a Holter monitor. Therefore a second EPS was performed. At control state, there were no anterograde and retrograde conductions over normal AV conduction system or over AP. After isoproterenol infusion, the
Table 1 Presentation of the case series. Gender: M = male, ECG: N = normal; 1 AVB = first d AV block, PS: preexcitation syndrome, 3rd D AVB: 3rd degree AV; symptoms: S syncope, PT T: poorly-tolerated documented tachycardia, PT AF = poorly-tolerated AF, HF: stage 3 or 4 heart failure; AP loc = AP location, LL left lateral, LPS left posteroseptal, R PS right posteroseptal, AS anteroseptal, RL right lateral; rate base: maximal heat rate conducted over AP in basal state (bpm); rate iso = maximal heat rate conducted over AP during isoproterenol infusion (bpm); ind T = induced tachycardia: ATD antidromic tachycardia, AVRT: AV re-entrant tachycardia, AF: atrial fibrillation. Case
Age
Gender
ECG
Symptoms
AP loc
Rate base
Rate iso
Ind T
1 2 3 4 5 6 7
46 43 25 57 25 64 58
M M M M M M M
N N N N N 1AVB 3rd d AVB
PT T PT AF PT AF PT AF PT AF PT AF HF
LL LL LL LPS RL LL RPS
220 240 230 260 220 220 0
280 290 300
AF AF AF AF AF AF AF
290 290 280
+ AVRT + ATD + AVRT + AVRT + ATD
350
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
Fig. 1. (Patient no. 1): On the left panel: induced sustained AF; AF was conducted over AP at high rate (N240 bpm). On the right panel: ECG recorded during AP ablation (arrow); before ablation the ECG was near normal. We note a transitory maximal conduction over AP (or radiofrequency-induced automaticity at AP) and then a disappearance of the r′ wave in V1 probably related to the conduction over AP.
right posteroseptal AP was capable of rapid anterograde AV conduction until 280 bpm reproducing the symptoms. After AP ablation, the patient was in complete AV block with QRS complexes of normal duration (0.10 s) (suprahisian AV block) and was dependent on its pacemaker. He became asymptomatic. Two other cases of complete AV block associated with PS were noted in our population: another iatrogenic AV block occurred in a patient with a concealed conduction over a left posteroseptal AP during the attempt of AP ablation; it was related to an inadvertent normal AV conduction ablation; an anterograde conduction over the AP reappeared later and the patient still presented reentrant tachycardias despite the complete AV block. A second procedure was required to ablate the AP. One natural paroxysmal AV block was noted in a patient complaining of syncope (0.3%). Pacemaker implantation suppressed syncope and ablation of the AP was not required. 4. Discussion We have reported some ECGs considered as normal, or with atypical presentation, that are considered as rare in PS. These patients were
studied because they complained of tachycardia or unexplained dizziness/syncope. Similar findings could be expected in apparently asymptomatic subjects; systematic ECG in subjects at risk of arrhythmias as athletes is probably not sufficient to eliminate the presence of a masked electrical abnormality as a PS sometimes at risk of serious events. The interpretation of symptoms by patient is variable and some patients with overt PS are presented as asymptomatic but after interrogatory, dyspnea, chest pain or transitory anxiousness are frequently noted in patients with induced tachycardia. The most frequent unusual ECG of PS was the masked pattern of PS, associated with minor signs of preexcitation retrospectively visible when ECG became slightly different after AP ablation. The reported cases had a masked preexcitation, defined as overt anterograde conduction through the AP masked by the normal AV conduction. These patients have a minimal preexcitation on the ECG that may become apparent when this ECG differed after ablation. These cases differed from patients with intermittent preexcitation defined as a normal ECG related to a normal AV conduction recorded among patients who presented overt preexcitation on another ECG.
Fig. 2. (Patient no. 2): On the left panel: spontaneous malignant form in a patient with a left lateral AP; On the middle panel: ECG before ablation. On the right panel: ECG after ablation: The size of R wave decreased in precordial leads from V1 to V5 after ablation (right ECG). There was a new appearance of T wave inversion in III and aVF just after ablation not explained by the site of ablation (left lateral). This figure was previously reported [14].
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
351
Fig. 3. (Patient no. 3): On the left panel: induced atrial fibrillation conducted at 300 bpm over AP in a patient with a left-lateral sided AP complaining of tachycardia. On the right panel: disappearance of conduction over AP only visible on the distal coronary sinus recording with an abrupt increase of AV interval.
We previously reported that the frequency of a normal or near normal ECG in patients who had a preexcitation syndrome proved by electrophysiologic study represented 11% of our population with anterograde conduction through an AP; this prevalence could be underestimated [14,15]. This prevalence included the patients with intermittent PS and the patients with masked PS. The risk to have an electrophysiological malignant form was reported as similar to patients with permanently overt preexcitation syndrome in sinus rhythm. The importance of ventricular preexcitation on ECG in sinus rhythm depends on the quality of the nodohisian conduction and the distance between the AP and the normal conduction system [9]. More AP is located away from the sinus node and the normal atrioventricular system, less ventricular preexcitation is visible. Concealed conduction in
anomalous AV bypass tracts can be demonstrated in both anterograde and retrograde directions in most patients with WPW syndrome and is an important factor in the clinical expression of their arrhythmias [16,17]. Changes in atrioventricular conduction may account for the variability of the QRS pattern in patients with a PS [18–20]. Most of our patients had a left lateral AP, but some of them had septal or right APs and we have no explanation for the absence of clear sign of preexcitation in sinus rhythm, except a preferential conduction over normal AV system. Exceptionally, the PR interval is greater than 0.12 s [16], the QRS complex is more or less wide and there is a delta wave. This form of pre-excitation is more common in left AP than in right APs. It is due to a disorder of intra-atrial conduction or a first degree block in the AP
Fig. 4. (Patient no. 3): ECGs recorded just before ablation and after successful ablation (patient of Fig. 3). On the left panel: ECG before ablation; On the right panel: ECG after ablation; the surface ECG is near similar before and after ablation. Only the size of R wave in leads V2 and V3 decreased after ablation (right ECG) with a change of a pattern of R/s to r/S after ablation.
352
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
Fig. 5. (Patient no. 4): On the left panel: poorly-tolerated atrial fibrillation conducted over a septal AP (QS pattern in leads II, III, VF) requiring emergent electrical shock and occurring in a patient with a preexcitation syndrome related to a left posteroseptal AP. On the right panel: ECG during ablation of the left posteroseptal AP indicated by the arrow; a small decrease of the size of ventriculograms in frontal leads was noted corresponding to the disappearance of anterograde conduction over AP. Precordial leads were unchanged.
[21]. In our case nodal AV conduction was abnormal. It was reported in less than 1/1000 patients with a PS. The long PR interval does not exclude a rapid conduction over AP in the case of AF as in our patient.
At least, disorders of conduction occurring simultaneously in both normal and AP's of patients with a PS have only rarely been observed [22]. Impaired conduction in both pathways in PS has been noted in
Fig. 6. (Patient no. 5): On the left panel: only short PR interval on the ECG before ablation. On the middle panel: AF using initially normal AV conduction system and a right lateral AP. On the right panel: ECG during ablation; on the right lateral atrium there was a site with a fusion of atrial and ventricular electrograms. The arrow on the lead of ablation indicated that application of radiofrequency energy at this site increased immediately the interval between atrial and ventricular electrograms. After ablation, ECG was unchanged (leads D1, D2, VF, V1, V6) with the same short PR interval despite increasing delay between atrial electrogram and ventriculogram at the site of ablation visible on the third beat of the right panel.
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
353
Fig. 7. (Patient no. 6): On the left panel: spontaneous malignant form in a patient with a left lateral AP. On the right panel: ECG during ablation; there is a long PR interval before ablation despite a presentation with a malignant form. After AP ablation, the PR interval was slightly longer.
patient with mitral annulus calcification [23]. Infrahisian conduction abnormalities were previously reported by our group in one patient with syncope [24]. One-to-one conduction through the AP occurred only at a distinct range of cycle lengths, at lower frequencies the accessory tracts were refractory and a 2nd or a 3rd degree A-V block occurred. In our case, the patient had adrenergic tachycardia rapidly conducted over AP and developed tachycardia-induced cardiomyopathy. Isoproterenol infusion frequently used to enhance conduction over AP is capable to demonstrate an anterograde rapid conduction over AP [25, 26]. Vagal stimulation was used several years ago to provoke the reappearance of ventricular preexcitation [27]. The clinical implications are important. Apparently normal ECG does not exclude the presence of an accessory pathway. Therefore systematic
ECG is probably not sufficient in asymptomatic subjects at high of arrhythmias as competitive athletes or military or police to exclude the diagnosis. We must be especially vigilant in symptomatic patients complaining of tachycardia associated or not with syncope. ECG should be repeated and non-invasive studies as exercise testing and ECG Holter monitoring are indicated to look for small variations of QRS morphology. If it is done locally, transesophageal atrial pacing is an easy way to reveal a preexcitation syndrome. The limitation of the study is the lack of repetition of ECG in sinus rhythm, of systematic exercise testing and vagal maneuvers to evaluate possible changes of ECG that have oriented the diagnosis. In conclusion preexcitation syndromes may present with several unusual patterns on ECG. Classical pattern of PS is not always present
Fig. 8. (Patient no. 7): On the left panel: intermittent conduction over a right posteroseptal AP (first and last complexes) in a patient with complete AV block; the other enlarged QRS complexes are stimulated electrograms. On the middle panel: after isoproterenol infusion, 1/1 conduction over AP. On the right panel: after AP ablation, complete AV block and QRS with a normal duration.
354
B. Brembilla-Perrot et al. / International Journal of Cardiology 174 (2014) 348–354
and in symptomatic patients minor signs of PS should be sought. All locations of AP's can be encountered, but left lateral location is the more frequent location presenting with a near normal ECG. References [1] Anderson RH, Becker AE, Brechenmacher C, Davies MJ, Rossi L. Ventricular preexcitation. A proposed nomenclature for its substrates. Eur J Cardiol 1975;3:27–36. [2] Klein GJ, Bashore TM, Sellers TD, Pritchett ELC, Smith WM, Gallagher JS. Ventricular fibrillation in the Wolff–Parkinson–White syndrome. N Engl J Med 1979;301:1080–5. [3] Brembilla-Perrot B, Aliot E, Louis P, et al. Devenir de 195 patients atteints de syndrome de Wolff–Parkinson–White. Arch Mal Coeur 1987;80:271–7. [4] Fitzsimmons PJ, Mc Whirter PD, Peterson DW, Kruyer WB. The natural history of Wolff–Parkinson–White syndrome in 228 military aviators: a long-term follow-up of 22 years. Am Heart J 2001;142:530–6. [5] Timmermanns C, Smeets JL, Rodriguez LM, Vrouchos G, Van den Dool A, Wellens HJ. Aborted sudden death in the Wolff–Parkinson–White syndrome. Am J Cardiol 1995;76:492–4. [6] Montoya P, Brugada P, Smeets J, et al. Ventricular fibrillation in the Wolff– Parkinson–White syndrome. Eur Heart J 1991;12:144–50. [7] Pelliccia A, Culasso F, Di Paolo FM, et al. Prevalence of abnormal electrocardiograms in a large, unselected population undergoing pre-participation cardiovascular screening. Eur Heart J 2007;28:2006–10. [8] Klein GJ, Gulamhusein SS. Intermittent preexcitation in the Wolff–Parkinson–White syndrome. Am J Cardiol 1983;52:292–6. [9] Garcia OL, Castellanos A, Vagueiro MC, Myerburg RJ, Gelband H. Arrival of excitation at the left ventricular apical endocardium in W.P.W. syndrome type B. J Electrocardiol 1982;15:165–72. [10] Hindman MC, Last JH, Rosen KM. W.P.W. syndrome observed by portable monitoring. Ann Intern Med 1973;79:654–63. [11] Khair GZ, Tristami FE, Bamrath VS. Dynamic QRS variations in Wolff–Parkinson– White syndrome: electrocardiographic and clinical observations. Am Heart J 1983;105:878–82. [12] Brembilla-Perrot B, Chometon F, Groben L, et al. Interest of non-invasive and semiinvasive testings in asymptomatic children with pre-excitation syndrome. Europace 2007;9:837–43. [13] Brembilla-Perrot B, Tatar C, Suty-Selton C. Risk factors of adverse presentation as the first arrhythmia in Wolff–Parkinson–White syndrome. Pacing Clin Electrophysiol 2010;33:1074–81.
[14] Brembilla-Perrot B, Brembilla-Perrot B, Valizadeh Moejezi R, et al. Missing diagnosis of preexcitation syndrome on ECG. Clinical and electrophysiological significance. Int J Cardiol 2013;163:288–93. [15] Brembilla-Perrot B, Moulin-Zinsch A, Sellal JM, et al. Impact of transesophageal EP study to elucidate the mechanism of arrhythmia in children with SVT and no preexcitation. Pediatr Cardiol 2013;34:1695–702. [16] Klein GJ, Yee R, Sharma AD. Concealed conduction in accessory atrioventricular pathways: an important determinant of the expression of arrhythmias in patients with Wolff–Parkinson–White syndrome. Circulation 1984;70:402–11. [17] Svinarich JT, Tai DY, Mickelson J, Keung EC, Sung RJ. Electrophysiologic demonstration of concealed conduction in anomalous atrioventricular bypass tracts. J Am Coll Cardiol 1985;5:898–903. [18] Parameswaran R, Ohe T, Nakhjavan FK, Goldberg H. Spontaneous variations in atrioventricular conduction in pre-excitation. Br Heart J 1976;38:427–30. [19] Teo WS, Klein GJ, Yee R, Leitch JW, Murdock CJ. Significance of minimal preexcitation in W.P.W. syndrome. Am J Cardiol 1991;67:205–7. [20] Fujiki A, Yoshida S, Tani M, Mizumaki K, Tsuji H, Sasayama S. Phase 3 and phase 4 block in the accessory pathway. J Cardiol 1990;20:217–25. [21] Guérot C, Valere P-E, Castillo-Fenoy A, Rl Tricot. Syndrome de W.P.W. et espace P R long. A propos d'une observation associant une double voie de préexcitation et un trouble de conduction intra-auriculaire. Ann Cardiol Angeiol 1975;24:51–7. [22] Seipel L, Mäurer W, Zebe H. Severe atrioventricular block in 2 cases with preexcitation syndrome. Z Kardiol 1976;65:616–23. [23] Kriwisky M, Goldstein J, Gotsman MS. Accessory atrioventricular pathway, supra-, and infrahisian conduction impaired due to mitral annulus calcification. Clin Cardiol 1987;10:818–20. [24] Brembilla-Perrot B, Chometon F, Groben L, et al. Are the results of electrophysiological study different in patients with a pre-excitation syndrome, with and without syncope? Europace 2008;10:175–80. [25] Easley Jr AR, Sensecqua JE, Mann DE, Reiter MJ. Intermittent preexcitation: marked enhancement of anterograde conduction in the atrioventricular accessory pathway with isoproterenol. Pacing Clin Electrophysiol 1988;11:349–54. [26] Yamamoto T, Yeh SJ, Lin FC, Wu DL. Effects of isoproterenol on accessory pathway conduction in intermittent or concealed Wolff–Parkinson–White syndrome. Am J Cardiol 1990;65:1438–42. [27] Przybylski J, Chiale PA, Halpern MS, Nau GJ, Elizari MV, Rosenbaum MB. Unmasking of ventricular preexcitation by vagal stimulation or isoproterenol administration. Circulation 1980;61:1030–7.
