Ventricular Tachycard ia in C o n g e n i t a l Pu l m o n a r y Stenosis Emily Sue Ruckdeschel, MD, Joseph Schuller, MD, Duy Thai Nguyen, MD* KEYWORDS Congenital heart disease Congenital pulmonary stenosis Ventricular tachycardia
KEY POINTS With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Although congenital pulmonary valve (PV) stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope.
A 53-year-old woman with history of congenital PV stenosis, status post–surgical valvotomy and transannular patch at the age of 13 years, presented with left bundle branch block morphology ventricular tachycardia (VT), inferior axis, and transition at leads V3 to V4 (Fig. 1), which was treated with amiodarone. Further evaluation was significant for severe pulmonary insufficiency, a dilated right ventricle (RV), and an RV outflow tract aneurysm. She ultimately underwent PV replacement with a #29 bovine Carpentier-Edwards valve and aneurysm imbrication. At the time of her valve replacement, she underwent surgical cryoablation of the RV outflow tract. Cryoablation was performed from the RV outflow tract to the PV, from below the PV annulus and around either side of the transannular patch, and from the tricuspid valve to the PV. After her surgery, she underwent an electrophysiology (EP) study and was not inducible for either atrial or ventricular
arrhythmias. One year later, she presented with recurrent episodes of the same VT requiring cardioversion. She was referred to the EP laboratory for evaluation.
CLINICAL QUESTION What is the approach to VT ablation in a patient with congenital pulmonary stenosis?
CLINICAL COURSE The initial approach to VT in this patient was similar for any patient with VT. The authors considered the presenting electrocardiogram and the underlying substrate that was predisposing to VT. This included the congenital cardiac lesion, the surgical history, and the prior surgical cryoablation. Although VT in patients with isolated pulmonary stenosis is rare, this patient’s history of a transannular patch and subsequent ventricular surgeries confer features that are similar to those
Cardiology Division, University of Colorado, Denver, Aurora, CO, USA * Corresponding author. University of Colorado, Denver, Anschutz Medical Campus, 12401 East, 17th Avenue, B-132, Aurora, CO 80045. E-mail address: [email protected] Card Electrophysiol Clin 8 (2016) 205–209 http://dx.doi.org/10.1016/j.ccep.2015.10.030 1877-9182/16/$ – see front matter Ó 2016 Elsevier Inc. All rights reserved.
cardiacEP.theclinics.com
CLINICAL PRESENTATION
206
Ruckdeschel et al
Fig. 1. Presenting electrocardiogram with VT at a rate of 160 beats per minute with left bundle branch block morphology.
in patients with tetralogy of Fallot, who are at higher risk of ventricular arrhythmias. Hence, the authors anticipated that the VT would have an RV origin. The patient presented to the EP laboratory in sinus rhythm, and delayed RV activation was noted at baseline (Fig. 2). A voltage map was performed in sinus rhythm, and she was found to have extensive scar in the RV outflow tract, anterior RV, RV apex, and around the tricuspid valve (Fig. 3). A potential isthmus was identified between the PV annulus and the region of scar extending from the RV outflow tract to the anterior RV (corresponding to the site of aneurysm imbrication). The ablation catheter was placed near this isthmus in preparation for entrainment and activation mapping, and programmed stimulation was performed to induce VT. Two separate VTs were induced, and the second VT was consistent with her clinical presentation (Fig. 4). Using entrainment and activation
mapping, the authors identified the circuit involved and the critical isthmus that was required to maintain the VT. Entrainment mapping at this site demonstrated concealed fusion with a post– pacing interval minus tachycardia cycle length (PPI TCL) of 0 ms (Fig. 5). Mid-diastolic potentials were present (Fig. 6), and pace mapping at the same site in sinus rhythm demonstrated a near-perfect pace map to the clinical VT (see Fig. 6). Ablation during VT at this isthmus terminated the VT, and further ablation was performed to eliminate the isthmus and to connect the dense scar in the RV outflow tract to the PV annulus (see Fig. 3). At the close of the procedure, she was no longer inducible for any VT, and the authors believe that the first VT was likely using the same isthmus, but in the counterclockwise direction, given that both VTs had similar cycle lengths. The patient also underwent placement of an implantable cardioverter-defibrillator for secondary prevention.
Fig. 2. Baseline sinus rhythm intracardiac electrograms with delayed RV activation at baseline. A, atrial electrogram; H, His electrogram; LP, late potential consistent with delayed RV conduction; V, ventricular electrogram.
Congenital Pulmonary Stenosis
Fig. 3. Electroanatomic voltage map (CARTO, Biosense Webster) in sinus rhythm. Extensive scar was found in the RV outflow tract, anterior RV, RV apex, and around the tricuspid valve. Red lesion tags are ablation lesions within critical isthmus connecting the dense RV outflow tract scar with the PV annulus. RAO, right anterior oblique; LAO, left anterior oblique.
DISCUSSION With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Surgical palliation is not a definitive cure, however. There are typically residual anatomic lesions, as well as consequences of the surgical repair, that cause longterm sequelae. Congenital pulmonary stenosis is a common congenital heart defect with a range of severity. It occurs in an isolated form in 8% to
10% of congenital heart disease and 25% to 30% in association with other lesions.1 It may not require any intervention, or it can be treated initially with either balloon valvuloplasty or surgical valvotomy and RV outflow tract augmentation. Historically, surgery was the only option until the advent of percutaneous techniques in the 1980s. In the early years of surgical palliation, there was thought to be little consequence of long-standing pulmonary insufficiency, and surgical techniques were geared toward opening the outflow tract without
Fig. 4. Two separate VTs were induced, the second (VT2) of which was consistent with the clinical presentation (left bundle branch block morphology, inferior axis, and transition at V4). The first VT (VT1) was likely using the same critical isthmus as the second VT, but in a counterclockwise direction, because both had similar cycle lengths and were noninducible after ablation of the same critical isthmus.
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Ruckdeschel et al
Fig. 5. Entrainment mapping near the critical isthmus demonstrated concealed fusion with a PPI
thought to preserving the PV. Consequently, many patients were left with severe pulmonary insufficiency. On its own, congenital PV stenosis is not often associated with significant arrhythmias.2 Surgical repair of congenital PV stenosis, however, results in similar RV fibrosis and scar, as may be seen with more complex congenital heart diseases, such as tetralogy of Fallot. In tetralogy of Fallot, there is subpulmonary and PV obstruction, which may require surgical resection of subvalvular and valvular tissue as well as possible use of a
TCL of 0 ms.
transannular patch. Additionally, patients with tetralogy of Fallot require closure of a ventricular septal defect. Any site of surgical repair can predispose to future arrhythmias. If relief of PV obstruction results in long-standing pulmonary insufficiency, RV dilation and dysfunction may occur. This is important because RV dilation can be associated with inducible ventricular arrhythmias.3,4 Much attention has been paid to patients with tetralogy of Fallot and their risk for sudden cardiac death due to ventricular arrhythmias as well as
Fig. 6. Mid-diastolic potentials (left panel) were present in the critical isthmus. Pace mapping (center panel) at the same site in sinus rhythm demonstrated a near-perfect pace map to the clinical VT (right panel).
Congenital Pulmonary Stenosis predictors for sudden cardiac death. Adult patients with repaired tetralogy of Fallot are at risk for sudden cardiac death at a rate of 6% to 10% per decade of follow-up.5,6 Many factors have been implicated as increasing the risk for sudden cardiac death in these patients. Some of the risk factors associated with sustained ventricular arrhythmias in patients with tetralogy of Fallot include ventricular dysfunction, RV enlargement, atrial arrhythmias, and QRS duration greater than 180 ms.7,8 In those patients with known risk factors, there is evidence that inducible VT at the time of EP study is associated with increased 5-year mortality.9 Targeted cryoablation at the time of surgical PV replacement in patients with tetralogy of Fallot has been shown to decrease the rate of ventricular and atrial arrhythmias postoperatively.10 Although there are few data, catheter ablation can be attempted for ventricular arrhythmias in patients with congenital heart disease. Small studies with short-term follow-up suggest reasonable outcomes.11,12 Nevertheless, challenges exist, including anatomic obstruction, unstable ventricular arrhythmias, and high-risk location near the His bundle or coronary artery.13
3.
4.
5.
6.
7.
SUMMARY Although congenital PV stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope.
REFERENCES 1. Moss AJ, Allen HD. Moss and Adams’ heart disease in infants, children, and adolescents: including the fetus and young adult. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2008. 2. Khairy P, Van Hare GF, Balaji S, et al. PACES/HRS expert consensus statement on the recognition and management of arrhythmias in adult congenital heart disease: developed in partnership between the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS). Endorsed by the governing bodies of PACES, HRS, the American College of Cardiology
8.
9.
10.
11.
12.
13.
(ACC), the American Heart Association (AHA), the European Heart Rhythm Association (EHRA), the Canadian Heart Rhythm Society (CHRS), and the International Society for Adult Congenital Heart Disease (ISACHD). Can J Cardiol 2014;30(10):e1–63. Daliento L, Rizzoli G, Menti L, et al. Accuracy of electrocardiographic and echocardiographic indices in predicting life threatening ventricular arrhythmias in patients operated for tetralogy of Fallot. Heart 1999;81(6):650–5. Marie PY, Marc¸on F, Brunotte F, et al. Right ventricular overload and induced sustained ventricular tachycardia in operatively “repaired” tetralogy of Fallot. Am J Cardiol 1992;69(8):785–9. Nollert G, Fischlein T, Bouterwek S, et al. Long-term survival in patients with repair of tetralogy of Fallot: 36-year follow-up of 490 survivors of the first year after surgical repair. J Am Coll Cardiol 1997;30(5): 1374–83. Gatzoulis MA, Balaji S, Webber SA, et al. Gillette PC and others. Risk factors for arrhythmia and sudden cardiac death late after repair of tetralogy of Fallot: a multicentre study. Lancet 2000;356(9234):975–81. Valente AM, Gauvreau K, Assenza GE, et al. Contemporary predictors of death and sustained ventricular tachycardia in patients with repaired tetralogy of fallot enrolled in the indicator cohort. Heart 2014;100(3):247–53. Walsh EP. Sudden death in adult congenital heart disease: risk stratification in 2014. Heart Rhythm 2014;11(10):1735–42. Khairy P, Landzberg MJ, Gatzoulis MA, et al. Value of programmed ventricular stimulation after tetralogy of fallot repair: a multicenter study. Circulation 2004; 109(16):1994–2000. Therrien J, Siu SC, Harris L, et al. Impact of pulmonary valve replacement on arrhythmia propensity late after repair of tetralogy of Fallot. Circulation 2001;103(20):2489–94. Gonska BD, Cao K, Raab J, et al. Radiofrequency catheter ablation of right ventricular tachycardia late after repair of congenital heart defects. Circulation 1996;94(8):1902–8. Furushima H, Chinushi M, Sugiura H, et al. Ventricular tachycardia late after repair of congenital heart disease: efficacy of combination therapy with radiofrequency catheter ablation and class III antiarrhythmic agents and long-term outcome. J Electrocardiol 2006;39(2):219–24. Morwood JG, Triedman JK, Berul CI, et al. Radiofrequency catheter ablation of ventricular tachycardia in children and young adults with congenital heart disease. Heart Rhythm 2004;1(3):301–8.
209
KEY POINTS With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Although congenital pulmonary valve (PV) stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope.
A 53-year-old woman with history of congenital PV stenosis, status post–surgical valvotomy and transannular patch at the age of 13 years, presented with left bundle branch block morphology ventricular tachycardia (VT), inferior axis, and transition at leads V3 to V4 (Fig. 1), which was treated with amiodarone. Further evaluation was significant for severe pulmonary insufficiency, a dilated right ventricle (RV), and an RV outflow tract aneurysm. She ultimately underwent PV replacement with a #29 bovine Carpentier-Edwards valve and aneurysm imbrication. At the time of her valve replacement, she underwent surgical cryoablation of the RV outflow tract. Cryoablation was performed from the RV outflow tract to the PV, from below the PV annulus and around either side of the transannular patch, and from the tricuspid valve to the PV. After her surgery, she underwent an electrophysiology (EP) study and was not inducible for either atrial or ventricular
arrhythmias. One year later, she presented with recurrent episodes of the same VT requiring cardioversion. She was referred to the EP laboratory for evaluation.
CLINICAL QUESTION What is the approach to VT ablation in a patient with congenital pulmonary stenosis?
CLINICAL COURSE The initial approach to VT in this patient was similar for any patient with VT. The authors considered the presenting electrocardiogram and the underlying substrate that was predisposing to VT. This included the congenital cardiac lesion, the surgical history, and the prior surgical cryoablation. Although VT in patients with isolated pulmonary stenosis is rare, this patient’s history of a transannular patch and subsequent ventricular surgeries confer features that are similar to those
Cardiology Division, University of Colorado, Denver, Aurora, CO, USA * Corresponding author. University of Colorado, Denver, Anschutz Medical Campus, 12401 East, 17th Avenue, B-132, Aurora, CO 80045. E-mail address: [email protected] Card Electrophysiol Clin 8 (2016) 205–209 http://dx.doi.org/10.1016/j.ccep.2015.10.030 1877-9182/16/$ – see front matter Ó 2016 Elsevier Inc. All rights reserved.
cardiacEP.theclinics.com
CLINICAL PRESENTATION
206
Ruckdeschel et al
Fig. 1. Presenting electrocardiogram with VT at a rate of 160 beats per minute with left bundle branch block morphology.
in patients with tetralogy of Fallot, who are at higher risk of ventricular arrhythmias. Hence, the authors anticipated that the VT would have an RV origin. The patient presented to the EP laboratory in sinus rhythm, and delayed RV activation was noted at baseline (Fig. 2). A voltage map was performed in sinus rhythm, and she was found to have extensive scar in the RV outflow tract, anterior RV, RV apex, and around the tricuspid valve (Fig. 3). A potential isthmus was identified between the PV annulus and the region of scar extending from the RV outflow tract to the anterior RV (corresponding to the site of aneurysm imbrication). The ablation catheter was placed near this isthmus in preparation for entrainment and activation mapping, and programmed stimulation was performed to induce VT. Two separate VTs were induced, and the second VT was consistent with her clinical presentation (Fig. 4). Using entrainment and activation
mapping, the authors identified the circuit involved and the critical isthmus that was required to maintain the VT. Entrainment mapping at this site demonstrated concealed fusion with a post– pacing interval minus tachycardia cycle length (PPI TCL) of 0 ms (Fig. 5). Mid-diastolic potentials were present (Fig. 6), and pace mapping at the same site in sinus rhythm demonstrated a near-perfect pace map to the clinical VT (see Fig. 6). Ablation during VT at this isthmus terminated the VT, and further ablation was performed to eliminate the isthmus and to connect the dense scar in the RV outflow tract to the PV annulus (see Fig. 3). At the close of the procedure, she was no longer inducible for any VT, and the authors believe that the first VT was likely using the same isthmus, but in the counterclockwise direction, given that both VTs had similar cycle lengths. The patient also underwent placement of an implantable cardioverter-defibrillator for secondary prevention.
Fig. 2. Baseline sinus rhythm intracardiac electrograms with delayed RV activation at baseline. A, atrial electrogram; H, His electrogram; LP, late potential consistent with delayed RV conduction; V, ventricular electrogram.
Congenital Pulmonary Stenosis
Fig. 3. Electroanatomic voltage map (CARTO, Biosense Webster) in sinus rhythm. Extensive scar was found in the RV outflow tract, anterior RV, RV apex, and around the tricuspid valve. Red lesion tags are ablation lesions within critical isthmus connecting the dense RV outflow tract scar with the PV annulus. RAO, right anterior oblique; LAO, left anterior oblique.
DISCUSSION With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Surgical palliation is not a definitive cure, however. There are typically residual anatomic lesions, as well as consequences of the surgical repair, that cause longterm sequelae. Congenital pulmonary stenosis is a common congenital heart defect with a range of severity. It occurs in an isolated form in 8% to
10% of congenital heart disease and 25% to 30% in association with other lesions.1 It may not require any intervention, or it can be treated initially with either balloon valvuloplasty or surgical valvotomy and RV outflow tract augmentation. Historically, surgery was the only option until the advent of percutaneous techniques in the 1980s. In the early years of surgical palliation, there was thought to be little consequence of long-standing pulmonary insufficiency, and surgical techniques were geared toward opening the outflow tract without
Fig. 4. Two separate VTs were induced, the second (VT2) of which was consistent with the clinical presentation (left bundle branch block morphology, inferior axis, and transition at V4). The first VT (VT1) was likely using the same critical isthmus as the second VT, but in a counterclockwise direction, because both had similar cycle lengths and were noninducible after ablation of the same critical isthmus.
207
208
Ruckdeschel et al
Fig. 5. Entrainment mapping near the critical isthmus demonstrated concealed fusion with a PPI
thought to preserving the PV. Consequently, many patients were left with severe pulmonary insufficiency. On its own, congenital PV stenosis is not often associated with significant arrhythmias.2 Surgical repair of congenital PV stenosis, however, results in similar RV fibrosis and scar, as may be seen with more complex congenital heart diseases, such as tetralogy of Fallot. In tetralogy of Fallot, there is subpulmonary and PV obstruction, which may require surgical resection of subvalvular and valvular tissue as well as possible use of a
TCL of 0 ms.
transannular patch. Additionally, patients with tetralogy of Fallot require closure of a ventricular septal defect. Any site of surgical repair can predispose to future arrhythmias. If relief of PV obstruction results in long-standing pulmonary insufficiency, RV dilation and dysfunction may occur. This is important because RV dilation can be associated with inducible ventricular arrhythmias.3,4 Much attention has been paid to patients with tetralogy of Fallot and their risk for sudden cardiac death due to ventricular arrhythmias as well as
Fig. 6. Mid-diastolic potentials (left panel) were present in the critical isthmus. Pace mapping (center panel) at the same site in sinus rhythm demonstrated a near-perfect pace map to the clinical VT (right panel).
Congenital Pulmonary Stenosis predictors for sudden cardiac death. Adult patients with repaired tetralogy of Fallot are at risk for sudden cardiac death at a rate of 6% to 10% per decade of follow-up.5,6 Many factors have been implicated as increasing the risk for sudden cardiac death in these patients. Some of the risk factors associated with sustained ventricular arrhythmias in patients with tetralogy of Fallot include ventricular dysfunction, RV enlargement, atrial arrhythmias, and QRS duration greater than 180 ms.7,8 In those patients with known risk factors, there is evidence that inducible VT at the time of EP study is associated with increased 5-year mortality.9 Targeted cryoablation at the time of surgical PV replacement in patients with tetralogy of Fallot has been shown to decrease the rate of ventricular and atrial arrhythmias postoperatively.10 Although there are few data, catheter ablation can be attempted for ventricular arrhythmias in patients with congenital heart disease. Small studies with short-term follow-up suggest reasonable outcomes.11,12 Nevertheless, challenges exist, including anatomic obstruction, unstable ventricular arrhythmias, and high-risk location near the His bundle or coronary artery.13
3.
4.
5.
6.
7.
SUMMARY Although congenital PV stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope.
REFERENCES 1. Moss AJ, Allen HD. Moss and Adams’ heart disease in infants, children, and adolescents: including the fetus and young adult. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2008. 2. Khairy P, Van Hare GF, Balaji S, et al. PACES/HRS expert consensus statement on the recognition and management of arrhythmias in adult congenital heart disease: developed in partnership between the Pediatric and Congenital Electrophysiology Society (PACES) and the Heart Rhythm Society (HRS). Endorsed by the governing bodies of PACES, HRS, the American College of Cardiology
8.
9.
10.
11.
12.
13.
(ACC), the American Heart Association (AHA), the European Heart Rhythm Association (EHRA), the Canadian Heart Rhythm Society (CHRS), and the International Society for Adult Congenital Heart Disease (ISACHD). Can J Cardiol 2014;30(10):e1–63. Daliento L, Rizzoli G, Menti L, et al. Accuracy of electrocardiographic and echocardiographic indices in predicting life threatening ventricular arrhythmias in patients operated for tetralogy of Fallot. Heart 1999;81(6):650–5. Marie PY, Marc¸on F, Brunotte F, et al. Right ventricular overload and induced sustained ventricular tachycardia in operatively “repaired” tetralogy of Fallot. Am J Cardiol 1992;69(8):785–9. Nollert G, Fischlein T, Bouterwek S, et al. Long-term survival in patients with repair of tetralogy of Fallot: 36-year follow-up of 490 survivors of the first year after surgical repair. J Am Coll Cardiol 1997;30(5): 1374–83. Gatzoulis MA, Balaji S, Webber SA, et al. Gillette PC and others. Risk factors for arrhythmia and sudden cardiac death late after repair of tetralogy of Fallot: a multicentre study. Lancet 2000;356(9234):975–81. Valente AM, Gauvreau K, Assenza GE, et al. Contemporary predictors of death and sustained ventricular tachycardia in patients with repaired tetralogy of fallot enrolled in the indicator cohort. Heart 2014;100(3):247–53. Walsh EP. Sudden death in adult congenital heart disease: risk stratification in 2014. Heart Rhythm 2014;11(10):1735–42. Khairy P, Landzberg MJ, Gatzoulis MA, et al. Value of programmed ventricular stimulation after tetralogy of fallot repair: a multicenter study. Circulation 2004; 109(16):1994–2000. Therrien J, Siu SC, Harris L, et al. Impact of pulmonary valve replacement on arrhythmia propensity late after repair of tetralogy of Fallot. Circulation 2001;103(20):2489–94. Gonska BD, Cao K, Raab J, et al. Radiofrequency catheter ablation of right ventricular tachycardia late after repair of congenital heart defects. Circulation 1996;94(8):1902–8. Furushima H, Chinushi M, Sugiura H, et al. Ventricular tachycardia late after repair of congenital heart disease: efficacy of combination therapy with radiofrequency catheter ablation and class III antiarrhythmic agents and long-term outcome. J Electrocardiol 2006;39(2):219–24. Morwood JG, Triedman JK, Berul CI, et al. Radiofrequency catheter ablation of ventricular tachycardia in children and young adults with congenital heart disease. Heart Rhythm 2004;1(3):301–8.
209
