RHYTHM PUZZLE
Not so usual J.M.E. van Dijen, L.V.A. Boersma, P.W. Hartingsveldt, E.F.D. Wever
Figure 1.
Figure 2A.
J.M.E. van Dijen. LV.A. Boersma. P.J. van Hartingsveldt. E.F.D. Wever. Department of Cardiology, Heart Lung Centre Utrecht, St. Antonius Hospital, Koekoekslaan 1, 3435 CM Nieuwegein.
did not terminate spontaneously, although after intravenous administration ofadenosine they resolved. The ECGs during sinus rhythm and during palpitations are shown in figure 1 and figure 2 A and B, respectively. Structural heart disease was ruled out, and she was referred for electrophysiological study (EPS) and catheter ablation using radio-frequency current (RFCA). During EPS, two types of narrow-QRS tachycardia were inducible as shown in figure 2A and B. What would be the underlying mechanism of these arrhythmias and what therapy would you suggest? c
Address for correspondence: E.F.D. Wever. E-mail: [email protected]
Answer You will find the answer on page 43.
A 55-year-old female had been experiencing episodes of palpitations for 30 years. These palpitations could start at any moment ofthe day. Normally, these episodes were self-limiting. Last year, however, she visited the emergency ward because her complaints
28
Netherlands Heart Journal, Volume 12, Number 1, January 2004
fibrillation) fell by 72%, and in the patients with the conductor in the right atrium it fell by nearly 50%. Professor A. Schuchert (Eppendorf University Clinic, Hamburg) stressed the importance ofcareftilly choosing which preventive AF algorithm to use in which patient. In earlier studies, such as the Atrial Therapy Efficacy and Safety Study Trial (ATIEST), Atrial Septal Lead Placement and Atrial Pacing Algorithms for Prevention of Paroxysmal Atrial Fibrillation (ASPECT) and AF Therapy, it appeared that if all the pacemaker algorithms were activated, then there was no significant reduction in the occurrence of atrial fibrillation. This could possibly have been caused by the proarhythmogenic effect of some algorithms. This suggestion is especially based on the preliminary results ofthe VIP
...
registry and the speaker's own Hamburg 3:4 study. Both these studies show that algorithms offering continuous atrial pacing are less effective in the prevention of AF than algorithms that respond to AF triggers.
In his presentation on the lessons learned about the treatment of atrial fibrillation from the pacemaker trials and what can be expected in the future Drj.H. Ruiter, (Alkmaar Medical Centre), concluded: Previous studies were too different in design to allow good comparisons. The results proved to vary considerably and were influenced by qualitatively inadequate atrial sensing. Much has been learned, however, about the mechanism for the onset of atrial fibrillation. In the future, on the basis of digital technique, a pacemaker will be able to automatically differentiate
between atrial flutter, atrial fibrillation, myopotentials, and far-field signals and itself deliver the therapy programmed by the pacemaker technician or cardiologist. With each treatment, the diagnosis and therapy with the accompanying intercardial ECG will be recorded in the pacemaker's arrhythmia logbook. It can be expected that in a few years time the pacemaker itself will be able to decide on the optimal therapy for the patient, so that pacemaker checkups can be greatly reduced in frequency and intensity. In Alkmaar Medical Centre, more than 2400 pacemaker checkups are undertaken a year; increased automation could perhaps halve this number. This means that pacemaker technicians will have more time for new or other activities. a
_ dE3g! g | | | EI .&R|_ ai
Answer rhythm puzzle (page 28) Figure 2A shows a narrow-complex tachycardia (QRS 0.08 msec) at a rate of 210 beats/min. The inferior leads (II, III, and aVF) show slight s waves at the end of the QRS complexes. Lead aVR shows a small r. During sinus rhythm (figure 1), the QRS complexes in these leads do not show these features, suggesting that these are pseudo s/r waves and in fact represent atrial activation (negative P waves in II, III, and aVF, and positive P waves in aVR) during tachycardia, almost hidden in the QRS complex. These features are compatible with a common-type AV nodal re-entry tachycardia (AVNRT) with the impulse travelling anterogradely over the slow and retrogradely over the fast AV nodal pathway. The differential diagnosis is an atrial tachycardia with a long PRinterval (RP
Not so usual J.M.E. van Dijen, L.V.A. Boersma, P.W. Hartingsveldt, E.F.D. Wever
Figure 1.
Figure 2A.
J.M.E. van Dijen. LV.A. Boersma. P.J. van Hartingsveldt. E.F.D. Wever. Department of Cardiology, Heart Lung Centre Utrecht, St. Antonius Hospital, Koekoekslaan 1, 3435 CM Nieuwegein.
did not terminate spontaneously, although after intravenous administration ofadenosine they resolved. The ECGs during sinus rhythm and during palpitations are shown in figure 1 and figure 2 A and B, respectively. Structural heart disease was ruled out, and she was referred for electrophysiological study (EPS) and catheter ablation using radio-frequency current (RFCA). During EPS, two types of narrow-QRS tachycardia were inducible as shown in figure 2A and B. What would be the underlying mechanism of these arrhythmias and what therapy would you suggest? c
Address for correspondence: E.F.D. Wever. E-mail: [email protected]
Answer You will find the answer on page 43.
A 55-year-old female had been experiencing episodes of palpitations for 30 years. These palpitations could start at any moment ofthe day. Normally, these episodes were self-limiting. Last year, however, she visited the emergency ward because her complaints
28
Netherlands Heart Journal, Volume 12, Number 1, January 2004
fibrillation) fell by 72%, and in the patients with the conductor in the right atrium it fell by nearly 50%. Professor A. Schuchert (Eppendorf University Clinic, Hamburg) stressed the importance ofcareftilly choosing which preventive AF algorithm to use in which patient. In earlier studies, such as the Atrial Therapy Efficacy and Safety Study Trial (ATIEST), Atrial Septal Lead Placement and Atrial Pacing Algorithms for Prevention of Paroxysmal Atrial Fibrillation (ASPECT) and AF Therapy, it appeared that if all the pacemaker algorithms were activated, then there was no significant reduction in the occurrence of atrial fibrillation. This could possibly have been caused by the proarhythmogenic effect of some algorithms. This suggestion is especially based on the preliminary results ofthe VIP
...
registry and the speaker's own Hamburg 3:4 study. Both these studies show that algorithms offering continuous atrial pacing are less effective in the prevention of AF than algorithms that respond to AF triggers.
In his presentation on the lessons learned about the treatment of atrial fibrillation from the pacemaker trials and what can be expected in the future Drj.H. Ruiter, (Alkmaar Medical Centre), concluded: Previous studies were too different in design to allow good comparisons. The results proved to vary considerably and were influenced by qualitatively inadequate atrial sensing. Much has been learned, however, about the mechanism for the onset of atrial fibrillation. In the future, on the basis of digital technique, a pacemaker will be able to automatically differentiate
between atrial flutter, atrial fibrillation, myopotentials, and far-field signals and itself deliver the therapy programmed by the pacemaker technician or cardiologist. With each treatment, the diagnosis and therapy with the accompanying intercardial ECG will be recorded in the pacemaker's arrhythmia logbook. It can be expected that in a few years time the pacemaker itself will be able to decide on the optimal therapy for the patient, so that pacemaker checkups can be greatly reduced in frequency and intensity. In Alkmaar Medical Centre, more than 2400 pacemaker checkups are undertaken a year; increased automation could perhaps halve this number. This means that pacemaker technicians will have more time for new or other activities. a
_ dE3g! g | | | EI .&R|_ ai
Answer rhythm puzzle (page 28) Figure 2A shows a narrow-complex tachycardia (QRS 0.08 msec) at a rate of 210 beats/min. The inferior leads (II, III, and aVF) show slight s waves at the end of the QRS complexes. Lead aVR shows a small r. During sinus rhythm (figure 1), the QRS complexes in these leads do not show these features, suggesting that these are pseudo s/r waves and in fact represent atrial activation (negative P waves in II, III, and aVF, and positive P waves in aVR) during tachycardia, almost hidden in the QRS complex. These features are compatible with a common-type AV nodal re-entry tachycardia (AVNRT) with the impulse travelling anterogradely over the slow and retrogradely over the fast AV nodal pathway. The differential diagnosis is an atrial tachycardia with a long PRinterval (RP
