Bedside Termination of Sustained Ventricular Tachycardia by Transesophageal Atrial Pacing AMOS KATZ, TIMOTHY K. KNILANS, and ERIC N. PRYSTOWSKY From the Indiana Heart Institute. St. Vincent Hospital, Indianapolis, Indiana KATZ, A.. ET AL.: Bedside Termination of Sustained Ventricular Tachycardia by Transesophageal Atrial
Pacing. Transesophageal atrial pacing tvcs used to terminate hemodynamically stable sustained monomorphic ventricular tachycardia in two patients. The procedure was performed at the bedside, no anesthesia was required, there were no compJications, and one of the patients went home after the procedure was performed. This method should be considered prior to using direct current cardioversion in patients with hemodynamicaliy stable sustained monomorphic ventricular tachycardia. (PACE, Vol. 15, June 1992}
sustained ventricular tachycardia, transesophageal pacing, atrial pacing
Introduction Esophageal pacing provides a relatively noninvasive method for pacing the atria that can be performed at the bedside. Transesophageal atrial recording and pacing were described for the diagnosis and treatment of supraventricular tachycardia/*^ although ventricular pacing with an esophageal electrode bas been reported using bigh energies.^'* Ventricular pacing metbods are usually required to terminate ventricular tachycardia, but very uncommonly intraatrial pacing can also terminate this arrbythmia.^'^ In this case report we present two patients in whom we could terminate bemodynamically stable sustained monomorphic ventricular tacbycardia witb transesopbageal atrial pacing. Use of this technique resulted in restoration of sinus rbythm witbout tbe necessity for anesthesia and direct current cardioversion.
Case Reports Patient 1
A 61-year-old man witb a bistory of recurrent hemodynamically stable sustained monomorphic
Address (or reprints: Eric N. Prystowsky, M.D., Northside Cardiology. PC. 8402 Harcourt Road, Suite 300. Indianapolis, IN 46260. Fax: (317) 871-6159. Received December 13, 1991; accepted January 7, 1992.
PACE, Vol. 15
ventricular tacbycardia presented witb an episode of bis arrbythmia. The tachycardia bad a cycle length of 520 msec with a rigbt bundle branch block, rigbt axis deviation morpbology. His blood pressure was 120/80 mmHg, and be did not have any chest pain or shortness of breath. Pbysical examination disclosed no signs of congestive heart failure. He was given 100 mg of intravenous lidocaine witbout effect. To avoid transthoracic direct current cardioversion we attempted to terminate this arrhytbmia using transesopbageal atrial pacing. Witb tbe patient in a supine position, a bipolar permanent transvenous pacing electrode [Medtronic 6992, Medtronic, Inc., Minneapolis, MN, USA) witb interelectrode spacing of 29 mm was passed tbrough the nares and positioned approximately 40 cm into the distal esophagus.^ Tbe lead was connected to a custom-built (Jack Kassel, Durbam, NC, USA) 2-cbannel recording and pacing device. An ECG monitor lead was recorded continuously in the top channel using a 0.5-100 Hz filter and an esopbageal bipolar tracing filtered at 40-100 Hz was recorded simultaneously on the bottom channel (Fig. 1). Tbe lead was positioned where the bipolar atrial electrogram exhibited tbe greatest amplitude. Tbe combined recording demonstrated a wide QRS tachycardia witb atrioventricular dissociation [Fig. 1). Bipolar esopbageal burst pacing at cycle lengtb 450 msec was performed with a stimulus of 10-msec duration and
June 1992
849
KATZ, ET AL.
I J4
Figure 1. Combined monitor electrocardiogram fECG) and esophageal (ESO) recording from custom device. During ventricular tachycardia esophageal lead showing afrioventricular dissociation (fop). During pacing the device is no( capable of recording the esophageaJ electrogram (B.C). The ECG demonstrates variable forms of fusion heats, one capture beat (Q, and Ihen sinus rhylhm (D).
pac Ing on
ECQ
E80.
\
I
I
\ \ \
- A
Q
•
pacing off
ECQ
ESO.
current output of 12 mA. After several fusion beats a capture beat was noted, the pacing was stopped, and sinus rhythm resumed. The patient did not notice any discomfort and there were no complications. He was sent home and told to call if the tachycardia recurred. During follow-up he returned on three separate occasions and his ventricular tachycardia was terminated with transesophageai atrial pacing (Fig. 2). Patient 2 A 67-year-old man with a history of coronary artery disease and sustained monomorphic ventricular tachycardia 9 years previously was admitted to the hospital because of chest pain and hemodynamically stable sustained monomorphic ventricular tachycardia. The tachycardia had a cycle length of 470 msec with a right bundle branch block, normal axis morphology. An identical ventricular tachycardia was subsequently induced at electrophysiology study. Intravenous procainam-
850
ide failed to terminate his arrhythmia. Using the same technique as in patient 1, the combined recordings demonstrate a wide QRS tachycardia witb 1:1 ventriculoatrial conduction (Fig. 3). Bipolar esophageal burst pacing at a cycle length of 300 msec could capture the atria and conduct to the ventricle with a narrow QRS but did not terminate the tachycardia. Incremental transesophageai atrial pacing to cycle length 250 msec captured the atria, conducted to the ventricle, and when pacing was stopped, sinus rhythm resumed (Fig. 4). There were no complications and only minor chest discomfort was noted by the patient.
Discussion Termination of ventricular tachycardia by Intracardiac atrial pacing is extremely uncommon,^ and rarely reported with transesophageai atrial pacing.^ Assuming reentry as the mechanism of
June 1992
PACE, Vol. 15
TERMINATION OF VT BY TRANSESOPHAGEAL ATRIAL PACING
V
V
V
V
S
S
S
S
S
3
F
C
C
C
C
Figure 2. Twelve-lead electrocardiogram during transesophageal atrial pacing. The left side shows ventricular tachycardia (V), followed by alrial pacing (S) with ventricular fusion beat fF), ventricular capture beats (C), and resumption of sinus rhythm fsinj when pacing is stopped.
ECG
B. ESO
\^
J1 .-
—™
\
1 ----I
1
-A
^—•
h
, —
1
i.
! i !—-i
-
Figure 3. Combined monitor electrocardiogram fECGJ and esophageal {ESO} recording from custom device. Ventricular (achycardia with esophageal lead showing 1:1 ventriculoatrial conduction (AJ. During sinus rhythm (B).
PACE, Vol. 15
June 1992
851
KATZ. ET AL.
T pacing
f pacing off
Figure 4. Bedside ECG monitor lead during transesophageal atrial pacing. The top ECG recording shows ventricu/ar tachycardia with initiation of atrial pacing with 1:1 capture of the ventricle producing a narrow QRS complex. The bottom recording demonstrates resumption of sinus rhythm after termination of pacing.
the ventricular tachycardia, an impulse must invade the reentrant circuit and create refractoriness in one of the pathways. The ability for one or more paced beats to terminate an arrhythmia depends on several factors, including the proximity of the pacing site to tbe tachycardia focus and the electropbysiological characteristics of tbe reentrant circuit and tissue between the paced site and arrhythmic focus. It is often difficult for ventricular pacing techniques to terminate ventricular tachycardia, and the problems encountered during atrial pacing are magnified by tbe limitation of AV nodal conduction to prevent the requisite paced rate or premature intervals from reaching the ventricle to end tachycardia. A relatively slow ventricular tachycardia would appear most susceptible to termination by atrial pacing techniques'-^ as demonstrated in the patients in our report. In this situation atrial impulses have the greatest likelihood of being conducted to tbe ventricle at the critical
852
rates or intervals necessary to interrupt tbe ventricular tachycardia circuit. However, even with a relatively slow ventricular tacbycardia rapid overdrive pacing may be needed to terminate ventricular tachycardia, as demonstrated in patient 2. If atrial pacing during ventricular tachycardia does not result in capture of the ventricle by atrial impulses, one could repeat pacing after administration of intravenous atropine to improve AV nodal conduction. Tbat atrial pacing and not ventricular pacing resulted in termination of tacbycardia in our two patients can be verified by the amplitude of the atrial electrogram, current used, and most importantly, tbe presence of capture beats prior to stopping pacing. In summary, transesopbageal atrial pacing is a safe and useful tecbnique to terminate ventricular tacbycardia in selected patients. If successful, the need for anesthesia and direct current cardioversion may be avoided in these individuals.
June 1992
PACE, Vol. 15
TERMINATION OF VT BY TRANSESOPHAGEAL ATRIAL PACING
References 1.
Montoyo |V, Angel ), Valle V, et al. Cardioversion of tachycardia by transesophageal atrial pacing. Am J Cardiol 1973; 32:85-90, 2. Gallagher JJ, Smith WM, Kerr CR, et al, Esophageal pacing: A diagnostic and therapeutic tool. Circulation 1982; 65:335-341. 3. Burak B, Furman S, Transesophageal cardiac pacing. Am J Cardiol 1964; 23:469-472. 4. Lubell DL. Cardiac pacing from the esophagus. Am J Cardiol 1971; 27:641-644. 5. Wellens HJJ, Bar FW, Farre J, et al. Initiation and termination of ventricular tachycardia by supraventricular stimuli. Am J Cardiol 1980; 56:546-582.
PACE, Vol. 15
June 1992
Waldo AL, Henthorn RW, Plumb VJ, et al. Demonstration of the mechanism of transient entrainment and interruption of ventricular tachycardia with rapid atrial pacing. J Am Coll Cardiol 1984; 3:422-430, Prystowsky EN, Pritcbett ELC, Gallagher JJ. Origin of the atria! electrogram recorded from tbe esopbagus. Circulation 1980; 61:1017-1023. Kerr CR, Cooper J, Chung DC, et al. Termination of sustained ventricular tachycardia by transesopbageal atrial pacing. Am J Cardiol 1988; 61: 463-464.
853
Pacing. Transesophageal atrial pacing tvcs used to terminate hemodynamically stable sustained monomorphic ventricular tachycardia in two patients. The procedure was performed at the bedside, no anesthesia was required, there were no compJications, and one of the patients went home after the procedure was performed. This method should be considered prior to using direct current cardioversion in patients with hemodynamicaliy stable sustained monomorphic ventricular tachycardia. (PACE, Vol. 15, June 1992}
sustained ventricular tachycardia, transesophageal pacing, atrial pacing
Introduction Esophageal pacing provides a relatively noninvasive method for pacing the atria that can be performed at the bedside. Transesophageal atrial recording and pacing were described for the diagnosis and treatment of supraventricular tachycardia/*^ although ventricular pacing with an esophageal electrode bas been reported using bigh energies.^'* Ventricular pacing metbods are usually required to terminate ventricular tachycardia, but very uncommonly intraatrial pacing can also terminate this arrbythmia.^'^ In this case report we present two patients in whom we could terminate bemodynamically stable sustained monomorphic ventricular tacbycardia witb transesopbageal atrial pacing. Use of this technique resulted in restoration of sinus rbythm witbout tbe necessity for anesthesia and direct current cardioversion.
Case Reports Patient 1
A 61-year-old man witb a bistory of recurrent hemodynamically stable sustained monomorphic
Address (or reprints: Eric N. Prystowsky, M.D., Northside Cardiology. PC. 8402 Harcourt Road, Suite 300. Indianapolis, IN 46260. Fax: (317) 871-6159. Received December 13, 1991; accepted January 7, 1992.
PACE, Vol. 15
ventricular tacbycardia presented witb an episode of bis arrbythmia. The tachycardia bad a cycle length of 520 msec with a rigbt bundle branch block, rigbt axis deviation morpbology. His blood pressure was 120/80 mmHg, and be did not have any chest pain or shortness of breath. Pbysical examination disclosed no signs of congestive heart failure. He was given 100 mg of intravenous lidocaine witbout effect. To avoid transthoracic direct current cardioversion we attempted to terminate this arrhytbmia using transesopbageal atrial pacing. Witb tbe patient in a supine position, a bipolar permanent transvenous pacing electrode [Medtronic 6992, Medtronic, Inc., Minneapolis, MN, USA) witb interelectrode spacing of 29 mm was passed tbrough the nares and positioned approximately 40 cm into the distal esophagus.^ Tbe lead was connected to a custom-built (Jack Kassel, Durbam, NC, USA) 2-cbannel recording and pacing device. An ECG monitor lead was recorded continuously in the top channel using a 0.5-100 Hz filter and an esopbageal bipolar tracing filtered at 40-100 Hz was recorded simultaneously on the bottom channel (Fig. 1). Tbe lead was positioned where the bipolar atrial electrogram exhibited tbe greatest amplitude. Tbe combined recording demonstrated a wide QRS tachycardia witb atrioventricular dissociation [Fig. 1). Bipolar esopbageal burst pacing at cycle lengtb 450 msec was performed with a stimulus of 10-msec duration and
June 1992
849
KATZ, ET AL.
I J4
Figure 1. Combined monitor electrocardiogram fECG) and esophageal (ESO) recording from custom device. During ventricular tachycardia esophageal lead showing afrioventricular dissociation (fop). During pacing the device is no( capable of recording the esophageaJ electrogram (B.C). The ECG demonstrates variable forms of fusion heats, one capture beat (Q, and Ihen sinus rhylhm (D).
pac Ing on
ECQ
E80.
\
I
I
\ \ \
- A
Q
•
pacing off
ECQ
ESO.
current output of 12 mA. After several fusion beats a capture beat was noted, the pacing was stopped, and sinus rhythm resumed. The patient did not notice any discomfort and there were no complications. He was sent home and told to call if the tachycardia recurred. During follow-up he returned on three separate occasions and his ventricular tachycardia was terminated with transesophageai atrial pacing (Fig. 2). Patient 2 A 67-year-old man with a history of coronary artery disease and sustained monomorphic ventricular tachycardia 9 years previously was admitted to the hospital because of chest pain and hemodynamically stable sustained monomorphic ventricular tachycardia. The tachycardia had a cycle length of 470 msec with a right bundle branch block, normal axis morphology. An identical ventricular tachycardia was subsequently induced at electrophysiology study. Intravenous procainam-
850
ide failed to terminate his arrhythmia. Using the same technique as in patient 1, the combined recordings demonstrate a wide QRS tachycardia witb 1:1 ventriculoatrial conduction (Fig. 3). Bipolar esophageal burst pacing at a cycle length of 300 msec could capture the atria and conduct to the ventricle with a narrow QRS but did not terminate the tachycardia. Incremental transesophageai atrial pacing to cycle length 250 msec captured the atria, conducted to the ventricle, and when pacing was stopped, sinus rhythm resumed (Fig. 4). There were no complications and only minor chest discomfort was noted by the patient.
Discussion Termination of ventricular tachycardia by Intracardiac atrial pacing is extremely uncommon,^ and rarely reported with transesophageai atrial pacing.^ Assuming reentry as the mechanism of
June 1992
PACE, Vol. 15
TERMINATION OF VT BY TRANSESOPHAGEAL ATRIAL PACING
V
V
V
V
S
S
S
S
S
3
F
C
C
C
C
Figure 2. Twelve-lead electrocardiogram during transesophageal atrial pacing. The left side shows ventricular tachycardia (V), followed by alrial pacing (S) with ventricular fusion beat fF), ventricular capture beats (C), and resumption of sinus rhythm fsinj when pacing is stopped.
ECG
B. ESO
\^
J1 .-
—™
\
1 ----I
1
-A
^—•
h
, —
1
i.
! i !—-i
-
Figure 3. Combined monitor electrocardiogram fECGJ and esophageal {ESO} recording from custom device. Ventricular (achycardia with esophageal lead showing 1:1 ventriculoatrial conduction (AJ. During sinus rhythm (B).
PACE, Vol. 15
June 1992
851
KATZ. ET AL.
T pacing
f pacing off
Figure 4. Bedside ECG monitor lead during transesophageal atrial pacing. The top ECG recording shows ventricu/ar tachycardia with initiation of atrial pacing with 1:1 capture of the ventricle producing a narrow QRS complex. The bottom recording demonstrates resumption of sinus rhythm after termination of pacing.
the ventricular tachycardia, an impulse must invade the reentrant circuit and create refractoriness in one of the pathways. The ability for one or more paced beats to terminate an arrhythmia depends on several factors, including the proximity of the pacing site to tbe tachycardia focus and the electropbysiological characteristics of tbe reentrant circuit and tissue between the paced site and arrhythmic focus. It is often difficult for ventricular pacing techniques to terminate ventricular tachycardia, and the problems encountered during atrial pacing are magnified by tbe limitation of AV nodal conduction to prevent the requisite paced rate or premature intervals from reaching the ventricle to end tachycardia. A relatively slow ventricular tachycardia would appear most susceptible to termination by atrial pacing techniques'-^ as demonstrated in the patients in our report. In this situation atrial impulses have the greatest likelihood of being conducted to tbe ventricle at the critical
852
rates or intervals necessary to interrupt tbe ventricular tachycardia circuit. However, even with a relatively slow ventricular tacbycardia rapid overdrive pacing may be needed to terminate ventricular tachycardia, as demonstrated in patient 2. If atrial pacing during ventricular tachycardia does not result in capture of the ventricle by atrial impulses, one could repeat pacing after administration of intravenous atropine to improve AV nodal conduction. Tbat atrial pacing and not ventricular pacing resulted in termination of tacbycardia in our two patients can be verified by the amplitude of the atrial electrogram, current used, and most importantly, tbe presence of capture beats prior to stopping pacing. In summary, transesopbageal atrial pacing is a safe and useful tecbnique to terminate ventricular tacbycardia in selected patients. If successful, the need for anesthesia and direct current cardioversion may be avoided in these individuals.
June 1992
PACE, Vol. 15
TERMINATION OF VT BY TRANSESOPHAGEAL ATRIAL PACING
References 1.
Montoyo |V, Angel ), Valle V, et al. Cardioversion of tachycardia by transesophageal atrial pacing. Am J Cardiol 1973; 32:85-90, 2. Gallagher JJ, Smith WM, Kerr CR, et al, Esophageal pacing: A diagnostic and therapeutic tool. Circulation 1982; 65:335-341. 3. Burak B, Furman S, Transesophageal cardiac pacing. Am J Cardiol 1964; 23:469-472. 4. Lubell DL. Cardiac pacing from the esophagus. Am J Cardiol 1971; 27:641-644. 5. Wellens HJJ, Bar FW, Farre J, et al. Initiation and termination of ventricular tachycardia by supraventricular stimuli. Am J Cardiol 1980; 56:546-582.
PACE, Vol. 15
June 1992
Waldo AL, Henthorn RW, Plumb VJ, et al. Demonstration of the mechanism of transient entrainment and interruption of ventricular tachycardia with rapid atrial pacing. J Am Coll Cardiol 1984; 3:422-430, Prystowsky EN, Pritcbett ELC, Gallagher JJ. Origin of the atria! electrogram recorded from tbe esopbagus. Circulation 1980; 61:1017-1023. Kerr CR, Cooper J, Chung DC, et al. Termination of sustained ventricular tachycardia by transesopbageal atrial pacing. Am J Cardiol 1988; 61: 463-464.
853
