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Left bundle-branch block with right axis deviation—a unique aberrancy during supraventricular tachycardia
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Journal of Electrocardiology 42 (2009) 674 – 676 www.jecgonline.com
Left bundle-branch block with right axis deviation—a unique aberrancy during supraventricular tachycardia Yash Lokhandwala, a,⁎ Gopi Krishna Panicker, b Mandar Shah, c Hein J.J. Wellens d a
Arrhythmia Associates, Mumbai, India Research Department, Quintiles ECG Services, Mumbai, India c Department of Cardiology, Holy Family Hospital, Mumbai, India d Cardiovascular Research Institute, Maastricht, The Netherlands Received 7 April 2009 b
Abstract
A tachycardia with left bundle-branch block morphology and right axis deviation points to the diagnosis of ventricular tachycardia. Conversely, any supraventricular tachycardia with left bundlebranch block is typically associated with a normal or leftward QRS axis. We present the case of a 34-year-old man showing atrioventricular nodal reentrant tachycardia with left bundle-branch block/ right axis deviation as an exception to this rule. © 2009 Elsevier Inc. All rights reserved.
Keywords:
Atrioventricular nodal reentrant tachycardia; Radiofrequency catheter ablation
Introduction The presence of left bundle-branch block (LBBB) in a structurally normal heart is usually accompanied by a frontal plane QRS axis that ranges between +30° and −20°. This is because the mean QRS vector moves leftward and superior as the left ventricle gets activated transseptally; the same holds true during supraventricular tachycardia (SVT).1 The occurrence of right axis deviation (RAD) is therefore extremely unusual when there is LBBB. Thus, a regular wide QRS complex tachycardia with LBBB morphology and RAD typically suggests a ventricular tachycardia arising in the outflow tract of the right ventricle.2 Our patient is an exception to this tenet, showing LBBB with RAD during SVT. The potential mechanism of this unique observation is also discussed.
Case report A 34-year-old man with recurrent paroxysmal palpitations and a normal electrocardiogram (ECG) during sinus ⁎ Corresponding author. Quintiles ECG Services, 502 A, Leela Business Park, M.V. Road, Andheri (East), Mumbai 400 059, India. E-mail address: [email protected] 0022-0736/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jelectrocard.2009.05.003
rhythm was referred for an electrophysiologic (EP) study. The baseline 12-lead ECG was normal, showing sinus rhythm with a PR interval of 135 milliseconds, QRS duration of 90 milliseconds, and a QRS frontal axis of +35° (Fig. 1A). The clinical examination and echocardiogram were normal. The EP study was performed using an EP Tracer V0.74 (Cardiotek, Maastricht, The Netherlands) system. Intracardiac recordings demonstrated normal basal intervals. The AH interval was 58 milliseconds and the HV interval was 50 milliseconds. There was no ventriculoatrial conduction during ventricular pacing at baseline. Also at baseline, no tachycardia could be induced during programmed atrial stimulation. After isoprenaline administration, ventriculoatrial conduction emerged, which was concentric and decremental. With single test atrial premature beat stimulation, a tachycardia with a cycle length of 280 milliseconds was induced (Fig. 1B) having a LBBB morphology (QRS 130 milliseconds) with a frontal plane axis of +120°. The intracardiac recordings were characteristic of slow-fast atrioventricular nodal reentrant tachycardia (AVNRT) (Fig. 2). Later, the LBBB spontaneously resolved without change in cycle length (Fig. 1B) or ventriculoatrial activation pattern. The patient underwent successful radiofrequency (RF) catheter ablation of the slow pathway. After this, no tachycardia was inducible and there were no echoes or AH
Y. Lokhandwala et al. / Journal of Electrocardiology 42 (2009) 674–676
675
Fig. 1. A, Twelve-lead surface ECG in sinus rhythm. B, Twelve-lead surface ECG recording of tachycardia induced during EP study. Note the LBBB morphology with RAD (QRS axis + 120). Later LBBB disappears (⁎) without a change in cycle length, confirming this to be SVT.
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Y. Lokhandwala et al. / Journal of Electrocardiology 42 (2009) 674–676
Fig. 2. Intracardiac recordings during the wide QRS tachycardia. The atrial activation (arrows) is earliest in the His bundle region and occurs simultaneous with the initial part QRS complex, confirming the tachycardia mechanism to be slow-fast AV nodal reentry tachycardia. CS 1, 2 and CS 3, 4 indicate distal and proximal coronary sinus, respectively; HISD and HISP indicate distal and proximal recordings, respectively, from the His bundle region.
jump, despite vigorous stimulation protocols using isoprenaline and atropine. Discussion The combination of LBBB with RAD in a structurally normal heart has not been described so far in SVT. Such a pattern would typically indicate a ventricular tachycardia arising in the outflow tract of the right ventricle.1 Rarely, supraventricular rhythms have been reported with LBBB/ RAD, namely, sinus rhythm, premature atrial complexes, or atrial fibrillation2 , usually in the setting of a dilated cardiomyopathy.2,3 In the present case, this pattern has been observed along with AVNRT in a structurally normal heart, which may be attributed to a functional aberrancy. In this context, Vera and coworkers3 have extensively discussed the possibility of left posterior fascicular block in the presence of predivisional LBBB resulting in combined LBBB and RAD. Khurana et al4 also described a case of Wegener granulomatosis with LBBB and RAD in which predivisional LBBB with predominant left posterior fascicular block secondary to ischemic or inflammatory involvement of the conduction system as a possible explanation. In a review of 36 cases with the electrocardiographic combination of LBBB and RAD, Childers et al5 clearly suggested
that the RAD was a rate-dependent or episodically occurring conduction defect added to predivisional LBBB. Ventricular tachycardia arising in the outflow tract of the right ventricle and AVNRT can coexist.6 However, in our patient, this is not tenable; with 2 tachycardia mechanisms, it would be implausible to expect exactly the same cycle length, and that too occurring at the same time. Moreover, after slow pathway ablation, there was no other tachycardia. References 1. Wellens HJ. Electrophysiology: ventricular tachycardia: diagnosis of broad QRS complex tachycardia. Heart 2001;86:579. 2. Nikolic G, Marriott HJ. Left bundle branch block with right axis deviation: a marker of congestive cardiomyopathy. J Electrocardiol 1985;18:395. 3. Vera Z, Ertem G, Cheng TO. Left bundle branch block with intermittent right axis deviation. Evidence for left posterior hemiblock accompanying predivisional left bundle branch block. Am J Cardiol 1972;30:896. 4. Khurana C, Mazzone P, Mandell B. New onset left bundle branch block with right axis deviation in a patient with Wegener's granulomatosis. J Electrocardiol 2000;33:199. 5. Childers R, Lupovich S, Sochanski M. Konarzewska H. Left bundle branch block and right axis deviation: a report of 36 cases. J Electrocardiol 2000;33(Suppl):93. 6. Wylie Jr JV, Milliez P, Germano JJ, et al. Atrioventricular nodal reentrant tachycardia associated with idiopathic ventricular tachycardia: clinical and electrophysiologic characteristics. J Electrocardiol 2007;40:94.
Journal of Electrocardiology 42 (2009) 674 – 676 www.jecgonline.com
Left bundle-branch block with right axis deviation—a unique aberrancy during supraventricular tachycardia Yash Lokhandwala, a,⁎ Gopi Krishna Panicker, b Mandar Shah, c Hein J.J. Wellens d a
Arrhythmia Associates, Mumbai, India Research Department, Quintiles ECG Services, Mumbai, India c Department of Cardiology, Holy Family Hospital, Mumbai, India d Cardiovascular Research Institute, Maastricht, The Netherlands Received 7 April 2009 b
Abstract
A tachycardia with left bundle-branch block morphology and right axis deviation points to the diagnosis of ventricular tachycardia. Conversely, any supraventricular tachycardia with left bundlebranch block is typically associated with a normal or leftward QRS axis. We present the case of a 34-year-old man showing atrioventricular nodal reentrant tachycardia with left bundle-branch block/ right axis deviation as an exception to this rule. © 2009 Elsevier Inc. All rights reserved.
Keywords:
Atrioventricular nodal reentrant tachycardia; Radiofrequency catheter ablation
Introduction The presence of left bundle-branch block (LBBB) in a structurally normal heart is usually accompanied by a frontal plane QRS axis that ranges between +30° and −20°. This is because the mean QRS vector moves leftward and superior as the left ventricle gets activated transseptally; the same holds true during supraventricular tachycardia (SVT).1 The occurrence of right axis deviation (RAD) is therefore extremely unusual when there is LBBB. Thus, a regular wide QRS complex tachycardia with LBBB morphology and RAD typically suggests a ventricular tachycardia arising in the outflow tract of the right ventricle.2 Our patient is an exception to this tenet, showing LBBB with RAD during SVT. The potential mechanism of this unique observation is also discussed.
Case report A 34-year-old man with recurrent paroxysmal palpitations and a normal electrocardiogram (ECG) during sinus ⁎ Corresponding author. Quintiles ECG Services, 502 A, Leela Business Park, M.V. Road, Andheri (East), Mumbai 400 059, India. E-mail address: [email protected] 0022-0736/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jelectrocard.2009.05.003
rhythm was referred for an electrophysiologic (EP) study. The baseline 12-lead ECG was normal, showing sinus rhythm with a PR interval of 135 milliseconds, QRS duration of 90 milliseconds, and a QRS frontal axis of +35° (Fig. 1A). The clinical examination and echocardiogram were normal. The EP study was performed using an EP Tracer V0.74 (Cardiotek, Maastricht, The Netherlands) system. Intracardiac recordings demonstrated normal basal intervals. The AH interval was 58 milliseconds and the HV interval was 50 milliseconds. There was no ventriculoatrial conduction during ventricular pacing at baseline. Also at baseline, no tachycardia could be induced during programmed atrial stimulation. After isoprenaline administration, ventriculoatrial conduction emerged, which was concentric and decremental. With single test atrial premature beat stimulation, a tachycardia with a cycle length of 280 milliseconds was induced (Fig. 1B) having a LBBB morphology (QRS 130 milliseconds) with a frontal plane axis of +120°. The intracardiac recordings were characteristic of slow-fast atrioventricular nodal reentrant tachycardia (AVNRT) (Fig. 2). Later, the LBBB spontaneously resolved without change in cycle length (Fig. 1B) or ventriculoatrial activation pattern. The patient underwent successful radiofrequency (RF) catheter ablation of the slow pathway. After this, no tachycardia was inducible and there were no echoes or AH
Y. Lokhandwala et al. / Journal of Electrocardiology 42 (2009) 674–676
675
Fig. 1. A, Twelve-lead surface ECG in sinus rhythm. B, Twelve-lead surface ECG recording of tachycardia induced during EP study. Note the LBBB morphology with RAD (QRS axis + 120). Later LBBB disappears (⁎) without a change in cycle length, confirming this to be SVT.
676
Y. Lokhandwala et al. / Journal of Electrocardiology 42 (2009) 674–676
Fig. 2. Intracardiac recordings during the wide QRS tachycardia. The atrial activation (arrows) is earliest in the His bundle region and occurs simultaneous with the initial part QRS complex, confirming the tachycardia mechanism to be slow-fast AV nodal reentry tachycardia. CS 1, 2 and CS 3, 4 indicate distal and proximal coronary sinus, respectively; HISD and HISP indicate distal and proximal recordings, respectively, from the His bundle region.
jump, despite vigorous stimulation protocols using isoprenaline and atropine. Discussion The combination of LBBB with RAD in a structurally normal heart has not been described so far in SVT. Such a pattern would typically indicate a ventricular tachycardia arising in the outflow tract of the right ventricle.1 Rarely, supraventricular rhythms have been reported with LBBB/ RAD, namely, sinus rhythm, premature atrial complexes, or atrial fibrillation2 , usually in the setting of a dilated cardiomyopathy.2,3 In the present case, this pattern has been observed along with AVNRT in a structurally normal heart, which may be attributed to a functional aberrancy. In this context, Vera and coworkers3 have extensively discussed the possibility of left posterior fascicular block in the presence of predivisional LBBB resulting in combined LBBB and RAD. Khurana et al4 also described a case of Wegener granulomatosis with LBBB and RAD in which predivisional LBBB with predominant left posterior fascicular block secondary to ischemic or inflammatory involvement of the conduction system as a possible explanation. In a review of 36 cases with the electrocardiographic combination of LBBB and RAD, Childers et al5 clearly suggested
that the RAD was a rate-dependent or episodically occurring conduction defect added to predivisional LBBB. Ventricular tachycardia arising in the outflow tract of the right ventricle and AVNRT can coexist.6 However, in our patient, this is not tenable; with 2 tachycardia mechanisms, it would be implausible to expect exactly the same cycle length, and that too occurring at the same time. Moreover, after slow pathway ablation, there was no other tachycardia. References 1. Wellens HJ. Electrophysiology: ventricular tachycardia: diagnosis of broad QRS complex tachycardia. Heart 2001;86:579. 2. Nikolic G, Marriott HJ. Left bundle branch block with right axis deviation: a marker of congestive cardiomyopathy. J Electrocardiol 1985;18:395. 3. Vera Z, Ertem G, Cheng TO. Left bundle branch block with intermittent right axis deviation. Evidence for left posterior hemiblock accompanying predivisional left bundle branch block. Am J Cardiol 1972;30:896. 4. Khurana C, Mazzone P, Mandell B. New onset left bundle branch block with right axis deviation in a patient with Wegener's granulomatosis. J Electrocardiol 2000;33:199. 5. Childers R, Lupovich S, Sochanski M. Konarzewska H. Left bundle branch block and right axis deviation: a report of 36 cases. J Electrocardiol 2000;33(Suppl):93. 6. Wylie Jr JV, Milliez P, Germano JJ, et al. Atrioventricular nodal reentrant tachycardia associated with idiopathic ventricular tachycardia: clinical and electrophysiologic characteristics. J Electrocardiol 2007;40:94.