572
EP Image
His-Bundle Bigeminy Evidenced by Short His–Ventricular Interval YOSHIAKI KANEKO, M.D., TADASHI NAKAJIMA, M.D., MASAKI OTA, M.D., and MASAHIKO KURABAYASHI, M.D. From the Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
catheter ablation, His arrhythmia, His-bundle ectopy A 59-year-old man with a history of anteroseptal myocardial infarction was emergently admitted to our hospital with a complaint of palpitation. A 12-lead electrocardiogram showed repetitive, nonsustained wide QRS tachycardias with right bundle branch block and superior axis morphology, characterized by initiation with a constant coupling interval of its first beat, QRS cycle length alternans, and appearance of sinus P waves between shorter intervals of the adjacent QRS complexes only, with a fixed PQ interval of 0.26 seconds and ending with sinus P wave, intervening between several sinus beats (Fig. 1). Intravenous administration of a beta-blocker and calcium antagonist was ineffective for suppression of the tachycardias. Atrial–Hisian and His–ventricular (HV) intervals during sinus rhythm were 123 and 86 milliseconds,
J Cardiovasc Electrophysiol, Vol. 26, pp. 572-573, May 2015. No disclosures. Address for correspondence: Yoshiaki Kaneko, M.D., Ph.D., Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma 371-8511, Japan. Fax: +81-27-220-8158; E-mail: [email protected] doi: 10.1111/jce.12613
respectively. No dual atrioventricular nodal physiology was elicited by atrial stimulation and no ventriculoatrial conduction was observed. During isoproterenol infusion, clinically documented tachycardias developed (Fig. 2); they were characterized by (1) alternating sinus cycles and extrasystoles with no preceding atrial activation, and (2) a shorter HV interval of 29 milliseconds and wider His-bundle electrograms (indicated by H’) than those in the sinus cycle (indicated by H), which were consistent with a diagnosis of His-bundle bigeminy. The main differential diagnosis included nonreentrant atrioventricular nodal tachycardia caused by repetitive dual ventricular responses that was ruled out by the detection of every other short HV interval during the ongoing tachycardia. The extrasystoles did not develop (1) consecutively, (2) immediately after antegrade conduction block over the fast pathway (FP) of sinus atrial activation, (3) immediately after ending with sinus atrial activation, and (4) immediately after ventricular stimulation, thus suggesting that the underlying mechanism involved an intra-Hisian reentry within the longitudinally dissociated His-bundle that was triggered by the preceding antegrade propagation over the FP. Since an empiric slow pathway ablation was ineffective for suppression of the tachycardia, FP ablation was performed on the atrial side, resulting in complete elimination of the extrasystoles closely associated with elimination of antegrade conduction over the FP, followed by implantation of a biventricular pacemaker.
Kaneko et al.
Figure 1.
Figure 2.
His-Bundle Bigeminy
573
EP Image
His-Bundle Bigeminy Evidenced by Short His–Ventricular Interval YOSHIAKI KANEKO, M.D., TADASHI NAKAJIMA, M.D., MASAKI OTA, M.D., and MASAHIKO KURABAYASHI, M.D. From the Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
catheter ablation, His arrhythmia, His-bundle ectopy A 59-year-old man with a history of anteroseptal myocardial infarction was emergently admitted to our hospital with a complaint of palpitation. A 12-lead electrocardiogram showed repetitive, nonsustained wide QRS tachycardias with right bundle branch block and superior axis morphology, characterized by initiation with a constant coupling interval of its first beat, QRS cycle length alternans, and appearance of sinus P waves between shorter intervals of the adjacent QRS complexes only, with a fixed PQ interval of 0.26 seconds and ending with sinus P wave, intervening between several sinus beats (Fig. 1). Intravenous administration of a beta-blocker and calcium antagonist was ineffective for suppression of the tachycardias. Atrial–Hisian and His–ventricular (HV) intervals during sinus rhythm were 123 and 86 milliseconds,
J Cardiovasc Electrophysiol, Vol. 26, pp. 572-573, May 2015. No disclosures. Address for correspondence: Yoshiaki Kaneko, M.D., Ph.D., Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, 3-39-22 Showa, Maebashi, Gunma 371-8511, Japan. Fax: +81-27-220-8158; E-mail: [email protected] doi: 10.1111/jce.12613
respectively. No dual atrioventricular nodal physiology was elicited by atrial stimulation and no ventriculoatrial conduction was observed. During isoproterenol infusion, clinically documented tachycardias developed (Fig. 2); they were characterized by (1) alternating sinus cycles and extrasystoles with no preceding atrial activation, and (2) a shorter HV interval of 29 milliseconds and wider His-bundle electrograms (indicated by H’) than those in the sinus cycle (indicated by H), which were consistent with a diagnosis of His-bundle bigeminy. The main differential diagnosis included nonreentrant atrioventricular nodal tachycardia caused by repetitive dual ventricular responses that was ruled out by the detection of every other short HV interval during the ongoing tachycardia. The extrasystoles did not develop (1) consecutively, (2) immediately after antegrade conduction block over the fast pathway (FP) of sinus atrial activation, (3) immediately after ending with sinus atrial activation, and (4) immediately after ventricular stimulation, thus suggesting that the underlying mechanism involved an intra-Hisian reentry within the longitudinally dissociated His-bundle that was triggered by the preceding antegrade propagation over the FP. Since an empiric slow pathway ablation was ineffective for suppression of the tachycardia, FP ablation was performed on the atrial side, resulting in complete elimination of the extrasystoles closely associated with elimination of antegrade conduction over the FP, followed by implantation of a biventricular pacemaker.
Kaneko et al.
Figure 1.
Figure 2.
His-Bundle Bigeminy
573
