A tailored, left ventricular-only pacing CRT programming strategy for transient left bundle branch block facilitated by Bachmann Bundle atrial pacing

Figures

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  Figure 1. A: 12-lead electrocardiogram from the time of congestive heart failure exacerbation showing left bundle branch block at a sinus rate of 77 beats per minute and a QRS duration of 148 ms. B: 12-lead electrocardiogram from the time of office consultation showing a narrow QRS duration of 88 ms at a sinus rate of 63 beats per minute. C: Left anterior oblique 30° view of the cardiac resynchronization therapy-defibrillator system with the Bachmann bundle atrial pacing lead. D: Right anterior oblique 30° view of the cardiac resynchronization therapy-defibrillator system with the Bachmann bundle atrial pacing lead.

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  Figure 2. A: P-wave duration of 148 ms with bifid P-wave morphology (II, aVF) indicative of interatrial conduction delay. PR interval of 258 ms at the time of cardiac resynchronization therapy-defibrillator implant. The QRS duration is 97 ms. Bipolar sensed Bachmann bundle EGM is seen on the electrophysiology recording system filtered at 30–500 Hz and 0.05–500 Hz as shown. B: Intracardiac EGMs from the cardiac resynchronization therapy-defibrillator showing a sensed AV interval of 222 ms in sinus rhythm at 63 bpm. C: With LV-only pacing prohibited by an AV interval of >220 ms, the biventricular paced QRS duration is 153 ms. D: With AAI pacing from the Bachmann bundle lead at 75 bpm, the PR interval is shortened to 206 ms. The P-wave duration is 116 ms, and the PR segment is 98 ms. E: Intracardiac EGMs showing AV intervals with Bachmann bundle atrial pacing at 70, 80, and 90 bpm. All remain within 270 ms to maintain LV-only pacing. F: AV sequential, LV-only pacing with the narrow baseline QRS complex with a minimal degree of fusion between the LV paced wavefront and the native QRS. QRS fusion is most apparent in leads II and III. AV = atrioventricular; bpm = beats per minute; EGM =…

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  Figure 3. A: 12-lead electrocardiogram of the underlying rhythm 3 months after implant showing recrudescence of left bundle branch block QRS morphology. B: 12-lead electrocardiogram 3 months after implant showing QRS duration of 134 ms with atrioventricular dual-paced rhythm. The ventricle is paced using fused, LV-only pacing. C: Device histogram data showing that the pacing programming strategy resulted in a high percentage of both atrial pacing and LV-only pacing. AF = atrial fibrillation; AT = atrial tachycardia; Bi-V = biventricular; LV = left ventricle.