This case presents a 67-year-old man with familial hypertrophic cardiomyopathy, severe heart failure (LVEF 31%, NYHA III), and significant interatrial conduction delay. After ruling out cardiac resynchronization therapy due to unsuitable ventricular activation characteristics, a dual-chamber implantable cardioverter-defibrillator was implanted, using Bachmann bundle pacing for the atrial lead to optimize interatrial synchrony. BBP successfully corrected the IACD, evidenced by P-wave shortening and normalization. This led to remarkable clinical improvements within 1 month: LVEF increased from 31% to 49%, and NYHA class improved from III to II. Echocardiography confirmed enhanced left atrial-left ventricular coupling. This case demonstrates BBP combined with ICD as a novel and effective strategy for HCM patients with IACD, offering both sudden cardiac death protection and substantial hemodynamic and functional benefits by optimizing atrial activation and atrioventricular synchrony.
Biatrial macro-reentrant tachycardias are rare in patients without prior atrial intervention and often pose diagnostic and therapeutic challenges. We present a case of de novo single-loop biatrial flutter in a structurally normal heart, in which high-density mapping was critical to understanding the reentrant circuit. Initial attempts at ablation in the left atrium were unsuccessful. Successful entrainment could be demonstrated from both the lateral mitral annulus and cavotricuspid isthmus. Ablation at the cavotricuspid isthmus resulted in termination with durable success. This case highlights the importance of reassessing the mechanism when attempts at ablation fail to modify tachycardia and reinforce CTI as a critical substrate even in complex biatrial activation patterns.
A 22-year-old man presented with aborted sudden cardiac arrest due to ventricular fibrillation and recurrent tachyarrhythmia related to a right inferoparaseptal accessory pathway. A previous electrophysiology study with both endocardial and epicardial ablation had failed. Repeat electrophysiology study demonstrated diffuse early activation on endocardial mapping but a focal earliest site during epicardial mapping. The successful ablation site showed a sharp QS in the unipolar electrogram with a contact force vector directed toward the visceral pericardium/myocardium and required careful catheter positioning away from the distal right coronary artery. Accessory pathway conduction was abolished within 4.9 seconds of radiofrequency delivery. This case highlights the importance of properly analyzing the electroanatomic map, detailed electrogram analysis, and procedural safety considerations during epicardial accessory pathway ablation.
