Left Bundle Pacing for Third-Degree Atrioventricular Block in a Patient with Obstructive Hypertrophic Cardiomyopathy

Ventricular arrhythmias are common in patients with obstructive hypertrophic cardiomyopathy (HOCM) and can cause syncope and sudden death, but conduction disturbances are rarely associated with obstructive hypertrophic cardiomyopathy. Cardiac physiologic pacing can be achieved by stimulating the intrinsic conduction system via conduction system pacing (Hiss bundle, left bundle branch-LBB- or left bundle branch area pacing). This technique can be challenging in HOCM due to septal hypertrophy. Our literature review did not find such a case reported so far where LBB area pacing was performed in a patient with HOCM with satisfying results and with the improvement of outflow obstruction of the left ventricle. Here we describe a case of a 57-year-old man with obstructive hypertrophic cardiomyopathy and third-degree atrioventricular (AV) block who presented in our cardiology department for dyspnea and fatigue. This patient was treated with LBB area pacing and recovered well.