Reversal of Acute Pacing-induced Cardiomyopathy by Cardiac Resynchronization Therapy in Setting of Post-tavr Heart Block

Abstract

Introduction Transcatheter aortic valve implantation (TAVR) has emerged as a viable alternative to surgical aortic valve replacement. Due to the anatomical relationship to atrial-ventricular (AV) node and valve implantation site, high grade AV block may happen necessitating pacemaker implantation. Pacing-induced cardiomyopathy may result from sustained, chronic right ventricular (RV) pacing causing electrical dyssynchrony and redistribution of myocardial strain, with subsequent development of left ventricular (LV) systolic dysfunction. Time to onset of heart failure is typically months to years, with rare instances in a matter of days. Case Illustration A 70-year-old woman with a past medical history of severe symptomatic aortic stenosis, pulmonary hypertension, essential hypertension, type 2 diabetes mellitus presented for elective TAVR. Baseline left ventricular ejection fraction (LVEF) was 60-64%. Pre-operative QRS duration was 170 ms (Figure 1a). The procedure was complicated by complete atrial-ventricular block for which a dual chamber pacemaker was implanted emergently. A transthoracic echocardiogram (TTE) performed post-operatively day 1 showed dramatic interval decrease in LVEF from 60-64% to 25-29% with significantly increased end diastolic volume (EDV) and end systolic volume (ESV) suggesting LV dilation (Figure 2). Investigations for potential causes were unrevealing for obvious culprits, including absence of prosthesis dysfunction, unchanged patent coronary anatomy on repeat invasive coronary angiogram. After exclusion of reversible causes, the patient underwent cardiac resynchronization therapy (CRT) with a bi-ventricular implantable cardioverter-defibrillator (ICD) on post-operative day 10. Her symptoms improved and patient was discharged. At one-month follow up, updated TTE showed recovered LVEF of 55-60% with reversal of LV dilation (Figure 2). Electrocardiography (ECG) showed appropriate biventricular pacing (Figure 1b). Device interrogation showed 97% bi-ventricular paced. Conclusion Early recognition of cardiomyopathy induced by pacemaker implantation after TAVR allows prompt appropriate therapy that can reverse the cardiomyopathy process.