Impact of Right Atrial-Left Ventricular Dual-Chamber Permanent Pacing in Patients With Severely Symptomatic Hypertrophic Obstructive Cardiomyopathy

Abstract

Background Effective alternatives to surgical myectomy for patients with symptomatic hypertrophic obstructive cardiomyopathy (HOCM) remain unestablished. Dual-chamber (DDD) pacing was evaluated in these patients using right atrial (RA) and epicardial left ventricular (LV) leads. Methods and Results In 6 patients with HOCM refractory to medical therapy and conventional RA-right ventricular (RV) DDD pacing, we implanted DDD pacemakers using RA and epicardial LV leads. The baseline intraventricular pressure gradient before pacemaker implantation was 103±44 mmHg. The pressure gradient decreased significantly to 8±16 mmHg by temporary RA-LV DDD pacing (p=0.006), while it decreased only to 68±25 mmHg by temporary RA-RV pacing (NS). It was nearly eliminated to 1±2 mmHg (p=0.027) 3 months after RA-LV DDD pacemaker implantation. LV end-diastolic pressure, cardiac index and systolic aortic pressure did not change significantly. New York Heart Association class improved in all patients (p=0.023). Brain and atrial natriuretic peptide concentrations, respectively 516±286 and 143±34 pg/ml at baseline, decreased significantly to 230±151 and 93±44 pg/ml 3 months after implantation (p=0.027 and 0.028). Conclusion RA-LV DDD pacemaker implantation is a useful option for patients with symptomatic HOCM. (Circ J 2005; 69: 536 - 542)