Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Cardiac & Cardiovascular Systems, Cardiovascular System & Cardiology, Biventricular pacing, Hypertrophic obstructive cardiomyopathy, Intraventricular gradient, Reverse remodeling, LEFT-VENTRICULAR OUTFLOW, CARDIAC RESYNCHRONIZATION THERAPY, SURGICAL SEPTAL MYECTOMY, TRACT OBSTRUCTION, DOUBLE-BLIND, ABLATION, CROSSOVER, RISK, Adult, Aged, Cardiac Resynchronization Therapy, Cardiomyopathy, Hypertrophic, Chi-Square Distribution, Echocardiography, Doppler, Female, Follow-Up Studies, Humans, Male, Middle Aged, Pilot Projects, Risk Assessment, Severity of Illness Index, Statistics, Nonparametric, Survival Analysis, Time Factors, Treatment Outcome, Ventricular Remodeling, 0903 Biomedical Engineering, 1102 Cardiorespiratory Medicine and Haematology, Cardiovascular System & Hematology, 3201 Cardiovascular medicine and haematology

Abstract:

BACKGROUND: Right ventricle apical (RVA) pacing for gradient reduction in hypertrophic obstructive cardiomyopathy (HOCM) with severe left ventricular (LV) obstruction showed conflicting results. OBJECTIVES: To assess the feasibility and effectiveness of biventricular pacing in HOCM. METHODS: Transvenous biventricular pacing was attempted in 12 severely symptomatic HOCM patients. Optimal intervals were programmed after implant. Echocardiographic LV pressure gradient and synchrony was assessed. LV lead implantation was successful in 9 patients. Optimal pacing mode was biventricular in 6 patients, LV-only in 2 patients and RV-only in 1 patient. RESULTS: Functional capacity and QoL progressively improved: NYHA class decreased from 3.2±0.4 at baseline to 1.9±0.3 at 3 months and to 1.4±0.5 at 1 year (p< /0.05); 6MWT increased from 349±116 m at baseline to 454±144 m at 3 months and to 517±206 m (p< /0.05); QoL increased from 54±16 points at baseline to 28±13 points at 3 months and 27±15 points at 1 year (p< /0.05). There was also a progressive reduction in LV gradient from 74±23 mm Hg at baseline to 50±27 mm Hg acutely, 40±26 mm Hg at 3 months and 28±17 mm Hg at 1 year (p< /0.05). Gradient reduction was associated with a diminished peak longitudinal displacement of the LV septum and an earlier displacement of the lateral wall. A progressive reduction of LV mass was observed, from 356±110 g at baseline to 315±70 g at 3 months (p=0.13) and to 284±42 g at 1 year (p< /0.05). CONCLUSIONS: Biventricular pacing is feasible and usually the best configuration for gradient reduction in HOCM. Biventricular pacing reduces LV hypertrophy.