Cardiac Resynchronization Therapy Reduces Metaboreflex Contribution to the Ventilatory Response in Heart Failure Population

[摘要] Background. Metaboreflex overactivation has been proprosed to explain exaggerated hyperventilation in heart failure population. We investigated the metaboreflex activation after cardiac resynchronization therapy (CRT).Methods. 10 heart failure patients (mean left ventricular ejection fraction (LVEF)27±4%) schedulded for CRT implantation were prospectively studied. At baseline and after 6 month follow up two maximal cardiopulmonary exercise tests with and without regional circulatory occlusion (RCO) during recovery were performed. RCO was achieved by inflation of bilateral upper thigh tourniquets 30 mmHg above peak systolic blood pressure during 3 minutes after peak exercise. Metaboreflex contribution to the ventilatory response was assessed as the difference in ventilatory data at the third minute during recovery between the two tests (Δ).Results. Patients had enhanced VE/VCO2slope (40±9) and an evident metaboreflex contribution to the high ventilatory response (ΔVE:3±4 L/min;P=0.05, ΔRR:4.5±4/min;P=0.003and ΔVE/VCO2:5.5±4;P=0.007). 6 months after CRT implantation, NYHA class, LVEF, peak VO2and VE/VCO2were significantly improved (1.4±0.5;P<0.001,42±7%;P<0.001,16.5±3 mL/kg/min;P=0.003;33±10;P=0.01). Metaboreflex contribution to VE, RR, and VE/VCO2was reducedcompared with baseline (P=0.08,P=0.01andP=0.4resp.).Conclusion. 6 months after CRT metaboreflex contribution to the ventilatory response is reduced.

[学科分类] 心脏病和心血管学