Response to Cardiac Resynchronization Therapy: The Muscular Metabolic Pathway

[摘要] Background. Changes in peripheral muscle in heart failure lead to a shift from aerobic to early anaerobic metabolism during exercise leading to ergoreflex overactivation and exaggerated hyperventilation evaluated by the VE/VCO2slope.Methods. 50 patients (38 males,59±12years) performed cardio-pulmonary exercise test with gaz exchange measurement and echocardiographic evaluation before and 6 months afterCRT.Results. The peak respiratory exchange (VCO2/ VO2) ratio was significantly reduced from1.16±0.14to1.11±0.07(P<.05) and the time to the anaerobic threshold was increased from153±82to245±140seconds (P=.01). Peak VO2, VE/VCO2, peak circulatory power and NYHA were improved after CRT (13±4to16±5ml/kg/min (P<.05),45±16to39±13(P<.01),1805±844to2225±1171 mmHg.ml/kg/min (P<.01) and3±0.35to1.88±0.4(P=.01)). In addition, left ventricular ejection fraction and end-systolic volumes were improved from24±8to29±7% (P<.01) and from157±69to122±55ml (P<.01).Conclusion. We suggest that CRT leads to an increase in oxidativemuscular metabolism and postponed anaerobic threshold reducing exaggerated hyperventilation during exercise.

[学科分类] 心脏病和心血管学