Diastolic Intra-Left Ventricular Pressure Difference During Exercise: Strong Determinant and Predictor of Exercise Capacity in Patients With Heart Failure

Background: Although the enhancement of early-diastolic intra-left ventricular pressure difference (IVPD) during exercise is considered to maintain exercise capacity, little is known about their relationship in heart failure (HF). Methods and Results: Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 50 HF patients (left ventricular [LV] ejection fraction 39 +/- 15%). Echocardiographic images were obtained at rest and submaximal and peak exercise. Color M-mode Doppler images of LV inflow were used to determine IVPD. Thirty-five patients had preserved exercise capacity (peak oxygen consumption [VO2] >= 14 mL.kg(-1).min(-1); group 1) and 15 patients had reduced exercise capacity (group 2). During exercise, IVPD increased only in group 1 (group 1: 1.9 +/- 0.9 mm Hg at rest, 4.1 +/- 2.0 mm Hg at submaximum, 4.7 +/- 2.1 mm Hg at peak; group 2: 1.9 +/- 0.8 mm Hg at rest, 2.1 +/- 0.9 mm Hg at submaximum, 2.1 +/- 0.9 mm Hg at peak). Submaximal IVPD (r = 0.54) and peak IVPD (r = 0.69) were significantly correlated with peak VO2. Peak IVPD determined peak VO2 independently of LV ejection fraction. Moreover, submaximal IVPD could well predict the reduced exercise capacity. Conclusion: Early-diastolic IVPD during exercise was closely associated with exercise capacity in HF. In addition, submaximal IVPD could be a useful predictor of exercise capacity without peak exercise in HF patients.