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, 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/min: 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 mmHg at rest, 4.1±2.0 mmHg at submaximum, 4.7±2.1 mmHg at peak; group 2: 1.9±0.8 mmHg at rest, 2.1±0.9 mmHg at submaximum, 2.1±0.9 mmHg 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.