Relationship of diastolic intraventricular pressure gradients and aerobic capacity in patients with diastolic heart failure

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 58; no. 5; pp. H2081 - H2088
• Main Authors: ROVNER, Aleksandr, GREENBERG, Neil L, THOMAS, James D, GARCIA, Mario J
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Physiological Society 01.11.2005
• Subjects: Biological and medical sciences; Blood pressure; Exercise; Fundamental and applied biological sciences. Psychology; Heart failure; Metabolism; Oxygen; Ultrasonic imaging; Vertebrates: cardiovascular system; Human; Heart failure; oxygen metabolism; Oxygen; cardiovascular system; Diastolic pressure; metabolic stress test; Cardiovascular disease; Pressure gradient; Metabolism; Stress; Vertebrata; Mammalia; Heart disease; Circulatory system
• ISSN: 0363-6135

We sought to elucidate the relationship between diastolic intraventricular pressure gradients (IVPG) and exercise tolerance in patients with heart failure using color M-mode Doppler. Diastolic dysfunction has been implicated as a cause of low aerobic potential in patients with heart failure. We previously validated a novel method to evaluate diastolic function that involves noninvasive measurement of IVPG using color M-mode Doppler data. Thirty-one patients with heart failure and 15 normal subjects were recruited. Echocardiograms were performed before and after metabolic treadmill stress testing. Color M-mode Doppler was used to determine the diastolic propagation velocity (Vp) and IVPG off-line. Resting diastolic function indexes including myocardial relaxation velocity, Vp, and E/Vp correlated well with O2 max (r = 0.8, 0.5, and -0.5, respectively, P < 0.001 for all). There was a statistically significant increase in Vp and IVPG in both groups after exercise, but the change in IVPG was higher in normal subjects compared with patients with heart failure (2.6 +/- 0.8 vs. 1.1 +/- 0.8 mmHg, P < 0.05). Increase in IVPG correlated with peak O2 max (r = 0.8, P < 0.001) and was the strongest predictor of exercise capacity. Myocardial relaxation is an important determinant of exercise aerobic capacity. In heart failure patients, impaired myocardial relaxation is associated with reduced diastolic suction force during exercise. [PUBLICATION ABSTRACT]