Background: The concept of ventricular-arterial coupling implies that LV-function is determined by the three factors left ventricular diastolic, left ventricular systolic and arterial elastance. We have previously documented an improvement in endothelial function and systolic LV-function in patients with chronic heart failure (CHF) after 6 months of exercise training (ET). It remains, however, unclear, how shorter ET periods may affect endothelial, systolic and diastolic ventricular function as echocardiographic parameters related to ventricular arterial coupling in patients with CHF.
METHODS: In this ongoing study we randomised 43 patients with stable CHF (age 60.3 ± 2.9 years, EF 27.4 ± 1.7%, VO
2
max 14.7 ± 4.3ml/kg*min) to a training or a control group (C). Patients in the training group exercised 4 times daily at 70% of the individual heart rate reserve for 4 weeks under supervision. At baseline and after 4 weeks the E/A ratio and septal/lateral E’/A’ velocities were determined by echocardiography with tissue Doppler. Exercise capacity was measured by ergospirometry and flow-mediated dilatation (FMD) was assessed by high-resolution radial ultrasound.
RESULTS: After only 4 weeks of ET oxygen uptake at peak exercise increased from 14.9 ± 3.3 to 18.1 ± 4.7 ml/min/kg, (p<0.01 vs. C) in training subjects. Left ventricular ejection fraction improved from 26.8 ± 4.6 to 33.1 ± 5.5% (p<0.05 vs. C) in patients of the training group while it remained unchanged in the control group. E/A-ratio mended from 0.63 ± 0.12 to 0.81 ± 0.22 (p<0.01 vs. C) in training patients. Septal E’ velocities increased from 5.5 ± 0.5 to 7.8 ± 1.4 cm/s in training patients (p<0.05 vs. C). FMD of the radial artery improved from 8.2 ± 2.1 to 15.2 ± 3.8% (p<0.01 vs. C) as a result of ET.
CONCLUSIONS: Only 4 weeks of endurance training are highly effective with significantly improved FMD accompanied by an emended systolic and diastolic LV-function. We hypothesise that the improvement in LV-EF in training patients may be caused by a corrected ventricular-arterial coupling: ventricular diastolic relaxation and effective endothelial function are ameliorated resulting in an augmentation of stroke volume.
Effects of Endothelin A Receptor Blockade on Endothelial Function in Patients With Chronic Heart Failure
