Reduced coronary flow reserve in patients with congestive heart failure assessed by transthoracic Doppler echocardiography.

Background: Although coronary flow reserve (CFR) has been reported to be restricted in various conditions, there has been no report of CFR for patients with congestive heart failure (CHF). The purpose of this study was to assess coronary flow characteristics for patients with CHF.

Methods: We studied 15 patients with CHF: 8 with dilated myocardiopathy and 7 with hypertensive heart disease. Phasic coronary flow velocities were obtained in the left anterior descending coronary artery at rest and during hyperemia (0.15 mg/kg/min adenosine triphosphate infusion intravenously) by transthoracic echocardiography before and after treatment of CHF. CFR was obtained from the ratio of hyperemic/baseline diastolic mean velocity.

Results: CFR was significantly restricted in the condition of CHF compared with that after improvement of CHF (1.5 +/- 0.2 vs 2.0 +/- 0.3, P < .01). Baseline diastolic mean velocity in the condition with CHF was significantly greater than that after improvement of CHF (41 +/- 13 cm/s vs 33 +/- 13 cm/s, P = .04), although maximal hyperemic diastolic mean velocity was not significantly different before and after improvement of CHF (63 +/- 20 cm/s vs 61 +/- 19 cm/s, P = .68). After improvement of CHF, heart rate, along with left ventricular end-diastolic volume and dimension, were significantly decreased, and deceleration time of transmitral early filling flow was increased compared with before treatment of CHF. Blood pressure and ejection fraction were not significantly different before and after treatment of CHF.

Conclusions: Restriction of CFR is demonstrated during CHF because of the elevation of baseline resting flow velocity, which might be related to increase in left ventricular preload and heart rate.