Effects of exercise training on myocardial blood flow reserve in patients with heart failure and left ventricular systolic dysfunction.
Exercise training has been shown to be effective in improving exercise capacity and quality of life in patients with heart failure and left ventricular (LV) systolic dysfunction. Real-time myocardial contrast echocardiography (RTMCE) is a new technique that allows quantitative analysis of myocardial blood flow (MBF). The aim of this study was to determine the effects of exercise training on MBF in patients with LV dysfunction. We studied 23 patients with LV dysfunction who underwent RTMCE and cardiopulmonary exercise testing at baseline and 4 months after medical treatment (control group, n = 10) or medical treatment plus exercise training (trained group, n = 13). Replenishment velocity (beta) and MBF reserves were derived from quantitative RTMCE. The 4-month exercise training consisted of 3 60-minute exercise sessions/week at an intensity corresponding to anaerobic threshold, 10% below the respiratory compensation point. Aerobic exercise training did not change LV diameters, volumes, or ejection fraction. At baseline, no difference was observed in MBF reserve between the control and trained groups (1.89, 1.67 to 1.98, vs 1.81, 1.28 to 2.38, p = 0.38). Four-month exercise training resulted in a significant increase in beta reserve from 1.72 (1.45 to 1.48) to 2.20 (1.69 to 2.77, p <0.001) and an MBF reserve from 1.81 (1.28 to 2.38) to 3.05 (2.07 to 3.93, p <0.001). In the control group, beta reserve decreased from 1.51 (1.10 to 1.85) to 1.46 (1.14 to 2.33, p = 0.03) and MBF reserve from 1.89 (1.67 to 1.98) to 1.55 (1.11 to 2.27, p <0.001). Peak oxygen consumption increased by 13.8% after 4 months of exercise training and decreased by 1.9% in the control group. In conclusion, exercise training resulted in significant improvement of MBF reserve in patients with heart failure and LV dysfunction.
Santos
João Manoel Theotonio
JM
Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
Kowatsch
Ingrid
I
Tsutsui
Jeane Mike
JM
Negrão
Carlos Eduardo
CE
Canavesi
Nancy
N
Carvalho Frimm
Clóvis
C
Mady
Charles
C
Ramires
José Antonio Franchini
JA
Mathias
Wilson
W
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity; D015331:Cohort Studies; D003326:Coronary Circulation / Q000502:physiology*; D015444:Exercise; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D013318:Stroke Volume; D016896:Treatment Outcome; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000503:physiopathology* / Q000628:therapy