title: Effects of exercise training on myocardial blood flow reserve in patients with heart failure and left ventricular systolic dysfunction.
abstract: 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.
authors.affiliation: Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: João Manoel Theotonio
authors.initials: JM
authors.lastname: Santos
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kowatsch
authors.forename: Jeane Mike
authors.initials: JM
authors.lastname: Tsutsui
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Negrão
authors.forename: Nancy
authors.initials: N
authors.lastname: Canavesi
authors.forename: Clóvis
authors.initials: C
authors.lastname: Carvalho Frimm
authors.forename: Charles
authors.initials: C
authors.lastname: Mady
authors.forename: José Antonio Franchini
authors.initials: JA
authors.lastname: Ramires
authors.forename: Wilson
authors.initials: W
authors.lastname: Mathias
mesh_terms: 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