RESUMO
In order to evaluate the left internal thoracic artery flow pattern, when the vessel is used as a graft to supply the left coronary artery system, we evaluated flow by Doppler measurement, both at rest and under dobutamine stress. There were 2 groups of 20 patients each: group A patients received only a left internal thoracic artery graft to the left anterior descending artery, and group B patients received a pedicled left internal thoracic artery graft associated with a vein graft, which together supplied the left anterior descending artery and another branch of the left coronary artery. Angiography showed patent grafts in all patients from both groups. The following characteristics were evaluated: systolic flow, diastolic flow, total flow, total flow under stress/total flow at rest ratio, systolic peak velocity, diastolic peak velocity, and systolic peak velocity/diastolic peak velocity ratio. In group A, the total flow was 45.5 +/- 21.6 mL/min at rest and 68.3 +/- 32.9 mL/min under stress. In group B, the total flow was 98.2 +/- 50.4 mL/min at rest and 175.7 +/- 79.2 mL/min under stress. Comparison between groups showed a total flow increase in group B of 115.8% (P=0.0002) at rest and 157.2% (P <0.0001) under stress. The other characteristics were also statistically significant, except systolic flow, total flow under stress/total flow at rest ratio, and systolic peak velocity. Our results showed that the left internal thoracic artery sufficiently supplies regional myocardium at rest and during exercise (stress), demonstrating its great adaptability in response to demand.
Assuntos
Angiografia Coronária , Ponte de Artéria Coronária , Circulação Coronária , Estenose Coronária/fisiopatologia , Vasos Coronários/fisiopatologia , Adulto , Idoso , Velocidade do Fluxo Sanguíneo , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/cirurgia , Coração/fisiopatologia , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , TransplantesRESUMO
BACKGROUND: Heart failure can present with asymptomatic dysfunction at decompensation, with limitations and decrease in the productive capacity. The Continuous Positive Airway Pressure (CPAP) is a non-pharmacological means to decrease afterload. OBJECTIVE: To analyze the effects of CPAP (10 cmH2O), for 30 days in patients with chronic heart failure. METHODS: We assessed 10 patients with heart failure (6 males, 4 females) of several etiologies, with a mean age of 54 +/- 14 years, with a BMI of 21 +/- 0.04 kg/m(2). The therapy was applied for 60 min., 5 times a week for 30 days, during the daytime. The echocardiogram and the ergospirometry were analyzed, before and 30 days after the therapy. RESULTS: There was a 19.59% increase in the left ventricular ejection fraction (LVEF): 23.9 +/- 8.91 vs 27.65 +/- 9.56%; p = 0.045. At the ergospirometry, the exercise time (ET) showed a significant increase from 547 +/- 151.319 vs 700 +/- 293.990 sec., p = 0.02; oxygen consumption (VO2) was 9.59 +/- 6.1 vs 4.51 +/- 2.67 ml x kg(-1) x min(-1), p = 0.01, whereas the carbon dioxide production (VCO2) at rest (9.85 +/- 4.38 vs 6.44 +/- 2.88 ml x kg(-1) x min(-1), p = 0.03) decreased. CONCLUSION: The CPAP resulted in an increase in the LVEF and ET, decreased the oxygen consumption and the carbon dioxide production at rest.