Study objective: The aim of this study was to measure systemic to pulmonary blood flow from bronchial circulation (Qbr[s-p]) in patients with heart failure.
Design: In the absence of pulmonary and coronary flows, Qbr(s-p) is the volume of blood accumulating in the left side of the heart; Qbr(s-p) was measured during total cardiopulmonary bypass for coronary artery surgery; bronchial blood was vented through a cannula introduced into the left side of the heart and its volume was measured.
Patients: Patients were subdivided according to the presence for more than 6 months (group 1, n = 6) or less than 2 months (group 2, n = 7), or the absence of heart failure (group 2, n = 15).
Measurements and results: Qbr(s-p) was 89 +/- 18* mL/min, 27 +/- 3, 22 +/- 2, in groups 1, 2, and 3, respectively (* = p < 0.01 group 1 vs groups 2 and 3). During total cardiopulmonary bypass, pulmonary venous pressure approximates atmospheric pressure and no differences between groups were observed in systemic artery pressure, extracorporeal circulation pump flow, and airway pressure. Therefore, vascular resistance through the bronchial vessels draining into the pulmonary circulation is reduced in patients with heart failure for more than 6 months (group 1).
Conclusions: During total cardiopulmonary bypass, Qbr(s-p) is increased in patients with chronic heart failure. Since with elevated pulmonary vascular pressure blood flow through Qbr(s-p) vessels is from the pulmonary to the systemic circulation, the lower resistance observed in group 1 suggests that bronchial vessels might contribute to reduced lung fluid overload in patients with chronic heart failure.