Forgotten driving forces in right heart failure (Part II): experimental study

Abstract

Cardiac-assist devices for right ventricular failure remain controversial with poor results. This study evaluated a pulsatile cardiac-assist device in an acute right ventricular failure model vs. current therapies. Pulmonary regurgitation was created in 12 piglets by valve avulsion and external transfixation of 2 pulmonary artery cusps suspended to the pulmonary arterial wall. The piglets were divided into 2 treatment groups: a pulsatile group P and a non-pulsatile group NP. Management started when severe right ventricular failure was observed (48.1 ± 24.5 min). In group P, pulsatile trousers driven by a pneumatic generator were pulsated intermittently at 40 beats min(-1). Group NP was treated with oral tadalafil 1 mg kg(-1), intravenous fluids, and adrenaline 0.3 μg kg(-1). After 1 h of therapy, cardiac output was significantly better in group P than group NP (1 ± 0.2 vs. 0.7 ± 0.2 L min(-1)). Mean right ventricular pressure (16 ± 6 vs. 24 ± 2 mm Hg) and pulmonary arterial pressure (22 ± 1 vs. 31 ± 2 mm Hg) were lower in group P. Vascular resistances indices were lower in group P than group NP: pulmonary resistance index was 174 ± 60 vs. 352 ± 118 dyne sec cm(-5)kg(-1); systemic resistance index was 611 ± 70 vs. 1215 ± 315 dyne sec cm(-5)kg(-1). Western-blot analysis showed higher endogenous NO synthase expression in group P pulmonary arteries. The pulsatile suit can be used safely as a noninvasive cardiac-assist device in acute right ventricular failure. This represents a cost-effective nearly physiological method, suitable for adults and children.