PULMONARY AND LEFT-VENTRICULAR DECOMPRESSION BY ARTIFICIAL PULMONARY VALVE INCOMPETENCE DURING PERCUTANEOUS CARDIOPULMONARY BYPASS SUPPORT IN CARDIAC-ARREST

Background In cardiac arrest, use of percutaneous cardiopulmonary bypa ss support (PCPS) may lead to left ventricular loading, with deleterio us effects on the myocardium, and is often accompanied by an increase in pulmonary artery pressure. The present study was designed to assess the potential of artificially induced pulmonary valve incompetency to retrogradely decompress the left ventricle during PCPS in ventricular fibrillation. Methods and Results Studies were performed using a stan dardized experimental animal model in sheep (n=12; body weight, 77 to 112 kg). When PCPS was used during fibrillation, an increase in left v entricular pressure (from 21.4+/-5.0 mm Hg after 1 minute to 28.4+/-9. 5 mm Hg after 10 minutes of fibrillation) was observed in all animals, with a simultaneous increase in pulmonary artery pressure in 6 animal s from 15.5+/- 3.8 to 24.3+/-5.4 mm Hg (group A). In these animals, ar tificial pulmonary valve incompetency, which was induced by a special ''pulmonary valve spreading catheter,'' led to effective decompression of both the pulmonary circulation (decrease in pulmonary artery press ure from 24.3 to 11.3 mm Hg) and the left ventricle (decrease in left ventricular pressure from 30.5 to 17.7 mm Hg). We simultaneously measu red a decrease in the myocardial release of lactate (increase in arter ial coronary-venous difference in lactate content from -0.01 to 0.14 m mol/L), demonstrating the myocardial protective effect of the procedur e. In contrast, in 6 animals without an increase in pulmonary artery p ressure during PCPS (group B), artificial pulmonary valve incompetency did not reduce left ventricular loading, which was probably because o f competent mitral valves in these animals. Conclusions In case of inc reasing pulmonary artery pressure during PCPS in cardiac arrest, artif icial pulmonary valve incompetency might be a useful tool for effectiv e pulmonary and retrograde left ventricular decompression.