心不全におけるTrapidilの急性静注効果

Effects of intravenous trapidil on patients with acute heart failure

　難治性心不全における血管拡張療法は，確固たる地位を築くに至ったが，難治性心不全の多くの例では低血圧を伴ない血管拡張剤のみでは治療は困難である。従って，強心剤や利尿剤を併用することになるが，強心剤としてのジギタリスやカテコラミンは不整脈や心筋酸素消費量の増加などの問題があり，副作用の少ない強心剤の登場が望まれている。

　また，高齢者における心不全では，冠硬化症における冠血流量の減少，慢性閉塞性肺疾患を合併することが多いため，肺循環がtissue oxygenationに果たす役割も検討していく必要があると考えられる。

Trapidil (T) is a unique vasodilator with positive inotropic action and bronchodilator action. Four patients with cor pulmonale, four patinets with acute myocardial infarction, two patients with dilated cardiomyopathy, one patient with thyro-toxic heart and one patient with mitral and aortic regurgitation (mean age 67) were examined through right heart catheterization. T (100 mg) was administered intravenously in 3 minutes. Wemeasured hemodynamic indices and blood gas. Systemic blood pressure (BP) was prone to fall, although not significantly. Mean pulmonary artery pressure (PAPm) fell significantly (-6.2%). Car-diac index (CI) and stroke volume index (SVI) rose significantly (+34.8%, +32.6%). Both sys-temic vascular resistance (SVR) and pulmonary vascular resistance (PVR) fell significantly (-34.2 %,-31.9%). Heart rate (HR) and double prod-uct (DP) also fell significantly (+6.9%,+7.8%). Pulmonary artery distolic pressure (PADP) and mean right atrial pressure (RAPm) remained unchanged. Alveolar-arterial O₂ difference (Aa-DO₂) fell significantly, which implies that bron-chodilator effect of T improved ventilation-perfu-sion relationships. These findings confirm beneficial effects of T on especially acute heart failure with hypotension and obstructive pulmonary involve-ments.