Ochiai Y, Morita S, Tanoue Y, Kawachi Y, Tominaga R, Yasui H
Department of Cardiovascular Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
J Thorac Cardiovasc Surg. 1998 Jul;116(1):139-47. doi: 10.1016/S0022-5223(98)70252-1.
Amrinone, a selective phosphodiesterase III inhibitor, is reported to have a potent inotropic effect on the left ventricle, but the effects of this drug on right ventricular contractility in the clinical setting are unknown. The concept of ventricular/arterial coupling was applied to investigate the effects of amrinone on right ventricular contractility and afterload with transesophageal echocardiography.
The study was performed in the intensive care unit with 11 patients who had undergone cardiac operations. Right ventricular cross-sectional area was measured with transesophageal echocardiography equipped with a capability of automated border detection as a surrogate for right ventricular volume. Multiple pressure-area loops were obtained by reducing preload to measure end-systolic elastance and effective arterial elastance. External work and pressure-volume area were also measured to calculate the efficiency of energy transfer from pressure-volume area to external work. Nitroprusside (0.3 to 0.5 microg x kg(-1) x min(-1)) and amrinone (1 mg x kg(-1) intravenously followed by 10 microg x kg(-1) x min(-1)) were administered. With nitroprusside infusion, end-systolic elastance and effective arterial elastance remained unchanged (end-systolic elastance, 4.73 +/- 2.18 mm Hg/cm2 to 4.65 +/- 2.09 mm Hg/cm2; effective arterial elastance, 8.05 +/- 3.84 mm Hg/cm2 to 7.70 +/- 3.64 mm Hg/cm2). In contrast, amrinone reduced afterload (effective arterial elastance, 8.82 +/- 3.99 mm Hg/cm2 to 7.05 +/- 4.01 mm Hg/cm2, p = 0.004) and enhanced contractility (end-systolic elastance, 4.47 +/- 1.79 mm Hg/cm2 to 6.56 +/- 2.22 mm Hg/cm2, p = 0.007). Consequently, amrinone decreased the ventricular/arterial coupling ratio (effective arterial elastance/end-systolic elastance, 2.40 +/- 1.45 to 1.16 +/- 0.63, p = 0.009) and improved the efficiency of energy transfer (external work/pressure-volume area, 0.44 +/- 0.15 to 0.54 +/- 0.15, p = 0.013).
Right ventricular pressure-area relations obtained with transesophageal echocardiography could successfully separate the simultaneous change in right ventricular systolic mechanics and afterload caused by amrinone. Amrinone caused enhancement of right ventricular contractility and afterload reduction.
氨力农是一种选择性磷酸二酯酶III抑制剂，据报道对左心室有强大的正性肌力作用，但在临床环境中该药物对右心室收缩性的影响尚不清楚。应用心室/动脉耦联的概念，通过经食管超声心动图研究氨力农对右心室收缩性和后负荷的影响。
该研究在重症监护病房对11例接受心脏手术的患者进行。使用具备自动边界检测功能的经食管超声心动图测量右心室横截面积，作为右心室容积的替代指标。通过降低前负荷获取多个压力-面积环，以测量收缩末期弹性和有效动脉弹性。还测量了外部功和压力-容积面积，以计算从压力-容积面积到外部功的能量传递效率。给予硝普钠（0.3至0.5微克·千克⁻¹·分钟⁻¹）和氨力农（静脉注射1毫克·千克⁻¹，随后10微克·千克⁻¹·分钟⁻¹）。输注硝普钠时，收缩末期弹性和有效动脉弹性保持不变（收缩末期弹性，从4.73±2.18毫米汞柱/平方厘米至4.65±2.09毫米汞柱/平方厘米；有效动脉弹性，从8.05±3.84毫米汞柱/平方厘米至7.70±3.64毫米汞柱/平方厘米）。相比之下，氨力农降低了后负荷（有效动脉弹性，从8.82±3.99毫米汞柱/平方厘米至7.05±4.01毫米汞柱/平方厘米，p = 0.004）并增强了收缩性（收缩末期弹性，从4.47±1.79毫米汞柱/平方厘米至6.56±2.22毫米汞柱/平方厘米，p = 0.007）。因此，氨力农降低了心室/动脉耦联比（有效动脉弹性/收缩末期弹性，从2.40±1.45至1.16±0.63，p = 0.009）并提高了能量传递效率（外部功/压力-容积面积，从0.44±0.15至0.54±0.15，p = 0.013）。
经食管超声心动图获得的右心室压力-面积关系能够成功分离氨力农引起的右心室收缩力学和后负荷的同时变化。氨力农可增强右心室收缩性并降低后负荷。
