左心室重塑：对压力-容积关系的影响

Kashem Abul, Hassan Sarmina, Crabbe Deborah L, Melvin David B, Santamore William P

Cardiovascular Research, Temple University, Philadelphia, PA 19140, USA.

J Thorac Cardiovasc Surg. 2003 Feb;125(2):391-9. doi: 10.1067/mtc.2003.4.

OBJECTIVE

We tested whether the CardioClasp device (CardioClasp, Inc, Cincinnati, Ohio), a non-blood contact device, would improve left ventricular contractility by acutely reshaping the left ventricle and reducing left ventricular wall stress.

METHODS

In dogs (n = 6) 4 weeks of ventricular pacing (210-240 ppm) induced severe heart failure. Left ventricular function was evaluated before and after placement of the CardioClasp device, which uses 2 indenting bars to reshape the left ventricle. Hemodynamics, echocardiography, and Sonometrics crystals dimension (Sonometrics Corporation, London, Ontario, Canada) were measured at steady state and during inferior vena caval occlusion.

RESULTS

The CardioClasp device decreased the left ventricular end-diastolic anterior-posterior dimension by 22.8% +/- 1.9%, decreased left ventricular wall stress from 97.3 +/- 22.8 to 67.2 +/- 7.7 g/cm(2) (P =.003), and increased the fractional area of contraction from 21.3% +/- 10.5% to 31.3% +/- 18.1% (P =.002). The clasp did not alter left ventricular end-diastolic pressure, left ventricular pressure, left ventricular dP/dt, or cardiac output. With the CardioClasp device, the slope of the end-systolic pressure-volume relationship was increased from 1.87 +/- 0.47 to 3.22 +/- 1.55 mm Hg/mL (P =.02), the slope of preload recruitable stroke work versus end-diastolic volume was increased from 28.4 +/- 11.0 to 44.1 +/- 23.5 mm Hg (P =.02), and the slope of maximum dP/dt versus end-diastolic volume was increased from 10.6 +/- 4.6 to 18.6 +/- 7.4 mm Hg x s(-1) x mL(-1) (P =.01). The CardioClasp device increased the slope of the end-systolic pressure-volume relationship by 68.0% +/- 21.7%, the slope of preload recruitable stroke work versus end-diastolic volume by 50.7% +/- 18.1%, and the slope of maximum dP/dt versus end-diastolic volume by 85.7% +/- 28.9%.

CONCLUSIONS

The CardioClasp device decreased left ventricular wall stress and increased the fractional area of contraction by reshaping the left ventricle. The CardioClasp device was able to maintain cardiac output and arterial pressure. The clasp increased global left ventricular contractility by increasing the slope of the end-systolic pressure-volume relationship, the slope of preload recruitable stroke work versus end-diastolic volume, and the slope of maximum dP/dt versus end-diastolic volume. In patients with heart failure, the CardioClasp device might be effective for clinical application.

目的

我们测试了一种非血液接触装置CardioClasp设备（CardioClasp公司，俄亥俄州辛辛那提）是否能通过急性重塑左心室和降低左心室壁应力来改善左心室收缩力。

方法

在犬类动物（n = 6）中，4周的心室起搏（210 - 240次/分钟）诱发了严重心力衰竭。在植入使用两根压痕棒重塑左心室的CardioClasp设备前后评估左心室功能。在稳态及下腔静脉闭塞期间测量血流动力学、超声心动图和Sonometrics晶体尺寸（Sonometrics公司，加拿大安大略省伦敦）。

结果

CardioClasp设备使左心室舒张末期前后径减小了22.8%±1.9%，左心室壁应力从97.3±22.8降至67.2±7.7 g/cm²（P = 0.003），收缩分数面积从21.3%±10.5%增加到31.3%±18.1%（P = 0.002）。该卡环未改变左心室舒张末期压力、左心室压力、左心室dP/dt或心输出量。使用CardioClasp设备时，收缩末期压力 - 容积关系的斜率从1.87±0.47增加到3.22±1.55 mmHg/mL（P = 0.02），可募集的前负荷搏功与舒张末期容积的斜率从28.4±11.0增加到44.1±23.5 mmHg（P = 0.02），最大dP/dt与舒张末期容积的斜率从10.6±4.6增加到18.6±7.4 mmHg·s⁻¹·mL⁻¹（P = 0.01）。CardioClasp设备使收缩末期压力 - 容积关系的斜率增加了68.0%±21.7%，可募集的前负荷搏功与舒张末期容积的斜率增加了50.7%±18.1%，最大dP/dt与舒张末期容积的斜率增加了85.7%±28.9%。

结论

CardioClasp设备通过重塑左心室降低了左心室壁应力并增加了收缩分数面积。CardioClasp设备能够维持心输出量和动脉血压。该卡环通过增加收缩末期压力 - 容积关系的斜率、可募集的前负荷搏功与舒张末期容积的斜率以及最大dP/dt与舒张末期容积的斜率，增加了整体左心室收缩力。在心力衰竭患者中，CardioClasp设备可能具有临床应用效果。