Lazzara R R, Trumble D R, Magovern J A
Allegheny-Singer Research Institute, Pittsburgh, Pennsylvania.
Ann Thorac Surg. 1994 Aug;58(2):366-70; discussion 371. doi: 10.1016/0003-4975(94)92209-8.
Descending thoracic aortomyoplasty (DTA) uses the latissimus dorsi muscle to compress the proximal descending thoracic aorta as an autogenous diastolic counterpulsator. We studied the hypothesis that DTA could confer hemodynamic benefits equivalent to those yielded by an intraaortic balloon pump (IABP) in dogs (n = 7) with heart failure. The left latissimus dorsi muscle was wrapped around the proximal thoracic aorta and subsequently electrically conditioned to induce fatigue resistance. Heart failure was produced by rapid ventricular pacing after muscle conditioning. Data were collected under three conditions: (1) after the induction of heart failure; (2) with the 20-mL IABP at 1:1; and (3) with the DTA stimulated at 1:1. Effective diastolic counterpulsation was achieved with both the IABP and the DTA. The mean diastolic aortic pressure increased from 66 +/- 5 mm Hg at baseline to 90 +/- 4 mm Hg with the IABP and to 75 +/- 4 mm Hg with the DTA. The left ventricular peak and end-diastolic pressures decreased with IABP (95 +/- 5 mm Hg versus 88 +/- 4 mm Hg and 16 +/- 4 mm Hg versus 12 +/- 4 mm Hg, respectively; p < 0.05) and with DTA (95 +/- 5 mm Hg versus 87 +/- 4 mm Hg and 16 +/- 4 mm Hg versus 12 +/- 4 mm Hg, respectively; p < 0.05). Counterpulsation with the IABP did not change the end-systolic pressure-volume relationship or the time constant for diastolic relaxation, whereas the DTA increased the end-systolic pressure-volume relationship (3.2 +/- 0.6 mm Hg/mL versus 4.0 +/- 0.7 mm Hg/mL; p < 0.05) and decreased the time constant for diastolic relaxation (49 +/- 5 msec versus 45 +/- 6 msec; p < 0.05). These data show that DTA using conditioned skeletal muscle can provide diastolic counterpulsation in animals with compromised cardiac function.(ABSTRACT TRUNCATED AT 250 WORDS)
降主动脉成形术（DTA）利用背阔肌作为自体舒张期反搏器来压迫降主动脉近端。我们研究了以下假设：在患有心力衰竭的犬（n = 7）中，DTA能产生与主动脉内球囊泵（IABP）相当的血流动力学益处。将左背阔肌包裹在胸主动脉近端，随后进行电调节以诱导抗疲劳能力。在肌肉调节后通过快速心室起搏诱发心力衰竭。在三种情况下收集数据：（1）心力衰竭诱导后；（2）使用20 mL的IABP，比例为1:1；（3）DTA刺激，比例为1:1。IABP和DTA均实现了有效的舒张期反搏。平均舒张期主动脉压从基线时的66±5 mmHg分别升至IABP时的90±4 mmHg和DTA时的75±4 mmHg。IABP（分别为95±5 mmHg对88±4 mmHg和16±4 mmHg对12±4 mmHg；p<0.05）和DTA（分别为95±5 mmHg对87±4 mmHg和16±4 mmHg对12±4 mmHg；p<0.05）使左心室峰值和舒张末期压力降低。IABP反搏未改变收缩末期压力-容积关系或舒张期松弛时间常数，而DTA增加了收缩末期压力-容积关系（3.2±0.6 mmHg/mL对4.0±0.7 mmHg/mL；p<0.05）并降低了舒张期松弛时间常数（49±5毫秒对45±6毫秒；p<0.05）。这些数据表明，使用经调节的骨骼肌的DTA可在心脏功能受损的动物中提供舒张期反搏。（摘要截短于250字）
