Acute descending aortomyoplasty induces coronary blood flow augmentation

Background. Aortomyoplasty is a procedure aimed to improve cardiac output i n patients suffering from heart failure. Stimulation of the latissimus dors i muscle around the aorta produces hemodynamic effects similar to those of the intraaortic balloon pump. These may be maintained without the accompany ing complications or the need for anticoagulation. The objective of this st udy was to test the acute effects of aortomyoplasty on coronary artery bloo d now. Methods. Eight mongrel dogs (18 to 30 kg) underwent acute descending aortom yoplasty. Several stimulation protocols were applied after wrapping of the latissimus dorsi muscle around the aorta in different surgical configuratio ns. The left anterior descending coronary blood now was measured using a tr ansonic Doppler now probe. Left ventricular and aortic pressures, proximal and distal to the aortomyoplasty site, were monitored continuously. Results. Significant aortic diastolic pressure augmentation was expressed b oth as an increase in peak values, from 110 +/- 24 mm Hg to 120 +/- 24 mm H g (p < 0.001) and as an increase in the diastolic integral, from 64 +/- 23 mm Hg x s to 84 +/- 37 mm Hg x s (p < 0.001). Concomitantly, peak left ante rior descending coronary blood flow increased from 26 +/- 10 mL/min to 32 /- 12 mL/min (p, < 0.001). This was associated with an increase in the dias tolic flow integral from 11 +/- 4 mt to 14 +/- 6 mt (p < 0.001). Conclusions. Descending aortomyoplasty induces significant augmentation of coronary blood flow. Optimal timing of muscle stimulation is important in a chieving the best assist. This procedure may prove beneficial for end-stage ischemic patients. (C) 1999 by The Society of Thoracic Surgeons.