Acute descending aortomyoplasty induces coronary blood flow augmentation

Background. Aortomyoplasty is a procedure aimed to improve cardiac output in patients suffering from heart failure. Stimulation of the latissimus dorsi muscle around the aorta produces hemodynamic effects similar to those of the intraaortic balloon pump. These may be maintained without the accompanying complications or the need for anticoagulation. The objective of this study was to test the acute effects of aortomyoplasty on coronary artery blood flow. Methods. Eight mongrel dogs (18 to 30 kg) underwent acute descending aortomyoplasty. Several stimulation protocols were applied after wrapping of the latissimus dorsi muscle around the aorta in different surgical configurations. The left anterior descending coronary blood flow was measured using a transonic Doppler flow probe. Left ventricular and aortic pressures, proximal and distal to the aortomyoplasty site, were monitored continuously. Results. Significant aortic diastolic pressure augmentation was expressed both as an increase in peak values, from 110 ± 24 mm Hg to 120 ± 24 mm Hg (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 anterior 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 diastolic flow integral from 11 ± 4 mL to 14 ± 6 mL (p < 0.001). Conclusions. Descending aortomyoplasty induces significant augmentation of coronary blood flow. Optimal timing of muscle stimulation is important in achieving the best assist. This procedure may prove beneficial for end-stage ischemic patients.