The Distribution of Cardioplegic Solution During Coronary Artery Grafting: The Value of Contrast Echocardiography

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Abstract

Myocardial distribution of cardioplegic solution infused during coronary artery bypass grafting was assessed with myocardial contrast echocardiography (CE) Levovist. We have analyzed the distribution and protection degree of both solutions infused together.

Objective

To disclose if myocardial protection with cardioplegic solution infused by combined anterograde/retrograde routes is better than infusion by the anterograde route exclusively.

Material and methods

Myocardial distribution of cardioplegic solution infused together with Levovist was evaluated in11 patients during coronary artery bypass grafting.Combined anterograde (AR)/retrograde (RR) route was assessed. An HDI 3000 with a transesophagic transductor (5mhz) was used and the transgastric short axis (6 segments) on papillary muscles was analyzed. Basal images prior to anesthetic induction were taken and compared to images obtained during anterograde route and after retrograde route. The following score (SC) was applied: 0=without contrast, 1 = heterogeneous distribution,2=homogeneous distribution, 3 = high contrast.

Results The differences between the SC with AR and the basal images were not statistically significant (0.92± 0.4 vs. 0.14 ± 0.13; p = 0.34 ns). During anterograde cardioplegic infusion, patients with poor collaterals showed a lower degree of myocardial opacification than patients with good collaterals (0.73 ± 0.32 vs. 1.24 ± 0.34; p < 0.05).The opacification differences between RR (after anterograde route)and the basal images were statistically significant with the higher score for the RR(1.54 ±0.28 vs. 0.14 ± 0.13; p < 0.05). The difference of score between anterograde and retrograde cardioplegy was not statistically significant (1.54 ± 0.28 vs. 1.01± 0.13; p = 0.21 ns). The lateral segment was the less protected with the cardioplegic solution in-fused by anterograde or retrograde route, without any relationship with the occlusion of circumflex artery. Conclusions The cardioplegic solution infused by combined anterograde/retrograde route provides adequate myocardial protection with homogeneous contrast distribution, in the subset of patients with any of the principal coronary arteries occluded. The use of Levovist infused together with cardioplegic solution makes it possible an evaluation of the efficacy of intraoperative myocardial protection.