Identifying stunned myocardium during cardiac surgery: the role of myocardial contrast echocardiography

Myocardial viability

This article reviews various means to assess myocardial viability by imaging, and provides recommendations for current clinical practice. This article also discusses future directions in assessing myocardial viability.

Update on myocardial contrast echocardiography: a surgeon's perspective

The ability to evaluate myocardial perfusion and microvascular structural integrity can help surgeons predict the necessity for surgical intervention, the sequence of intraoperative interventions, the risk of perioperative infarction, the likelihood of successful surgical recovery, and the degree of long-term clinical benefit. The ability to directly assess perfusion intraoperatively may allow surgeons to reliably evaluate a patient's myocardial perfusion at any time during the operative procedure. As this article will discuss, surgeons may use myocardial contrast echocardiography intraoperatively to evaluate myocardial function and integrity, to determine the order of graft placement, to determine the success of bypass graft patency, and to help predict those patients who will experience successful cardiac function after recovering from surgery.

Assessing myocardial perfusion with Albunex during coronary artery bypass surgery: technical considerations and safety of aortic root injections

OBJECTIVE

To test the safety and report on limiting technical considerations, including optimal dosing of Albunex (Molecular Biosystems, Inc, Mallinckrodt Medical, St. Louis, MO) for myocardial opacification after intra-aortic root injections during cardiac surgery.

DESIGN

This was a prospective randomized study with a control group who did not receive Albunex and a group who received intra-aortic root injections of Albunex.

SETTING

Multicenter (two) independent university hospitals.

PARTICIPANTS

32 patients scheduled for elective coronary artery bypass surgery were evaluated after individual informed consent was obtained.

INTERVENTIONS

2 to 8 mL of Albunex were injected before and after coronary revascularization.

MEASUREMENTS AND MAIN RESULTS

Quality of enhancement in each of four regions of the left ventricle was assessed from a short-axis mid-papillary ultrasound image by three experienced observers blinded to dose. Electrocardiogram (ECG), creatine phosphokinase (CPK) (MB fraction), and hemodynamics were evaluated at baseline and throughout the study period for up to 72 hours. No differences were noted between groups with respect to preoperative and postoperative CPK enzymes (CPK-MB fraction), ECG changes, hemodynamics, requirements for separation from CPB, need for postoperative inotropes, time to extubation, and time to discharge from the intensive care unit. The average total dose of Albunex injected was 19 mL +/- 4 (0.25 mL/kg). A single dose of 4.2 +/- 1.2 mL (0.05 mL/kg) appeared to offer optimal enhancement of contrast effect for myocardial perfusion assessment.

CONCLUSION

Albunex is safe and easy to use for myocardial opacification when administered via an antegrade cardioplegia catheter into the aortic root during CPB.