During coronary artery bypass surgery, myocardial protection, especially of the right ventricle, may be inadequate in the presence of severe coronary lesions that obstruct the antegrade delivery of cold cardioplegia

Asymetric myocardial cooling has been reported to yield postoperative right ventricular dysfunction, which may contribute to postoperative morbidity and mortality. Retrograde coronary sinus perfusion was introduced in 1956 to facilitate surgery involving the aortic valve. This technique was introduced as a means of myocardial protection for coronary artery bypass surgery in 1967 and has recently received renewed interest. An innovative method of delivering retrograde cardioplegia through the right atrium was recently developed by Fabiani and associates. This technique has obviated the need to directly cannulate the coronary sinus and thus has eliminated concerns regarding coronary sinus rupture due to cannulation, and concerns of inadequate right ventricular perfusion. In contrast to antegrade delivery, retrograde delivery of cardioplegia through the right atrium is not subject to the problem of limited distribution in the presence of coronary artery occlusive disease and thus allows more uniform cooling of the left ventricle,so the study will compare the results of combined antegrade and retrograde versurs antegrade cardioplegia in complex coronary artery bypass surgeries

Inclusion Criteria:

• Age between 18 and 60 years
• LV ejection fraction between 30 and 50%
• left main stem CAD
• mitral or aortic valve disease associated with ischemic heart disease

Exclusion Criteria:

• Double valve disease or other valve disease
• mitral or aortic valve disease associated with congenital heart disease
• patients subjected to prior heart surgery
• emergency operation
• poorly controlled diabetes mellitus