Myocardial rewarming mirrors intraoperative mammary artery graft function.
BACKGROUND
The internal mammary artery (IMA) bypass graft provides a satisfactorily long-lasting blood supply to the myocardium. However, its initial flow capacity can be insufficient with subsequent regional myocardial ischemia. We evaluated a method to assess the IMA graft function intraoperatively.


METHODS
Twenty-five patients with three-vessel coronary artery disease underwent coronary artery bypass grafting on cardiopulmonary bypass. The in situ IMA was grafted to the left anterior descending coronary artery (LAD) in combination with two saphenous vein grafts to the left circumflex and right coronary artery. Distal anastomoses were performed during cold intermittent blood cardioplegia. After unclamping of the aorta and of the grafted IMA, the temperature at the cardiac anterior and posterior side was measured during the first 5 minutes of warm reperfusion.


RESULTS
A sufficient IMA graft function was expressed by a typical rise in temperature: the cardiac anterior and posterior sides showed a parabolic and exponential course, respectively. The rewarming velocity expressed as the first derivative of temperature over time led to a sharp and early peak for the anterior side, and a smaller and delayed peak for the posterior side. Insufficient IMA graft function could be recognized by an atypical temperature course.


CONCLUSIONS
Temperature measurement of the heart during warm reperfusion after hypothermic cardioplegia can help to assess the effectiveness of the IMA-LAD graft function.
Baretti
Rufus
R
Deutsches Herzzentrum Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany. baretti@dhzb.de
Eckel
Lothar
L
Krabatsch
Thomas
T
Siniawski
Henryk
H
Matheis
Georg
G
Baumann-Baretti
Bärbel
B
Keller
Harald
H
Hetzer
Roland
R
D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000601:surgery*; D005260:Female; D006085:Graft Survival; D006324:Heart Arrest, Induced / Q000379:methods*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008323:Mammary Arteries / Q000637:transplantation*; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D015425:Myocardial Reperfusion / Q000379:methods*; D009204:Myocardial Revascularization; D013817:Thermography; D014654:Vascular Patency