[Role of circumflex coronary artery involvement in non-Q wave myocardial infarction].

PURPOSE

To determine the patency and incidence rates of left circumflex coronary artery (LCX) as the infarct related artery (IRA) in Q-wave and non-Q wave acute myocardial infarction (AMI).

METHODS

Two-hundreds and twenty one patients (172 men) with AMI were stratified in Q and non-Q waves groups. All patients were submitted to cinecoronary angiography 72 hours after the beginning of symptoms and the IRA and its patency were evaluated.

RESULTS

In non-Q wave AMI, the LCX was considered to be the IRA in 35% of the patients. In Q wave AMI, this incidence was 8% (p < 0.001). Occlusion of LCX was seen in all non-Q wave AMI patients when it was the IRA.

CONCLUSION

The incidence of LCX as IRA was significantly higher in non-Q wave AMI patients. This group did not have the previously expected greater patency rates, what could result in different clinical and evolutive characteristics.