A Study on Ventricular Late Potentials by Signal Averaged Electrocardiogram in Myocardial Infarction Patients.

Fifty patients who presented with Myocardial Infarction (MI), diagnosed by history, ECG, enzymes were subjected to late potential analysis between 7-10 days post MI by Signal Averaged Electrocardiography (SAECG). There were 42 male and 8 female patients. 34 had anterior wall MI and 16 had inferior wall MI, and all of them had Q wave infarction. History of previous MI in 12, diabetes in 14, hypertension in 34, smoking in 24 and hypercholesterolemia in 8 was noted. Patients were followed up for one year. Late potentials were positive in 10 patients (62.5%) of inferior wall MI and 6 patients (17.5%) of anterior wall MI. Those with episodes of ventricular tachycardia had increased incidence of late potentials. There was no correlation of late potentials and LV function assessed by echocardiography. Thrombolysed group had decreased incidence of late potentials.

Effect of coronary collateral vessels in left ventricular segmental motions and myocardial viability using color kinesis dobutamine stress echocardiography

To detect the functional importance of coronary collaterals, which develop after acute myocardial infarctions [AMI]. Forty patients with acute AMI whose coronary angiography demonstrated a total occlusion of the left anterior descendant [LAD] artery were included in the study, between January 2003 and June 2004. All of the study patients underwent coronary angiography and left ventriculography using standard Judkins techniques [Phillips Integris-3000]. Left ventricular [LV] free walls were divided into 5 segments, and all of these segments motions were evaluated then LV free wall motion score index [WMSI] was calculated. The study patients were divided into 2 groups: good [Rentrop 3; group I; n = 14] and poor coronary collateral circulation [Rentrop 0-2; group II; n = 26] according to the Rentrop grading. Then, color kinesis dobutamine stress echocardiography [CK-DSE] was performed to all patients with standard techniques 6 weeks after AMI. There were no significant differences for age, gender, risk factors for the coronary artery disease and use of the fibrinolytic therapy between the groups. There were no significant statistical differences for angiographic WMSI, left ventricular ejection fraction [LVEF], end-diastolic volume, end-systolic volume and end-diastolic pressures between the 2 groups. No difference was detected between Group I and II for initial EF, WMSI and peak dose WMSI in CK-DSE procedure. Viability was determined in all of the 14 patients in group I [100%] and 12 of 26 patients in group II [46%] [p=0.03]. In early periods of an AMI genesis of the coronary collateral circulation does not affect left ventricular global and regional systolic functions, but increase viability quite significantly. According to our findings early revascularization could be carried out in patients with good coronary collateral circulation without doing any test for viability