IDENTIFICATION OF THE OPTIMAL ELECTROCARDIOGRAPHIC LEADS FOR DETECTING ACUTE EPICARDIAL INJURY IN ACUTE MYOCARDIAL-INFARCTION

Current coronary care electrocardiographic (ECG) monitoring techniques are aimed at detection of cardiac arrhythmis rather than myocardial ischemia. However, in patients with acute myocardial infarction (AMI) who undergo reperfusion therapy, monitoring ST-segment deviation could provide an early noninvasive indicator of coronary artery reocclusion. In this study, the admission 12-lead ECGs of patients with initial AMI were used to propose optimal lead locations for ST-segment monitoring. The study population was selected from consecutive Duke University Medical Center admissions during 1965 to 1981 who met the following inclusion criteria: (1) chest pain for no more than 8 hours, (2) initial AMI documented by ECG and 3 of 4 enzyme criteria, (3) .gtoreq. 0.1 mV (1 mV = 10 mm) of ST elevation in at least 1 of the standard 12 leads (not aVR) on admission ECG, and (4) no ECG evidence of conduction disturbances, ventricular hypertrophy or tachycardia. ST-segment deviation was quantified; AMI location was assigned based on the lead with maximal deviation. Of the 80 patients who had an inferior AMI, lead III was both the most frequent location for ST elevation (94%) and the most common site with maximal ST deviation. Lead V2 had the highest incidence of ST-segment depression (60%). In the 68 patients who had an anterior AMI, lead V2 had the highest frequency of ST elevation (99%). Leads V2 and V3 were the most common sites of maximal elevation. Thus, for monitoring ST deviation, leads III and V2 may be superior to leads II and V1, which are commonly used in arrhythmia monitoring. Studies of patients who have undergone thrombolytic therapy are needed to examine the performance of these leads for detecting coronary artery occlusion.