Prediction of isolated first diagonal branch occlusion by 12-lead electrocardiography: ST segment shift in leads I and aVL

• Published in: Journal of the American College of Cardiology Vol. 23; no. 7; pp. 1557 - 1561
• Main Authors: Iwasaki, Kohichiro, Kusachi, Shozo, Kita, Toshimasa, Taniguchi, Gyou
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.06.1994; Elsevier Science
• Subjects: Adult; Aged; Biological and medical sciences; Cardiology. Vascular system; Coronary heart disease; Electrocardiography; Female; Heart; Heart - diagnostic imaging; Humans; Male; Medical sciences; Middle Aged; Multivariate Analysis; Myocardial Infarction - diagnosis; Myocardial Infarction - diagnostic imaging; Myocardial Infarction - pathology; Radionuclide Imaging; Vascular disease; Human; Arteriopathy; Electrodiagnosis; Bypass; Branch; Electrocardiography; ST interval; Cardiovascular disease; Anterior intraventricular artery; Obliteration; Differential diagnostic
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/0735-1097(94)90656-4

Objectives. This study was performed to determine electrocardiographic (ECG) features that could distinguish first diagonal branch occlusion from left anterior descending coronary artery occlusion. Background. The ECG findings associated with first diagonal branch obstruction have not previously been compared with those of left anterior descending coronary artery obstruction. Methods. The ECG findings in 34 patients with isolated diagonal branch occlusion (group 9) were compared with those in 20 patients with occlusion at site 6 (group 6) and 20 with occlusion at site 7 (group 7), according to American Heart Association classification. This study had a power >80% to detect a 50% difference between groups at a probability value of 0.05. Results. ST segment elevation was observed in leads I and aVL for all group 9 patients, in 80% (p < 0.05) of group 6 patients for lead I and 90% for lead aVL and in 50% (p < 0.01) of group 7 patients for lead I and 55% (p < 0.01) for lead aVL. Similarly, there was a higher incidence of abnormal Q waves and inverted T waves in leads I and aVL in group 9 than in groups 6 and 7. In contrast, group 9 showed a significantly lower incidence of ST segment elevation (3.4%), abnormal Q waves (3.0%) and inverted T waves (0%) in lead VIthan group 6 (80%, 40% and 90%, respectively) and group 7 (75%, 60% and 70%, respectively) (p < 0.01 for each). Multivariate analysis revealed that abnormalities in leads I and aVL, combined with a normal lead V1(and V6), provided good criteria for distinguishing isolated diagonal branch occlusion from left anterior descending coronary artery occlusion. Conclusions. Isolated diagonal branch occlusion more frequently caused ECG abnormalities in leads I and aVL and less frequently caused changes in the precordial leads compared with left anterior descending coronary artery obstruction, indicating that leads I and aVL represent myocardium perfused by the diagonal branch.