Importance of left anterior hemiblock development in inferior wall acute myocardial infarction

The aim of this study was to investigate the clinical and angiographic impo rtance of left anterior hemiblock (LAHB) during acute inferior myocardial i nfarction (AIMI) by comparing patient groups with and without LAHB after AI MI. One hundred seventy-two patients (141 men and 31 women) between 28 and 84 y ears of age (mean 55 +/- 10 years) with AIMI were included in the study, Pa tients were divided into 2 groups according to electrocardiogram (ECG) crit eria: group I comprised 25 patients in whom ECG pattern characteristic of L AHB developed, group II comprised 147 patients without this pattern. Accord ing to the electrocardiogram, patients were placed in group I if the mean Q RS axis was deviated to the left < 30 degrees in the frontal plane with the following pattern: increased S-wave voltage and decreased R-wave voltage i n leads II, the appearance of a deep S-wave in lead II, and a terminal posi tive R-wave in lead aVR. Coronary angiography was performed within 2 weeks. A coronary stenosis was considered if the vessel diameter was narrowed by > 50%. The dominant coronary artery was classified as right or left or bala nced. The left ventricular ejection fraction (LVEF) was calculated from lef t ventriculography. The mean age of the patients in group I was significantly higher (58 vs 54 years, p=0.007), while the risk factors were similar in both groups. Left a nterior descending (LAD) and multivessel coronary artery disease (CAD) were found to be significantly higher in group I compared with group II (80% vs 38%, p=0.0001; 84% Vs 52%, p=0.001, respectively). The mean LVEF was found to be lower in group I (51% vs 56%, p=0.04). Peak creatine phosphokinase M B (CKMB) values were not different (216 vs 162 IU/L, p=0.09). The frequency of left dominant or balanced coronary artery was determined to be higher i n group I (44% vs 17%, p=0.018). LAHB development during AIMI can be an indicator of LAD lesions, multivesse l coronary artery disease, and impaired left ventricular systolic function.