Prognostic significance of isolated left anterior hemiblock and left axis deviation in the course of acute myocardial infarction.

Abstract

In 700 patients with acute myocardial infarction admitted to the intensive coronary care unit of our hospital, the incidence and significance of left anterior hemiblock and left axis deviation has been studied in the acute phase of disease. In 102 (14-6%) of the 700 patients, isolated left axis deviation (mean QRS axis -45O) was found and 69 of them (9. 9%) met the criteria of left anterior hemiblock. Of the 69 patients with left anterior hemiblock, 61 had acute anterior myocardial infarction, 5 had inferior infarction, and 3 had subendocardial infarction. The left anterior hemiblock was transient in 5 patients, but persisted in 64. All patients with and without isolated left anterior hemiblock and left axis deviation were compared statistically with reference to mortality rate and the incidence of arrythmias; no significant difference was noted. However, in patients over the age of 65 and also in those with hypertension, the incidence of left axis deviation was significantly higher (P<0 05 and P<0-001, respectively).It was concluded that isolated left anterior hemiblock and left axis deviation occurring in the course of acute myocardial infarction had no influence on the prognosis of acute myocardial infarction.

Electrocardiology of Hyperacute Right Ventricular Infarction with Precordial S-T Elevation: Comparison with Anterior Left Ventricular Infarction

“…Rightward deviation of the frontal QRS axis was observed more in RV infarction, which can be explained by the fact that the posterior fascicle receives its blood supply from the posterior descending artery, the vessel involved in most patients with RV infarction complicated by inferior wall LV infarction, resulting in an incomplete form of left posterior hemiblock [27]. Contrary to this, left anterior hemiblock or leftward frontal QRS axis shift of < 0° was observed more often in acute anterior LV infarction as in a previous report [28]. As for RV conduction delay, there was a higher incidence of this complication in RV infarc tion than in anterior LV infarction, which agrees with our previous observations [16,17].…”

Prognostic Significance of Left Anterior Hemiblock in Patients With Suspected Coronary Artery Disease

“…By logistic regression analysis, the odds ratio for development of LAHB was 27.5 (p ϭ 0.0001) for left anterior descending artery stenosis compared with 2.9 (p ϭ 0.05) and 0.3 (p ϭ 0.3) for circumflex and right coronary artery, respectively. However, LAHB after acute MI has not been found to be related to an increased mortality (7)(8)(9)(10).…”

“…In patients with acute inferior MI, LAHB was associated with a larger infarct extension and left anterior descending CAD (6). However, its occurrence in patients after acute MI has not been related to a higher mortality rate (7)(8)(9)(10). We sought to study the association of LAHB with abnormalities on the stress echocardiogram and prognosis in patients with suspected CAD who have no history of MI.…”