Right Ventricular Function in Inferior Wall Myocardial Infarction: case study

Abstract

Acute myocardial infarction (MI) involving only the right ventricle is an uncommon event. Right ventricular myocardial infarction has been an independent predictor of major complications and mortality. Electrocardiogram (ECG) through right precordial leads (V4R) is a useful & convenient tool of diagnosing right ventricular infarction. Standard surface ECG by using V4R could aid clinical recognition of concomitant right ventricular infarction in patients with inferior wall myocardial infarction. Increasing age, male sex & previous history of ischemic heart disease were found to be important risk factors for the occurrence of right ventricular infarction. Keyword: electrocardiography, inferior wall myocardial infarction, myocardial infarction, right ventricular function. Myocardial performance index, Tricuspid annular motion I. Introduction Inferior wall of the heart is formed by both left ventricle and right ventricle. In about 50 percent of the patient with inferior wall myocardial infarction (1, 2, 3), the right ventricle is involved. Recognition of right ventricle infarction is important because of its various hemodynamic consequences. Presence of right ventricular myocardial infarction may enforce an increased risk of shock, arrhythmia and death in inferior wall myocardial infarction (4). The increased risk is related to the presence of right ventricle involvement itself rather than the extent of left ventricular myocardial damage (5). Inferior wall myocardial infarction patients with right ventricular infarction comprises a high risk subset of patient with a mortality rate as high as 25 to 30 % as opposed to an overall mortality rate of approx 6 % of patients with inferior myocardial infarction without right ventricular infarction. Occlusion of proximal dominant RCA is usually responsible for right ventricular infarction in inferior wall myocardial infarction (6). Right ventricular function has not widely been studied after a MI unlike a LV function. There is right ventricular involvement in more than 1/3 rd of patients with acute inferior wall myocardial infarction. Right ventricle involvement has been reported to be an independent predictor of major complications and in hospital mortality after acute MI (7). ST segment elevation in right precordial lead, V4R is one of the most reliable echocardiographic signs of acute right ventricular infarction. ECG is one of the major diagnostic tool being cost effective and easily available. A hypokinetic or akinetic segment of RV observed by ECG can also be used to detect RV dysfunction after right ventricular infarction. The presence of ST segment elevation on leads II, III, and AVF on ECG are always suggestive of RVI (8, 9). The present study has been made to estimate the correlation using clinical examination and surface ECG.