Clinical outcome, risk factors and angiographic evaluation of inferior myocardial infarction with or without right ventricular involvement

Abstract

Introduction: Assessment and quantification of right ventricular function is difficult and challenging. Nevertheless, an understanding of right ventricular function may be useful in the management of patients with an inferior acute MI that involves the right ventricle. The extent of involvement of the right ventricle varies in different series and angiographic analysis of the right ventricle can shed light on the severity of the disease. Objective: To assess the clinical outcome, risk factors and angiographic evaluation of inferior myocardial infarction with or without right ventricular involvement. Methods: This was a prospective observational comparative study carried out in National Institute of Cardiovascular diseases (NICVD) Dhaka, during the period from October 2010 to June 2011. One hundred (100) patients both group included. Among the patients we selected 50 patients with RV myocardial involvement (Group I= ST elevation >1mm in V4R) and 50 patients without RV myocardial involvement (Group II= ST isoelectric or depression in V4R). Patients admitted in CCU with AMI (inferior) fulfilling the inclusion and exclusion criteria were included in the study. According to ECG finding in right precordial lead V4R, patients were categorized into two groups. Echocardiography was done in all the patients within 24 hours of onset of chest pain. After 7 to 10 days all patients had undergone coronary angiography and then evaluation done. All data were recorded in preformed data sheet and analysis was done by computer based on SPSS program. P-value less than (< 0.05) considered as statistically significant. Results: One hundreds (100) patients were both group included. The mean age of Group I and Group II patients were (54.5±11.2 vs 54.5±11.2 years. P=0.08). The highest number of patients was in the age group (50-59) years. Majority of patients were male 94% vs. 92% respectively. On admission, chest pain was the most common presenting compliant both Groups (100% vs. 98%), breathlessness (60% vs. 24%), nausea (54% vs. 58%), vomiting (90% vs. 86%), sweating (90% vs. 98%), syncope (60% vs. 20%) and dizziness (70 vs. 28%) between Group I and Group II respectively. CAG report of coronary artery showed that 68% of the patients had lesion in proximal of the RCA in Group I.  In middle of the RCA had 6% vs. 44% of patients in between Group I and Group II. The difference was statistically significant (p<0.001). There were no patients in distal part of RCA in Group I and had 36% of patients in Group II. LCX had 34% vs.26% in Group I and Group II respectively and (p=0.38). Among the studied patients, the most important frequent complications were hypotension followed by sinus bradycardia, cardiogenic shock, arrhythmias, acute LVF and cardiac arrest and death.