Can right ventricular myocardial infarction occur without right ventricular dysfunction in inferior wall myocardial infarction?

摘要

Background: Patients with right ventricular infarction (RVI) inInferior Wall Myocardial Infarction (IWMI) continue to be at highrisk of complications when compared to patients withoutinvolvement of right ventricle. The relationship between electrocardiographic(ECG) diagnosis of RVMI and right ventricle (RV)dysfunction in echocardiogram is not linear. In this context, thestudy is done to find out the incidence of RV dysfunction in patientswith ECG diagnosis of Inferior and RV infarction.Methods: The study was conducted in the Dept of Cardiology RajivGandhi Govt General hospital during the period of June to July2014. A total of 50 consecutive patients with First Acute IWMI wereincluded in the study. All patients were thrombolysed withstreptokinase. Echocardiographic assesment of RV function wasdone within 12 hrs of admission by a single operator. RV dysfunction by Echo was defined by TAPSE < 16mm and Peaksystolic velocity at tricuspid annulus < 10cm/sec. Out of 50 patients,24 patients underwent coronary angiogram within oneweek of their admission.Results: In our study, out of 50 patients with IWMI 20 patients hadelectrocardiographic evidence of RV infarction. Among the 20patients, 14 were male and 6 were female with age group between35 and 65 yrs of age. Echocardiographic evidence of RV dysfunctionwas present in 14 patients (Group 1) out of 20 patients withelectrocardiographic RV infarction, remaining 6 patients (Group 2)had preserved RV function. 11 patients (7 in Group 1 and 4 in group2 ) out of the 20 underwent coronary angiogram(CAG). CAGrevealed proximal RCA lesions in 6 patients, double vessel diseasein 1 patient (Group 1) and in Group 2, two patients had normalcoronaries and two had Proximal RCA lesion. This study suggeststhat preserved RV function can occur despite evidence of RVMI inECG probably because of recanalisation of infarct related artery(IRA) or collateralisation from left coronary arteryConclusion: This study suggests 30% of patients can have presevedRV function despite ECG evidence of RVMI in patients withIWMI. Significant coronary artery lesion is comparatively lesscommon in patients with preserved RV function. This explains thevariable outcomes in patients with Inferior wall and RV infarction.