Radionuclide assessment of right-ventricular involvement in inferior acute myocardial infarction: clinical correlations and in-hospital follow-up.

Abstract

We studied 33 patients (28 males, 5 females) with first inferior acute myocardial infarction (AMI) and 12 normal volunteers. They underwent first-pass (FP) and equilibrium-gated radionuclide angiography (EGRA) within 4 days of the onset of symptoms. The parameters [ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR)] of the time-activity curve (TAC) of both ventricles [left ventricle (LV), right ventricle (RV)] were computed. The regional wall motion (RWM) was evaluated by parametric images (amplitude and phase). In 43% of the patients with AMI, we found a depressed RVEF, while the LVEF was decreased in only 33%. The sensitivity of diastolic parameters was shown to be clearly superior to that of the systolic parameters (RVPFR, 78%; LVPFR, 79%). The abnormalities of the overall performance of both ventricles were significantly correlated with those of the RWM. The abnormal RVEF allowed us to assess the necrotic involvement of the RV, while a depressed RVPFR suggested an impaired RV compliance mostly on an ischemic basis. Congestive heart failure (CHF) and shock syndrome were significantly correlated with depressed RV parameters, while the LVEF, despite RWM abnormalities, was in the normal range. EGRA with computation of the TAC parameters of both ventricles appeared to be useful for in-hospital prognostic evaluation, therapeutic planning and clinical follow-up of patients with inferior myocardial infarction.