[Incidence and clinical significance of involvement of the right ventricle in acute inferior myocardial infarction].

The purpose of our study was to evaluate, with noninvasive procedures, the incidence and the clinical picture of right ventricular involvement in patients with acute transmural inferior myocardial infarction. Our study group was constituted of 107 consecutive patients admitted to our Coronary Care Unit within 10 hours from the onset of symptoms; in every patient a standard 12-leads ECG and the precordial leads V3R and V4R were obtained at admission in CCU and then every 12 hours. 80 patients underwent B-mode echocardiographic evaluation within 36 hours and in 93 patients a myocardial scintigraphy was performed, between the 48th and 72nd hour from the onset of chest pain, 1-2 hours after injection of Tc-99m-pyrophosphate. Results: 45 patients (42.1%) had ECG positive for right ventricular infarction, 49 patients (51.6%) had positive Tc-99m-pyrophosphate scintigraphy and 24 patients (30%) positive echocardiography. By using the positivity of ECG and another method at least, patients were separated into 2 groups: group A (associated inferior and right infarction) was constituted of 45 patients, and group B (isolated inferior infarction) was constituted of 62 patients. In group A we noted a higher incidence of hypotension (systolic blood pressure less than 100 mmHg) and oliguria (less than 30 ml/h)- p less than 0.01-, of 2nd and 3rd A-V blocks-p less than 0.001- and primary ventricular fibrillation -p less than 0.01. The incidence of parossistic atrial fibrillation, severe bradycardia or SA blocks and of mortality was not statistically different between the two groups.