Right ventricular involvement with acute inferior wall myocardial infarction identifies high risk of developing atrioventricular nodal conduction disturbances.

In 67 consecutive patients with inferior wall acute myocardial infarction (AMI), 99m-technetium pyrophosphate scintigraphy was performed 36 to 72 hours after the onset of chest pain to detect right ventricular (RV) involvement. All patients were continuously monitored during at least 3 days to detect rhythm and conduction disturbances. In 29 patients RV involvement was diagnosed by scintigraphy. None of these 29 patients showed clinical signs of right-sided heart failure. Fourteen of the 19 patients showing atrioventricular (AV) nodal condution disturbances in the setting of inferior AMI also had RV involvement. Therefore, the incidence of high-degree AV nodal block in patients with RV involvement (14 of 29 patients) was 48% compared to only 13% (5 of 38) in patients with inferior AMI without RV involvement.

Value of electrocardiogram in diagnosing right ventricular involvement in patients with an acute inferior wall myocardial infarction.

To study the value of the electrocardiogram in diagnosing right ventricular involvement in acute inferior wall myocardial infarction, the electrocardiographic findings were analysed in 67 patients who had had scintigraphy to pin-point the infarct. All 67 patients were consecutively admitted because of an acute inferior wall infarction. A 12 lead electrocardiogram with four additional right precordial leads (V3R, V4R, V5R, and V6R) was routinely recorded on admission and every eight hours thereafter for three consecutive days. Thirty-six to 72 hours after the onset of chest pain a 99mtechnetium pyrophosphate scintigraphy and a dynamic flow study were performed to detect right ventricular involvement, which was found in 29 of the 67 patients (43%). ST segment elevation greater than or equal to 1 mm in leads V3R, V4R, V5R, and V6R is a reliable sign of right ventricular involvement. ST segment elevation greater than or equal to 1 mm in lead V4R was found to have the greatest sensitivity (93%) and predictive accuracy (93%). The diagnostic value of a QS pattern in lead V3R and V4R or ST elevation greater than or equal to 1 mm in lead V1 was much lower. ST segment elevation in the right precordial leads was short lived, having disappeared within 10 hours after the onset of chest pain in half of our patients with right ventricular involvement. When electrocardiograms are recorded in patients with an acute inferior wall infarction within 10 hours after the onset of chest pain, additional right ventricular infarction can easily be diagnosed by recording lead V4R.

The influence of bilirubin, alcohol and certain drugs on the kinetics of 99mTc-Diethyl IDA (EHIDA) in humans.

On the basis of the mathematical analysis of 99mTc-EHIDA hepatobiliary time-activity curves of normal individuals two rate constants, one related to accumulation of radioactivity (uptake) and the other to excretion, were calculated indicating a two-compartmental model. By means of computerized fitting the rate constant of excretion (Kb), the time of maximum uptake (Tmax) and the rate constant of uptake (Ka) were calculated. In severely jaundiced patients (serum bilirubin concentrations greater than 140 mumol/l) a markedly decreased or absent uptake of 99mTc-EHIDA was observed. In moderately jaundiced patients a low Kb was invariably observed; in obstructive jaundice due to malignant disease--but not in jaundice of benign obstructive or hepatocellular origin--an increase in Ka was frequently present. This latter finding was not always present, however, and consequently kinetic studies do not unequivocally differentiate between jaundice of obstructive and hepatocellular origin. A markedly increased uptake (a high Ka) was noticed in alcoholics and patients taking phenobarbital and diphenylhydantoin possibly because of drug-induced membrane alterations. When the alcoholics developed hepatocellular injury the Ka converted to normal values. Thus, 99mTc-EHIDA kinetics may be useful in the follow-up of patients with established or suspected alcoholism by virtue of the fact that it appears to be a sensitive monitor of functional changes in hepatocyte plasma membrane properties.