The diagnosis of previous non-Q wave myocardial infarction by standard electrocardiographic investigation is uncertain, particularly in elderly patients because of concomitant disease. We have studied 31 elderly patients (aged 63-72 years) with a diagnosis of non-Q wave myocardial infarction between 1-6 months after this acute event. The patients underwent clinical-anamnestic examination, standard electrocardiography, vectorcardiography according to the Frank system and M-mode and 2-D echo-cardiography with continuous and pulsated Doppler. The ECG showed ST-T anomalies in 12 patients (38.7%) whereas the VCG showed anomalies of QRS-loop normal convexity in 27 patients (87%) and 16 of these (51.6%) showed bites criteria (duration > or = 10 msec, voltage > or = 0.1 mV, present at least on two planes). By echocardiography, regional hypo-akinesia was observed in 19 patients (61.3%). Although bites are not only present in myocardial infarction, they indicate an interruption of myocardial gradual electric activation, compatible with fibrous areas, and should be evaluated as a part of the clinical-anamnestic, laboratory and instrumental data.