A statistical approach to the recognition of inferior wall myocardial infarction by the Q/R ratios.
To sharpen ECG criteria for diagnosis of inferior wall myocardial infarction (IWMI), the distribution of Q duration and Q/R ratios in leads 3 and aVF in four groups have been analyzed. Two of these groups are teaching samples (200 ECGs of patients with various diagnoses, but in whom no myocardial infarction was found on post-mortem, and 123 ECGs of patients in whom IWMI was found on post-mortem examinations) and two control samples (408 ECGs of healthy men and 60 ECGs of patients with clinically proved IWMI). The chosen combination of conditions Q/R3 greater than 25 percent and Q/RaVF greater than 10 per cent gives minimal number of errors for the teaching samples. The diagnostic rule gave 5-7 percent errors over the control samples. It is shown that use of Q duration greater than 0.04'' gives less satisfactory results in the diagnosis of IWMI.
D003936:Diagnosis, Computer-Assisted; D003951:Diagnostic Errors; D004562:Electrocardiography; D006801:Humans; D009203:Myocardial Infarction / Q000175:diagnosis*; D013223:Statistics as Topic