ECG Criteria for Angina Pectoris Derived from Resting Frank Lead Electrocardiograms

¹ Research Cardiologist, Department of Medicine, Queen's University, Kingston, Ontario, Canada

Eighty-one men patients in the age range 40 to 80 with uncomplicated angina were evaluatede for ST segment and ST-T interval abnormalities using the orthogonal lead system of Frank. Electrocardiograms were recorded on FM magnetic tape and analyzed by a digital computer. It was found that by using one of the following three criteria: 0.0 sec ST ampiltude in X -0.09 mV, 4/8 ST-T amplitude in Y -0.03 mV or 0.04 sec ST amplitude in Z 0.02 mV, the diagnosis of angina could be made correctly is 51.8 percent of the cases. These criteria would also misclassify 7.8 percent of normal persons as angina patients. Left ventricular hypertrophy (LVH) cannot be separated from angina on the basis of ST segment and ST-T interval abnormalities. Patients have to be tested for high voltage for effective separation of these two entities. Comparison between the diagnostic value of the exercise electrocardiogram and the resting VCG (Frank) in angina pectoris was made.