Diagnostic incapacity of exercise-induced QRS wave amplitude changes to detect coronary artery disease and left ventricular dysfunction

To evaluate the diagnostic potential of exercise-induced QRSwave amplitude changes, we studied exercise test responses indifferent clinical subsets. The lead system used was a modified12-lead ECG, supplemented with CC5, CM5 and CL5. The potentialof QRS wave amplitude changes compared to conventional ST segmentchanges, to detect coronary artery disease was examined in patientswith no prior myocardial infarction, divided into those witha history of typical angina pectoris and those with atypicalangina pectoris. A similar analysis was undertaken to detectadditional coronary artery disease in patients with prior myocardialinfarction, divided into those with typical and atypical anginapectoris. Finally, the diagnostic ability of QRS wave amplitudechanges to detect left ventricular dysfunction was examinedin all the patients. It is concluded that QRS wave amplitude changes, induced byexercise, have no relevant diagnostic value in detecting (additional)coronary artery disease or left ventricular dysfuntion.