Diagnosis of coronary artery disease by thallium 201 myocardial scintigraphy during atrial pacing

Rapid atrial pacing may reveal myocardial ischemia but the sensitivity for the diagnosis of coronary artery disease is not high enough for routine use. Therefore, the value of atrial pacing coupled with Thallium 201 scintigraphy was evaluated. Sixty-two patients (53 men and 9 women) referred for investigation of angina or chest pain were divided into two groups: a control group of 13 patients (9 men and 4 women, average age: 57.1 years) with insignificant coronary lesions (less than 50%) (N = 5) or normal coronary angiography (N = 8), and a group of 49 patients (44 men and 5 women, average age: 55.5 years) 27 of whom had a history of myocardial infarction (17 posterior, 10 anterior). Coronary angiography showed single vessel disease in 44.9% of cases, double vessel disease in 34.7% and triple vessel disease in 18.4% of cases, and 1 patient with left main stem disease. All 62 patients underwent the same study protocol which comprised: incremental atrial pacing (to the calculated maximal heart rate), Thallium 201 myocardial scintigraphy immediately after pacing and during the redistribution phase, and coronary angiography. The sensitivities of anginal pain (36.7%) and ECG changes during atrial pacing (57.1%) were too low for the diagnosis of myocardial ischemia. On the other hand, Thallium 201 scintigraphy with atrial pacing was more sensitive (87.8%) and specific (84.6%) for coronary artery disease. Stenosis of the left anterior descending artery was diagnosed with a sensitivity of 96.4% and that of the right coronary artery with a sensitivity of 90.9%.(ABSTRACT TRUNCATED AT 250 WORDS)