SENSITIVITY AND SPECIFICITY OF QTC DISPERSION FOR IDENTIFICATION OF RISK OF CARDIAC DEATH IN PATIENTS WITH PERIPHERAL VASCULAR-DISEASE

Objective-To determine whether QTc dispersion, which is easily obtaine d from a standard electrocardiogram, can predict those patients with p eripheral vascular disease who will subsequently suffer a cardiac deat h, despite having no cardiac symptoms or signs. Design-Patients with p eripheral vascular disease were followed up for five years after they had had coronary angiography, radionuclide ventriculography, and their QTc dispersion calculated from their 12 lead electrocardiogram. Subje cts-49 such patients were then divided into three groups: survivors (3 4), cardiac death (12), and non-cardiac death (3). Main outcome measur e-Survival. Results-The mean (SD; range) ejection fractions were simil ar in all three groups: survivors 45.9 (11.0; 27.0-52.0), cardiac deat h 44.0 (7.90; 28.5-59.0), and non-cardiac death 45.3 (4.55; 39.0-50.0) . QTc dispersion was significantly prolonged in the cardiac death grou p compared with in the survivors (86.3 (23.9; 41.0-139) v 56.5 (25.4; 25.0-164); P=0.002). A QTc dispersion greater than or equal to 60 ms h ad a 92% sensitivity and 81% specificity in predicting cardiac death. QTc dispersion in patients with diffuse coronary artery disease was si gnificantly (P<0.05) greater than in those with no disease or disease affecting one, two, or three vessels. Conclusions-There is a strong li nk between QTc dispersion and cardiac death in patients with periphera l vascular disease. QTc dispersion may therefore be a cheap and non-in vasive way of assessing the risk of cardiac death in patients with per ipheral vascular disease.