Clinical symptomatology of coronary artery disease and results of exercise thallium scintigraphy: gender-related differences.

Exercise thallium stress test is the mainstay of the noninvasive assessment of patients with symptomatology suggestive of coronary artery disease. The diagnostic accuracy of thallium scintigraphy as a screening test for coronary artery disease in women as compared to men, however, remains controversial. In order to determine whether gender-related differences in the detection of coronary artery disease using exercise thallium scintigraphy are demonstrable in all age groups, we analyzed the exercise thallium results in 335 outpatients (189 male, 146 female), who were referred by their primary physicians to our institution for evaluation of clinically suspected coronary artery disease. Overall, 50.3 percent of men had a positive for ischemia thallium stress test vs 29.5 percent of women (p < 0.0002). In the subgroup of patients 65 years of age or above, 67.4 percent of men had a positive for ischemia thallium stress test vs 27.6 percent of women (p < 0.003). In the subgroup of patients upto 40 years of age, 37.9 percent of men had a positive for ischemia thallium stress test vs 25.0 percent of women (p = NS). We conclude that symptoms suggestive of coronary artery disease are less predictive of positive exercise thallium stress tests in women as compared to men even above age 65 when the prevalence of coronary artery disease is known to be similar. This suggests that women may have lower threshold for perception of symptoms or that physicians have lower threshold for referring women for screening of coronary artery disease.

Time-limited efficacy of pacing electrodes following open heart surgery.

Temporary epicardial pacing electrodes have been utilised since the 1960s in the postoperative management of cardiac surgical patients, both as a diagnostic tool and therapeutic intervention. To determine the efficacy of the epicardial pacing wires over time after open heart surgery, 30 patients (20M/10F) who underwent coronary artery bypass surgery, were evaluated by standard 12-lead EKG, atrial electrogram, and atrial and ventricular pacing thresholds immediately after surgery and on postoperative day 5. Both atrial and ventricular pacing thresholds were significantly increased on postoperative day 5 as compared to baseline. The ability for effective AAI, VVI and DDD pacing was lost in 38.89 percent, 37.5 percent and 61.11 percent of patients, respectively, on postoperative day 5. We conclude that both atrial and ventricular pacing wires have limited efficacy after postoperative day 4 for pacing after open heart surgery due to a marked increase in pacing thresholds over this time period.