775-2 Deleterious Effect of Smoking on the Elastic Properties of the Aorta

Cigarette smoking alters vascular reactivity and thus may alter the elastic properties of the aorta (Ao). To test this hypothesis, serial pressure-diameter loops (figure A) were obtained from the simultaneous recordings of the thoracic Ao diameter (D) and pressure (P) before and atterthe initiation of smoking of one cigarette (nicotine content 1.3mg) in 20 healthy smokers who underwent diagnostic cardiac catheterization. Ao 0 were measured by a Yshaped catheter, developed in our institution, which incorporates at its distal tips a pair of ultrasonic dimension crystals (Crystal Biotech, MA). This highdefinition diameter gauge was validated in in-vitro and experimental studies. Ao Pwere recorded by a Millar micromanometer. The pressure-diameter relationship changed significantly with smoking (figure A). Ao distensibility (=2Δd/dx ΔP, where Δd and ΔP: changes from systole to diastole of the Ao D and P respectively, and d: diastolic Ao D) was decreased significantly after smoking (figure B). These changes suggest that the Ao became stiffer atter smoking.This effect of smoking on the elastic properties of the aorta adds to the multiple other deleterious effects of smoking on human health

Stress echocardiography in elderly patients with coronary artery disease Applicability, safety and prognostic value of dobutamine and adenosine echocardiography in elderly patients

AbstractObjectives. Our aim was to determine the applicability, safety and prognostic value of adenosine and dobutamine stress echocardiography in patients ≥70 years old.Background. These tests are sometimes mandatory because of difficulties and inaccuracies in interpreting traditional electrocardiographic stress tests. Furthermore, if these tests could be used to avoid coronary arteriography and cardiac catheterization, they would become essential in the care of the elderly, whose numbers are increasing.Methods. We performed coronary arteriography and dobutamine and adenosine stress echocardiographic tests in 120 patients (72 men) ≥70 years old who entered the hospital because of chest pain and had known or suspected coronary artery disease. The stress tests were performed on separate days, within 2 weeks of coronary arteriography. Both the arteriograms and the echocardiograms were analyzed by two experts who had no knowledge of the patients' other data or the other interpreter's report. Tests were judged to have positive or negative results, and the patients were followed up for the development of cardiac events. Univariate and multivariate analyses and other statistical modalities were applied for comparisons.Results. Documented coronary artery disease was found in 89 patients. During the 14 ± 7 months of follow-up, cardiac events developed in 50 patients, including 3 (7.9%) of 38 patients with negative dobutamine and 12 (20.7%) of 58 patients with negative adenosine test results. Demonstration of any abnormality on stress echocardiography was an independent factor for cardiac events, both for dobutamine (relative risk 7.3) and for adenosine (relative risk 3.0). Both cessation of dobutamine or adenosine tests and diagnosis of disease in two or more coronary vessels were also independent predictors. ST segment depression ≥1 mm was related to future events only with the dobutamine test.Conclusions. These echocardiographic stress tests proved safe and well tolerated. They successfully stratified this cohort of elderly patients with coronary artery disease to low or high risk subgroups for subsequent cardiac events