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Biomedical subjects

L Tokgözoglu

Publications and source records attributed to L Tokgözoglu.

4 recordsLinked to original sources

T wave alternans can decrease after coronary revascularization.

Clinical observations and animal experiments indicate that T wave alternans (TWA) is associated with an increased propensity for ventricular fibrillation, and thus it may be considered as a noninvasive marker of life-threatening ventricular arrhythmias. There is substantial evidence indicating that TWA is an intrinsic property of ischemic myocardium. This study was performed to determine the role of percutaneous transluminal coronary angioplasty (PTCA)-induced myocardial ischemia in the development of TWA and the effects of revascularization. The authors recorded bipolar X, Y, and Z leads of 111 consecutive patients (mean age: 56 years) undergoing PTCA before, during, and 24 hours after the procedure. T wave alternans signal was calculated in 97 patients (43 left anterior descending, 26 right coronary artery, and 28 circumflex or major obtuse margin branch) by fast Fourier transformation technique after signal processing. Twenty-four hours after the procedure, the mean and peak X, Y, and Z values for TWA had all been significantly reduced from baseline and during balloon inflation (p<0.01). The findings point out that induced ischemia could be a trigger for T wave alternans, and successful revascularization can reduce alternans.

Angioplasty, Balloon, Coronary↗

Effects of ACE inhibition on left ventricular dimensions and haemodynamics in systemic hypertension: a radionuclide and echocardiographic study.

The aim of this study was to assess the effects of Angiotensin Converting Enzyme (ACE) inhibition on cardiac systolic and diastolic parameters and left ventricular muscle mass in hypertensive patients. For this purpose 30 patients (22 female and eight male) with mild to moderate essential hypertension, aged 47 +/- 2 years, were treated with enalapril maleate (MK 421, an ACE inhibitor) for six weeks. They underwent M-mode and Doppler echocardiography and radionuclide ventriculography at the beginning and after six weeks of enalapril treatment. In this study all patients treated with the ACE inhibitor enalapril responded with a significant decrease in mean arterial pressure (p < 0.001). A significant reduction in left ventricle and mass index were shown after six weeks of treatment with enalapril (p < 0.01). Total peripheral resistance and end-systolic stress decreased in the same time course (p < 0.001). Ejection fraction increased in both examinations after six weeks of therapy with enalapril, but this increase was not statistically significant. In radionuclide examinations, time to peak filling rate decreased significantly after six weeks of enalapril therapy (p < 0.02). Despite these improvements in cardiac systolic and diastolic parameters, cardiac output and stroke volume decreased slightly after enalapril treatment. We concluded that enalapril improves diastolic and systolic parameters in LV function but causes slight decreases in cardiac output and stroke volume in addition to lowering blood pressure.

Echocardiography, Doppler↗

Atrial fibrillation after coronary artery bypass surgery: predictors and the role of MgSO4 replacement.

BACKGROUND: Supraventricular arrhythmias continue to complicate the postoperative course of patients undergoing myocardial revascularization. The aim of the study was to identify factors associated with atrial fibrillation (AF) and to determine the efficacy of postoperative magnesium sulphate (MgSO4) replacement on the incidence of AF after coronary artery bypass grafting (CABG) operation. METHODS: Fifty patients undergoing CABG were studied prospectively. Consenting patients with good left ventricular function and without any documented arrhythmias were randomly divided into two groups of 25 patients each in a double-blind fashion. The clinical characteristics of both groups were similar. In the study group, 200 mEq MgSO4 was given for the first 5 postoperative days, in the control group, placebo was given instead of MgSO4. RESULTS: Five (20%) patients in the control group and one (4%) patient in the MgSO4 group experienced AF. There was no significant relationship between the development of AF and the following variables: age; sex; diabetes mellitus; hypertension; previous myocardial infarction; smoking; extension of coronary artery disease; aortic cross-clamp time; number of grafts; cardiopulmonary bypass time; postoperative pericarditis; and anemia. CONCLUSION: The use of MgSO4 in early postoperative period is effective in reducing the incidence of AF after CABG in patients with good ventricular function.

Atrial Fibrillation↗