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Biomedical subjects

S Kes

Publications and source records attributed to S Kes.

At least 37 records · Page 2Linked to original sources
PubMed2000

P wave dispersion on 12-lead electrocardiography in patients with paroxysmal atrial fibrillation.

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses have been shown in patients with atrial fibrillation. Recently P wave dispersion (PWD), which is believed to reflect inhomogeneous atrial conduction, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (PAF). Ninety consecutive patients (46 men, 44 women; aged 55 +/- 13 years) with a history of idiopathic PAF and 70 healthy subjects (42 men, 28 women; mean age 53 +/- 14 years) were studied. The P wave duration was calculated in all 12 leads of the surface ECG. The difference between the maximum and minimum P wave duration was calculated and this difference was defined as P wave dispersion (PWD = Pmax-Pmin). All patients and controls were also evaluated by echocardiography to measure the left atrial diameter and left ventricular ejection fraction (LVEF). There was no difference between patients and controls in gender (P = 0.26), age (P = 0.12), LVEF (66 +/- 4% vs 67 +/- 5%, P = 0.8) and left atrial diameter (36 +/- 4 mm vs 34 +/- 6 mm, P = 0.13). P maximum duration was found to be significantly higher in patients with a history of PAF (116 +/- 17 ms) than controls (101 +/- 11 ms, P < 0.001). P wave dispersion was also significantly higher in patients than in controls (44 +/- 15 ms vs 27 +/- 10 ms, P < 0.001). There was a weak correlation between age and P wave dispersion (r = 0.27, P < 0.001). A P maximum value of 106 ms separated patients with PAF from control subjects with a sensitivity of 83%, a specificity of 72%, and a positive predictive accuracy of 79%. A P wave dispersion value of 36 ms separated patients from control subjects with a sensitivity of 77%, a specificity of 82%, and a positive predictive accuracy of 85%. In conclusion, P maximum duration and P wave dispersion calculated on a standard surface ECG are simple ECG markers that could be used to identify the patients with idiopathic paroxysmal atrial fibrillation.

Atrial Fibrillation↗
PubMed2000

P wave dispersion in hypertensive patients with paroxysmal atrial fibrillation.

It is important to assess the risk of developing paroxysmal atrial fibrillation (PAF) in hypertensive patients since hypertension is a common disorder predisposing to PAF. We sought to determine if patients with hypertension at risk of PAF can be identified while in sinus rhythm by measurements of P wave dispersion. Twelve-lead surface electrocardiograms were recorded in 44 hypertensive patients with history of PAF (group I, mean age = 60) and in 50 hypertensive patients without history of AF (group II, mean age = 57). The maximum P wave duration, the minimum P wave duration, and P wave dispersion (Pd = Pmax - Pmin) were calculated from 12-lead surface ECGs. Left atrial dimension (LAD) and left ventricular ejection fraction (LVEF) were measured by echocardiography. P wave dispersion was significantly greater in group I than group II (50 +/- 12 vs 38 +/- 8 ms, P = 0.001). P minimum (75 +/- 13 vs 87 +/- 11 ms, P = 0.001) and LVEF (0.63 +/- 0.05 vs 0.67 +/- 0.04, P = 0.03) were significantly lower in group I than group II. However P maximum and LAD were not significantly different in group I than group II (P > 0.05). In univariate analysis, P minimum, P wave dispersion, and LVEF were significant predictors of PAF, whereas only P wave dispersion remained a significant independent predictor of PAF in a multivariate analysis. Measurement of P wave dispersion in sinus rhythm may be a useful noninvasive clinical tool to identify patients with hypertension at risk of developing atrial electrical instability and atrial fibrillation.

Adult↗
PubMed2000

Detection of Chlamydia pneumoniae and Helicobacter pylori DNA in human atherosclerotic plaques by PCR.

Chlamydia pneumoniae and Helicobacter pylori can cause persistent infections of the respiratory and gastrointestinal tract, respectively. It has been suggested that persistent infection of arteries with these bacteria can contribute to the development of atherosclerosis. The aims of this study were to determine the presence of C. pneumoniae and H. pylori DNA in atherosclerotic plaque samples by PCR and to evaluate the correlation between clinical status and DNA positivity of these bacteria. Eighty-five consecutive patients (mean age, 59 +/- 10; 75 male, 10 female) undergoing coronary artery bypass grafting, carotid endarterectomy, and surgery of the abdominal aorta for atherosclerotic obstructive lesions were included in the study. Forty-six endarterectomy specimens from the atherosclerotic lesions and 39 specimens from healthy regions of the ascending aorta, which were accepted as the control group, were excised. The presence of microorganism DNA in endarterectomy specimens was assessed by PCR. C. pneumoniae DNA was found in 12 (26%) of 46 endarterectomy specimens and none of the healthy vascular-wall specimens (P < 0.001), while H. pylori DNA was found in 17 (37%) of 46 endarterectomy specimens and none of the controls (P < 0.001). Either C. pneumoniae or H. pylori DNA was positive in 23 (50%) of 46 patients and none of the controls (P < 0. 001). Six of the atherosclerotic lesions showed coexistence of both of the microorganism DNAs. The presence of C. pneumoniae and H. pylori DNA in a considerable number of atherosclerotic plaques but their absence in healthy vascular wall supports the idea that they may have a role in the development of atherosclerosis, especially in countries where infection is prevalent and where conventional risk factors fail to explain the high prevalence of atherosclerotic vascular disease.

Adult↗
PubMed2000

Echocardiographic findings of pericardial involvement in patients with malignant pleural mesothelioma with a history of environmental exposure to asbestos and erionite.

OBJECTIVE: The aim of the present study was to evaluate the pericardial involvement in patients with malignant mesothelioma caused by exposure to different minerals. METHODOLOGY: Forty-two patients (mean age of 52 +/- 12 years) with malignant mesothelioma were examined with transthoracic echocardiography. Thirty-three (78.9%) patients had a history of environmental exposure to asbestos and nine (21.4%) had a history of environmental exposure to erionite. RESULTS: In 19 (45.2%) patients with malignant pericardial mesothelioma, pericardial involvement was determined by echocardiography. The other 23 (54.8%) patients had no pericardial involvement. Pericardial effusion was detected in nine (64.3%) patients and pericardial effusion was small in six (14.3%) patients, moderate in one (2.4%) patient and large in two patients. Thickening of the pericardium was observed in eight (19%) patients. In another two (7.1%) patients pericardial calcification was observed. Among the 33 patients who had been exposed to asbestos, 15 (45.5%) had pericardial involvement, and among the nine patients with a history of exposure to erionite, four (44.4%) had pericardial involvement. There was no difference in terms of pericardial involvement in different stages of the tumour (P > 0.05). CONCLUSIONS: Pericardial involvement is commonly seen in patients with malignant mesothelioma. Among patients exposed to asbestos or zeolite there was no difference in terms of pericardial involvement. Furthermore, pericardial involvement was not related with the stage of the tumour.

Adult↗
PubMed1999

Circadian variations of QTc dispersion: is it a clue to morning increase of sudden cardiac death?

BACKGROUND: Several studies related to cardiac events including sudden death have shown a peak incidence in the early morning hours. It has also been known that acute ischemia is a potent stimulus to increased dispersion of repolarization and development of malignant arrhythmias. HYPOTHESIS: The purpose of the present study was to investigate diurnal variations of corrected QT dispersion (QTcD) in patients with coronary artery disease (CAD) (Group 1) compared with controls with normal coronary angiograms (Group 2). METHODS: We investigated a total of 110 patients who had been referred for coronary angiography, of whom 62 (42 men, 20 women; age 55 +/- 7 years) had double- or triple-vessel disease, and of whom 48 (31 men, 17 women; age 54 +/- 9 years) had normal coronary angiograms. QTcD measurements were calculated from a 12-lead resting electrocardiogram (ECG) during sinus rhythm. These ECGs were obtained for each patient in the morning, at noon, in the evening, and at night on the day after performance of coronary angiography. QTcD was significantly greater in patients with abnormal coronary angiograms (Group 1) than in patients with angiographically documented normal coronary arteries (Group 2). This difference appeared to be more prominent in the morning hours (p < 0.001) than at other times. QTcD in the evening and night hours was not statistically different (p > 0.05) between both groups. We also compared intragroup QTcD values: QTcD values were significantly increased in the morning hours and were more prominent in Group 1 than in Group 2. CONCLUSIONS: Our data suggest that QTcD has a circadian variation with an increase in the morning hours, especially in patients with coronary artery disease. This finding was thought to be an explanation for the role played by sympathetic nervous system in the occurrence of acute cardiac events and sudden death during these hours.

Acute Disease↗
PubMed1999

Methylene tetrahydrofolate reductase genotype and the risk and extent of coronary artery disease in a population with low plasma folate.

OBJECTIVE: To determine the effects of the thermolabile methylene tetrahydrofolate reductase (MTHFR) mutation on the presence and extent of coronary atherosclerosis in a population with low plasma folate. METHODS: 242 consecutive patients undergoing coronary angiography were prospectively evaluated for conventional risk factors, plasma homocysteine, vitamin B-12, and folate, and MTHFR genotype. The severity of coronary atherosclerosis was determined by the Leaman score. RESULTS: Mean (SD) plasma homocysteine was 15.6 (10) micromol/l in controls and 18.5 (11) micromol/l in patients with coronary artery disease (p > 0.05). Plasma homocysteine concentrations above 15 micromol/l were a risk factor for coronary artery disease (p = 0.03, risk ratio 2.1, 95% confidence interval (CI) 1.07 to 4.4). Homocysteine remained an independent risk factor on multivariate analysis when conventional risk factors were taken into account (p = 0.04). Homocysteine concentrations above 15 micromol/l were correlated with the extent of atherosclerosis (p = 0. 04, risk ratio 3.2, 95% CI 1.3 to 8.2). Homocysteine had no effect on other lipid variables (p > 0.05). Plasma folate was 15.8 (7.2) nmol/l in controls and 11.5 (2.9) nmol/l in patients with coronary artery disease. Plasma folate concentrations below 12.9 nmol/l (5.7 ng/ml) conferred a risk for coronary artery disease (p = 0.03, risk ratio 2.42, 95% CI 1.05 to 5.59). When the MTHFR genotype was determined, the TT genotype was present in 7.4% of patients and 5.2% of controls (p > 0.05). The prevalence of alleles was within the Hardy-Weinberg equilibrium (TT 7, CT 40, CC 53, chi2 = 2.3, p = 0.3). The highest homocysteine concentrations were found in patients with the TT genotype and folate below the median of the population (p = 0. 01). The extent of coronary atherosclerosis judged by the Leaman score was significantly higher in patients with the TT genotype (p = 0.03). CONCLUSIONS: Plasma homocysteine over 15 micromol/l was a significant risk factor for the presence and extent of coronary artery disease. The mean plasma folate of the population was low and correlated negatively with homocysteine. Although TT genotype was not an independent predictor of coronary artery disease, it was an important predictor of the extent of coronary atherosclerosis and plasma homocysteine, especially in the presence of plasma folate values below the median of the population. These findings may have important implications for folate replacement in patients with the TT genotype.

Case-Control Studies↗
PubMed1999

Effects of stroke localization on cardiac autonomic balance and sudden death.

BACKGROUND AND PURPOSE: Stroke has been shown to alter autonomic function. The purpose of this study was to show the differential effects of stroke localization on autonomic function parameters assessed by heart rate variability (HRV). METHODS: To determine the differential effect of ischemic stroke localization on autonomic cardiac innervation, we evaluated 62 patients with ischemic stroke and 62 age- and sex-matched controls. The localization of the infarct was determined by CT and MRI. Power spectrum analysis of HRV was performed. Myocardial necrosis was ruled out by echocardiography and creatine kinase myocardial isoenzymes measurements. RESULTS: All stroke patients had significantly decreased low frequency, high frequency, and standard deviation of all relative risk intervals values (P<0.001). However, patients with right-middle cerebral artery (R-MCA) and insula lesions had significantly lower power spectrum analysis values compared with all other localizations (P<0.001). In addition, 5 patients with R-MCA insular lesions died suddenly compared with 2 patients with left-middle cerebral artery insular lesions during hospitalization. Both sympathetic- and parasympathetic-controlled HRV were decreased in patients with ischemic stroke. The most pronounced decrease was found in the territory of R-MCA insular cortex, which suggests that cardiac autonomic tone may be regulated by insula and that these patients are more prone to cardiac complications such as arrhythmias and sudden death due to autonomic imbalance. CONCLUSION: We conclude that stroke in the region of insula (especially the right) leads to decreased HRV and to increased incidence of sudden death.

Aged↗
PubMed1997

Measurement of right ventricular ejection fraction by contrast echocardiography.

We evaluated 20 healthy subjects with no cardiac disease (8 males, 12 females, age 49+/-12) to determine the accuracy of right ventricular ejection fraction measurement with contrast echocardiography performed with D-galactose (Echovist 300). All patients underwent two dimensional echocardiography where the right ventricular ejection fraction was calculated by the Simpson's rule first without contrast, then after the injection of 5 ml D-galactose in the same position and compared to the right ventricular ejection fraction measured by the first pass radionuclide angiography on the same day. Subjects had a normal left ventricular ejection fraction of 66+/-5 and a body mass index of 28.9+/-1.2. The correlation between echocardiographic and radionuclide derived right ventricular ejection fraction significantly increased when contrast was used (r=0.81 vs. r=0.6). The r value for interobserver variability also increased significantly with contrast use (r=0.98 vs. r=0.7). We conclude that D-galactose contrast injection significantly enhances border detection and improves the accuracy of right ventricular ejection fraction calculations with echocardiography making it a simple and reliable method.

Adult↗
PubMed1997

Effect of an additional atropine injection during dobutamine infusion for myocardial SPET.

The aim of this study was to examine the value of an additional atropine injection in patients who do not achieve an adequate heart rate during dobutamine infusion for myocardial perfusion SPET (single photon emission tomography). Patients undergoing dobutamine myocardial SPET who failed to achieve > or = 85% of their age-predicted maximal heart rate at the end of dobutamine infusion (D protocol) had a second dobutamine myocardial SPET study on a separate day with the addition of an atropine injection during the dobutamine infusion (D + A protocol). Twenty-nine patients were studied. 201Tl was used in 27 patients and 99Tc(m)-MIBI in two patients. All patients underwent coronary angiography and significant coronary artery disease was found in 19 of 29 patients. The mean heart rate obtained at the peak of dobutamine infusion in the D + A protocol was significantly higher than that in the D protocol (153.8 +/- 13.8 vs 117.5 +/- 15.3 beats min[-1]). The D + A protocol resulted in a higher diagnostic sensitivity for the detection of stenosed coronaries compared with the D protocol (87 vs 80%, P > 0.05) without changing the specificity (89% for both protocols). On the other hand, the frequency of side-effects and ECG changes during the D + A protocol was higher than that with the D protocol (32 vs 47). In conclusion, the addition of an atropine injection during dobutamine infusion resulted in a higher diagnostic sensitivity for identifying stenosed coronaries compared to dobutamine alone.

Adrenergic beta-Agonists↗
PubMed1997

Dobutamine thallium-201 myocardial SPECT in patients with left bundle branch block and normal coronary arteries.

UNLABELLED: Dobutamine is a positive inotropic and chronotropic agent and is being widely used as a pharmacologic stress agent in patients unable to achieve maximal dynamic exercise test. The purpose of the current study was to document the dobutamine induced false-positive septal defect in terms of its frequency and extent on 201Tl myocardial SPECT in patient with left bundle branch block (LBBB). METHODS: Twenty-five symptomatic patients with LBBB underwent dobutamine and redistribution 201Tl myocardial SPECT studies. Coronary angiographies were also performed. Only those patients with normal coronaries (n = 19) were included in the study. For each study, tomograms were divided into 19 segments, and each segment was analyzed qualitatively as to presence and type of perfusion defect (reversible or fixed). In addition, septal perfusion was scored in each patient (1 = markedly, 2 = moderately reduced, 3 = normal uptake). RESULTS: Sixteen of 19 patients (84.21%) had false-positive septal reversible perfusion defect, and the remaining 3 had normal images. Perfusion defects were confined to only the septum in 5 of 16 patients (31.25%), whereas a greater proportion of patients had septal defect extending to the contiguous myocardial areas, mainly to the anterior wall. Five of 16 patients with false-positive defects had a septal perfusion score of 1, while the remaining 11 had a score of 2. CONCLUSION: Dobutamine myocardial scintigraphy in patients with LBBB was misleading for the diagnosis of coronary artery disease, since up to 84.21% of patients had false-positive septal perfusion defects.

Adult↗
PubMed1995

Echocardiography in patients with constrictive pericarditis before and after pericardiectomy: Are there predictors of surgical outcome?

Fifteen patients with constrictive pericarditis were prospectively evaluated with echocardiography and Doppler recordings during respiratory monitoring. Eleven who agreed to surgery also underwent right heart catheterization and a repeat echocardiography with Doppler 10 days after pericardiectomy. Preoperatively, there was a significant inspiratory decrease in the mitral E wave (P < 0.05) and increase in the tricuspid E wave velocities (P < 0.05), which both normalized after pericardiectomy. The mitral deceleration times increased from 110 +/- 40 to 149 +/- 46 msec (P < 0.05) postoperatively. The preoperative hepatic vein velocities showed an accentuated systolic flow pattern. The systolic to diastolic ratio of the hepatic vein velocities was higher in patients who improved with surgery (1.42 +/- 0.31 vs 0.65 +/- 0.13) (P < 0.05). Postoperatively the diastolic flow became more pronounced. There was a 100% expiratory diastolic flow reversal in eight patients preoperatively, which normalized after pericardiectomy. Clinically these patients improved significantly postoperatively. Left atrial size, ejection fraction, and mitral and tricuspid filling velocities during respiratory monitoring could not predict surgical outcome. Pericardiectomy improved Doppler filling dynamics in all patients although this was not parallel to clinical improvement.

Adult↗
PubMed1995

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↗
PubMed1993

Alterations in left ventricular function in patients with Behçet's disease using radionuclide ventriculography and Doppler echocardiography.

Behçet's syndrome is a multisystem disease; however, cardiac involvement in this disorder has been relatively less recognized. Noninvasive imaging methods may reveal a cardiac disorder which has not manifested itself clinically. In this study, radionuclide ventriculography and Doppler echocardiography were performed in 24 patients with Behçet's disease to assess the left ventricular systolic and diastolic function. Patients had neither known heart disease nor cardiac symptoms. Radionuclide ventriculography was performed using 99mTc-labeled red blood cells. Ejection fraction (EF), EF fraction in the first 100 ms (EFV), peak ejection rate, time to peak ejection, 1/3 EF, time to end systole, peak filling rate (PFR), time to peak filling and 1/3 filling fraction (1/3 FF) values were computed using Fourier analysis of the time activity curve of the left ventricle with 3 harmonics. Doppler echocardiography (DE) has described impairment of diastolic compliance using analysis of mitral flow. The mean EF (54.7 +/- 9%), EFV (11.6 +/- 3.6%), PFR (2.49 +/- 0.58 EDC/s) and 1/3 FF (33.64 +/- 14%) values were significantly lower in patients than those of the control group. Nine (37.5%) patients demonstrated an impairment of diastolic function and 3 (12.5%) had abnormal systolic function observed by the radionuclide method. DE showed abnormal ventricular compliance in 13.6% of patients. As a conclusion, noninvasive imaging methods such as radionuclide ventriculography and DE may be valuable to detect diastolic impairment as an early sign of cardiac involvement in Behçet's disease.

Adult↗