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Biomedical subjects

Aylin Yildirir

Publications and source records attributed to Aylin Yildirir.

At least 19 recordsLinked to original sources
PubMed2008

Echocardiographic diagnosis of left ventricular-right atrial communication (Gerbode-type defect) in an adult with chronic renal failure: a case report.

Left ventricular-right atrial communication, known as a Gerbode-type defect, is a rare form of ventricular septal defect. It is usually congenital, but rarely acquired. Clinical presentation is associated with the volume of the shunt. Transthoracic echocardiography is the most useful diagnostic method. We present a 63-year-old man with chronic renal failure and left ventricular-right atrial shunt.

Echocardiography, Doppler, Color↗
PubMed2007

Assessment of biochemical aspirin resistance at rest and immediately after exercise testing.

Some aspirin-treated patients experience thromboembolic events, a phenomenon termed 'aspirin resistance', which may be clinical or biochemical by definition. Physical exercise is known to enhance platelet secretion and aggregability. To evaluate the presence of biochemical aspirin resistance at rest and immediately after exercise in individuals with stable coronary artery disease or coronary artery disease risk factors. We prospectively enrolled 101 patients who had received 100 or 300 mg/day enteric-coated aspirin for at least 7 days. Biochemical aspirin resistance (defined as normal collagen-epinephrine closure time < 165 s) was studied using the standardized platelet function analyzer. Of the 101 patients, 63 were aspirin sensitive both at rest and immediately after exercise, 18 exhibited biochemical aspirin resistance both at rest and after exercise, and 20 were aspirin sensitive at rest but exhibited biochemical aspirin resistance immediately after exercise. The results of exercise testing were similar in all three groups (each P > 0.05). Our results indicate that in almost 20% of the patients, aspirin did not seem to protect against exercise-induced platelet activation, despite the presence of aspirin sensitivity at rest. We did not, however, determine the extent to which the biochemical aspirin resistance noted in our study applied to clinical events.

Aged↗
PubMed2007

Recombinant human-activated protein C inhibits cardiomyocyte apoptosis in a rat model of myocardial ischemia-reperfusion.

OBJECTIVES: Myocardial apoptosis is recognized as a major mechanism of cell death during ischemia-reperfusion. In this study, we assessed the hypothesis that activated protein C may have a cardioprotective effect via preventing apoptosis in a rat model of myocardial ischemia-reperfusion. METHODS: Thirty male Sprague-Dawley rats were anesthetized, instrumented for hemodynamic measurements and ventilated mechanically. Twenty rats were subjected to 20 min of left anterior descending coronary artery occlusion and 2 h of reperfusion. They were randomly assigned to receive intravenous Ringer lactate (vehicle) or activated protein C (2 mg/kg/h) 10 min after occlusion and during reperfusion. The other 10 rats were sham-operated. At the end of the reperfusion period, serum samples were obtained for evaluation of creatine kinase, C-reactive protein and tumor necrosis factor-alpha. Apoptosis was measured quantitatively by the terminal deoxynucleotide transferase-mediated dUTP nick-end labeling method. RESULTS: Serum creatine kinase, C-reactive protein and tumor necrosis factor-alpha values and percentage of terminal deoxynucleotide transferase-mediated dUTP nick-end labeling- positive myocyte nuclei demonstrated negligible myocardial injury in sham-operated controls. During reperfusion, mean arterial pressures were significantly higher in activated protein C-treated rats than in the control group (68.2+/-10.3 vs. 55.4+/-11.6 mmHg, P=0.01). Number of apoptotic cells was significantly reduced from 47.7 to 24.8% with activated protein C administration (P=0.008). No difference was seen between activated protein C-treated and untreated animals with respect to creatine kinase, C-reactive protein and tumor necrosis factor-alpha levels. CONCLUSIONS: Treatment with activated protein C significantly improved hemodynamics after ischemia-reperfusion and reduced ischemia-reperfusion-induced myocardial apoptosis in rats.

Animals↗
PubMed2006

Impaired coronary microvascular and left ventricular diastolic functions in patients with ankylosing spondylitis.

BACKGROUND: It has been shown that the patients with inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis have an increased risk of developing atherosclerosis. However, the association of ankylosing spondylitis (AS) to atherosclerosis and related diseases is still controversial. Accordingly, we investigated coronary flow reserve (CFR) and left ventricular (LV) diastolic function in patients with AS using transthoracic Doppler echocardiography. METHODS: CFR and LV diastolic function were studied in 40 patients with AS (38.9+/-10.2 years, 26 males) and 35 healthy volunteers (37.5+/-6.4 years, 23 males). Coronary diastolic peak flow velocities (DPFV) were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline DPFV. LV diastolic function was assessed by both standard and tissue Doppler imaging. RESULTS: Demographic features and coronary risk factors except diastolic blood pressure were similar between the groups. CFR were significantly lower in the AS group than in the control group (2.20+/-0.46 versus 3.02+/-1.50, P<0.0001). Reflecting LV diastolic function mitral A-wave and E/A ratio were borderline significant, and mitral E-wave deceleration time and isovolumic relaxation time were significantly different between the groups. Serum hsCRP and TNF-alpha levels were significantly higher in the patients with AS, and hsCRP and TNF-alpha levels independently correlated with CFR. CONCLUSION: These findings show that CFR reflecting coronary microvascular function and LV diastolic function are impaired in patients with AS, and severity of these impairments correlate well with hsCRP and TNF-alpha. These results suggest that impaired CFR may be an early manifestation of cardiac involvement in patients with AS.

Adult↗
PubMed2006

Elevated serum uric acid levels impair coronary microvascular function in patients with idiopathic dilated cardiomyopathy.

In patients with idiopathic dilated cardiomyopathy (IDC), attenuated coronary flow reserve (CFR) and elevated serum uric acid levels have been reported. In this study, we investigated whether increased uric acid levels correlate with the degree of coronary microvascular dysfunction. Serum uric acid levels were measured in 29 patients with IDC (mean age: 57.0+/-10.8 years, 10 female), and each patient also underwent transthoracic echocardiographic examination including CFR measurement. The study population was divided into two groups according to the median CFR value (lower CFR group and higher CFR group). Uric acid levels were significantly higher in the lower CFR group than in the higher CFR group (7.59+/-2.56 vs 4.80+/-0.80 mg/dL, P=0.000). CFR correlated significantly and inversely to serum uric acid (r=-0.570, P=0.001). Logistic regression analysis revealed that uric acid level was the only independent predictor of CFR (B=-1080, P=0.015). We found a possibly clinically important negative association between serum uric acid levels and CFR in patients with IDC.

Adult↗
PubMed2006

Serum gamma-glutamyl transferase activity: a new marker for stent restenosis?

Stent restenosis remains the main limitation of percutaneous coronary intervention. Elevated serum gamma-glutamyl transferase (GGT) level is associated with an inflammatory response. We aimed to determine the correlation of stent restenosis with the serums level of GGT. One hundred and twenty patients (age 58.56+/-10.46 years, 66% male) with a history of coronary stent implantation and had undergone control coronary angiography (60 with restenosis and 60 without) were included. All had baseline serum GGT activity and were free of systemic and hepatobiliary disease. Median baseline serum GGT activity was significantly higher in patients with restenosis (34.00 U/L (24.00-47.75)) than in those without restenosis (21.00 U/L (17.25-26.7500)) (P<0.0001). Stent restenosis was identified in 38% of the patients with a serum GGT value >40 U/L and in 5% of patients with a serum GGT value <or=40 U/L (P<0.001). Serum C-reactive protein (CRP) and total bilirubin levels were significantly higher (P=0.011 and 0.037, respectively) and alkaline phosphatase levels were significantly lower in patients with restenosis (P=0.029). Levels of GGT, CRP, and alkaline phosphatase were independent predictors of restenosis (P=0.001, 0.019 and 0.004, respectively). In conclusion, the serum level of GGT may be an independent marker for stent restenosis.

Adult↗
PubMed2006

Nebivolol improves coronary flow reserve in patients with idiopathic dilated cardiomyopathy.

BACKGROUND: Impaired coronary flow reserve (CFR) is a significant predictor of poor prognosis in patients with idiopathic dilated cardiomyopathy (IDC). Nebivolol reduces mortality and morbidity in patients with heart failure and left ventricular dysfunction, including cases caused by IDC. OBJECTIVE: To assess the effects of nebivolol on CFR in patients with IDC. METHODS: CFR was measured in 21 clinically stable patients with IDC (mean (SD) ejection fraction 35.7 (6.2)) at baseline and after 1 month of treatment with nebivolol once daily. A control group of apparently healthy subjects who were matched for age and sex was used for comparison. Resting and hyperaemic coronary flows were measured using transthoracic second-harmonic Doppler echocardiography. None of the subjects had any systemic disease. RESULTS: After 1 month of treatment, heart rate was reduced significantly (p<0.001). The blood pressure was decreased significantly (p<0.001). The left ventricular end-diastolic diameter and stroke volume were not changed significantly, but end-systolic diameter was decreased significantly (p<0.05). Resting rate-pressure product was lower after treatment with nebivolol, but dipyridamole-induced change was not influenced by the treatment. Nebivolol treatment reduced significantly coronary velocities at rest (p<0.02) and also caused a significant increase in coronary velocities after dipyridamole (p<0.02), leading to a greater CFR (2.02 (0.35) vs 2.61 (0.43), p<0.001). Nebivolol induced an absolute increase of 6% in the CFR in 17 of 21 patients (80.9%). CONCLUSIONS: In patients with IDC, 1 month of treatment with nebivolol induces a marked increase in CFR.

Benzopyrans↗
PubMed2006

Coronary flow reserve is impaired in patients with slow coronary flow.

BACKGROUND: Slow coronary flow (SCF) in a normal coronary angiogram is a well-recognized clinical entity, but its etiopathogenesis remains unclear. However, previous studies have suggested that microvascular abnormalities and endothelial dysfunction responsible for SCF. Accordingly, we hypothesized that SCF phenomenon may be a form, at least early phase, of atherosclerosis that involve both small vessels and epicardial coronary arteries, and therefore we investigated coronary flow reserve (CFR) reflecting coronary microvascular function in patients with SCF. METHODS: Twenty subjects with SCF and 15 control subjects with normal coronary flow were studied. Coronary flow was quantified according to TIMI frame count (TFC). Coronary diastolic peak flow velocities were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic peak velocities. RESULTS: Demographic features, coronary risk factors, echocardiographic measurements except diastolic function parameters, and biochemical measurements were similar between the groups. CFR values were significantly lower in subjects with SCF than in the control group (1.99+/-0.38 versus 2.99+/-0.47, P<0.0001). In addition, TIMI frame count independently correlated with CFR. CONCLUSION: These findings suggest that CFR, which reflects coronary microvascular function, is impaired in patients with SCF, and corrected TFC well correlates with CFR.

Adult↗
PubMed2006

Effects of metoprolol therapy on cardiac troponin-I levels after elective percutaneous coronary interventions.

AIMS: Beta-blockers (BBs) have been shown to improve survival and reduce the risk of re-infarction in patients following myocardial infarction. There are conflicting data about the effects of BB therapy on cardiac biomarkers after percutaneous coronary interventions (PCIs). The aim of the study was to investigate the effects of BB use on cardiac troponin-I (cTnI) levels in patients who had undergone elective PCI. METHODS AND RESULTS: In this prospective study, 287 patients with coronary artery disease were included. Patients were randomized either to BB or control groups prior to the intervention. Blood samples for cTnI were obtained before and at 6, 24, and 36 h after the procedure. Of the 287 patients included, 143 received metoprolol succinate 100 mg/day, and 144 received no BB and served as the control group. Baseline clinical characteristics of both groups, except for history of coronary artery bypass graft surgery, were similar. We observed no significant difference in the elevation of cTnI levels between the two groups after PCI (BB group, 17 patients, 11.9%; control group, 10 patients, 6.9%; P=0.2). CONCLUSION: Metoprolol succinate therapy seems to have no cardioprotective effect in limiting troponin-I rise after PCI.

Administration, Oral↗
PubMed2006

Frequency of atrial fibrillation and factors related to its development in dialysis patients.

BACKGROUND: The frequency of atrial fibrillation is increased in patients with end-stage renal disease. In this study, we sought to determine the incidence of persistent and paroxysmal atrial fibrillation in patients with end-stage renal disease and to identify the risk factors associated with this arrhythmia. METHODS: Two hundred seventy-five patients with end-stage renal disease who were in a hemodialysis program for at least 4 months were included in the study. Patients with permanent, persistent, or paroxysmal atrial fibrillation were identified and recorded. All patients were evaluated for cardiac risk factors and arrhythmias. RESULTS: Thirty (10.9%) of the 275 patients were found to have atrial fibrillation. Ten (33.3%) of these patients had permanent or persistent atrial fibrillation, and 20 (66.6%) of these patients had paroxysmal atrial fibrillation. Patients with atrial fibrillation were older. Incidences of hypertension, coronary artery disease, left ventricular systolic dysfunction, right atrial diameters, and mitral and/or aortic calcification were significantly higher in patients with atrial fibrillation. Serum albumin and high-density lipoprotein levels were significantly lower in patients with atrial fibrillation. CONCLUSIONS: Our data indicate that atrial fibrillation is a frequent arrhythmia in patients with end-stage renal disease, and the most frequently encountered form is paroxysmal atrial fibrillation. In this patient group, presence of coronary artery disease, age, and right atrial diameter are independent factors for determination of the risk of development of atrial fibrillation.

Aged↗
PubMed2006

Heart rate variability in young women with polycystic ovary syndrome.

BACKGROUND: Limited data are available related to the effects of sex hormones on cardiac autonomic function. Few studies investigated the heart rate variability (HRV) parameters during regular menstrual cycle or in postmenopausal women using hormone replacement therapy, but the results were contradictory. The aim of the study was to compare the characteristics of the autonomic innervation of the heart in polycystic ovary syndrome (PCOS) patients with regularly cycling controls. METHODS: Thirty PCOS patients and 30 healthy regularly cycling controls were included in the study. Groups were compared with respect to age and various cardiovascular risk factors. Characteristics of autonomic innervation of the heart were evaluated with HRV. Power spectral analysis of HRV was performed to calculate the low frequency peak (LF 0.04-0.15 Hz), high-frequency peak (HF 0.15-0.40 Hz), LF in normalized unit (LF nu), HF in normalized unit (HF nu) and LF/HF ratio. RESULTS: PCOS patients had adverse cardiovascular risk profile than controls. As the HRV parameters, PCOS patients had significantly higher LF nu (P = 0.005) and LF/HF ratio (P = 0.001) and significantly lower HF (P = 0.006) and HF nu (P < 0.001) compared to controls. CONCLUSION: Autonomic innervation of the heart can be affected in PCOS with increased sympathetic and decreased parasympathetic components of HRV. As a result, sympathetic to parasympathetic ratio may increase in PCOS. This finding should be confirmed with larger studies also evaluating the clinical implications of altered HRV parameters.

Adult↗
PubMed2006

Rhesus positivity and low high-density lipoprotein cholesterol: a new link?

The aim of the study was to investigate the relationship of ABO and Rh blood groups with lipid profile in patients with established multivessel coronary artery disease in a population with low levels of high-density lipoprotein cholesterol. The records of 978 patients with multivessel coronary artery disease, in whom coronary bypass surgery was performed, were investigated. Coronary risk factors including diabetes, hypertension, smoking, and obesity were noted for each patient. Serum lipid profiles: total cholesterol, low-density and high-density lipoprotein cholesterol, and triglyceride levels, were also recorded. The mean age of the patients was 59.3 +/- 9.7 years (range, 25-84 years) and 80% were male. The risk factors and lipid profiles of ABO blood types were similar. Rh-negative patients had higher levels of high-density lipoprotein cholesterol (46.9 +/- 9.9 vs. 41.6 +/- 10.4 mg.dL(-1), p = 0.001) and a lower total/high-density lipoprotein cholesterol ratio (4.8 +/- 1.3 vs. 5.2 +/- 1.6, p = 0.029) compared to Rh-positive patients. The other lipid levels and risk factors had no association with Rh typing. These results indicate a significant association between rhesus positivity and low levels of high-density lipoprotein cholesterol in patients with multivessel coronary artery disease.

ABO Blood-Group System↗
PubMed2006

Cardiac enzymes, renal failure and renal transplantation.

Diagnostic accuracy of the currently available serum markers of cardiac injury, such as myoglobin, creatine kinase and its myocardial isoform, are altered in patients with renal failure. It is shown that cardiac troponins have decreased diagnostic sensitivity and specificity in patients receiving renal replacement therapy. Data regarding serum levels of these cardiac biomarkers, especially those of the cardiac troponins, in patients with a transplanted kidney are limited. Current data show that levels of cardiac troponin I are unaltered in patients who have undergone renal transplantation, while levels of cardiac troponin T may be elevated.We believe that cardiac troponin I should be the biomarker of choice for diagnosis of myocardial injury in these patients. However, further trials are required for conclusive results.

Biomarkers↗
PubMed2005

Do young women with polycystic ovary syndrome show early evidence of preclinical coronary artery disease?

BACKGROUND: It is thought that women with polycystic ovary syndrome (PCOS) are at increased risk of developing cardiovascular diseases. METHODS: In this study, we used transthoracic echocardiography to measure coronary flow reserve (CFR) in 28 women with PCOS and in 26 healthy women. RESULTS: The PCOS and the control groups were similar in terms of age (27.1 +/- 4.5 versus 28.8 +/- 4.4 years) and BMI (26.6 +/- 5.7 versus 24.7 +/- 4.4 kg/m2). Fasting insulin levels and homeostasis model assessment insulin resistance index were higher in the PCOS group. LH, the LH/FSH ratio, total testosterone, free testosterone and androstenedione were higher in the PCOS group. FSH, estradiol, prolactin, progesterone, cholesterol, triglyceride and high-sensitive C-reactive protein were similar between the two groups, but homocysteine levels were higher in the PCOS group. Baseline diastolic peak f low velocity (DPFV) (25.0 +/- 4.6 versus 23.3 +/- 2.7 cm/s, P > 0.05), hyperaemic DPFV (71.2 +/- 12.8 versus 73.0 +/- 12.9 cm/s, P > 0.05) and CFR (2.8 +/- 0.8 versus 3.2 +/- 0.8 cm/s, P > 0.05) of the left anterior descending coronary artery were similar between the two groups. CONCLUSION: We conclude that in young women with PCOS and without cardiovascular risk factors, CFR is preserved.

Adult↗
PubMed2005

Beta blocker effects on plasma homocysteine levels in patients with hypertension.

Recent studies have shown that hyperhomocysteinemia might play a role in the pathogenesis of hypertension. The effects of antihypertensive agents on plasma homocysteine levels have not been tested extensively. We investigated the effects of beta-blocker therapy on homocysteine levels in patients with hypertension. In the study, 120 patients with newly diagnosed hypertension were enrolled. All patients received metoprolol succinate 100 mg/day initially. If blood pressure was above normal on the 15th day of follow-up, the metoprolol dosage was doubled. Before initiation of the antihypertensive medication and after the fourth month of treatment, homocysteine levels were measured. Of the 120 patients enrolled, 39 could not complete the study. Homocysteine levels decreased significantly by the end of the fourth month when compared with basal values (13.5+/-4.5 micromol/l versus 12.4+/-4.9 micromol/l; P = 0.001). There was no relation between homocysteine level and blood pressure control. There was a significant decrease in homocysteine levels in the women treated in this study (P = 0.001); however, this effect was absent in men (P = 0.185). We demonstrate that metoprolol succinate treatment significantly decreases plasma homocysteine levels in patients with hypertension, especially in women.

Adrenergic beta-Antagonists↗
PubMed2005

The effects of prior beta-blocker therapy on serum C-reactive protein levels after percutaneous coronary intervention.

BACKGROUND: There are no studies in the literature related to the effect of beta blockers (BB) on changes in C-reactive protein (CRP) levels after percutaneous coronary intervention (PCI). HYPOTHESIS: We designed a prospective randomized study to investigate the impact of BB therapy on CRP in patients who underwent elective PCI. METHODS: In all, 300 patients with coronary artery disease were included. Patients were randomized to either a metoprolol or to a control group before PCI. Blood samples for CRP levels were obtained before BB treatment, and at the 6th, 24th, and 36th h after PCI. RESULTS: Of 300 patients, 150 received metoprolol 100 mg/day (mean age, 59.0 +/- 10.2 years; 106 men, 44 women), and 150 received no BB (mean age, 59.8 +/- 9.8 years; 114 men, 36 women) and served as the control group. Baseline clinical characteristics of both groups were similar. Basal CRP levels between the two groups were similar. Of the patients included in the study, 40.8% in the BB group and 39.6% in the control group had elevated basal CRP levels. The CRP levels increased above baseline values in 85% of patients in the BB group and in 89.3% of patients in the control group (p > 0.05) during follow-up. The CRP levels in patients in the BB group at the 6th, 24th, and 36th h were lower than those in the control group; however, this difference did not reach statistical significance. CONCLUSIONS: Prior BB therapy seems to have no effect on CRP levels after PCI.

Adrenergic beta-Antagonists↗