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    Comparison of the effects of amlodipine and verapamil on autonomic activity in hypertensive patients
    (2004) Sahin I.; Kosar F.; Altunkan S.; Günaydin M.
    Background: Many studies have shown that autonomic activation is one of the major factors in the etiology of hypertension. Furthermore, sympathovagal imbalance may be responsible for arrhythmias and sudden cardiac death. The aim of the present study was to compare and to evaluate the effects of short-term therapy with amlodipine and verapamil on heart rate variability (HRV) in patients with essential hypertension. Methods: Forty patients with essential hypertension (11 men and 29 women, mean age 50.5±10.4 years) were included in the study. Patients with cardiac, metabolic, or any other systemic disease were excluded. Patients were randomized to receive either amlodipine (10 mg; n=20) or verapamil (240 mg; n=20). Patients underwent 24-h Holter monitoring assessment before treatment and after the 4-week treatment period. Standard deviation of normal RR intervals (SDNN), standard deviation of all 5-min mean normal RR intervals (SDANN), square root of the mean of the sum of the squares of differences between adjacent RR intervals (r-MSSD), and pNN50 (time domain variables) and TF, high-frequency power (HF), low-frequency power (LF), and sympathovagal balance (LF/HF; frequency domain variables) were analyzed before and after treatment. Results: Blood pressure (BP) was reduced to a similar degree, from 182/104 to 128/85 mmHg with verapamil and from 174/100 to 124/86 mmHg with amlodipine (verapamil p<0.001; amlodipine p<0.001). This study revealed that amlodipine had no significant effect on any of the time or frequency domain parameters. In contrast, in patients on verapamil, there were significant increases in all time domain parameters, and the LF/HF ratio was significantly decreased (p<0.05). Conclusions: These results suggest that verapamil may have additional positive effects on sympathico-parasympathetic control beyond lowering blood pressure compared with amlodipine, even after short-term treatment in hypertensive patients. © 2004 Elsevier B.V. All rights reserved.
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    Interdialytic weight gain and pulmonary membrane diffusing capacity in patients on hemodialysis
    (Springer Netherlands, 2004) Taskapan H.; Ulu R.; Gullu H.; Taskapan M.C.; Yıldırım Z.; Kosar F.; Sahin I.
    Background: Measurement of pulmonary diffusion capacity for carbon monoxide (DLCO) may be useful for assessing disease affecting the alveolar-capillary bed or the pulmonary vasculature. It was reported that hemodialysis (HD) therapy causes DLCO reduction via decrease of pulmonary capillary blood volume components. The aim of the study was to evaluate the effect of interdialytic weight gain on pulmonary function and especially DLCO. We further determined whether intravascular volume status, assessed by inferior vena cava diameter (IVCD) contributes to DLCO in patients on HD. Methods: Routine pulmonary function testing including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, forced mid-expiratory flow rate (FEF 25-75 ), DLCO IVCD index and other echocardiographic parameters were evaluated in 20 patients (mean age 48.6 ± 18.3 years, mean dialysis duration 17.4 ± 19.2 months) on chronic HD, 1 hour after HD and after an interdialytic period (1 hour before HD therapy). Single-breath DLCO measurements were corrected for hemoglobin concentration (cDLCO). Results: Routine pulmonary function tests (spirometry) showed no significant changes in FEV1, FVC and FEF 25-75 whereas a statistically significant fall in FEV/FVC was found. At the end of the interdialytic period a statistically significant increase in weight, IVCD index, left ventriculer diastolic diameter (LVDD), and diastolic blood pressure (DBP) were observed (P < 0.05). Using the single-breath DLCO, we found unchanged cDLCO at the end of the interdialytic period. There was no correlation of cDLCO with increases in weight, DBP, IVCD index, LVDD (P > 0.05). Conclusion: The accumulation of body water between dialyses has no significant influence on DLCO. © 2004 Kluwer Academic Publishers.
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    Partial dehiscence of mechanical aortic valve due to infective endocarditis
    (Asia Publishing Exchange Pte Ltd, 2003) Battaloglu B.; Erdil N.; Nisanoglu V.; Kosar F.
    [No abstract available]
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    Serum levels of selenium, zinc and copper in patients with coronary artery ectasia
    (2007) Kosar F.; Taskapan C.; Kucukbay Z.
    BACKGROUND: It is well established that the deficiency of trace elements may lead to oxidative stress in many tissues. Several studies have shown that the deficiency of trace elements may play a role in the pathogenesis of various heart diseases, including coronary artery disease. This study was designed to determine the serum levels of trace elements, such as selenium, zinc, and copper, in patients with isolated coronary artery ectasia and to confirm previously documented changes in the trace element status in coronary artery disease. It also investigated the relationship between the level of trace elements and the extent of ectatic involvement in patients of coronary artery ectasia. METHODS AND RESULTS: The serum selenium, zinc and copper levels were measured in 37 patients of coronary artery ectasia, 56 patients of coronary artery disease and 30 controls. The trace element levels were measured by atomic absorption photometry methods. The serum selenium (Se) and zinc (Zn) levels in both sets of patients were significantly lower than in the control group (Se: 127 ± 10 ?g/L and 126 ± 9 ?g/L vs. 147 ± 12 ?g/L, p < 0.001; Zn: 557 ± 11 ?g/L and 554 ± 13 ?g/L vs. 620 ± 13 ?g/L, p < 0.001). However, the serum copper (Cu) levels were similar in all patients and controls (964 ± 12 ?g/L and 973 ± 14 ?g/L vs. 956 ± 17 ?g/L, p > 0.05). CONCLUSION: These results suggest that coronary artery ectasia is associated with the deficiency of the trace elements selenium and zinc. Thus, these elements may play an important role in the pathogenesis of coronary artery ectasia, as well as in coronary artery disease.
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    Spirometric predictors for the exclusion of severe hypoxemia in chronic obstructive pulmonary disease
    (Hindawi Limited, 2001) Gunen H.; Kosar F.
    Background: Controversy has existed over the need for routine arterial blood gas (ABG) analysis in patients with chronic obstructive pulmonary disease (COPD). Some authors recommended it in all patients with COPD, but others find it unnecessary if the forced expiratory volume in 1 s (FEV1) is 50% of predicted or greater. Objectives: To clarify this controversy, and to investigate correlations between severe hypoxemia and multiple spirometric parameters in patients with COPD with FEV1 50% of predicted or greater. Patients and methods: In 103 consecutive patients with COPD with FEV1 50% of predicted or greater, and without any other cardiopulmonary disorder, the incidence of severe hypoxemia (partial pressure of arterial oxygen less than 60 mmHg) was established by ABG analysis. Positive and negative predictive values (PPVs and NPVs, respectively) for severe hypoxemia for multiple spirometric parameters (FEV1,FEV1/forced vital capacity [FVC], peak expiratory flow [PEF], maximal midexpiratory flow rate [FEF25-75]) were evaluated in a stepwise manner. Results: Twenty-two patients (21%) were found to be severely hypoxemic. In the severely hypoxemic group, the mean values for FEV1, FEV1/FVC, PEF and FEF25-75 were 59.0±8.19%, 53.6±11.3, 50.6±9.3 and 34.4±14.2% of predicted, respectively. The mean values for the same parameters in the other patients were 58.0±4.6%, 52.7±7.8, 51.5±7.5 and 39.1±7.7% of predicted, respectively. Comparing these parameters between the two groups, only the difference in FEF25-75 was statistically significant (P<0.01). Valid PPVs and NPVs could not be established for any of the parameters at any level, except for the NPV for FEF25-75 50% of predicted or greater, which was 92%. This threshold value resulted in a false negative finding in less than 5% of the patients with hypoxemia. Conclusions: The results of the present study showed that one in five patients with COPD with FEV1 50% of predicted or greater was severely hypoxemic. In such patients, hypoxemia may be excluded, and ABG analysis may not be needed when the FEF25-75 is also 50% of predicted or greater. The FEV1, FEV1/FVC and PEF parameters failed to predict or exclude severe hypoxemia.