Aziz Karabulut

The association between NT-proBNP levels, functional capacity and stage in patients with heart failure

Objective — Amino-terminal probrain natriuretic peptide (NT-proBNP), a biologically inactive derivative of BNP, is clinically more useful owing to its longer half-life, higher plasma concentrations, lesser variation among individuals, and higher in vitro stability. In this regard, NT-proBNP may be a better indicator of the severity of ventricular dysfunction. In this study, the association of NT-proBNP levels with functional capacity and stage of heart failure was explored in patients with CHF. Also, we particularly focused on the presence and significance of neurohormonal activation in the group of patients classified as stage-A according to ACC/AHA guidelines. Methods and results — 64 patients with CHF (31 men, 33 women; mean age 58.26 ± 10.59 y) and 36 healthy controls (24 men, 12 women; mean age 57.47 ± 10.83) were included in this study.The New York Heart Association (NYHA) classification system (I, II, III, IV) was used to define the functional capacity; and the stage of the heart failure was based on the ACC/AHA guidelines (A, B, C, D). Healthy female participants had higher NT-proBNP levels compared to their male counterparts (p < 0.001). Left ventricular ejection fraction (LVEF) did not correlate significantly with functional capacity and stage of the disease. CHF patients had higher NT-proBNP compared to controls (p < 0.001). There was a positive correlation between NT-proBNP and functional capacity in patients, and NT-proBNP increased significantly with each increasing class of the disease. Similarly, a positive correlation existed between the stage of heart failure and NT-proBNP levels, which increased significantly with increasing stages of the disease. Patients with NYHA I and stage A disease had higher NT-proBNP levels compared to controls (p = 0.04). Conclusions — The severity of CHF can be objectively assessed by measuring the circulating levels of NT-proBNP. Even in NYHA I and stage A disease, NT-proBNP levels are higher compared to controls (p = 0.04).NT-proBNP can provide objective information regarding the severity of the disease and also aid in treatment decisions in patients with CHF.

Electrocardiologic and echocardiographic features of patients exposed to scorpion bite

The purpose of this study is to examine clinical progress and hemodynamic and electrocardi ologic features (QT depression and heart rate variability [HRV]) of patients exposed to a scorpion bite. Seventeen patients bitten by scorpions, and, as a control group, 15 healthy subjects were included in the study. Standard electrocardiograph (ECG) records, 24-hour Holter-ECG, and Doppler echocardiographic examinations were performed. Holter ECG indicated sinus tachycardia, sinus bradycardia, paroxysmal supraventricular tachycardia, atrial fibrillation, first-degree and second-degree atrioventricular block not requiring treatment, early atrial beats, and early ventricular beats in the patients at frequen cies of 82%, 12%, 35%, 12%, 8%, 70%, and 47%, respectively. HRV parameters that reflected parasympathetic activity (SD 35 ±13-43 ±16, RMS-SD: 20 ±9-30 ± 12, high frequency: 7.8 ±2-4.3 ±3, p<0.05) were significantly lower (p<0.05). Low frequency, which especially showed sympathetic activity (LF: 11 ± 13-11 ±23, p>0.05), was similar in both groups. In addition, the LF/HF ratio, which reflected sympathovagal balance, was significantly increased in the patient group (1.5 ±1-3.0 ±2, p = 0.005). Corrected QT and QT dispersion values were not significantly different with respect to the control (p>0.05). In the patient group compared to the control, a significant decrease was determined in the proportion of mitral E velocity to mitral A velocity (mEv/mAv), diastolic filling period (DFP), and left ventricular ejection fraction (LVEF), while a significant increase was noticed in pulmonary artery pressure (PAP) (mEv/mAv: 0.9 ±0.4-1.7 ±0.6, DFP: 362 ±8.5-425 ±89, LVEF: 53.1 ±6.7-68.6 ±5.8, PAP: 38.1 ±13-27.2 ±6, p<0.05). Scorpion bite leads to serious cardiovascular disorders, associated with decreased HRV, decreased systolic and diastolic functions, increased arrhythmic events, and hemodynamic disturbance with sympathetic and parasympathetic balance disturbance.

Contribution of the peak exercise QT dispersion to the accuracy of an exercise test during the evaluation of coronary artery disease.

OBJECTIVE Regional defects in ventricle repolarization are extremely sensitive to ischaemia which can be measured as QT dispersion (QTd). We investigated the role of QTd calculated at the time of peak exercise during treadmill studies. METHODS AND RESULTS Thirty-three women and eighty men, whose treadmill test results and coronary angiography studies had been examined, were divided into four groups according to the test results: 1) subjects with a negative treadmill test and without significant stenosis results in the angiography, were considered normal (N; n = 35); 2) subjects with both a positive exercise test and a significant presence of stenotic coronary arteries, were considered true positive (TP; n = 52); 3) subjects with a positive exercise test, but without significant stenosis results in the angiography, were considered false positive (FP; n = 14); 4) subjects with a negative treadmill study, despite significantly stenotic arteries, were considered false negative (FN; n = 12). All subjects were evaluated on the basis of age, significant ST-segment depression, peak heart rate, rest and peak exercise QT, and QpT (measured from the beginning of the QRS complex to the highest point of the T wave) dispersion, and corrected (QTcd, QpTcd) values for heart rate. The most significant differences were observed between the N and the TP groups in terms of QTd and QTcd (p < 0.01), with a higher correlation (r = 0.48). A significant relationship was also observed in terms of QpT and QpTcd values during peak exercise (p < 0.01). The sensitivity of the peak exercise QTcd and QTcd > or = 70 ms in determining coronary artery disease was found to be 74%. In cases of QTcd > or = 70 ms, in addition to ST-segment depression, the test was found to be less sensitive, but more specific at 96%. CONCLUSION It suggests that when peak exercise QTd and QpTd values are taken into account, with the exception of the ST-segment depression, the accuracy of the exercise test will increase and false positive results will decrease.

The Relationship of Fluid Overload as Assessed by Bioelectrical Impedance Analysis with Pulmonary Arterial Hypertension in Hemodialysis Patients

Background Pulmonary arterial hypertension (PAH) is common disease among hemodialysis (HD) patients and is associated with increased morbidity and mortality. However, its pathogenesis has not been completely elucidated. We aimed to evaluate the frequency of PAH in HD patients, as well as the relationship between fluid status and PAH. Material/Methods We enrolled 77 HD patients in this study. Multifrequency bioimpedance analysis (BIA) was used to assess fluid status. BIA was performed before and 30 min after the midweek of HD. Overhydration (OH)/extracellular water (ECW)% ratio was used as an indicator of fluid status. Fluid overload was defined as OH/ECW ≥7%. Echocardiographic examinations were performed before and after the HD. Pulmonary arterial hypertension was defined as systolic pulmonary artery pressure at rest (sPAP) higher than 35 mmHg. Results PAH was found in 33.7% of the HD patients. OH/ECW and the frequency of fluid overload were significantly higher in HD patients with PAH than those without PAH, whereas serum albumin and hemoglobin levels were significantly lower. sPAP level was significantly higher in HD patients with fluid overload than in those without fluid overload after hemodialysis session. Furthermore, sPAP, OH/ECW levels, and the frequency of PAH were significantly reduced after HD. We also found a significant positive correlation between sPAP and OH/ECW. Multivariate logistic regression analysis demonstrated fluid overload to be an independent predictor of PAH after HD. Conclusions PAH is prevalent among HD patients. This study demonstrated a strong relationship between fluid overload and PAH in HD patients.

Myocardial Performance Index for Patients with Overt and Subclinical Hypothyroidism

Background Hypothyroid has several effects on the cardiovascular system. Global myocardial performance index (MPI) is used in assessment of both left ventricular (LV) systolic and diastolic function. We compared MPI in hypothyroidism patients vs. normal control subjects. Material/Methods Eighty-two hypothyroid patients were divided into 2 groups: a subclinical hypothyroid (SH) group (n=50), and an overt hypothyroid (OH) group (n=32). The healthy control group (CG) constituted of 37 patients. TSH, FT3, and FT4, anti-TPO, anti-TG, insulin, lipid values, and fasting glucose levels were studied. All patients underwent an echocardiographic examination. Myocardial performance indexes were assessed and standard echocardiographic examinations were investigated. Results MPI averages in OH, SH, and control groups were 0.53±0.06, 0.51±0.05, and 0.44±0.75 mm, respectively. MPI was increased in the OH and SH groups in comparison to CG (p<0.001, p<0.001, respectively). Conclusions MPI value was significantly higher in hypothyroid patients in comparison to the control group, showing that regression in global left ventricular functions is an important echocardiographic finding. Future studies are required to determine the effects of this finding on long-term cardiovascular outcomes.