Irfan Barutcu

Cigarette smoking and heart rate variability: dynamic influence of parasympathetic and sympathetic maneuvers.

Background: Cigarette smoking has been associated with increased activity of the sympathetic nervous system. In this study, we investigated cardiac autonomic function in heavy smokers and nonsmoker controls by analysis of heart rate variability (HRV).

Acute effect of cigarette smoking on heart rate variability

Acute cigarette smoking enhances adrenergic activity and thus may be associated with hemodynamic changes in the cardiovascular system. In this study, the acute effect of cigarette smoking on heart rate variability (HRV) was studied. Fifteen subjects were included in the study. Time domain (the mean R-R interval, the standard deviation of R-R interval, and the root mean square of successive R-R interval differences) and frequency domain (high-frequency, low-frequency ratio, and low-frequency/high-frequency ratio) parameters of HRV were obtained from all participants for each 5-minute segment: 5 minutes before and 5, 10, 15, 20, 25, and 30 minutes after smoking a cigarette. The mean R-R interval, the standard deviation of R-R interval, and the root mean square of successive R-R interval differences significantly decreased within the first 5-minute period compared with baseline, and then the standard deviation of R-R interval increased within the 20- to 30-minute period. The low-frequency high-frequency ratio significantly decreased within the first 5 minutes after smoking and then remained unchanged throughout the study period. Similarly, low-frequency and high-frequency power increased within the first 5 minutes compared with baseline. Acute cigarette smoking alters HRV parameters, particularly within the first 5 to 10 minutes after smoking.

Predictive value of noninvasively determined endothelial dysfunction for long-term cardiovascular events and restenosis in patients undergoing coronary stent implantation: a prospective study.

BackgroundEndothelial dysfunction plays a key role in atherosclerosis and predicts future cardiovascular events in individuals with or without coronary artery disease and improves with risk reduction therapy. We sought to determine the predictive value of endothelial dysfunction for long-term cardiovascular events and in-stent restenosis in patients undergoing percutaneous coronary intervention (PCI). MethodsUsing high-resolution ultrasound, we assessed endothelial function by using the brachial artery flow-mediated dilation (FMD) method in 135 patients with coronary artery disease before elective coronary stenting. Patients were prospectively followed up for an average of 12 months after PCI. ResultsThirty patients had an event during follow-up including cardiac death (four patients), myocardial infarction (nine patients), unstable angina/non-ST elevation myocardial infarction (15 patients), and stroke (two patients) and in-stent restenosis was determined in 16 of these patients. Endothelium-dependent FMD was significantly lower in patients who had an event compared with those without an event (4.7±1.9 vs. 6.0±2.0%, P=0.007), whereas endothelium-independent vasodilation to nitroglycerin was similar in both groups. FMD was the only predictor of cardiovascular events (P=0.03). Impaired endothelial function was associated with a significantly higher incidence of cardiovascular events and in-stent restenosis by Kaplan–Meier analysis. When a cutoff point of 7.5% was used, flow-mediated dilation had a sensitivity of 93%, specificity of 37%, and negative predictive value of 95% for cardiovascular events. ConclusionImpaired brachial artery FMD is associated with long-term cardiovascular events and in-stent restenosis in patients undergoing PCI. Noninvasive assessment of endothelial function may serve as a surrogate marker for the estimation of future cardiovascular event risk and long-term follow-up in these patients.

Impaired left ventricle filling in slow coronary flow phenomenon : An echo-doppler study

Slow coronary flow (SCF) in a normal-appearing coronary angiogram is a well-recognized clinical entity, but its etiopathogenesis remains unclear. The aim of the study was to evaluate echocardiographic features in patients with SCF. Thirty-four patients with angiographically proven SCF (group I) and 25 patients with normal coronary flow (group II) were enrolled in the study. The diagnosis of SCF was made with use of the “TIMI frame count (TFC)” method. All patients underwent complete transthoracic echocardiographic examination (M-mode, 2-dimensional [2-D], and Doppler parameters such as color, continuous, pulsed wave). There were no significant differences with respect to systolic parameters between the 2 groups; in spite of these, group I showed impaired left ventricular diastolic patterns compared to group II. Group I patients had higher peak late diastolic filling velocities due to enhanced atrial systole (A), lower peak (E/A) diastolic filling velocity ratios, and longer isovolumetric relaxation times compared with group II, and these were statistically significant (p<0.001). In conclusion; the authors detected diastolic filling abnormalities and showed diastolic dysfunction in patients with SCF.

Increased High Sensitive CRP Level and Its Significance in Pathogenesis of Slow Coronary Flow

Previous studies have suggested that microvascular abnormalities cause slow coronary flow (SCF). The role of inflammation has not been investigated, to date. The purpose of this study was to determine the role of inflammation in pathogenesis of SCF. The study included 32 patients with angiographically proven SCF (mean age 49 ±9 years) (group I) and 30 subjects with normal coronary flow (mean age 48 ±8 years) (group II). Blood samples were collected for high sensitive CRP (hs-CRP) measurements. Thrombolysis in myocardial infarction frame count (TFC) was compared in both groups. Distribution of sex, age, body mass index (BMI), arterial blood pressure, and ejection fraction were similar in the 2 groups. TFC was significantly higher in group I than in group II for each artery including left anterior descending coronary artery (LAD), left circumflex artery (Cx), and right coronary artery (RCA) (38.9 ±6.6 vs 22.1 ±1.8 frames, p = 0.0001; 39.6 ±4.9 vs 22.3 ±1.8 frames, p = 0.001 ; 39.0 ±3.8 vs 22.0 ±1.8 frames, p = 0.001, respectively). In group I, serum hs-CRP concentration was significantly higher than that of group II (0.6 ±0.58 vs 0.24 ±0.1 mg/dL p = 0.03). Correlation analysis showed a positive correlation between hs-CRP level and TFC for each artery (for CTFCLAD, r = 0.36 p = 0.004; for TFCCx, r = 0.42 p = 0.003; and for TFCRCA, r = 0.42, p = 0.0001 respectively). Increased hs-CRP level suggests that inflammation may be associated with pathogenesis of SCF or at least in part contributes to its pathogenesis. Increased hs-CRP level may also be an early marker of impaired coronary blood flow.

Uric Acid as a Marker of Oxidative Stress in Dilatation of the Ascending Aorta

BACKGROUND Increased serum uric acid (UA) has been shown to directly promote oxidative stress. Recent studies point toward a role for oxidative stress in the pathogenesis of ascending aortic aneurysms (AscAAs). This study was designed to examine the relationship between serum UA concentrations, total antioxidant reductive capacity, and AscAAs. METHODS The serum UA concentrations, total antioxidant reductive capacity were compared in 60 patients with ascending aortic dilatation (ectasia group (3.8-4.3 cm), 34 patients; aneurysmal group (≥4.4 cm), 26 patients) vs. 30 control subjects. The patients were evaluated by a complete transthoracic echocardiographic examination including measurement of the aortic dimensions. RESULTS The serum UA concentration and total antioxidant reductive capacity were significantly higher in patients with AscAAs. In multiple linear regression analysis, hypertension and serum UA concentration were significantly associated with aortic dilatation (β = 0.3, P = 0.03; β = 0.15, P < 0.001, respectively). CONCLUSIONS In conclusion, we found that serum UA concentration and total antioxidant capacity (TAC) were significantly associated with aortic dilatation. The higher serum UA concentration may be responsible for the elevated serum antioxidant capacity that was observed among individuals with AscAA. Large-scale epidemiological studies conducted over several years are required to correlate the cross-sectional findings from this study with clinical outcome.

Tissue Doppler Evaluation of Tricuspid Annulus for Estimation of Pulmonary Artery Pressure in Patients with COPD

Because transthoracic echocardiography is an inexpensive, easy, and reproducible method, it is the most commonly used noninvasive diagnostic tool to determine pulmonary artery pressure (PAP). Tissue Doppler imaging (TDI) emerged as a new echocardiographic method that can be applied in various clinical conditions. In our study we aimed to evaluate the relationship between tricuspid lateral annulus TDI parameters and pulmonary artery systolic pressure (PASP) as estimated by continuous wave Doppler in patients with chronic obstructive pulmonary disease (COPD). A total of 51 (42 men, mean age: 62.3 ± 8.2 years) patients with clinically stable COPD were included in the study. The tricuspid annular systolic myocardial velocity (Sm), velocity time integral of Sm (SmVTI), early (Em) and late (Am) peak diastolic myocardial velocities, and myocardial isovolumic relaxation time (IVRTm) were acquired as well as two-dimensional (2-D) and conventional Doppler data. When compared with values of patients without pulmonary hypertension (PHT), Sm, SmVTI, Em, and Em/Am values were found to be lower and IVRTm values higher in patients with PHT. When all the patients were analyzed, there was a significant negative correlation between PASP and Sm and SmVTI (r = −0.82, p < 0.001 and r = −0.84, p < 0.001, respectively). Sm velocity ≤ 12 cm/s had a sensitivity of 85% and a specificity of 93.3% for predicting PASP > 40 mmHg. SmVTI ≤ 2.5 cm had a sensitivity of 85.7% and a specificity of 90% for detecting PHT. In our study, there was significant negative correlation between tricuspid lateral annular Sm and SmVTI values and PASP in patients with stable COPD irrespective of the presence of PHT. Tricuspid annular Sm and SmVTI had very good level sensitivity and specificity for predicting PHT. In conclusion, it might be suggested that in cases where noninvasive PASP measurement is not possible, TDI can be used as an alternative and reliable method to assess PAP.

Comparison of direct stenting versus conventional stent implantation on blood flow in patients with ST-segment elevation myocardial infarction

As compared with balloon angioplasty, stent implantation in treatment of acute myocardial infarction (AMI) reduces abrupt vessel closure, restenosis, and reocclusion rate. However, a few studies have demonstrated the safety and feasibility of direct stenting compared to conventional stent implantation technique. This study was designed to compare possible advantages of direct stenting with conventional stent implantation on immediate coronary blood flow and short-term clinical benefits in patients with AMI. Fifty patients with AMI who underwent mechanical revascularization were eligible for the study. The patients were randomly assigned to undergo either direct stenting (n=25) or conventional stent implantation (n=25). Before and after the procedure thrombolysis in myocardial infarction (TIMI) flow and postprocedural corrected TIMI frame count (cTFC) of the infarct-related artery were measured. There was no difference in TIMI flow distribution at baseline between the 2 groups. TIMI 3 flow rate significantly increased after procedure in both groups compared to baseline (p<0.05). Postprocedural cTFC was found significantly lower in the direct stent arm compared to conventional stenting (p<0.001). Both during and after the procedure the complication rate and procedural time were lower in the direct stenting arm. Direct stenting provides better immediate coronary blood flow and is a safe and feasible method compared with conventional stenting in patients with AMI. Improvement in coronary blood flow measured by the corrected TIMI frame count method may suggests a significant reduction of microvascular injury.

Elevated Oxidative Stress Markers and its Relationship With Endothelial Dysfunction in Behçet Disease

Behçet’s disease (BD) is a multisystemic disorder characterized by endothelial dysfunction. However, the relationship between oxidative stress and endothelial function has not been clearly shown. We investigated the relationship between oxidative stress markers and endothelial function in patients with BD. Patients with BD (n = 40) having active disease and sex- and age-matched 40 controls were included. Endothelial function was assessed by flow-mediated dilatation (FMD) technique. Serum gamma-glutamyltransferase (GGT) and high-sensitive C-reactive protein levels (hsCRP) were measured in all participants. Brachial artery FMD was significantly lower in patients with BD than in controls. Gamma-glutamyltransferase and hsCRP levels were higher in patients with BD than in controls. Also, GGT and hsCRP levels were inversely correlated with endothelial function. Oxidative stress markers are elevated in patients with BD having active disease. This may be one of the reasons behind the vasculitis in active BD.

Effect of slow coronary flow on electrocardiographic parameters reflecting ventricular heterogeneity

QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have showed that QT interval dispersion changes during episodes of myocardial ischemia. Slow coronary flow (SCF) in epicardial coronary arteries is a rare and unique angiographic finding. Whether this pattern of flow is associated with electrocardiographic abnormalities is unknown. Therefore, this study was designed to investigate whether SCF results in electrocardiographic (ECG) changes compared to normal coronary flow. For this aim 24 patients with angiographically proven SCF who had no obstructive coronary lesion (group I) and 25 patients without coronary artery disease (group II) were included in the study. Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distributions of sex, age, body mass index (BMI), and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 ±8 vs 77 ± 7 p > 0.05). Mean QRS interval durations were similar in the groups (92 ±7 vs 90 ±6 ms p > 0.005). In group I, QTd, QTcd, and QTc, were significantly higher than in group II (QTd: 73 ±14 vs 40 ±14; QTcd: 71 ±15 vs 42 ±9; QTc: 414 ±14 vs 388 ±13, respectively p <0.05). In conclusion, SCF was found to be associated with prolonged QT interval and increased QT dispersion. Ischemia in microvascular level and/or altered autonomic regulation of the heart may be responsible mechanisms.