Yasin Karakus

Subclinical left ventricular dysfunction in Behcet's disease assessed by two-dimensional speckle tracking echocardiography

AIMS The aim of this study was to evaluate the left ventricular (LV) systolic strain by speckle tracking echocardiography (STE) in order to provide the early detection of myocardial dysfunction in patients with Behcets disease (BD). We also aimed to examine the relationship between LV systolic strain and N-terminal pro-B type natriuretic peptide (NT-proBNP), which is a cardiac biomarker of ventricular dysfunction. METHODS AND RESULTS Longitudinal and circumferential systolic strain assessed by STE was obtained in 32 BD patients and 27 age-matched controls. NT-proBNP levels were also measured in all subjects. Regional and mean longitudinal strain (-17.8 ± 2.7 vs. -20.5 ± 1.8%; P < 0.0001) was significantly lower in BD patients when compared with the healthy controls. Whereas regional and mean circumferential strain values (-22.0 ± 1.6 vs. -22.2 ± 2.3%; P = 0.62) did not reveal a significant difference between the patients and the controls. NT-proBNP was significantly higher in the patients than in the controls (65.18 ± 84.51 vs. 30.84 ± 14.75 pg/mL; P = 0.003). Linear regression analyses revealed only NT-proBNP as the independent correlate of mean LV longitudinal strain (R = 0.603, P = 0.001). CONCLUSION Longitudinal myocardial systolic function assessed by STE, which is a sensitive marker of subclinical ventricular dysfunction is impaired in BD. Increased NT-proBNP levels may be a sign of subclinical ventricular dysfunction in these patients.

Assessment of atrial electromechanical delay by tissue Doppler echocardiography in obese subjects.

Our aim was to evaluate whether atrial electromechanical delay measured by tissue Doppler imaging (TDI), which is an early predictor of atrial fibrillation (AF) development, is prolonged in obese subjects. A total of 40 obese and 40 normal‐weight subjects with normal coronary angiograms were included in this study. P‐wave dispersion (PWD) was calculated on the 12‐lead electrocardiogram (ECG). Systolic and diastolic left ventricular (LV) functions, inter‐ and intra‐atrial electromechanical delay were measured by TDI and conventional echocardiography. Inter‐ and intra‐atrial electromechanical delay were significantly longer in the obese subjects compared with the controls (44.08 ± 10.06 vs. 19.35 ± 5.94 ms and 23.63 ± 6.41 vs. 5.13 ± 2.67 ms, P < 0.0001 for both, respectively). PWD was higher in obese subjects (53.40 ± 5.49 vs. 35.95 ± 5.93 ms, P < 0.0001). Left atrial (LA) diameter, LA volume index and LV diastolic parameters were significantly different between the groups. Interatrial electromechanical delay was correlated with PWD (r = 0.409, P = 0.009), high‐sensitivity C‐reactive protein (hsCRP) levels (r = 0.588, P < 0.0001). Interatrial electromechanical delay was positively correlated with LA diameter, LA volume index, and LV diastolic function parameters consisting of mitral early wave (E) deceleration time (DT) and isovolumetric relaxation time (IVRT; r = 0.323, P = 0.042; r = 0.387, P = 0.014; r = 0.339, P = 0.033; r = 0.325, P = 0.041; respectively) and, negatively correlated with mitral early (E) to late (A) wave ratio (E/A) (r = −0.380, P = 0.016) and myocardial early‐to‐late diastolic wave ratio (Em/Am) (r = −0.326, P = 0.040). This study showed that atrial electromechanical delay is prolonged in obese subjects. Prolonged atrial electromechanical delay is due to provoked low‐grade inflammation as well as LA enlargement and early LV diastolic dysfunction in obese subjects.

Ivabradine Improves Heart Rate Variability in Patients with Nonischemic Dilated Cardiomyopathy

Background Ivabradine is a novel specific heart rate (HR)-lowering agent that improves event-free survival in patients with heart failure (HF). Objectives We aimed to evaluate the effect of ivabradine on time domain indices of heart rate variability (HRV) in patients with HF. Methods Forty-eight patients with compensated HF of nonischemic origin were included. Ivabradine treatment was initiated according to the latest HF guidelines. For HRV analysis, 24-h Holter recording was obtained from each patient before and after 8 weeks of treatment with ivabradine. Results The mean RR interval, standard deviation of all normal to normal RR intervals (SDNN), the standard deviation of 5-min mean RR intervals (SDANN), the mean of the standard deviation of all normal-to-normal RR intervals for all 5-min segments (SDNN index), the percentage of successive normal RR intervals exceeding 50 ms (pNN50), and the square root of the mean of the squares of the differences between successive normal to normal RR intervals (RMSSD) were low at baseline before treatment with ivabradine. After 8 weeks of treatment with ivabradine, the mean HR (83.6 ± 8.0 and 64.6 ± 5.8, p < 0.0001), mean RR interval (713 ± 74 and 943 ± 101 ms, p < 0.0001), SDNN (56.2 ± 15.7 and 87.9 ± 19.4 ms, p < 0.0001), SDANN (49.5 ± 14.7 and 76.4 ± 19.5 ms, p < 0.0001), SDNN index (24.7 ± 8.8 and 38.3 ± 13.1 ms, p < 0.0001), pNN50 (2.4 ± 1.6 and 3.2 ± 2.2 %, p < 0.0001), and RMSSD (13.5 ± 4.6 and 17.8 ± 5.4 ms, p < 0.0001) substantially improved, which sustained during both when awake and while asleep. Conclusion Our findings suggest that treatment with ivabradine improves HRV in nonischemic patients with HF.

Uric acid level and its association with carotid intima-media thickness in patients with cardiac syndrome X.

Objective: The aim of our study was to evaluate serum uric acid level and its relationship with carotid intima-media thickness (CIMT) in patients with cardiac syndrome X (CSX). Subjects and Methods: A total of 50 patients with CSX (28 females/22 males, 51.0 ± 10.9 years) and 40 controls (27 females/13 males, 53.0 ± 10.2 years) were included in the study. All subjects underwent a noninvasive stress test and conventional coronary angiography. Serum uric acid levels were measured and B mode ultrasonography was performed to assess CIMT in all subjects. Results: Serum uric acid levels were higher in patients with CSX than in the control subjects (5.1 ± 1.8 vs. 3.9 ± 1.3 mg/dl; p = 0.002). The CIMT was higher in patients with CSX than in the control subjects (0.75 ± 0.18 vs. 0.63 ± 0.09 mm; p < 0.001). A significant correlation was found between serum uric acid values and CIMT measurements in patients with CSX (r = 0.666, p < 0.001). Conclusions: Serum uric acid levels were higher in patients with CSX and elevated serum uric acid levels were associated with carotid atherosclerosis, thereby indicating that elevated serum uric acid levels might contribute to the development of subclinical atherosclerosis in CSX patients.

Endothelial nitric oxide synthase levels and their response to exercise in patients with slow coronary flow

Summary Background Endothelial dysfunction plays a key role in the aetiopathogenesis of slow coronary flow (SCF) even if there is no obstructive epicardial lesion. Reduced plasma levels of endothelial nitric oxide synthase (eNOS) are an important indicator of endothelial dysfunction. We aimed to determine plasma levels of eNOS and their relationship with exercise in patients with SCF. Methods Twenty-two patients with SCF in at least one coronary artery and 17 healthy individuals were included in this study. The TIMI frame count method was used to determine SCF. Plasma levels of eNOS before and after effort were determined in the patient and control groups. Results Basal eNOS levels in the patient group were lower than in the control group (p = 0.040), and plasma eNOS levels after exercise decreased more significantly in the patient group compared to the control group (p = 0.002). Median decreases of eNOS in response to exercise were higher in the SCF group than in the control group (p < 0.001), and the decrease observed in the control group was not statistically significant (p = 0.35). There were significantly negative correlations between TIMI frame count and plasma levels of eNOS at baseline and after exercise (r = –0.51, p = 0.015, r = –0.58, p = 0.005, respectively). Moreover, there was also a positive correlation between the rate–pressure product and plasma levels of eNOS after exercise in patients with SCF (r = 0.494, p = 0.019). Conclusion Our findings indicate an important pathophysiological relationship between the severity of SCF in which endothelial dysfunction plays a role in its pathogenesis and the level of circulating plasma levels of eNOS.

Assessment of atrial conduction time by tissue Doppler echocardiography and P-wave dispersion in smokers.

IntroductionThe aim of this study was to evaluate the relationship between cigarette smoking and atrial rhythm disorders with the use of noninvasive methods.MethodsThe study population consisted of 50 healthy volunteer smokers and 40 healthy volunteer non-smokers who had normal echocardiographic parameters and similar sex and age profiles. P-wave dispersion (PWD) was calculated from the 12-lead surface ECG. Left ventricle (LV) end-systolic and end-diastolic diameters, LV ejection fraction, and interatrial and intraatrial electromechanical delay were measured by tissue Doppler imaging and conventional echocardiography.ResultsIsovolumetric relaxation time and deceleration time were significantly higher (91.5 ± 11 vs. 82.35 ± 8.6, p < 0.0001; 215.7 ± 37.1 vs. 175.3 ± 17.7, p < 0.0001, respectively), and HDL cholesterol was significantly lower in smokers (39.34 ± 7.5 vs.44.3 ± 8.07, p = 0.003). There were no significant differences between the groups with respect to Sm and Em values, Am value, and E/A and E/Em ratios. However, the Em/Am ratio was significantly lower in smokers (1.28 ± 0.21 vs. 1.44 ± 0.33, p < 0.006). Inter- and intraatrial electromechanical delay were significantly higher in smokers when compared with non-smokers (51.11 ± 1.54 vs. 27.30 ± 3.36, p < 0.0001, and 30.63 ± 3.2 vs. 12.24 ± 3.26, p < 0.0001, respectively). The amount of smoking was strongly correlated with interatrial electromechanical delay (r = 0.567, p < 0.0001), and a significant correlation was detected between PWD and interatrial electromechanical delay (r = 0.653, p = 0.001).ConclusionWe have demonstrated the relationship between inter- and intraatrial electromechanical delay and PWD. These parameters may be useful predictive markers for the development of AF in the asymptomatic period before cardiac rhythm disturbances occur. This finding may indicate that smokers have an increased risk of developing atrial rhythm disturbances.

Assessment of the left ventricular systolic function in cardiac syndrome X using speckle tracking echocardiography.

Objective: The aim of this study was to evaluate left ventricular (LV) systolic strain by speckle tracking echocardiography (STE) and real-time three-dimensional echocardiography (3-DE) for the early detection of myocardial dysfunction in patients with cardiac syndrome X (CSX). Methods: We compared 34 patients with CSX (18 females, mean age 47.9±10.0 years) with 41 healthy persons as a control group (23 females, mean age 50.6±9.9 years). Inclusion criteria for CSX were typical angina, a positive exercise ECG stress test, and angiographically documented normal coronary arteries. Exclusion criteria for both groups were hypertension, valvular heart disease, cardiomyopathies, inflammatory diseases, myocarditis, vasculitis, arthropathies, Tietzes syndrome, gastrointestinal diseases, aortic diseases, hormone replacement therapy, arrhythmias, liver diseases, and alcohol use. All subjects underwent two-dimensional STE and 3-DE to assess resting LV function. STE measures were taken from the basal septum, mid-septum, apical septum, apex, apicolateral, mid-lateral, basal lateral, anteroseptal, anterior, anterolateral, inferolateral, inferior, and inferoseptal walls. Students t-test, Mann–Whitney U test, and chi-square test were used to statistically analyze data. Results: LV echo ejection fraction (EF) and systolic wave peak velocity were similar for both groups. Regional mean longitudinal strain (-17.7±2.5% vs. -19.8±1.8%; p<0.0001) was significantly lower in patients with CSX than in healthy control patients. However, regional mean circumferential strain values (-22.0±1.6% vs. -22.2±2.3%; p=0.78) did not differ significantly between the two groups. Conclusion: Significant impairment of LV longitudinal myocardial systolic function was detected with STE in patients with CSX, although normal 3-D EF and tissue Doppler imaging systolic parameters were observed. Arteriosclerosis of small coronary arteries and microvascular dysfunction may affect myocardial longitudinal strain.

The unnormalized spectral indices of heart rate variability should be presented in conjunction with normalized versions of the same variables.

To the Editor In their article, Vlahandonis et al. [1] investigated the long-term effects of pediatric sleep-disordered breathing (SDB) which either resolved or remained unresolved on spectral indices of heart rate variability (HRV). The authors found that control, resolved, and unresolved groups all exhibited a significant reduction in total power (TP), low-frequency (LF) power, and high-frequency (HF) power, as well as an increase in LF/HF ratio from baseline to the follow-up period of 4 years. They concluded that spectral HRV did not differ between controls, resolved, and unresolved SDB groups after the follow-up period [1]. HRV indices frequently are used in sleep research studies to quantify modulation of the sympathetic and parasympathetic branches of the autonomic nervous system [2,3]. Parameters of frequency domain HRV such as LF and HF power components usually are measured in absolute values of power (ms). LF and HF also can be measured in normalized units, which show the relative value of each power component in comparison to the TP. The appearance of LF and HF powers in normalized units highlights controlled and balanced behavior of the two branches of the autonomic nervous system. Furthermore, the normalization seems to decrease the effects of the changes in TP on the values of LF and HF power. Nonetheless, it will be appropriate and useful to display normalized units together with their unnormalized versions of the same variables to identify the complete distribution of power in spectral components [4].