Browsing by Author "Guntekin, U."

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Comparison of Effects of Nebivolol and Atenolol on P-Wave Dispersion in Patients With Hypertension
(Russian Heart Failure Soc, 2008) Tuncer, M.; Fettser, D.; Gunes, Y.; Batyraliev, T. A.; Guntekin, U.; Gumrukcuoglu, H. A.; Sidorenko, B. A.
Background. P-wave dispersion has been shown to be a noninvasive electrocardiographic predictor for development of atrial fibrillation. Thus it may be possible to attenuate atrial fibrillation risk through normalization of P-wave variables and improvement in P-wave dispersion may be an important goal in treatment of hypertension. Objective. To compare the effects of nebivolol, a new P-blocker that have additional vasodilating activity via acting on endothelium and nitric oxide release, and atenolol on P-wave duration and dispersion in patients with mild-to-moderate hypertension. Methods. A total of 34 newly-diagnosed hypertensive patients were enrolled in the study. The patients were randomly assigned to receive treatment with either nebivolol (5 mg) or atenolol (50 mg). P-wave durations (Pmin and Pmax) and P-wave dispersion were measured before and one month after treatment. Results. While Pmin increased (50,6 +/- 11,2 ms to 54,7 +/- 9,1 ms, p=0,05), Pmax decreased (111,9 +/- 9,1 ms to 104,0 +/- 12,4 ms, p=0,003) and P-wave dispersion decreased (62,5 +/- 10,6 ms to 51,3 +/- 8,9 ms, p<0,001) with nebivolol, Pmin increased (44,4 +/- 9,8 ms to 58,0 +/- 15,5 ms, p=0,02), Pmax didn't change (106,1 +/- 13,8 ms to 107,0 +/- 11,6 ms, p=NS) and P-wave dispersion decreased (61,7 +/- 15,0 ms to 49,0 +/- 13,7 ms, p<0.001) with atenolol. However, there was no statistical difference between pre- and post-treatment values of two groups. Conclusions. Both nebivolol and atenolol are effective in improvement of P-wave dispersion in patients with hypertension and there's no significant difference between them.
P Wave Dispersion in Hypertensive Urgency
(Russian Heart Failure Soc, 2008) Tuncer, M.; Fettser, D.; Gunes, Y.; Batyraliev, T.; Guntekin, U.; Gumrukcuoglu, H. A.; Guler, N.
Background and purpose: P wave dispersion (PWD) has been accepted as a predictor for atrial fibrillation (AF) in hypertension and some other cardiac diseases. The aim of this study was to compare the P wave parameters between patients with mild-moderate hypertension and those with hypertensive crises. Methods: A total of 48 patients, 24 of who presented to the emergency department with hypertensive urgency and 24 patients who were followed in the cardiology clinic with mild-moderate essential hypertension were included in this study. P wave durations were measured manually by two investigators blinded to data of patients. Results: The maximal duration of P wave (P-max) and the PWD were found to be significantly different between groups, being longer in patients with hypertensive urgency (p=0,05 and 0,02; respectively). Conclusions: PWD increases in hypertensive urgency states. Clinical implication of this finding should be addressed with further, prospective studies conducted on larger samples.
P Wave Duration and Dispersion in Patients With Hyperthyroidism and the Short-Term Effects of Antithyroid Treatment
(2009) Guntekin, U.; Gunes, Y.; Simsek, H.; Tuncer, M.; Arslan, S.
Background: Prolonged P wave duration and P wave dispersion (PWD) have been associated with an increased risk for atrial fibrillation (AF). Hyperthytodism is a frequent cause of atrial fibrillation (AF). Methods: Forty-two patients with newly diagnosed overt hyperthyroidism and 20 healthy people were enrolled in the study. Transthoracic echocardiography, 12 lead surface ECG and thyroid hormone levels were studied at the time of enrollment and after achievement of euthyroid state with propylthiouracil treatment. Results: Maximum P wave duration (Pmax) (97.4±14.6 vs. 84.2±9.5 msec, p<0.001), PWD (42.9±10.7 vs. 31.0±6.2 msec, p<0.001), deceleration (DT) (190.7±22.6 vs. 177.0±10.2 msec, p=0.013) and isovolumetric relaxation times (IVRT) (90.9±11.2 vs. 79.6±10.5 msec, p<0.001) were significantly higher in hyperthyroid patients compared to control group. Pmax and PWD were significantly correlated with the presence of hyperthyroidism. Pmax (97.4±14.6 to 84.3±8.6 msec, p<0,001) Pmin (54.1±8.6 to 48.1±8.5 msec, p=0.002), PWD (42.9±10.7 to 35.9±8.1 msec, p=0.002) and DT (190.7±22.6 to 185.5±18.3, p=0.036) were significantly decreased after achievement of euthyroid state in patients with hyperthyroidism. Diastolic dyfunction was seen in 5 patients at hyperthroid state but only in one patient at euthyroid state. Conclusions: Hyperthyroidism is associated with prolonged P wave duration and dispersion. Achievement of euthyroid state with propylthiouracil treatment results in shortening of P wave variables. Diastolic function may have a partial effect for the increased Pmax and PWD. Shortening of Pmax and PWD may be a marker for the prevention of AF with the anti-thyroid treatment.
Regional Functions of the Left Ventricle in Patients With Coronary Slow Flow and the Effects of Nebivolol
(2009) Gunes, Y.; Tuncer, M.; Guntekin, U.; Ceylan, Y.; Sahin, M.; Simsek, H.
Background: Microvascular and endothelial dysfunction have been implicated for coronary slow flow (CSF). Nebivolol, besides its beta-receptor blocking activity, causes an endothelium-dependent vasodilatation through increased nitric oxide release. Methods: This study included 27 patients with CSF and 27 subjects with normal coronary arteries. Segmental functions of the left ventricle (LV) were assessed using myocardial tissue Doppler velocities before and 3 months after treatment with nebivolol 5 mg/day. Results: Compared with the control group, mitral deceleration time (DT) was significantly longer, and E/A ratio, systolic velocity of lateral mitral annulus (Sm) and regional myocardial peak systolic and early diastolic velocities (Vs, Vd) were significantly lower in patients with CSF. The reason for coronary angiography was typical angina in 21 (77.8%) and positive treadmill test in six (22.2%) CSF patients. There were significant correlations between presence of CSF in left anterior descending artery (LAD) with Sm (r =-0.404, p =0.002) and Vs in anterior (r =-0.531, p < 0.001 ) and lateral (r =-0.495, p < 0.001 ) segments and between presence of CSF in RCA and Vs in posterior segments (r =-0.501, p < 0.001). Treatment with nebivolol significantly decreased blood pressures (128.5±12.5/82.5±8.8 to 119.8± 12.6/76.4± 7.4 mmHg, p < 0.001), DT (252.3±53.6 to 222.0±41.0 ms, p < 0.001 ) and IVRT (115.7±19.9 to 103.3±17.0 ms, p <0.001), and increased exercise capacity (8.7±1.3 to 10.4±0.9 METs, p < 0.001), E/A ratio (0.87±0.26 to 1.08±0.23, p <0.001) and myocardial velocities (p < 0.001). All the patients were free of angina after treatment. Patients with CSF had impaired diastolic and regional LV functions. Conclusions: Nebivolol may therefore be useful in improving angina, exercise capacity and LV functions in patients with CSF. © 2009, SAGE Publications. All rights reserved.