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Dive into the research topics where Osman Akdemir is active.

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Featured researches published by Osman Akdemir.


European Journal of Heart Failure | 2002

Echocardiographic prediction of long-term response to biventricular pacemaker in severe heart failure

Enis Oguz; Bahadir Dagdeviren; Tuba Bilsel; Osman Akdemir; İzzet Erdinler; Ahmet Akyol; Tanju Ulufer; Tuna Tezel; Kadir Gürkan

Biventricular pacing substantially improves LV systolic function and symptom status in some patients with dilated cardiomyopathy.


International Journal of Cardiology | 2002

An interesting diagnostic dilemma: double right coronary artery or high take off of a large right ventricular branch.

Armagan Altun; Osman Akdemir; Okan Erdogan; Gültaç Özbay

We would like to present and discuss the dilemma of an unusual right coronary artery anomaly in two cases. Double right coronary artery or a high take off of a large right ventricular branch are two diagnostic possibilities that may provide difficulty in differentiating such an unusual orientation of coronary arteries based on angiographic views.


International Journal of Cardiology | 2001

The effects of trimetazidine on heart rate variability and signal-averaged electrocardiography in early period of acute myocardial infarction

Mehmet Sıddık Ülgen; Osman Akdemir; Nizamettin Toprak

BACKGROUND Acute myocardial infarction (AMI) is accompanied by electrophysiological changes in cardiovascular system as well as those in autonomic cardiac control. Heart rate variability (HRV) is depressed due to increased sympathetic activity and/or decreased parasympathetic activity following AMI. Moreover, the frequency of ventricular late potentials (VLP) is increased due to the electrophysiological changes. Based on the hypothesis that the treatments increasing HRV and decreasing the frequency of VLP can improve the prognosis of AMI, we investigated the short-term effects of trimetazidine (TMZ) on HRV and VLP in patients with AMI. METHODS The study group consisted of 64 patients (men 49, mean age 55+/-12 years, range 26-70) suffering from first Q-wave AMI. Thirty-one of them were treated with conventional therapy (thrombolytic therapy, aspirin, beta-blocker, heparin and intravenous nitroglycerin) plus TMZ 20 mg tid. The remaining 33 patients served as controls. Holter monitorization between 24 and 48 h, echocardiography at average day 6 (range 4-7 days) and SAECG and sub-maximal exercise at average day 7 (range 6-9 days) were performed to all patients. RESULTS While HRV parameters reflecting parasympathetic activity (SDSD: 43+/-16 ms-35+/-13 ms, RMSSD: 34+/-14 ms-27+/-8 ms, HF: 7.8+/-5 ms(2) -4.3+/-4 ms(2), P<0.05) were of significantly higher levels in TMZ group, the low frequency component mainly reflecting sympathetic activity (LF: 10+/-6 ms(2)-10+/-5 ms(2), P>0.05) was similar in both groups. In addition, LF/HF ratio showing sympatho-vagal balance was significantly decreased in TMZ group (1.5-3.0, P=0.005). About VLP, the mean FQRS (105+/-8 ms-107+/-10 ms), LAS (28+/-10 ms-30+/-11 ms) and RMS-40 (34+/-15 microV-41+/-12 microV) were not different in both two groups (P>0.05). CONCLUSION Our results suggest that TMZ treatment causes changes in sympatho-vagal balance in favor of vagal activity by increasing parasympathetic activity in AMI at early period; however, no effect on VLP was observed.


Clinical and Applied Thrombosis-Hemostasis | 2006

Hypercoagulopathy in Stroke Patients with Nonvalvular Atrial Fibrillation: Hematologic and Cardiologic Investigations

Nilda Turgut; Osman Akdemir; Burhan Turgut; Muzaffer Demir; Galip Ekuklu; Özden Vural; Gültaç Özbay; Ufuk Utku

The coagulation system is activated and coagulation activation markers are elevated in acute ischemic stroke with nonvalvular atrial fibrillation (NVAF). The etiology, severity, and prognosis of the ischemic stroke might be estimated with the level of the activation of the coagulation system. In this study, prothrombin F1+2 (F1+2), D-dimer, and fibrinogen levels were measured in patients with acute ischemic stroke with and without NVAF, and stroke severity was compared with these hemostatic parameters. Of 55 patients, 29 had sinus rhythm (group I), 26 had NVAF (group II); 20 healthy subjects (group III) were included in the study. Subtypes of cerebral infarction were classified. The patients underwent stroke severity, electrocardiography, echocardiography, cranial computed tomography, cervical duplex ultrasonography, and hemostatic parameter studies. In group II, F1+2 level (2.83±0.89) was significantly higher than in group I (2.33±0.80) and III (1.94±0.64) (p values: group I-II, 0.036; groups II-III, 0.001; groups I-III, 0.104). In group III, fibrinogen level (251.64±60.96) was significantly lower than that in groups I (347.97±111.49) and II (364.04±86.20) (p=0.001). D-dimer was not significantly different between groups. In group I, lacunar syndrome (LACS), and in group II, partial and total anterior circulation syndrome (PACS+TACS) were more common (p=0.013, p=0.001, respectively). In group II, Scandinavian Stroke Scale scores were lower than those in group I (group I=45.2±14, group II=35.4±18.9, p=0.02). In conclusion, activation of coagulation, demonstrated by increment F1+2, is more abundant in the stroke patients with NVAF than in the stroke patients with sinus rhythm. Our results also showed that activation of the hemostatic system might be related to stroke subtype and stroke severity. It is suggested that the oral anticoagulation treatment as prophylaxis is important in the prevention of stroke in patients with NVAF.


Cardiology in The Young | 2009

Assessment of the effects of physiological release of melatonin on arterial distensibility and blood pressure.

Mustafa Yıldız; Osman Akdemir

AIM The aim of our study was to investigate the effects of endogenous melatonin on arterial distensibility using measurements of the velocity of the aortic pulse wave between the carotid and femoral arteries in healthy young students assessed in the supine position. MATERIAL AND METHODS We studied 29 healthy young students, aged between 18 and 27 years, with 19 being male. The measured the velocity of the aortic pulse wave between the carotid and femoral arteries, along the blood pressures and heart rate, while the subjects were in the supine position at two time points, namely from 01.30-02.30 and 13:30-14:30 hours, during a day, also taking plasma to measure the concentrations of melatonin. The velocity of the pulse waves was determined using an automatic device, the Complior Colson (France), which allowed on-line recording and automatic calculation of the velocity, the calculations being made by measuring the transit time of the pulse wave as it traversed the distance between two sites of recording according, the velocity of the pulse wave in meter per second being equal to the distance in meters divided by the time of transit in seconds. RESULTS Although the velocity of the pulse wave, systolic, diastolic, and mean blood pressures, and heart rate were all increased in the morning relative to measurement made later in the day, levels of melatonin in the plasma were increased in the night. There was negative correlation between diurnal levels of melatonin and the velocity of the pulse wave. CONCLUSION Our findings indicate that increased levels of melatonin during the night may cause a decreased velocity of the aortic pulse wave, along with blood pressures and heart rate.


Angiology | 2002

Left ventricular pacemaker lead insertion through the foramen ovale--a case report.

Armagan Altun; Osman Akdemir; Okan Erdogan; Özgür Aslan; Gültaç Özbay

This report describes a patient with a 6-year-old pacemaker lead in the left ventricle. Both transthoracic and transesophageal echocardiography unequivocally showed that the lead enters the left ventricle via the foramen ovale and the mitral valve. The patient did not suffer from a thromboembolic event; therefore, we did not proceed with extraction. The importance of this case report is to emphasize the conditions and precautions of proper pacemaker implantation.


Acta Cardiologica | 2002

Right ventricular function in patients with acute anterior myocardial infarction: tissue Doppler echocardiographic approach.

Osman Akdemir; Mustafa Yildiz; Hüseyin Sürücü; Bahadir Dagdeviren; Okan Erdogan; Gültaç Özbay

Objective — Our purpose was to investigate the right ventricular (RV) performance of patients with a first acute anterior myocardial infarction (AAMI) by using pulsed wave Doppler tissue (PWDT) samplings of tricuspid annulus and RV free wall. Methods and results — The study group included 31 patients with AAMI and 20 age-matched controls. Conventional indexes of RV functions were the magnitude of tricuspid annular plane systolic excursion (TAPSE), and the transpulmonary and transtricuspid Doppler parameters. PWDT velocities were obtained by placing the sample volume at the lateral tricuspid annulus and the mid-segment of RV free wall; the peak systolic (S), early (E) and late (A) diastolic PWDT velocities and time intervals from ECG-Q wave to their peaks were analysed. Standard indexes were comparable except TAPSE that was significantly lower in AAMI-patients (p < 0.001). S velocities were similar; A of both regions (p = 0.018 and 0.012) and E of RV free wall (p = 0.011) were significantly increased in AAMI-group. Q-Sa intervals in both regions (p = 0.007 and 0.015) and Q-Ea of tricuspid annulus (p = 0.045) were significantly shorter in patients with AAMI.TAPSE and E of RV free wall had significant negative correlations with left ventricular systolic volume index and right atrial filling fraction (AFF), respectively (r = -0.46, p = 0.01 for both). A of tricuspid annulus had a positive correlation with left AFF (r = 0.42, p = 0.02). Conclusion — PWDT imaging of tricuspid annulus and RV free wall is capable to sensitively detect the adaptive mechanisms and unfavourable diastolic properties of RV dynamics in patients with AAMI.


Coronary Artery Disease | 2001

The effect of glucose-insulin-potassium solution on ventricular late potentials and heart rate variability in acute myocardial infarction.

Mehmet Sıddık Ülgen; Sait Alan; Osman Akdemir; Nizamettin Toprak

BackgroundBlunted heart rate variability (HRV) and presence of ventricular late potentials (VLPs) are known to correlate with an increased risk of ventricular tachycardia and sudden cardiac death in acute myocardial infarction (AMI). In the present study, we investigated the effect of glucose–insulin–potassium (GIK) solution on the VLPs and HRV in AMI. MethodsSeventy‐two consecutive patients with first Q wave AMI were randomized to GIK solution and placebo. HRV analysis and ambulatory electrocardiographic recordings were taken in all patients between 24 and 48 h. Sub‐maximal exercise testing and echocardiography were performed and signal‐averaged electrocardiography (SAECG) was recorded before discharge. ResultsTotal filtered QRS duration (FQRS: 102 ± 7 versus 108 ± 11 ms;P  < 0.05), low‐amplitude signal (LAS: 25 ± 8  versus 32 ± 11 ms;P  < 0.01) and frequency of VLPs (21 versus 45%;P  < 0.05) were found to be significantly lower while root‐mean‐square voltage of the terminal 40 ms of QRS (RMS‐40: 45 ± 18  versus 36 ± 20 μV;P  < 0.05), and left ventricular ejection fraction (EF: 55 ± 6 versus 48 ± 7;P  < 0.05) were significantly higher in the GIK group when compared to placebo. During the hospital period, the presence and frequency of post‐myocardial infarction angina were significantly lower in the GIK group (15 versus 29%, P  < 0.05), whereas an insignificant decrease in frequency of ventricular arrhythmias was observed in these patients. On HRV analysis, there was no significant difference between two groups in either time domain (SD, SDNN, RMS‐SD) or frequency domain (HF, LF, LF/HF ratio) parameters. ConclusionGIK solution may be beneficial to VLPs, ischaemic events, and left ventricular systolic performance in the early period of AMI. This therapy has no significant effect on HRV in AMI patients.


European Journal of Heart Failure | 2002

Prognostic implication of myocardial texture analysis in idiopathic dilated cardiomyopathy.

Bahadir Dagdeviren; Osman Akdemir; Mehmet Eren; Osman Bolca; Enis Oguz; Yekta Gurlertop; Tuna Tezel

Abnormal myocardial acoustic properties have been reported in patients with idiopathic dilated cardiomyopathy (IDC). The aim of this study was to investigate the relationship between quantitative ultrasonic textural alterations of myocardium and clinical outcome in IDC.


Acta Cardiologica | 2001

Right ventricular aneurysm complicating right ventricular infarction.

Osman Akdemir; Çetin Gül; Gültaç Özbay

Right ventricular (RV) involvement commonly occurs in patients with acute inferior myocardial infarction and is associated with high mortality and morbidity. RV dysfunction and dilatation commonly recover in survivors; chronic RV dyskinesia and failure are rare complications.This case report presents a patient in whom an isolated RV aneurysm complicates a RV involvement of acute inferiorposterior myocardial infarction.

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