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Dive into the research topics where Muzaffer Degertekin is active.

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Featured researches published by Muzaffer Degertekin.


IEEE Transactions on Medical Imaging | 2013

Vessel Tractography Using an Intensity Based Tensor Model With Branch Detection

Suheyla Cetin; Ali Demir; Anthony J. Yezzi; Muzaffer Degertekin; Gözde B. Ünal

In this paper, we present a tubular structure segmentation method that utilizes a second order tensor constructed from directional intensity measurements, which is inspired from diffusion tensor image (DTI) modeling. The constructed anisotropic tensor which is fit inside a vessel drives the segmentation analogously to a tractography approach in DTI. Our model is initialized at a single seed point and is capable of capturing whole vessel trees by an automatic branch detection algorithm developed in the same framework. The centerline of the vessel as well as its thickness is extracted. Performance results within the Rotterdam Coronary Artery Algorithm Evaluation framework are provided for comparison with existing techniques. 96.4% average overlap with ground truth delineated by experts is obtained in addition to other measures reported in the paper. Moreover, we demonstrate further quantitative results over synthetic vascular datasets, and we provide quantitative experiments for branch detection on patient computed tomography angiography (CTA) volumes, as well as qualitative evaluations on the same CTA datasets, from visual scores by a cardiologist expert.


European Journal of Echocardiography | 2008

Tissue Doppler imaging to predict clinical course of patients with hypertrophic cardiomyopathy

Fatih Bayrak; Gokhan Kahveci; Bulent Mutlu; Kenan Sonmez; Muzaffer Degertekin

AIMS Diastolic tissue Doppler (TD) parameters allow prediction of patients with hypertrophic cardiomyopathy (HC) at risk of sudden death, ventricular tachycardia, or cardiac arrest. The aim of this study was to assess the value of TD imaging in predicting the clinical course of patients with HC. METHODS AND RESULTS Eighty-six HC patients were prospectively included in the study and followed-up for clinical endpoints (cardiovascular death or hospitalization due to worsening of heart failure symptoms). Patients with clinical endpoints (n = 25) had larger left atrium diameters, thicker left ventricle (LV) walls, more often LV outflow obstruction and lower TD velocities of LV. LV outflow tract obstruction (r=0.54, R(2)=0.29, P<0.03) and LV lateral mitral annular systolic tissue Doppler velocity (LMSa) (r=0.50, R(2)=0.25, P<0.0001) were found to be independent predictors for clinical endpoints in forward stepwise regression. The best value of LMSa with the highest sensitivity (75%) and specificity (88%) was 4 cm/s for predicting clinical endpoints. Patients with LMSa velocities > 4 cm/s were significantly free of clinical endpoints. CONCLUSION In conclusion, LMSa seems to be a reliable parameter that can be used in predicting the HC patients at risk for clinical deterioration or death at long-term follow-up.


Angiology | 1995

A new echocardiographic formula to calculate ejection fraction by using systolic excursion of mitral annulus

Y. Çevik; Muzaffer Degertekin; Yelda Basaran; Fikret Turan; O. Pektaş

The correlation between echocardiographically and angiographically calculated ejection fraction and systolic excursion of the mitral annulus was studied in 81 patients. Knowing that the mitral annulus changes its size, shape, and position during the cardiac cycle, the authors measured systolic excursion of the annulus by 2D echocardiography. Displacement of the mitral annulus was measured from four different points (medial, lateral, anterior, posterior) by apical four-chamber and apical two-chamber approaches. Patients with and without regional wall motion abnormalities were included. Left ventric ular volumes and ejection fraction (EF) were calculated in the standard manner intro duced by Teichholz et al and also with biplane left ventriculography. As a result, EF calculated by cineangiography, was moderately correlated with the Teichholz method (r=0.66) while it was highly correlated with measurements of mitral annular motion (MAM) (r=0.87). The correlation can be expressed by the regression equation, EF (angiography) =5.7 MAM (in mm) - 6.5. They conclude that measurements of annular motion is an easy and reliable index of left ventricular function as an alter native to traditional methods.


CardioRenal Medicine | 2012

A Single-Centre Study of Acute Cardiorenal Syndrome: Incidence, Risk Factors and Consequences

Zehra Eren; Olcay Ozveren; Elif Buvukoner; Elif Cigdem Kaspar; Muzaffer Degertekin; Gulcin Kantarci

Objective: Cardiac and kidney diseases are common, and the impact of acute kidney injury (AKI) on patient outcome is well known. We aimed to investigate the incidence of acute cardiorenal syndrome (CRS) and the risk factors and outcomes associated with the disease. Methods: We conducted a retrospective cohort study comprising 289 patients with acute coronary syndrome (ACS) and acute decompensated heart failure (ADHF), examining the incidence of AKI defined according to the Acute Kidney Injury Network (AKIN) classification, the factors contributing to AKI, and the impact of AKI on in-hospital mortality and hospital re-admission. Results: Of 71 patients with AKI, 36 (50.7%) had ACS and 35 (49%) had ADHF. Overall in-hospital mortality was 5.5% (n = 16). Multivariate logistic regression identified the following independent predictors of AKI in male patients with ACS: previous myocardial infarction at age >65 years (OR 5.967, 95% CI 1.16–30.47, p = 0.03), chronic kidney disease (OR 3.72, 95% CI 1.31–16.61, p = 0.01), and decreased hemoglobin levels (OR 0.684, 95% CI 0.53–0.88, p = 0.03). No variable was identified as an independent risk factor in ADHF patients. Kaplan-Meier survival curves indicated that patients with ACS plus AKI had significantly higher in-hospital mortality (log rank = 0.007). Conclusion: Acute CRS (type 1 CRS) is more frequent in patients with ADHF and can be considered multifactorial. Although CRS is less frequent in ACS patients, it is associated with longer hospital stay and with higher in-hospital mortality. The heart-kidney interaction should be managed collaboratively between cardiologists and nephrologists to increase our knowledge and enhance clinical approaches.


American Heart Journal | 1999

Microbubbles associated with mechanical heart valves: Their relation with serum lactic dehydrogenase levels

Murat Gençbay; Muzaffer Degertekin; Yelda Basaran; Bengi Yaymaci; Akin Izgi; İsmet Dindar; Fikret Turan

BACKGROUND There has been no consensus about the prevalence and mechanism of generation of microbubbles in mechanical prosthetic heart valves (PHV). The aim of this study was to determine the prevalence of microbubbles in PHV and their relation to serum lactic dehydrogenase (LDH) levels. METHODS AND RESULTS We prospectively studied 150 normally functioning mitral PHV (98 bileaflet and 52 monoleaflet) in 150 patients with the use of transesophageal echocardiography with a multiplane 5-MHz probe. None of the patients had an aortic prosthetic valve. Blood was drawn to determine serum LDH level. None of the patients had any factors that might affect the LDH level other than the PHV-related hemolysis. Patients with spontaneous echo contrast in the left atrium that might affect the assessment of the microbubbles were excluded. We devised a method to determine the amount of microbubbles for each PHV. Microbubbles were detected in 118 (79%) of 150 PHV, including 97 (99%) of 98 bileaflet valves and 21 (40%) of 52 monoleaflet (tilting disk) valves (P <. 0001). Intraobserver variability was not statistically significant for the determination of the amount of microbubbles (z = 1.7, P =. 08). There was a strong correlation between serum LDH levels and the amount of microbubbles (rs = 0.69, P <.001). CONCLUSIONS Microbubbles were detected in more patients than reported previously. They were found to be associated more with the bileaflet than the monoleaflet PHV. Sorin monoleaflet valves were associated with microbubbles significantly less often than the others. There was a strong correlation between serum LDH levels and microbubble counts, which suggests that hemolysis may be related to microbubble formation.


International Journal of Cardiology | 2009

Acute myocardial infarction in a 24 year-old man possibly associated with sibutramine use

Elif Eroglu; Gökmen Gemici; Fatih Bayrak; Ali Kemal Kalkan; Muzaffer Degertekin

Sibutramine is an anti-obesity drug, which acts by inhibiting neuronal re-uptake of noradrenaline and serotonin. Although the most frequently seen effect of sibutramine on cardiovascular system is an increase in blood pressure and pulse rate, rare but severe side effects such as sibutramine-induced ventricular arrhythmias, heart failure and cardiovascular disease-related death are also reported. We describe a 24 year-old man with low atherosclerotic risk profile who had acute myocardial infarction possibly associated with sibutramine use.


International Journal of Cardiac Imaging | 2000

Cardiac thrombosis in a patient with Behçet's disease: Two years follow-up

Yelda Basaran; Muzaffer Degertekin; Cevat Yakut

A 28-year-old man with Behçets disease was presented with cardiac symptoms in addition to previous complaints of oral and genital ulcers. A diagnosis of thrombosis was made and patient began to receive anticoagulant and immunosupressive therapy and was followed by echocardiographic examination. Despite medical therapy, thrombosis recurred. Surgical excision was performed and histological findings were consistent with organizing thrombus. Nature of cardiac involvement and review of literature on cardiac thrombosis in Behçets disease was discussed.


Clinical Cardiology | 2009

Paclitaxel‐induced ST‐Segment Elevations

Gökmen Gemici; Altug Cincin; Muzaffer Degertekin; Ahmet Oktay

A 51‐year‐old woman presented with severe chest pain minutes after starting intravenous paclitaxel as a part of the systemic chemotherapy due to ovarian carcinoma. The electrocardiogram (ECG) revealed sinus rhythm with ST‐segment elevations in inferior and anterior leads. The ST‐segment elevations resolved immediately after sublingual nitroglycerine. Cardiac troponin T and CPK MB levels remained in the normal range at repeat measurements. It was presumed that in spite of standard premedication, paclitaxel had induced acute coronary syndrome with ST‐segment elevations in this patient. Copyright


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2009

Chronic Cigarette Smoking Affects Left and Right Ventricular Long‐Axis Function in Healthy Young Subjects: A Doppler Myocardial Imaging Study

Elif Eroglu; Sinan Aydın; Firat Yalniz; Ali Kemal Kalkan; Fatih Bayrak; Muzaffer Degertekin

Objective: Cigarette smoking is one of the major risk factors for coronary artery disease. However, chronic smoking has additional cardiac adverse effects independent of coronary atherosclerosis. We assessed the possible effects of chronic smoking on left and right ventricular (LV, RV) long‐axis function using Doppler myocardial imaging (DMI). Methods: Forty otherwise healthy smokers (mean age = 26±3 years) and 40 age‐matched nonsmoking controls enrolled. Standard echocardiography protocol was followed by DMI. Peak systolic (VS), early (VE) and late diastolic (VA) velocities, peak systolic strain (S), and strain rate (SR) were measured from septal, lateral, and RV free walls. Results: The baseline characteristics of two groups were similar. There were significant differences regarding Doppler myocardial velocity, S, and SR indices. Septal VE (P < 0.04), S (P < 0.0001) and SR (P < 0.02) were significantly reduced in smokers. For both lateral and RV free wall, VS (P < 0.003, P < 0.002, respectively), VE (P < 0.0001, P < 0.002, respectively), S (P < 0.0001 for both), and SR (P < 0.0001, P < 0.002, respectively) were significantly reduced in smokers. There were significant correlations between the amount of smoking and septal, lateral, and RV free wall S and SR. Conclusions: Chronic cigarette smoking causes alterations in long‐axis systolic and diastolic functions of right and left ventricles in healthy young subjects. These changes can be accurately detected with Doppler myocardial velocity and SR imaging.


Journal of Cardiovascular Medicine | 2009

Giant hydatid cyst of the interventricular septum mimicking acute myocardial infarction on ECG: an unusual cause of ST segment elevation

Elif Eroglu; Gökmen Gemici; Mehmet Umit Ergenoglu; Cenk Eray Yildiz; Suha Kucukaksu; Muzaffer Degertekin

Hydatid disease is a parasitic infection caused by larvae of Echinococcus granulosus, which is still endemic in many cattle-raising areas. Cardiac involvement is a rare, but potentially a very serious complication of the hydatid disease. The diagnosis of cardiac cyst hydatid may be difficult due to the nonspecific symptoms and varying clinical presentations. With this report, we describe a case of giant hydatic cyst of the interventricular septum that caused ischemic changes on ECG, mimicking acute myocardial infarction. The final diagnosis was made by combining echocardiography, MRI, and serological tests. Surgical resection of the cyst, followed by albendezol treatment yielded a favorable outcome.

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Fatih Bayrak

Vrije Universiteit Brussel

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