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Dive into the research topics where Mehmet Akif Duzenli is active.

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Featured researches published by Mehmet Akif Duzenli.


Heart and Vessels | 2009

Comparison of myocardial performance index obtained either by conventional echocardiography or tissue Doppler echocardiography in healthy subjects and patients with heart failure

Mehmet Akif Duzenli; Kurtulus Ozdemir; Nazif Aygul; Ahmet Soylu; Meryem Ulku Aygul; Hasan Gök

This study was planned to investigate the normal reference values of myocardial performance index (MPI) obtained by tissue Doppler echocardiography (TDE) and the agreement between MPI measured by TDE and conventional MPI measured by pulsed-wave Doppler (PWD) in healthy subjects and patients with heart failure (HF). Two hundred and three patients with HF and 190 healthy subjects were enrolled in this study. Isovolumic contraction and relaxation time (ICT and IRT) and ejection time (ET) were measured from mitral inflow and left ventricular (LV) outflow. Tissue Doppler echocardiography recordings were obtained at the septal, lateral, inferior, and anterior of the mitral annulus and same time intervals were measured. Myocardial performance index was calculated. The functional capacity of the patients with HF was determined according to New York Heart Association classification. TDE-MPI values were higher than conventional PWD-MPI values in both groups (53% ± 8% vs 48% ± 11%, P < 0.0001 in the healthy subjects; 84% ± 21% vs 72% ± 19%, P <0.0001 in the patients with HF). Moderate agreement was found between PWD-MPI and LV mean TDE-MPI in both groups. In identifying patients with moderately or severely decreased LV ejection fraction, TDE-MPI had higher cutoff values than conventional PWD-MPI, and TDE-MPI had higher specificity, sensitivity, negative predictive value, and diagnostic accuracy. In patients with HF, TDE-MPI had a stronger correlation with LV ejection fraction and functional capacity than did PWD-MPI. TDE-MPI is an alternative to conventional PWD-MPI in assessment of cardiac function. However, the higher MPI cutoff points should be considered when this method is used for the evaluation of cardiac function.


Journal of Electrocardiology | 2008

Value of lead aVR in predicting acute occlusion of proximal left anterior descending coronary artery and in-hospital outcome in ST-elevation myocardial infarction: an electrocardiographic predictor of poor prognosis

Nazif Aygul; Kurtulus Ozdemir; Mehmet Tokaç; Meryem Ulku Aygul; Mehmet Akif Duzenli; Adnan Abaci; Ahmet Bacaksiz; Hüseyin Uğur Yazıcı; Sait Bodur

BACKGROUND We aimed to investigate the value of ST elevation in lead aVR (ST upward arrow aVR) in predicting the left anterior descending coronary artery (LAD) occlusion site proximal to first septal perforator (S(1)) and its effect on in-hospital outcome in ST-elevation myocardial infarction (STEMI). METHODS The study included 950 patients with STEMI. Patients were divided into 2 groups as aVR(+) and aVR(-) according to the presence of an ST upward arrow aVR of 0.5 mm or greater. RESULTS ST elevation in lead aVR was seen in 155 (16%) patients, and LAD occlusion proximal to S(1) was detected in 52% of patients in the aVR(+) group and in 9% of patients in the aVR(-) group. aVR positivity was associated with higher heart rate, lower systolic blood pressure and ejection fraction, and worse Killip class at the hospital admission. In-hospital mortality was 19% in the aVR(+) group and 5% in the aVR(-) group. aVR positivity was an independent predictor of in-hospital death. CONCLUSION This study revealed that ST upward arrow aVR was not only a good indicator of LAD occlusion proximal to S(1) but also a source of valuable information about in-hospital outcome in patients with STEMI.


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

The Effect of Nondipping Blood Pressure Patterns on Cardiac Structural Changes and Left Ventricular Diastolic Functions in Normotensives

Ahmet Soylu; Mehmet Akif Duzenli; Mehmet Yazici; Kurtulus Ozdemir; Mehmet Tokaç; Hasan Gök

Background: Cardiac structural changes have been reported to be more prominent in nondipper normotensives than the dipper ones. But the influence of nondipping status on cardiac diastolic functions of normotensives has not been studied yet. In this study, we investigated the effect of nondipping status on both cardiac structural changes and left ventricular (LV) diastolic functions in normotensives. Methods: We performed ambulatory blood pressure (BP) monitoring (ABPM) and echocardiography in 62 normotensive subjects with the following criteria: (1) office BP < 140/90 mmHg; (2) average 24‐hour ambulatory BP < 130/80 mmHg. Results: In the evaluation by tissue Doppler imaging (TDI), the early diastolic myocardial peak velocity (Em) and Em/late diastolic myocardial peak velocity (Am) ratio (Em/Am ratio) were lower in nondippers than those in dippers (P = 0.009 and P < 0.001, respectively). Isovolumic relaxation time (IRT) and myocardial performance index (MPI) were higher in nondippers than those in dippers (P = 0.036 and P = 0.026, respectively). Nondipping status, independent of other factors, was observed to cause both a decrease in the Em and Em/Am ratio and an increase in IRT. However, its effect on IRT was not statistically significant (coefficient =−0.27, P = 0.027; coefficient =−0.37, P = 0.002; coefficient = 0.20, P = 0.082, respectively). Conclusions: Nondipping of nocturnal BP seems to be a determinant of cardiac remodeling and LV diastolic dysfunction (LVDD) and may result in a cardiovascular (CV) risk independent of the increase in LV mass (LVM) in normotensives.


Journal of Electrocardiology | 2009

Type II bidirectional ventricular tachycardia in a patient with myocardial infarction

Osman Sonmez; Enes Elvin Gul; Cetin Duman; Mehmet Akif Duzenli; Mehmet Tokaç; Jonni Cooper

A 84-year-old man presented to the emergency department complaining of chest pain and palpitations. He had no history of coronary artery disease. The 12-lead electrocardiography showed bidirectional ventricular tachycardia (BVT). Coronary angiography revealed severe mid left anterior descending and mid left circumflex lesions. The BVT, in this case, was most likely due to myocardial ischema. The ethiology of published BVT cases are most commonly digitalis toxicity and rarely herbal aconitine poisoning, hypokalemic periodic paralysis, cathecolaminergic VT, myocarditis, and Anderson-Tawil syndrome. The patient had neither of these underlying conditions. To the best of our knowledge and research in the literature, there was no report of bidirectional VT in the patients with myocardial infarction.


American Journal of Cardiology | 2008

Comparison of increased aspirin dose versus combined aspirin plus clopidogrel therapy in patients with diabetes mellitus and coronary heart disease and impaired antiplatelet response to low-dose aspirin.

Mehmet Akif Duzenli; Kurtulus Ozdemir; Nazif Aygul; Ahmet Soylu; Mehmet Tokaç

The effects of therapy with aspirin 300 mg/day and with combined aspirin 100 mg/day plus clopidogrel 75 mg/day on platelet function were compared in patients with diabetes mellitus and coronary artery disease and impaired antiplatelet responses to aspirin 100 mg/day. The study population consisted of 151 outpatients with type II diabetes mellitus and coronary artery disease who were taking aspirin 100 mg/day. Of the 151 patients, a subgroup of subjects with impaired aspirin response were selected on the basis of the results of platelet aggregometry. Nonresponsiveness to aspirin was defined as mean aggregation > or =69% with 3 micromol/L adenosine diphosphate and mean aggregation > or =70% with 2 micromol/L collagen. Aspirin semiresponders were defined as meeting 1 but not both of these criteria. Nonresponders and semiresponders were randomized equally to aspirin 300 mg/day and aspirin 100 mg/day plus clopidogrel 75 mg/day, and aggregation tests were repeated after 2 weeks. Sixty of the 151 patients with diabetes (40%) were found to respond to aspirin inadequately. Platelet aggregation induced by adenosine diphosphate and collagen decreased significantly after aspirin 300 mg/day or combined therapy. Combined treatment was found to have a stronger inhibitory effect on platelet aggregation induced by adenosine diphosphate than aspirin 300 mg/day (p = 0.002). Impaired aspirin response was resolved by increasing the aspirin dose or adding clopidogrel to aspirin (p <0.0001 for each). However, desired platelet inhibition was achieved in significantly more patients by combined treatment than by aspirin 300 mg/day (p <0.05). In conclusion, aspirin 100 mg/day does not inhibit platelet function adequately in a significant number of patients with diabetes mellitus and coronary artery disease. Increasing the aspirin dose to 300 mg/day or adding clopidogrel to aspirin can provide adequate platelet inhibition in a significant number of those patients with impaired responses to low-dose aspirin.


Toxicon | 2010

A case report of an unusual complication of Amanita phalloides poisoning: Development of cardiogenic shock and its successful treatment with intra-aortic balloon counterpulsation

Nazif Aygul; Mehmet Akif Duzenli; Kurtulus Ozdemir; Bülent Behlül Altunkeser

Amanita phalloides is responsible for the majority of the fatalities caused by mushroom poisoning. It causes damage in liver, kidneys and rarely pancreas, causing encephalopathic coma, disseminated intravascular coagulation, hemorrhage and hypovolemic shock. However, its effect on cardiac functions has not been established yet. In this case report, we aimed to present a female patient poisoned by A. phalloides mushroom complicated with multi-organ failure and cardiogenic shock due to advanced left ventricular systolic dysfunction. This case report was the first to show a successful treatment of cardiogenic shock due to mushroom poisoning with intra-aortic balloon counterpulsation, whereas she did not respond to other therapies.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2007

The Effect of Isolated Left Bundle Branch Block on the Myocardial Velocities and Myocardial Performance Index

Mehmet Akif Duzenli; Kurtulus Ozdemir; Ahmet Soylu; Nazif Aygul; Mehmet Yazici; Mehmet Tokaç

Objectives: This study was planned in order to investigate the effect of left bundle branch block (LBBB) on myocardial velocities obtained by tissue Doppler echocardiography (TDE) and myocardial performance index (MPI). Methods: Subjects with LBBB (n = 61) and age‐matched healthy subjects (n = 60) were enrolled in the study. Left ventricular (LV) ejection fraction (EF), mitral inflow velocities (E‐wave and A‐wave), isovolumetric contraction and relaxation time (ICT and IRT), ejection time (ET), and flow propagation velocity (Vp) were measured by conventional echocardiography. Systolic velocity (Sm), early and late diastolic velocities (Em and Am) and time intervals were measured by TDE. MPI was calculated by the formula (ICT + IRT)/ET. Results: LVEF and mitral E/A ratio were similar in both groups. Vp was lower in the LBBB group than in the control group, whereas the E/Em and the E/Vp ratio was higher. LV Sm and Em/Am ratio were lower in LBBB group. Right ventricular Sm and Em/Am ratio were similar in both groups. LV mean and RV MPI were significantly increased in LBBB group. Conclusion: These findings obtained by TDE show that isolated LBBB impairs the ventricular functions. Both of the LV and RV dysfunctions shown by the new parameters may contribute to increased morbidity and mortality in cases with isolated LBBB.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2008

Relationship between systolic myocardial velocity obtained by tissue Doppler imaging and left ventricular ejection fraction: systolic myocardial velocity predicts the degree of left ventricular dysfunction in heart failure.

Mehmet Akif Duzenli; Kurtulus Ozdemir; Nazif Aygul; B. Bulent Altunkeser; Kadriye Zengin; Murat Sizer

This study was planned to research the relationship between systolic myocardial velocity (Sm) obtained by tissue Doppler imaging (TDI) and left ventricular ejection fraction (LVEF) measured according to conventional Simpsons method in healthy subjects and patients with heart failure (HF). Two hundred eight patients with HF whose LVEF < 50% (mean age 59 ± 11 years) and 187 healthy subjects (mean age 57 ± 11 years) were enrolled in this study. LVEF was measured and TDI recordings were obtained at the septal, lateral, inferior, and anterior of the mitral annulus, and Sm was measured. LV mean Sm was calculated. In patients with HF, a significant correlation was detected between LVEF and Sm (r = 0.71, P < 0.0001), while no relationship was found between these parameters in healthy subjects (r = 0.16, not significant). The cutoff value of Sm < 8 cm/s for identifying patients with LVEF between 30% and 49% had a sensitivity of 86%, a specificity of 93%, and a negative predictive value of 92%, and the cutoff value of Sm < 6.0 cm/s for identifying patients with LVEF < 30% had a sensitivity of 92%, a specificity of 84%, and a negative predictive value of 97%. The time required to calculate the LVEF was significantly longer than that of LV mean Sm (327 ± 98 sec vs. 110 ± 29 sec, P < 0.0001), and LVEF had higher inter‐ and intraobserver variability. LV mean Sm obtained by TDI, a parameter that is reproducible, easily obtained, reliable, and practical, can be used to evaluate LV systolic function in patients with HF.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2008

Is There Any Relationship between Metabolic Parameters and Left Ventricular Functions in Type 2 Diabetic Patients without Evident Heart Disease

Mehmet Yazici; Kurtulus Ozdemir; Mustafa Sait Gonen; Mehmet Kayrak; Mehmet Sıddık Ülgen; Mehmet Akif Duzenli; Raziye Yazici; Ahmet Soylu; Hasan Gok

Background: The aim of the present study was to evaluate left ventricle (LV) systolic and diastolic function, using tissue Doppler echocardiography (TDE) and color M‐mode flow propagation velocity, in relation to blood glucose status in normotensive patients with type 2 diabetes mellitus (T2DM) who had no clinical evidence of heart disease. Methods: Seventy‐two patients with T2DM (mean age 49.1 ± 9.8 years) without symptoms, signs or history of heart disease and hypertension, and 50 ages matched healthy controls (mean age 46.1 ± 9.8 years) had echocardiography. Systolic and diastolic LV functions were detected by using conventional echocardiography, TDE and mitral color M‐mode flow propagation velocity (VE). Fasting blood glucose level (FBG) after 8 hours since eating a meal, postprandial blood glucose level (PPG), and HbA1C level were determined. The association of FBG, PPG and HbA1C with the echocardiographic parameters was investigated. Results: It was detected that although systolic functions of two groups were similar, diastolic functions were significantly impaired in diabetics. No relation of FBG and PPG with systolic and diastolic functions was determined. However, HbA1C was found to be related to diastolic parameters such as E/A, Em/Am, VE and E/VE (β=−0.314, P = < 0.05; β=–0.230, P < 0.05; β=–0.602, P < 0.001, β= 0.387, P < 0.005, respectively). In addition to HbA1C, LV, diastolic functions were also correlated with age and diabetes duration. Conclusion: Diastolic LV dysfunction may develop even in absence of ischemia, hypertension, and LVH in T2DM. FBG and PPG have no effect on LV functions, but HbA1C levels may affect diastolic parameters.


The Cardiology | 2009

The Comparative Effects of Long-Term Carvedilol versus Bisoprolol Therapy on QT Dispersion in Patients with Chronic Heart Failure

Nazif Aygul; Kurtulus Ozdemir; Mehmet Akif Duzenli; Meryem Ulku Aygul

Objectives: Carvedilol and bisoprolol reduce QT dispersion (QTD) in chronic heart failure (CHF). However, it is unclear whether there is a difference between the effects of the two drugs. The aim of the present study was to compare the long-term effects of carvedilol and bisoprolol on QTD in patients with CHF. Methods: Eighty-one patients with CHF with no previous β-blocker therapy were included in this prospective study. The patients were randomly allocated to carvedilol or bisoprolol therapy. Left ventricular ejection fraction (LVEF), heart rate (HR), QTD, and corrected QTD (QTcD) were calculated at baseline and at the 6th month of therapy. Results: In comparison to baseline values in both therapy groups, LVEF was significantly improved, and a statistically significant decrease was found in HR (carvedilol from 76 ± 12 to 65 ± 10 beats/min, p < 0.001; bisoprolol from 78 ± 13 to 65 ± 8 beats/min, p < 0.001) and QTcD (carvedilol from 85 ± 28 to 65 ± 22 ms, p < 0.001; bisoprolol from 83 ± 22 to 61 ± 20 ms, p < 0.001). In our study, carvedilol and bisoprolol were found to have similar effects on LVEF, HR, and QTcD. Conclusions: Carvedilol and bisoprolol decrease HR and QTcD in patients with CHF, and there is no meaningful difference between the two β-blockers as regards their effects on these parameters.

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