Yazar "Ozbay, G" seçeneğine göre listele
Listeleniyor 1 - 20 / 22
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Acute short-term effect of VVI pacing mode on P wave dispersion in patients with dual chamber pacemakers(Elsevier Sci Ireland Ltd, 2002) Erdogan, O; Altun, A; Ozbay, GThe acute or chronic effect of VVI pacing on P wave duration in the same patient with dual chamber pacemaker has not been studied before. Hence, with the purpose of determining whether VVI pacing increases dispersion of atrial refractoriness. we undertook a comparative study with the aid of a simple noninvasive approach. namely P wave dispersion (PWD) determined from surface electrocardiogram in the same patients who were implanted with dual chamber pacemakers. Pmax duration calculated in VVI paced mode was significantly higher than in VDD paced mode (121+/-21 vs. 111+/-17 ins, P=0.021). PWD (33+/-15 vs. 40 23 tris, P=0.062) did not demonstrate any significant difference between VDD and VVI paced modes, respectively. In conclusion. the findings of our study suggest that short-term VVI pacing itself does not have any direct effect on PWD in patients with dual chamber pacemakers. Different pacing modes in the long term might be responsible for altering PWD and the occurrence of atrial fibrillation while affecting the autonomic nervous system. (C) 2002 Elsevier Science B.V. All rights reserved.Öğe C-reactive protein and immunoglobulin-E response to coronary artery stenting in patients with stable angina(Japan Heart Journal, Second Dept Of Internal Med, 2003) Erdogan, O; Altun, A; Gul, C; Ozbay, GRecent reports indicate that inflammatory mechanisms play a crucial role in the patho-genesis of atherosclerosis and neointimal proliferation as well as coronary restenosis. To provide baseline data for further Studies regarding stenting, restenosis and inflammatory response, we prospectively conducted a clinical study to investigate the time related response of plasma levels of immunoglobulin-E (IgE) and C-reactive protein (CRP) which are two different inflammatory markers mediated by different cytokines in stable patients who underwent elective coronary artery stenting. Thirteen consecutive stable patients who underwent coronary artery stenting were included in the Study. Levels of I-E and CRP were determined pre- and poststent implantation on four consecutive days and at the end of the first as well as third month. Levels of these two markers were gradually elevated on postprocedure days while reaching peak values oil the second and third days for IgE (initial 278 335 IU/mL vs peak 350 489 IU/mL, P = 0.01) and CRP (initial 0.5 +/- 0 mg/dL vs peak 2.7 +/- 3 mg/dL, P = 0.002), respectively. High levels gradually returned to baseline values determined at the end of the first and even third months after stent implantation implying an acute inflammatory reaction. Stent implantation seems not to cause any persistent and ongoing inflammatory response in the long term.Öğe Chronic sympathetic activation affects dispersion of ventricular repolarization in syndrome X(Medimond S R L, 1997) Altun, A; Ozkan, B; Ozcelik, F; Altun, G; Ozbay, GPrevious studies of syndrome X (typical chest pain, positive treadmill exercise test, negative ergonovine test, negative hyperventilation test and angiographically normal coronary arteries) have suggested a potential etiologic role for excessive activation of the sympathetic nervous system. We evaluated the dispersions of Tapex-Tend(TT) and corrected TT as markers of sympathetic effects. Because TTd reflects inhomogeneity of the terminal part of ventricular repolarization. The present study we found TTd and TTcd increased in patients with syndrome X. We suggest these dispersions may be used to show chronic excessive sympathetic activation in patients with syndrome X or other diseases (LQTS etc) and predict the risk for arrhythmias and cardiac sudden death.Öğe Comparison of ventricular escape rates after administration of atropine, dopamine, and aminophylline in stable patients with chronic, high-grade atrioventricular block: An open-label, crossover pilot study in Turkish patients(Excerpta Medica Inc, 2002) Altun, A; Akdemir, O; Erdogan, O; Kirdar, C; Birsin, A; Tatli, E; Ozbay, GBackground: Bradyasystolic episodes are frequently observed in patients who present with presyncope, syncope, or sudden cardiac death to emergency departments. Current therapeutic modalities in treating patients with bradyasystolic episodes include pharmacotherapeutic agents (eg, atropine, epinephrine, and dopamine) and cardiac pacing. Objective: The aim of this open-label, crossover, prospective, sequential, pilot study was to compare the effects of 3 agents-atropine, dopamine, and aminophylline-on ventricular escape rate in Turkish patients. Methods: Eligible patients were stable and had chronic, symptomatic, second-degree 2:1 or third-degree atrioventricular (AV) block with a narrow complex escape rhythm. Patients who were receiving a pharmacotherapeutic regimen or who presented with a wide QRS complex escape rhythm, severely disturbed hemodynamic status, an electrolyte disturbance, previous heart surgery, myocarditis, or a reversible underlying cause (eg, acute ischemia) were excluded from the study. Study drugs were given in the same sequential order to all patients, without a washout period, until the ventricular escape rate returned to the initial level. Atropine (1 mg), dopamine (7.5 and 15 mug/kg/min), and aminophylline (240 mg, twice) were sequentially given to each patient. Results: Twelve consecutive patients (5 women, 7 men; mean age, 69 +/- 14 years) were enrolled. Compared with the baseline rate, a significantly improved ventricular escape rate was found after the beta-mimetic dose of dopamine (44 +/- 6 beats/min vs 49 +/- 10 beats/min; P = 0.005). Improvement in ventricular escape rate was also shown after the alpha-mimetic dose of dopamine, but it was not as dramatic as with the beta-mimetic dose (49 +/- 10 beats/min vs 52 +/- 13 beats/min; P = NS). Compared with the baseline rate, the ventricular escape rate was significantly increased after the second dose of aminophylline (45 +/- 10 beats/min vs 50 +/- 8 beats/min; P = 0.04). Conclusions: This study revealed that, in this patient population, significant acceleration of the ventricular escape rate was found after both the betamimetic dose of dopamine and high-dose aminophylline. This study may have been limited by its small sample size and short duration. Additional studies with larger sample sizes and of longer duration are needed to prove that dopamine and high-dose aminophylline can be used as therapy for patients with high-grade AV block and a slow escape rate.Öğe Decreased nocturnal synthesis of melatonin in patients with coronary artery disease(Elsevier Sci Ireland Ltd, 2003) Yaprak, M; Altun, A; Vardar, A; Aktoz, M; Ciftci, S; Ozbay, GIn human beings, cardiovascular activity has a distinct circadian variation: Heart rate, blood pressure, and vascular tone decrease at night. Nocturnal cardiovascular blunting is at least partially linked to the autonomic activity and increased risk of cardiac and cerebral events. To assess whether decreased nocturnal melatonin synthesis and secretion in coronary artery disease (CAD), we investigated nocturnal secretion pattern of melatonin in patients with CAD and healthy subjects. The present study performed in 16 patients with angiographically documented CAD (aged 46-71 years) and in nine healthy controls (aged 36-66 years). Blood samples were collected every 2 h between 22:00 and 08:00 h. Melatonin levels were measured with a commercially available radioimmunoassay kit. We found large interindividual variation in the pattern of melatonin secretion in both groups. Patients with CAD secreted less nocturnal melatonin at 02:00, 04:00 and 08:00 h than control subjects (P=0.014, P=0.04 and P=0.025, respectively). Peak and A melatonin (peak-lowest melatonin) were found lower in patients with CAD (48.6 [19.1-75.4] vs. 131.4 [67.8-137.2] pg/ml, P=0.006 and 43 [10.5-68.5] vs. 107.6 [55.7-113.1] pg/ml, P=0.002, respectively). Peak time of melatonin secretion was observed earlier in patients with CAD (02:00 h [23:00-02:00 h] vs. 03:45 h [02:00-05:00 h], P=0.04). Our study provides useful and preliminary information about decreased nocturnal melatonin synthesis and release in patients with CAD might help physicians in managing these patients. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.Öğe Effect of aminophylline in patients with atropine-resistant late advanced atrioventricular block during acute inferior myocardial infarction(Clinical Cardiology Publ Co, 1998) Altun, A; Kirdar, C; Ozbay, GBackground: Advanced atrioventricular (AV) block is a frequent complication in patients with acute inferior myocardial infarction (AIMI). This conduction abnormality is associated with narrow QRS complex in conducted or junctional escape beats, suggesting that the site of block is the AV node; however, its pathophysiology has not been properly established. Hypothesis: This study investigated the effect of aminophylline in eight patients (5 men, 3 women, age range 51 to 78 years, mean 67.5 +/- 8.8 years) with atropine-resistant late advanced AV block during AIMI. Methods: Advanced AV block was late in appearance in all patients, starting 2 to 5 days after AIMI, and consisted of second-degree Mobitz II type in two patients and of complete AV block in six patients; all patients had narrow QRS complexes. Before aminophylline administration, all patients had a temporary pacemaker installed which was switched off throughout the study. They were given intravenous atropine (1 mg) that was found to be ineffective. One-half h after atropine, the first aminophylline injection (240 mg) was given intravenously over 10 min. One h following the first injection, a second aminophylline dose (240 mg) was administered. Electrocardiographic rhythm strips were obtained before and after drug administration, and the type of AV block and atrial and ventricular rate were noted. Results: Aminophylline restored 1:1 conduction with first-degree AV block in six patients, Mobitz I AV block in one patient, and normal sinus rhythm in one patient. Mean atrial and ventricular rates before aminophylline were 104 +/- 16 beats/min and 57 +/- 9 beats/min, respectively, and after drug administration 95 +/- 25 beats/min and 89 +/- 17 beats/min, respectively, (p = 0.012). Conclusion: These results indicate that aminophylline improves AV conduction in atropine-resistant late advanced AV block complicating AIMI.Öğe Impaired nocturnal synthesis of melatonin in patients with cardiac syndrome X(Elsevier Sci Ireland Ltd, 2002) Altun, A; Yaprak, M; Aktoz, M; Vardar, A; Betul, U; Ozbay, GWe investigated nocturnal secretion pattern of melatonin in patients with cardiac syndrome X and healthy subjects. The present study performed in five patients with cardiac syndrome X and in nine healthy controls. Blood samples from all subjects were collected every 2 h intervals between 22:00 and 08:00 h. Melatonin levels were measured with a radioimmunoassay kit. Patients with cardiac syndrome X secreted less nocturnal melatonin at 02:00 h than control subjects (P = 0.04). Peak and Delta melatonin (peak-lowest melatonin) were found lower in patients with cardiac syndrome X (P = 0.039 and P = 0.028, respectively). In conclusion patients with cardiac syndrome X show a markedly decreased nocturnal melatonin synthesis. Our study provides useful information about melatonin synthesis and release in patients with cardiac syndrome X might help physicians in managing these patients. (C) 2002 Published by Elsevier Science Ireland Ltd.Öğe Increased immunoglobulin E response in acute coronary syndromes(Westminster Publ Inc, 2003) Erdogan, O; Gul, C; Altun, A; Ozbay, GThe role of inflammation and mast cell activation has been implicated in atherosclerotic plaque destabilization and rupture. To investigate the role of immunoglobulin E (IgE) in acute coronary syndrome, a prospective clinical study was conducted in patients with acute myocardial infarction (AMI), unstable angina pectoris (UAP), stable angina pectoris (SAP), and healthy controls. IgE levels were serially measured and compared in consecutive patients with AMI (n = 16) and UAP (n= 14) on days 1, 3, 7, 21 after admission and 3 months later and only once in stable angina pectoris (n = 15) and healthy controls (n = 14). In addition, blood eosinophil and basophil levels on admission were measured in all groups and compared. Initial IgE levels determined at admission in patients with AMI, UAP, and SAP were significantly higher than levels in the control group (p=0.002). Initial high IgE level in AMI on day I increased to a peak by day 7 (p = 0.024), then gradually decreased by day 21 and at 3 months (p = 0.052). High IgE level in UAP persisted by day 7 and gradually decreased by day 21 and 3 months (p = 0.037 and p = 0.018, respectively). Blood eosinophil count on admission was significantly higher in UAP than in the control group (p = 0.005). Basophil levels of both AMI and UAP groups on admission were found to be elevated as opposed to control group (p = 0.02 and p = 0.012, respectively). This study demonstrates that the level of IgE significantly increased during the acute phase of acute coronary syndromes and gradually decreased, supporting the role of acute inflammatory response and mast cell involvement in plaque rupture.Öğe Increased P wave dispersion: A new finding in patients with syndrome X(Pulsus Group Inc, 2002) Altun, A; Erdogan, O; Tatli, E; Ugur-Altun, B; Durmus-Altun, G; Ozbay, GThe present clinical study was undertaken in patients with syndrome X, namely angina with normal coronary arteries, to investigate the presence of increased P wave dispersion by comparing patients with coronary artery disease (CAD) and healthy control subjects. Three groups were studied - group A, 21 patients (48 6 years) with syndrome X; group B, 16 patients (56 9 years) with CAD; and group C, 16 healthy subjects (49 8 years). Patients with CAD were older than those in groups A and C (P=0.005 and P=0.035, respectively). All groups demonstrated similar PQ, QRS and RR intervals. Group B had a lower minimum P wave duration than group C (P=0.05). P wave dispersion in group A was found to be higher than that in groups B and C (P=0.018 and P=0.0001, respectively). Patients with syndrome X demonstrated increased P wave dispersion compared to patients with CAD and healthy subjects. High sympathetic tone or autonomic imbalance observed in patients with syndrome X may affect intra-atrial and interatrial conduction times, and leave them prone to develop atrial arrhythmias.Öğe Increased pulse wave velocity and shortened pulse wave propagation time in young patients with rheumatoid arthritis(Elsevier Science Inc, 2004) Yildiz, M; Soy, M; Kurum, T; Ozbay, GBACKGROUND: Rheumatoid arthritis (RA) is a systemic immune and inflammatory disease associated with excess cardiovascular morbidity and mortality. Pulse wave velocity (PWV) is an index of arterial stiffness and a marker of cardiovascular events. OBJECTIVE: To investigate arterial stiffness using carotid-femoral (aortic) PWV measurements in young patients with RA. PATIENTS AND METHODS: Eight patients (aged 21 to 34 years, seven women, mean RA duration 13.8+/-12.6 months) with RA according to the criteria of the American College of Rheumatology, and eight age- and sex-matched control subjects (aged 22 to 34 years, seven women) were recruited. Aortic PWV was determined using an automatic device, the Complior (Complior Colson, France), which allowed on-tine pulse wave recording and automatic calculation of PWV RESULTS: The carotid-femoral PWV, systolic blood pressure and heart rate were higher in young patients with RA than in sex- and age-matched control subjects (P=0.03, P=0.02 and P=0.002, respectively). In the young patients with RA, pulse wave propagation time between measurement sites was significantly shorter than in the control group (P=0.02). There were no significant differences in the sex, age, body mass index, waist to hip ratio, diastolic blood pressure, mean blood pressure or pulse pressure between the two groups (P=1.00, P=0.71, P=0.20, P=0.66, P=0.55, P=0.07 and P=0.11, respectively). CONCLUSION: The carotid-femoral PWV is increased and Pulse wave propagation time is decreased in young patients with RA. Measurements of carotid-femoral PWV may provide a simple and noninvasive technique for identifying patients at increased risk of vascular disease.Öğe Inferolateral myocardial perfusion defect caused by right ventricular outflow tract pacing(Wiley, 2004) Erdogan, O; Altun, A; Durmus-Altun, G; Ozbay, GThis case report describes a patient who was free of coronary artery disease and showed reversible inferolateral myocardial perfusion defect after having undergone a permanent dual chamber pacemaker implantation and an active-fixation ventricular lead insertion in the right ventricular outflow tract.Öğe An interesting diagnostic dilemma: Double right coronary artery or high take off of a large right ventricular branch(Elsevier Sci Ireland Ltd, 2002) Altun, A; Akdemir, O; Erdogan, O; Ozbay, GWe 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. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.Öğe Intermittent mode reversion to VOO of a dual chamber pacemaker model(Futura Publ Co, 2001) Erdogan, O; Altun, A; Ozbay, GThis report describes an asymptomatic patient with a DDDR pacemaker system (Inos Cls, Biotronik) that showed intermittent mode reversion to VOO and sometimes to VVI without a detectable source of electromagnetic interference and oversensing. Patients with this Biotronik model should be carefully assessed along with a surface ECG before placing the programming head.Öğe Left ventricular pacemaker lead insertion through the foramen ovale - A case report(Westminster Publ Inc, 2002) Altun, A; Akdemir, O; Erdogan, O; Aslan, O; Ozbay, GThis 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.Öğe Loratidine improves ischemic parameters of exercise stress test in patients with acute myocardial infarction(Mosby, Inc, 2004) Erdogan, O; Altun, A; Gazi, S; Ozbay, GBackground: This study sought to determine whether adding an anti-histaminic medication, loratidine, to anti-ischemic treatment would ameliorate or improve ischemic parameters induced by exercise stress test in patients who suffered an acute myocardial infarction. Methods: Twenty stable patients with acute inferior myocardial infarction who had a positive EST were randomly allocated into 2 groups, A and B. Patients in group A and B received a 10 mg loratidine tablet added daily to their anti-ischemic regimen for 7 days during the second and third week post-event, respectively. As the end of each period they underwent an exercise stress test (EST). Exercise parameters in each group were then compared before and after loratidine therapy. Results: Both groups showed improvements in exercise parameters after loratidine therapy compared to a basal EST results. STmax (group A: 1.9+/-0.74 vs 0.9+/-1.29 mm, P=.046, group B: 2.5+/-0,7 1 vs 1.4+/-1.17 mm, P=.041), STlead (group A: 3.4+/-1.08 vs 1.5+/- 2.12, P=.027;group B: 4.6+/-1.71 vs 2.22+/- 2.25, P=.011, STlead group A: 4.7 +/-2.18 vs 2.1+/-3.11 mm, P=.024; group B: 7.9+/-2.92 vs 3.33+/-3.81 mm, P =.005). Conclusion: Our study revealed that loratidine, a histamine-1 receptor blocker, improves ischemic parameters of EST when given as additive therapy to a routine anti-ischemic regimen during the sub-acute phase of myocardial infarction.Öğe Management of a patient with active rheumatoid arthritis and suspected tuberculosis causing effusive-constrictive pericarditis(Elsevier Sci Ireland Ltd, 2003) Yildiz, M; Erdogan, O; Aktoz, M; Gul, C; Ozbay, GIn the following case report we present a patient who has been admitted for pericardial effusion causing cardiac compression with active rheumatoid arthritis and suspected tuberculosis. The patient was successfully treated with intravenous pulse steroid for active rheumatoid arthritis, with prophylactic anti-tuberculosis agents for suspected tuberculosis and with surgical pericardiectomy for the thickened pericardium as well as recurrent pericardial effusion. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.Öğe A new method for determination of dispersion of ventricular repolarization(Monduzzi Editore, 1997) Altun, A; Ozbay, GQT dispersion may provide an indirect measure of the underlying inhomogeneity of myocardial repolarization. However there are several important unresolved issues regarding the technique and the diagnostic value of assessment of QT dispersion from electrocardiogram. Methodologic problem relates to the issue of lead selection for determination of QT dispersion in order to obtain maximal information on ventricular recovery times. In present study we showed new chest leads groups are more sufficient than limb and standard chest leads groups for reflect regional inhomogeneity of repolarization.Öğe Normalization of negative T waves in the chronic stage of Q wave anterior myocardial infarction as a predictor of myocardial viability(Karger, 2005) Altun, A; Durmus-Altun, G; Birsin, A; Gultekin, A; Tatli, E; Ozbay, GWe investigated whether spontaneous normalization of negative T waves ( TWN) on infarct-related ECG leads ( IRLs) in the chronic phase of Q wave anterior myocardial infarction ( MI) could be a predictor of residual viability in infarct areas. We prospectively studied 35 patients ( age 60 +/- 8.6 years) in the chronic phase of Q wave anterior MI. Spontaneous TWN ( group A, n = 23) were defined as negative T waves that became upright ( greater than or equal to0.15 mV) in 62 IRLs. The presence of negative T waves ( group B, n = 12) was defined as symmetric or biphasic negative T wave of greater than or equal to0.15 mV. All patients underwent same-day rest Tl-201-stress Tc-99m sestamibi dual-isotope myocardial perfusion SPECT and 24-hour Tl-201 reinjection imaging for ischemia and viability analysis. On scintigraphic examination, ischemic or viable myocardial segments were found in 18 patients ( 78%) with TWN and 4 patients ( 33%) of group B ( p = 0.013). The use of TWN as a parameter had a marked influence on the sensitivity ( 82%), specificity ( 62%), positive ( 78%) and negative ( 67%) predictive values and accuracy ( 74%) of the diagnosis of viable smyocardium. If we add the criterion of positive T waves in aVR with negative T waves to our criteria, we found that sensitivity ( 90%), positive ( 80%) and negative ( 80%) predictive values and accuracy ( 80%) increased. The results of our study suggest that analysis of TWN on IRLs is an accurate marker of residual viability and/or persistent peri-infarct ischemia in patients in the chronic stage of Q wave anterior MI, and therefore optimizes the diagnostic and therapeutic strategies after MI. Copyright (C) 2005 S. Karger AG, Basel.Öğe Right ventricular function in patients with acute anterior myocardial infarction(Acta Cardiologica, 2002) Akdemir, O; Yildiz, M; Sürücü, H; Dagdeviren, B; Erdogan, O; Ozbay, GObjective - 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 = 0.0 18 and 0.0 12) and E of RV free wall (p = 0.0 11) were significantly increased in AAMI-group. Q-Sa intervals in both regions (p = 0.007 and 0.0 IS) 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 = 0.0 1 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.Öğe Specific tissue Doppler predictors of preserved systolic and diastolic left ventricular function after an acute anterior myocardial infarction [Meeting Abstract](W B Saunders Co Ltd, 2002) Akdemir, O; Dagdeviren, B; Yildiz, M; Gul, C; Surucu, H; Ozbay, G[Abstract Not Available]
