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Biomedical subjects

K Bayazit

Publications and source records attributed to K Bayazit.

70 records · Page 4Linked to original sources
PubMed1986

Fistulous communication of aortic sinuses into the cardiac chambers. Fifteen years surgical experience and a report of 23 patients.

Over the past 15 years 23 patients, aged 14-50, with aortic sinus-cardiac chamber fistulous communication have been operated upon. All were symptomatic and had angiographic evaluation before surgery. The last 5 were diagnosed by two-dimensional echocardiography. The origin of the fistula was the right aortic sinus in 22 and the non-coronary sinus in 1. The involved cardiac chamber was the right ventricle in 18, right atrium in 3 and left ventricle in 2. Associated lesions were ventricular septal defect (VSD) in 9, ventricular septal defect + atrial septal defect (VSD + ASD) in 1, ventricular septal defect + pulmonary stenosis (VSD + PS) in 1, atrial septal defect (ASD) in 3 and congenital aortic stenosis (AS) in 1. At surgery both the aorta and involved cardiac chamber were opened. No recurrence was encountered when the fistula was repaired using teflon felts on both ends. Three patients, 2 of whom had been operated upon before the use of cardioplegic arrest, died (13%).

Adolescent↗
PubMedDate not supplied

Effects of carnitine on preconditioned latissimus dorsi muscle at different burst frequencies.

Exercise and electrical stimulation may result in a decrease in carnitine levels associated with preconditioned latissimus dorsi muscles. Therefore, the effects of exogenous carnitine were studied in a model of latissimus dorsi muscle contraction. Twelve dogs were studied. Under anesthesia, the latissimus dorsi was placed around an implantable mock circulation system. The muscle was made fatigue-resistant with the aid of chronic low-frequency electrical stimulation. Six animals received carnitine 0.15 mmol/kg; the other six served as control. The muscles were stimulated with 20, 43, and 85 Hz pulse training. During the 90-minute stimulation period, the pressure that developed in the mock circulation was measured at 15 minute intervals. The changes in ATP and lactate levels were measured every 30 minutes. Stimulations at 20 and 43 Hz did not result in any change in pressure or metabolic data over the course of 90 minutes of stimulation. When the 85 Hz burst was applied, ATP levels decreased, while lactate levels increased, with an associated drop in pressure in the control group. ATP and lactate levels were, respectively, 13.8 +/- 1.4 mumol/g and 15.0 +/- 4.0 mumol/g in the carnitine group and 10.3 +/- 1.1 mumol/g and 23.0 +/- 3.0 mumol/g in the control group at the end of 90 minutes (p < 0.06). The pressure at the same time interval was 74 +/- 4 mmHg in the control group, and 85 +/- 3 mmHg in the carnitine group (p < 0.05). In this study, we demonstrated that carnitine administration enhances muscle performance in terms of metabolic and pressure changes during high-frequency electrical stimulation at 85 Hz.

Adenosine Triphosphate↗
PubMedDate not supplied

Results of right coronary artery endarterectomy with or without patchplasty.

We report preoperative and early postoperative findings of 286 coronary bypass patients operated between 1988 and 1998 who had endarterectomy and/or patchplasty to the right coronary artery. In this retrospective study there were 61 cases with only saphenous vein patchplasty to the right coronary artery (patch group), 57 patients who underwent endarterectomy and patchplasty (open-patch group), and 229 patients having closed endarterectomy to the right coronary artery (closed group). A group of 150 patients having a saphenous vein graft to the right coronary artery without endarterectomy were chosen as a control group. Gender, age, family history, smoking history, diabetes, hyperlipidemia, hypertension, nature of the angina, severity of the coronary artery disease, left ventricular functions, preoperative rhythm, and electrocardiographic patterns were evaluated for their effect on early mortality among groups. No significant difference was detected. Positive inotropic and mechanical support need was higher in the closed group at the end of the operation and in the intensive care unit. Duration of cardiopulmonary bypass and clamp time was higher in the open-patch group. Atrial fibrillation in the early postoperative period was more frequent in the patch and closed groups. Complete atrioventricular block development and the need for a pacemaker were higher in the open-patch and closed groups. Non-Q wave myocardial infarction was more frequent in the closed group. Mortality rates were higher in the open-patch and closed groups. We conclude that endarterectomy to right coronary artery should be avoided if possible, and patchplasty with saphenous vein should be preferred.

Cardiopulmonary Bypass↗
PubMedDate not supplied

Is left main coronary artery stenosis a risk factor for early mortality in coronary artery surgery?

It is accepted universally that the treatment of critical left main coronary artery (LMCA) stenosis is surgical revascularization. This study was designed to evaluate critical LMCA stenosis as a risk factor in coronary artery bypass surgery. We compared the surgical results of 760 patients with critical LMCA disease, including 58 cases who were operated under emergency conditions (LMCA-em) and 702 patients who were operated electively (LMCA-el), with randomly chosen 707 coronary bypass patients (CONT-el) without LMCA disease, but who had double- or triple-vessel disease. Another group of patients (n = 99) who were operated on under emergency conditions (CONT-em) but without LMCA disease were also compared with the corresponding groups. The mortality of LMCA-em group and CONT-em group was markedly higher from the other two groups. Univariate analysis revealed that female gender, older age, presence of diabetes mellitus, poor left ventricular function, and the presence of unstable angina were major risk factors for fatal outcome in LMCA-el and CONT-el groups. Age was also a risk factor in LMCA-em group, as well as unstable angina pectoris. The coexistence of critical right coronary artery disease did not affect the early outcome in both groups with LMCA lesions. In the multivariate analysis, critical LMCA disease was not a risk factor for mortality. Logistic regression analysis revealed diabetes [odds ratio (OR): 3.66], poor left ventricular function (higher left ventricle end-diastolic pressure, OR: 1.08), and emergent operations (OR: 5.09) were risk factors for early mortality. Patients with LMCA disease should have surgery promptly for favorable results, because emergency conditions have higher mortality rates.

Adult↗
PubMedDate not supplied

Clinical results of mitral valve replacement with and without preservation of the posterior mitral valve leaflet and subvalvular apparatus.

In this study we attempted to investigate the importance of posterior leaflet preservation during mitral valve replacement (MVR). One hundred and forty randomly selected patients with isolated mitral insufficiency were studied, half of whom had MVR with preservation of the posterior leaflet (Group I), whereas in the other half conventional MVR was performed, without preservation of the posterior leaflet (Group II). Within these two groups there were no in hospital deaths, but 5 patients in Group II were admitted to the hospital with congestive heart failure and 3 of them died after approximately 6 months. Long term mortality rate was 4.2% in Group II. Ejection fraction (EF) decreased postoperatively from 56% to 50% in Group I (p less than 0.05), and from 59% to 49% in Group II (p less than 0.05). Fifteen patients in each group and aged below 30 with sinus rhythm and in the first functional capacity according to the New York Heart Association classification (NYHA) were subjected to exercise study, 18 months after the operation. After exercise EF increased from 47% to 64% in Group I and decreased from 51% to 47% in Group II. These findings suggested that MVR with the preservation of the chordae tendineae can be done with a low morbidity and mortality rate in the early and late postoperative period.

Chordae Tendineae↗
PubMedDate not supplied

Mediastinitis after open heart surgery. Analysis of risk factors and management.

Mediastinitis developed following 58 of 8803 operative procedures involving median sternotomy at Türkiye Yüksek Ihtisas Hospital. There were 40 men and 18 women. Mediastinitis occurred within, on average, 10 days after the operation. No positive cultures were obtained in 37 patients; Staphylococcus aureus was the responsible pathogen in 18, Escherichia coli in 2, and Enterococcus in 1 patients. Thirty patients had a valve procedure, 24 aortocoronary bypass grafting, 1 a total correction for tetralogy of Fallot, 1 a primary closure of an atrial septal defect, and 2 had Bentall's procedure for an ascending aortic aneurysm. Fifty patients were treated by radical debridement and closed irrigation of the mediastinum with antibiotic solutions and 8 patients were treated with sternal debridement and transposition of the omentum. The mortality rate was 36% for the former, and 12.5% for the latter technique. Omentum transposition promoted rapid healing with a low mortality rate.

Adult↗
PubMedDate not supplied

Heparin need of the patients with cyanotic congenital heart disease during cardiopulmonary bypass. Comparison of cyanotic, acyanotic, rheumatic and atherosclerotic subjects.

Four groups of patients were studied. Group I: Congenital cyanotic heart disease (CCHD), consisting of 24 subjects aged 5 to 28 (1.4); 18 males and 4 females. Group II: Acyanotic congenital heart disease (ACHD), consisting of 34 patients aged 5 to 42 (20.1); 17 males and 17 females. Group III: Rheumatic heart disease (RHD), consisting of 30 patients aged 11-54 (42.4); 9 males and 21 females. Group IV: Atherosclerotic heart disease (AHD), consisting of 35 patients aged 36 to 65 (49.2); 33 males and 2 females. The haematocrit value (Hct) was the highest in the CCHD group. Total amount of heparin (mg/kg) used during cardiopulmonary bypass was 5.4 in CCHD, 4.66 in ACHD, 4.8 in RHD and 4.6 in AHD group. Mean protamine values was 4.02; 4; 4.03; and 4 respectively. Although the difference of Hct value was statistically different between CCHD and RHD group (p less than 0.001), heparin need was not (p less than 0.1). One-way analysis of variance (F test) showed no difference for heparin need between the four groups (F3.119 = 0.64). Prothrombin time (PT) and activated partial thromboplastin time (aPTT) showed a positive correlation (r = 0.36 and r = 0.25) with heparin need in CCHD group but no correlation was found in RHD group.

Adult↗
PubMedDate not supplied

Surgical treatment of Ebstein's anomaly: valve replacement and reconstruction.

Because of the relative infrequency of Ebstein's anomaly the type of effective surgical treatment remains controversial. Various authors have reported different results depending upon the type of surgical treatment involved. In TYIH between 1974-1987, 30 cases with Ebstein's anomaly have been operated upon; 12 cases underwent surgical repair and in the remaining 18 cases a tricuspid valve replacement was performed. Four out of the 12 reconstruction cases remained on cardiopulmonary by-pass (CPB) because of the failure of the right ventricle and artificial valves were implanted in these cases. One of these patients died. In all, 3 patients died as a result of annuloplasty and the postoperative courses of these patients were eventful. Among the remaining 18 patients with artificial valve replacement only one patient died and the remainder of the tricuspid valve replacement group had an uneventful postoperative period.

Adolescent↗