Biomedical subjects
Publications and source records attributed to Ahmet Akyol.
Subacute thyroiditis is a possibly viral, inflammatory thyroid disorder which can cause thyrotoxicosis. Ventricular arrhythmias are uncommon in thyrotoxicosis and usually occur only in those with marked heart failure or associated cardiac disease. In this case, we present a 52-year-old woman having incessant ventricular tachycardia due to subacute thyroiditis without underlying cardiac disease.
BACKGROUND: We hypothesized that prophylaxis with an anti-oxidant should prevent potential adverse outcomes of laparoscopy related to increased oxidative stress in splanchnic organs, including small intestine, liver, and kidneys, and melatonin is the most appropriate agent for this purpose. METHODS: Twenty-four Sprague-Dawley rats weighing 300 to 350 g were allocated randomly into three groups consisting of eight in each as follows: Group I: gasless (control); group II: 15 mmHg intraabdominal pressure (IAP) with CO2 pneumoperitoneum for 60 min; group III: 15 mmHg IAP with CO2 pneumoperitoneum for 60 min, and melatonin (10 mg/kg) was administered at two occasions, 5 min before insufflation and immediately before the desufflation. In group II and III, rats left resting for 30 min after abdominal deflation, the small intestine (terminal ileum), liver and kidney examples were excised from same locations. The specimens were also obtained using the same time points in group I rats, comprising the control group. The specimens were immediately placed at -80 degrees C for the malondialdehyde (MDA) measurements. In addition, segments of terminal ileum were taken from the similar places in all of the animals for the histological examinations. RESULTS: Comparisons among the groups revealed that highest mean MDA levels in liver, small intestine and kidney were in the group II, followed by the group III and control group. There was significant difference between mean MDA levels in small intestine, liver and kidney of group II and III (P < 0.0005). However, no significant difference was found between mean MDA levels in small intestine, liver, and kidney of the group III and control group. Mucosa and submucosa were affected significantly in 15 mmHg IAP group (no prophylaxis) when compared with the control and melatonin prophylaxis groups (P = 0.002). However, there was not a significant difference in mean damage score of mucosa, submucosa, and muscular layers in control group when compared to melatonin prophylaxis group. CONCLUSIONS: This experimental study indicated that melatonin prophylaxis, with anti-oxidant and anti-inflammatory actions, may have an important role in the prevention of potential complications related to oxidative stress injury on splanchnic organs induced by laparoscopy.
BACKGROUND: To investigate the effects of propofol and caffeic acid phenethyl ester (CAPE) on prevention of lung injury as a remote organ after performing hindlimb ischaemia-reperfusion (IR) in a rat model. METHODS: The animals were divided randomly into one of four groups: sham, no IR (n = 8), control, IR, (n = 8), CAPE group, IR with CAPE, (n = 8), propofol group, IR with P, (n = 8). After the rats were anaesthetised, the animals in the CAPE group received CAPE of 10 micromol, in the propofol group received propofol 50 mg/kg, in the control group received a similar volume of saline solution by means of intraperitoneal injection 1 h before reperfusion. After 4 h of ischaemia the tourniquet was removed and the animals were released for reperfusion for 4 h thereafter. At the end of the reperfusion period, a median sternotomy was performed. A blood sample was obtained for plasma malondialdehyde (MDA). The lung tissues were also removed for MDA assays, myeloperoxidase (MPO) activity, and histopathological examination. RESULTS: Plasma and lung MDA levels, and lung MPO activity were significantly higher in the control group compared to the other groups (p < 0.0005). In the CAPE group, these were significantly lower compared to the control group (p < 0.0005). Also, propofol caused a marked reduction in the MDA levels and MPO activity compared with control group (p < 0.0005), with no significant difference compared to that of the sham group. Histopathologically, the scores resulted in a grade zero (8/8) in the sham group, 3 (3/8) or 4 (5/8) in the control group, 1 (2/8) or 2 (6/8) in the CAPE group, and 1 (3/8) or 2 (5/8) in the propofol group. CONCLUSION: Propofol and CAPE seem to be effective in protecting against lung injury caused by increased oxidative stress and neutrophil accumulation after hindlimb IR in a rat model.
Spontaneous tracheobronchial ruptures are uncommon injuries, especially in the pediatric age group. Tracheal injuries, independent of their origin, may be life-threatening. Here we present the first report of a 14-year-old boy who presented with subcutaneous emphysema, pneumomediastinum, and pneumothorax on day 3, due to spontaneous posterior tracheal-wall rupture following paroxysmal productive coughing. The diagnosis was established using a computed tomography scan of the chest, and tracheobronchoscopy and esophagoscopy under general anesthesia. He was endotracheally intubated and ventilated in the intensive care unit. Such tracheal defects, bridgeable by an endotracheal tube, may permit conservative treatment. The patient was discharged on day 10, and follow-up revealed no late complications.
PURPOSE: The identification of subjects with systemic sarcoidosis at higher risk for sudden death is an unresolved issue. An influence of the autonomic activity on the genesis of ventricular arrhythmias was postulated. Heart rate variability (HRV) analysis provides a useful method to measure autonomic activity, and is a predictor of increased risk of death in various conditions. Therefore, the aim of the study was to evaluate HRV in patients with systemic sarcoidosis. METHODS: The study included 35 patients with biopsy proven systemic sarcoidosis who were not taking antiarrhythmic medications. Thallium scintigraphy was performed to all patients with systemic sarcoidosis. The cardiac sarcoidosis was accepted in 16 patients as abnormal thallium scintigraphy and normal coronary arteriography. The time-domain analysis of HRV was expressed as the standard deviation of all normal to normal NN intervals (SDNN) detected during 24-hour Holter monitoring. Twenty-four healthy subjects represented a control group for HRV analysis. RESULTS: There were no differences in age (44 +/- 13 years for cardiac sarcoidosis, 42 +/- 15 years for noncardiac sarcoidosis, and 40 +/- 10 years for control group; P = NS), sex (the ratio of female; 63%, 68%, and 55%, respectively; P = NS), and echocardiographic ejection fraction (63 +/- 10%, 67 +/- 8%, and 69 +/- 6%, respectively; P = NS) among study groups. The mean SDNN value of the group with cardiac sarcoidosis was significantly lower than both the group with noncardiac sarcoidosis and the control group (72 +/- 32 ms vs 110 +/- 46 ms and 152 +/- 36 ms; P < 0.05, respectively). CONCLUSION: HRV is decreased in patients with systemic sarcoidosis compared to the control group. This decreasing is more obvious in patients with cardiac sarcoidosis.
Congestive heart failure is characterized by significant autonomic dysfunction. Development of left bundle branch block in congestive heart failure is a predictor of worse outcome. There are several lines of evidence that cardiac resynchronization therapy (CRT), by biventricular stimulation in patients with severe heart failure and left bundle branch block, improves autonomic functions which can be quantified by measuring heart rate variability. The aim of the present study was to assess the effect of CRT on autonomic functions quantified by heart rate variability and mean heart rate (HR) in patients with advanced heart failure and left bundle branch block in short and long-term follow-up. A total of 35 patients with systolic heart failure and left bundle branch block (mean-age 60 +/- 11 years; 24 male and 11 female; mean left ventricular ejection fraction [EF]: 22.3 +/- 3%) were enrolled. Clinical assessment and echocardiographic examination were performed at baseline and every three months. Continuous electrocardiographic monitorization by 24-hour Holter recordings was performed pre-implantation, 3 months and 2 years after implantation. Mean HR and one of the time-domain parameters of heart rate variability, standard deviation of the R-R intervals (SDNN) were measured. CRT was associated with a decrease in the mean duration of QRS, and an increase in diastolic filling time, the rate with which the left ventricular pressure rises (dP/dt), and left ventricular ejection fraction. Decrease in mean heart rate and increase in SDNN were statistically significant in the third month and second year recordings when compared to baseline recording (p values were < 0.001 for both). In conclusion, CRT with biventricular pacing provides sustained improvement in autonomic function in patients with advanced heart failure and left bundle branch block.
BACKGROUND: Radiofrequency (RF) catheter ablation is the procedure of choice for the potential cure of atrioventricular nodal reentrant tachycardia (AVNRT) with high success rates. We hypothesed that as a result of the close proximity of Koch's triangle and low inter-atrial septal fibers, the RF ablation applied at this region may result in prolongation of inter-atrial conduction time (IACT). METHODS: RF ablation of AVNRT was performed by conventional technique. IACT was measured before and 20 minutes after RF ablation during sinus rhythm. Number of ablations given and duration of ablation were noted. RESULTS: The study group was consisted of 48 patients (36 [75%] female, 12 [25%] male, mean age 43.4 +/- 14. 5 years). RF ablation was successful in all patients. Mean RF time was 4. 0 +/- 3. 3 minutes and mean number of RF was 11. 9 +/- 9, 8. The mean IACT was 70.1 +/- 9.0 ms before ablation and 84.9 +/- 12.7 ms after ablation, which demonstrated a significant prolongation (p<0.001). The prolongation of IACT was very well correlated with the number of (r=0.897, p<0.001) and duration of RF (r=0.779; p<0.001). CONCLUSIONS: RF ablation of AVNRT results in prolongation of IACT. The degree of prolongation is associated with the duration and number of RF ablations given. The relationship between this conduction delay and late arrhythmogenesis need to be evaluated.
PURPOSE: The aim of the study was to determine the natural course and select appropriate therapy for pneumatocele (PC) in children with postpneumonic empyema. MATERIALS AND METHODS: Records of 134 children treated for postpneumonic empyema between October 1997 and June 2003 were reviewed retrospectively, and 58 (43%) of them were found to have PC. Their chest x-rays and computed tomography scans as well as patient profiles were evaluated to assess the size, location, course, and complications. Clinical course, treatment indications, and results were also reviewed. RESULTS: The patients were aged from 14 months to 15 years (mean 3.8 years). There were 36 boys and 22 girls. The PC was located on the right hemithorax in 34 patients and on the left in 24. Staphylococcus aureus was the most common isolated infective agent. Of the 58 children, 37 (63.7%) showed complete resolution with improvement of the infection within 2 months. Thirteen PCs had evidences of gradual decrease in size without any indication for invasive approaches, and they resolved completely, with a mean time of 6.1 (ranging from 1-13) months. One tension PC, 3 large PCs (>50% of hemithorax), 1 case with bad tolerance to follow-up, and 2 persistent PCs had no reduction in size on follow-up; a total of 7 patients underwent image-guided catheter drainage procedure, and 5 of them resolved completely. In the last 2 cases, surgical excision was required because of persistent cystic cavity caused by thickened PC wall. One patient whose PC had not been decreasing in size developed findings of severe lung abscess with thickened wall and directly underwent surgery. In none of these patients recurrences or complaints related to PC were noted on their control visits. CONCLUSION: Most of these PCs are simple PC and show spontaneous resolution with improvement of the infection within the first 2 months. However, some decrease gradually by time, and close follow-up should be continued in case of complicated PC. Persistent features of chest infection, more than 50% involvement of hemithorax and severe atelectasis, development of broncopleural fistulae (tension PC), and bad tolerance to follow-up remind complicated PC, and they are indications of image-guided catheter drainage procedure. Its failure occurs in PC with thickened wall that does not collapse, as was in our cases with persistent PC and severe infected PC, and thus, this is an indication for surgical excision.
This case report describes a late perforation of right heart wall, pericardium, and diaphragm by an active-fixation ventricular lead without development of pericardial effusion and cardiac tamponade even under oral warfarin treatment.
Risperidone is an atypical antipsychotic drug used for the treatment of schizophrenia. Both positive and negative symptoms are prominent with its use. Metabolism occurs mainly in the liver, where risperidone is changed by CUP2D6 to an active metabolite, 9-hydroxyrisperidone. The half-lives of risperidone and its metabolite are 3 and 7 h, respectively. Genetic polymorphism is seen in the 6%-8% of white patients who are considered poor metabolizers. In poor metabolizers, the half-life extends to 20-30 h. We present an unusual case of unanticipated delayed respiratory depression after risperidone overdose.
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Radiofrequency (RF) catheter ablation has become standard therapy for many types of arrhythmias. RF energy may cause deterioration in left ventricular function by damaging the myocardium. The aim of the present study was to assess the changes in left ventricular function after catheter ablation using various echocardiographic parameters. Forty patients (22 women), aged 37 +/- 14 years (range, 15-76 years), underwent catheter ablation for various tachycardias. Routine echocardiogaphic examination was done in all patients. Left ventricular systolic function was evaluated by the modified Simpson method and tissue Doppler. With regard to left ventricular diastolic function parameters, diastolic early (E) and late (A) transmitral filling velocities, deceleration time (DT), isovolumetric relaxation time (IVRT), and tissue Doppler parameters were assessed. All ventricular function parameters were assessed before, and 1 hour, 1 day, and 1 month after the catheter ablation procedure. To avoid any influence of heart rate on diastolic function parameters, the E/A ratio, DT, and IVRT were adjusted to heart rate (cE/A, cDT, cIVRT). No changes in left ventricular systolic function after the ablation were observed. After the ablation procedure (1 hour, 1 day, and 1 month) the cE/A ratio decreased from 1.42 +/- 0.43 to 1.19 +/- 0.40, 1.18 +/- 0.40, and 1.30 +/- 0.33 (P = 0.009), respectively. cDT increased from 210 +/- 54 to 272 +/- 64, 255 +/- 60, 240 +/- 64 (P = 0.001), respectively. Likewise cIVRT increased from 113 +/- 22 to 133 +/- 54, 123 +/- 27, 117 +/- 19 (P = 0.007), respectively. Significant changes were also observed concerning tissue Doppler parameters in assessing diastolic function. Although no significant changes were observed in systolic function after RF ablation, this procedure may have some detrimental effects on ventricular diastolic function para-meters.
BACKGROUND: Immunonutrition has been demonstrated to modulate gut function, reduce infectious complications, hospital stay, and ventilator days in the critical patients. AIM OF THE STUDY: We assessed the effect of immunonutrition for the prevention of intestinal mucosal atrophy, apoptosis, and bacterial translocation in head injured rats. METHODS: Thirty five rats were randomised into 5 groups. Following moderate closed head injury, in Group 1; Standard Enteral Nutrition, Group 2; Immunonutrition, Group 3; TPN, Group 4; pe. saline were applied. Group 5 was control group (chow-fed). The rats were sacrificed and segments of the ileum were removed for histologic examination, and samples of tissues taken for microbiologic evaluation. RESULTS: Both intestinal apoptosis and mucosal atrophy were significantly lower in Group 2 and Group 5 (p<0.008). Bacterial translocation was significantly lower in Group 2 than Group 1 (p<0.008). CONCLUSION: The enteral immunonutrition prevents intestinal barrier function in brain injured rats.
Vagal paraganglioma is one of the rare tumors of the neuroendocrine system. We are reporting a vagal paraganglioma case presented with uncommon features of the disease: asystole and syncope. Syncope episodes occurred 3 years before the major symptoms of the disease. Dual chamber pacemaker failed to prevent syncope attacks because of the vasodepressor component. The patient was treated successfully with en bloc removal of tumor and vagal nerve. Syncope episodes disappeared after operation.
BACKGROUND: Biventricular pacing substantially improves LV systolic function and symptom status in some patients with dilated cardiomyopathy. AIMS: To assess whether the long-term benefit could be predicted from the echocardiographic parameters. METHODS AND RESULTS: Sixteen patients with dilated cardiomyopathy who underwent atrio-biventricular pacemaker implantation were analyzed in two groups: the responders (n=11) were those with a symptomatic improvement of one or more NYHA functional class; the non-responders (n=5) failed to improve at follow-up (7.6+/-5 months). Echocardiography was performed at baseline, the day after the implantation and then every 3 months. Besides the conventional parameters, the following variables were included: LV diastolic filling time (DFT); the duration of mitral regurgitation (dMR); and LV dP/dt obtained from the continuous wave mitral regurgitation curve. While the baseline DFT and dP/dt were not significantly different between non-responders and responders (256+/-105 vs. 358+/-115, P=0.14 and 564+/-199 vs. 468+/-117, P=0.44, respectively), the QRS width (149+/-15 vs. 175+/-24 ms, P=0.05) and the dMR (343+/-70 vs. 443+/-49 ms, P=0.007) were higher in the responders. The changes of dMR, DFT and QRS width by pacing were not significantly different between groups (P=0.18, 0.30 and 0.77, respectively). However, the change of LV dP/dt by pacing in the responders was significantly different than for non-responders (from 468+/-117 to 676+/-216 mmHg/s vs. from 564+/-199 to 483+/-94, P=0.002). An acute increase in LV dP/dt over 22% by pacing yielded only two false negatives and no false positives in predicting the long-term responsiveness. CONCLUSION: Patients with longer QRS and dMR are more likely to benefit from atrio-biventricular stimulation. The acute changes of Doppler derived LV dP/dt may provide valuable information in predicting the long-term response to biventricular pacing.
This case report describes a patient with biventricular pacemaker in whom a far-field sensing of left atrial activity by the pacemaker's ventricular channel resulted in ventricular pacing inhibition. Placing of the left ventricular pacing electrode in the proximal part of the coronary sinus tributary resulted in this far-field sensing problem, which was resolved following decreasing the ventricular sensitivity. The authors suggest that the far-field sensing of the left atrial activity should be kept in mind for troubleshooting of an atrio-biventricular pacing system.
BACKGROUND: Previous studies have shown that only 80% of narrow QRS supraventricular tachycardia (SVT) types can be differentiated by standard 12-lead electrocardiographic (ECG) criteria. This study was designed to determine the value of some new ECG criteria in differentiating narrow QRS SVT. METHODS AND RESULTS: 120 ECGs demonstrating paroxysmal narrow QRS complex tachycardia (QRS < or = 0.11 ms and rate > 120 beats/min) were analyzed. Forty atrioventricular reciprocating tachycardia (AVRT), 70 atrioventricular nodal reentrant tachycardia (AVNRT), and 10 atrial tachycardia defined with electrophysiologic study (EPS) consisted the study group. Eight surface ECG criteria were found to be significantly different between tachycardia types by univariate analysis. P waves separate from the QRS complex were observed more frequently in AVRT (70%) and atrial tachycardia (80%). Pseudo r' deflection in lead V(1), pseudo S wave in inferior leads, and cycle length alternans were more common in AVNRT (55, 20, and 6%, respectively). QRS alternans was also present during AVRT (28%). ST-segment depression (> or = 2 mm) or T-wave inversion, or both, were present more often in AVRT (60%) than in AVNRT (27%). During sinus rhythm, manifest preexcitation was observed more often in patients with AVRT (42%). When a P wave was present, RP/PR interval ratio > 1 was more common in atrial tachycardia (90%). By multivariate analysis, presence of a P wave separate from the QRS complex, pseudo r' deflection in lead V(1), QRS alternans, preexcitation during sinus rhythm, ST-segment depression > 2 mm or T-wave inversion, or both, were independent predictors of tachycardia type. CONCLUSIONS: Several new ECG criteria may be useful in differentiation of SVT types. Prediction of mechanism prior to EPS may provide additional benefits concerning the fluoroscopic exposure time and cardiac catheterization procedure.
Vegetative electrode infection following permanent pacemaker implantation is a rare and serious complication. Among 1920 patients who underwent permanent pacemaker implantation in our institute between 1980 and 2000, 7 patients aged 65 to 78 years were diagnosed to have pacemaker related endocarditis. In this study, the clinical course and management strategies for these patients are reviewed. The most frequently encountered factors contributing to development of pacemaker infection were local complications such as postoperative hematoma and inflammation, and recurrent surgical interventions on the pacemaker system. In blood cultures S. aureus was the most common causative microorganism. Echocardiography could be performed in 5 patients. Three patients were referred to open-heart surgery for total removal of the pacemaker system, and one patient had his pacemaker system removed percutaneously. The remaining 3 patients did not agree to either surgical or percutaneous removal. These patients have been under antibiotic therapy for approximately 3 years and they still do not have any signs of a serious infection. Consequently, in patients with permanent pacemakers, infective endocarditis should be considered in the presence of fever and local symptoms. Blood cultures should be obtained and echocardiography should be performed. Complete removal of the pacemaker system with intensive antibiotic treatment is necessary for complete eradication of the infection. However, if percutaneous or surgical removal of the electrodes cannot be done because of high perioperative risk or the patient does not agree to undergo either method, medical treatment with long term antibiotic use may be considered as an alternative.