PubMed Health⌕ Search

Biomedical subjects

K Tokel

Publications and source records attributed to K Tokel.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the potential role of echocardiography in the detection of allograft rejection in heart transplant recipients.

PURPOSE: Our objective was to determine the most relevant systolic and diastolic echocardiographic parameters to detect left ventricular (LV) dysfunction associated with allograft rejection among heart transplant recipients. PATIENTS AND METHODS: Seven consecutive recipients underwent serial echocardiographic studies with two-dimensional spectral Doppler and tissue Doppler (TD) according to our institutional protocol. Results were compared with clinical status and endomyocardial biopsies (EMB) whenever available. RESULTS: The time since transplantation was 22 to 850 days. Patient no. 2 had a biopsy-proven acute rejection at the 11th week which was associated with decreased TD velocities, ejection fraction (EF), and stroke volume (SV), as well as increased pericardial effusion and posterior wall thickness. Interestingly, changes in TD parameters preceded those in EF and SV. However, similar but less remarkable changes in TD velocities, EF, SV, pericardial effusion, and posterior wall thickness also occurred during other events, such as systemic infection and immediate postoperative hemodynamic compromise despite no rejection. A biopsy performed 7 months later in a patient with a previous rejection episode due to a relatively low EF and SV as well as increasing pericardial effusion with normal TD velocities revealed no rejection. CONCLUSIONS: These data suggest that echocardiographic findings, although not specific for acute rejection, may play a potential role as a screening test to exclude rejection in heart transplant recipients.

Adult↗
PubMed2001

A family with Jeune syndrome.

Jeune syndrome is a rare autosomal recessive disease characterized by narrow thoracic cage and short-limbed dwarfism. Seventy percent of affected individuals die in early childhood from pulmonary hypoplasia and respiratory distress due to the small size of the thorax. Growth retardation and chronic renal insufficiency due to nephronophthisis may occur in patients who survive the respiratory failure. We report a family that exhibited clinically heterogeneous features of Jeune syndrome. The 6-year-old male proband presented with skeletal deformities and chronic renal failure. A kidney biopsy revealed that nephronophthisis was the cause of the patient's kidney failure, and we diagnosed Jeune syndrome. A retrospective diagnosis of Jeune syndrome was also established for the proband's older sister, who had died of renal failure at 8 years of age. The oldest female child in the family also had thoracic deformity, and the father and paternal uncle were both of short stature and exhibited brachydactyly. Their renal function and blood pressure were normal. The findings in this family are important in that they demonstrate the clinical heterogeneity of Jeune syndrome and underline the association of renal disease with this syndrome.

Child↗
PubMed2001

One center's experience with remifentanil infusions for pediatric cardiac catheterization.

OBJECTIVE: To investigate the efficacy of a remifentanil infusion for pediatric cardiac catheterization. DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Children undergoing cardiac catheterization (n = 55). INTERVENTIONS: All patients (age range, 2 months to 12 years) were premedicated with an oral mixture of hydroxyzine and midazolam 60 minutes before the procedure. A remifentanil infusion was initiated at 0.1 microg/kg/min before the start of cardiac catheterization. Noninvasive systolic blood pressure, heart rate, oxygen saturation (SpO(2)), respiratory rate, and sedation score were recorded before the remifentanil infusion and every 15 minutes thereafter throughout the procedure. Episodes of apnea, vomiting, pruritus, and muscle rigidity and recovery time were noted. MEASUREMENTS AND MAIN RESULTS: There were no significant changes in systolic blood pressure, heart rate, SpO(2), or respiratory rate during the procedure. The sedation scale scores at 30, 45, 60, 75, and 90 minutes of remifentanil infusion were significantly lower than the scores recorded at baseline and 15 minutes. In 23 patients, the remifentanil infusion maintained a satisfactory level of sedation, but 32 patients required additional drugs (18 received midazolam, and 14 received midazolam plus ketamine). Recovery was rapid after the remifentanil infusion was discontinued, with a mean time of 2.04 +/- 2.32 minutes to reach a recovery score of > or =5. Three patients experienced apnea after bolus doses of remifentanil, 1 patient vomited, and 1 patient complained of pruritus. CONCLUSION: In pediatric cases in which other intravenous analgesics and sedatives are contraindicated, remifentanil infusion appears to be a suitable alternative based on its associated rapid recovery and stable hemodynamics.

Anesthetics, Intravenous↗
PubMed2001

Activated protein C resistance and false type 2 protein C deficiency detected after multiple shunt failures in a patient with hydrocephalus.

A 2-year-old hydrocephalic boy who had suffered multiple shunt failures was evaluated for hypercoagulability after a thrombus was removed from his right atrium. The work-up revealed that the patient had the heterozygous form of activated protein C resistance and false type 2 protein C deficiency by the clotting method. His protein C activity was normal by the chromogenic method. We suggest that patients having hydrocephalus, shunt-associated thrombus formation, or both should be evaluated for thrombophilic disorders, and protein C activity should be measured by chromogenic assay in patients with documented activated protein C resistance.

Activated Protein C Resistance↗
PubMed2000

Malformations Due to Warfarin: A Case Report.

We report a 5-month-old infant with severe growth retardation who was exposed to in utero warfarin for the first 4 months. She had a dysmorphic face with depressed nasal hypoplasia and low-set ears. Cranial computerized tomography revealed bifrontal atrophy, agenesis of corpus callosum, and dilation of lateral ventricles. In addition she had patent ductus arteriosus with pulmonary hypertension, which had to be ligated.

Journal Article↗
PubMed2000

Evaluation by exercise testing of children with mild and moderate valvular aortic stenosis.

BACKGROUND: The aim of the present paper was to determine the factors related to sudden death in aortic stenosis. METHODS: The factors related to sudden death were investigated in 40 asymptomatic children with mild and moderate aortic stenosis by treadmill testing. RESULTS: The QT interval of aortic stenosis cases were significantly longer than those of healthy children with increasing heart rates during exercise. CONCLUSIONS: A longer QT interval of aortic stenosis cases compared to normal children during exercise is the first sign of myocardial ischemia and leads to fatal ventricular arrhythmias and sudden death. For this reason we recommend that exercise testing should be performed frequently in aortic stenosis patients and that close follow up is necessary for patients with long QT segments that can be a marker for severe arrhythmias.

Adolescent↗
PubMed1999

Malnutrition and growth failure in cyanotic and acyanotic congenital heart disease with and without pulmonary hypertension.

AIM: To investigate the effect of several types of congenital heart disease (CHD) on nutrition and growth. PATIENTS AND METHODS: The prevalence of malnutrition and growth failure was investigated in 89 patients with CHD aged 1-45 months. They were grouped according to cardiac diagnosis: group aP (n = 26), acyanotic patients with pulmonary hypertension; group ap (n = 5), acyanotic patients without pulmonary hypertension; group cp (n = 42), cyanotic patients without pulmonary hypertension; and group cP (n = 16), cyanotic patients with pulmonary hypertension. Information on socioeconomic level, parental education status, birth weight and nutrition history, number of siblings, and the timing, quality, and quantity of nutrients ingested during weaning period and at the time of the examination were obtained through interviews with parents. RESULTS: There was no significant difference between groups in terms of parental education status, socioeconomic level, duration of breast feeding, and number of siblings (p > 0.05). Group cP patients ingested fewer nutrients for their age compared to other groups. 37 of the 89 patients were below the 5th centile for both weight and length, and 58 of 89 patients were below the 5th centile for weight. Mild or borderline malnutrition was more common in group aP patients. Most group cp patients were in normal nutritional state, and stunting was more common than wasting. Both moderate to severe malnutrition and failure to thrive were more common in group cP patients. CONCLUSION: Patients with CHD are prone to malnutrition and growth failure. Pulmonary hypertension appears to be the most important factor, and cyanotic patients with pulmonary hypertension are the ones most severely affected. This study shows the additive effects of hypoxia and pulmonary hypertension on nutrition and growth of children with CHD.

Child, Preschool↗
PubMed1998

Anatomic correction in transposition of the great arteries with unusual coronary pattern and side-by-side location.

Switch operation is the treatment of choice in infants with transposition of the great arteries. The anatomic correction restores the left ventricle to its normal systemic function. In complete transposition, however, the diverse spectrum of coronary pattern influences the surgical outcome. We describe a successful arterial switch operation without LeCompte manoeuvre in a neonate with unusual coronary artery anatomy and side-by-side great arteries.

Abnormalities, Multiple↗
PubMed1998

Effect of carnitine supplementation on cardiac function in hemodialyzed children.

Thirteen carnitine-deficient children (mean age, 16.1 +/- 2.56 years) on a three-times-weekly hemodialysis program for at least 1 year, and 11 healthy age matched children were involved in the study. All the patients had stable blood pressure and hemoglobin (Hb) levels with a maintenance dose of erythropoetin and none were digitalized. The total carnitine (TC) and free carnitine (FC) plasma levels were sampled prior to hemodialysis (HD) before and after 3 months of carnitine supplementation. A free carnitine (FC) to acylcarnitine (AC) ratio less than 4 was defined as carnitine deficiency. Intravenous L-carnitine was injected at a dose of 20-40 mg/kg three times weekly at the end of each dialysis session for a 3-month period. Echocardiographic examination was performed the day following HD, before and after carnitine treatment. Systolic and diastolic functions of the left ventricle, including the ejection fraction, were measured. Almost all the parameters were significantly different in controls and hemodialyzed patients. In carnitine-deficient hemodialyzed patients, 3 months of L-carnitine supplementation resulted in a significant increase in blood carnitine levels and the FC/AC ratio, but this was not associated with any significant improvement of cardiac function. Furthermore no significant changes were observed in plasma triglycerides, total cholesterol or other lipoprotein parameters before or after carnitine supplementation. Although there was a moderate increase in mean hematocrit (Hct) and Hb levels, these also did not reach statistically significant levels. These results suggest that the 3 months of carnitine supplementation is not sufficient to ameliorate cardiac function or increase Hb levels in children.

Adolescent↗
PubMed1997

Dual sensor pacemakers in children: what is the choice of sensor blending?

UNLABELLED: Dual sensor pacemakers were developed to obtain more appropriate responses to activity. We evaluated ten children with dual sensor pacemakers in different sensor blending circumstances using exercise testing to assess which ratio was optimal. Ten patients with several bradydysrhythmias (ages 6-16 years; mean 10.1 years) were included in the study. Eight patients had VVIR pacemakers (Vitatron Topaz), models and two patients had VDD pacemakers implanted via the transvenous route. All patients were in a paced rhythm (98.5% pacing). Accurate T wave sensing ranged from 81%-100%; mean 92%, median 95%. Voluntary exercise testing with a CAEP protocol was performed using a treadmill with the pacemaker in VVIR mode. Medium activity threshold with three sensor blending ratios (QT = ACT, QT > ACT, and QT < ACT) were done in all patients. The mean duration of exercise was not statistically different among the three sensor blending ratios. After 90 seconds of exercise, the mean pacing rate had increased by 12%, 3%, and 5%, respectively, in the three groups. At maximal exercise, the increases were 45%, 42%, and 54%. Mean HRs during exercise in each of the three ratios were not significantly different, although we found a statistically significant increase in HR during the first two stages of rest period in the QT = ACT sensor blending ratio compared to the QT > ACT ratio. No difference was observed after the second stage. IN CONCLUSION: (1) there is no difference between the QT = ACT, QT < ACT, and QT > ACT sensor blending ratios; and (2) each child has to be evaluated by exercise testing to program a correct sensor blending ratio.

Adolescent↗
PubMed1996

Subpulmonary and subaortic ridges in doubly committed subarterial ventricular septal defect: an echocardiographic study.

BACKGROUND: Certain conditions, including discrete subaortic stenosis and right ventricular outflow tract obstruction are well-known associations with ventricular septal defect. However, the association of discrete type subpulmonary and subaortic stenosis with ventricular septal defect has not been described to date. PATIENTS: In this report we present our experience in nine patients with doubly committed subarterial ventricular septal defect in whom associated discrete subpulmonary and subaortic stenosis were diagnosed by two-dimensional echocardiography. The mean age of the patients was 5.7 years, and eight of them were male. Two patients had additional hypertrophied anomalous muscle bundles with pressure gradients across the right ventricular outflow tract. Aortic valve prolapse was detected in two patients with one of them having mild aortic regurgitation. INTERVENTION: Cardiac catheterization was performed in four patients, and three underwent surgery. Doubly committed subarterial ventricular septal defect was closed, and subpulmonary and subaortic ridges were resected in each patient. Histological findings were similar for both ridges, which were composed of thin, short and irregularly arranged elastic fibres covered by endothelial cells. RESULTS: The finding of fibrous ridge on both sides of the doubly committed ventricular septal defect, where the turbulence is likely to be maximum, and the histopathological similarities of subpulmonary and subaortic ridges, may suggest a common mechanism for the development of fibrous ridges. CONCLUSION: Serial echocardiographic assessment of patients with doubly committed ventricular septal defect is recommended.

Adolescent↗
PubMed1995

Double-chambered right ventricle: experience with 52 cases.

The presence of anomalous muscle bundles may produce a pressure gradient between the inflow and outflow portions of the right ventricle, thus resulting in double-chambered right ventricle bearing troublesome clinically in its diagnosis. The aim of the present study was to review the diagnostic criteria. Fifty-two patients with a double-chambered right ventricle were seen during an 8-year period. They ranged in age at the catheterization from 4 months to 17 years (mean 7.5 +/- 4.4 years). Diagnosis was confirmed in 51 patients at cardiac catheterization and in other one on operation. The majority of the patients had associated cardiac anomalies: there were 33 ventricular septal defect (63%), 21 pulmonary valve stenosis (40%), nine atrial septal defect (17%), and four double-outlet right ventricle. The electrocardiograms revealed upright T waves alone in right precordial leads suggesting right ventricular hypertrophy in 33% of the patients. At cardiac catheterization, there was a pressure gradient of 20-160 mmHg between the right ventricular inflow and outflow portions. Forty patients have had surgery and four have undergone balloon pulmonary valvuloplasty. Surgical treatment was planned for two patients and other six had no indication for treatment.

Adolescent↗
PubMed1994

Adenosine induced torsades de pointes in a child with congenital long QT syndrome.

Torsades de pointes is a rare arrhythmia characterized by its bradycardia dependence and increased adrenergic discharge, whether it occurs as a congenital anomaly or as an acquired problem resulting from drug intoxication or other conditions. There are no reliable tests to assess the propensity toward torsades de pointes or evaluate the efficacy of treatment in these patients. Adenosine can result in marked slowing of sinus and ventricular rate and leads to increased sympathetic discharge when given intravenously. We induced torsades de pointes in a child with congenital long QT syndrome (Jervell-Lange-Nielsen syndrome) using 200 micrograms/kg IV adenosine bolus. Higher dosage of adenosine (600 micrograms/kg) did not lead to torsades de pointes after beta blockade. Adenosine may induce torsades de pointes in patients with the long QT syndrome and may be used as a test to reproduce the clinical arrhythmia. Whether adenosine proves to be useful for assessing the efficacy of treatment will require extensive investigation in larger series of patients.

Adenosine↗