Sema Özer

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.

Clinical experiences of patients with catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia is a rare entity that can occur in children without cardiac disease and with a normal QT interval. It may cause syncope, convulsions, and sudden death during physical activity or emotional distress. We report the clinical features, treatment, and follow-up of 16 children with this diagnosis, emphasizing the potentially fatal nature of the disease.The mean age of patients at the onset of symptoms and at the time of diagnosis was 7.8 plus or minus 2.5 years, and 10.6 plus or minus 3.5 years, respectively. Syncope was the main complaint in 11, and 7 were treated as erroneously as having epilepsy. Diagnosis was confirmed by exercise and/or infusion of isoproterenol. Once the diagnosis was made, we started propranolol in all patients, and added verapamil if ventricular tachycardia was still inducible on a treadmill exercise test. An intracardiac defibrillator was implanted in 4 patients. Of the 16 patients, 4 died suddenly, giving a rate of mortality of 25%. In 2 of those dying suddenly, there was evidence of poor compliance to the recommended treatment. Another 2 patients had been resuscitated because of sudden cardiac arrest.Catecholaminergic polymorphic ventricular tachycardia must be considered in the differential diagnosis of syncope in children without heart disease but with a normal QT interval. Medical treatment with propranolol and verapamil may decrease the incidence of arrhythmia. Implantation of intracardiac defibrillators should be considered in those resistant to drug therapy. Delay in diagnosis, and inadequate treatment, can result in sudden cardiac death.

The effects of sevoflurane and desflurane anesthesia on QTc interval and cardiac rhythm in children

Background:  Inhalational anesthetics may prolong QTc interval (QT interval corrected for heart rate) of the ECG and cause life‐threathening arrythmias. The effects of desflurane on QTc interval and cardiac rhythm have not been reported previously in children. We assessed the effects of desflurane anesthesia on QTc interval and cardiac rhythm and compared them with sevoflurane anesthesia in children.

Comparison of sensitivity and specificity of tilt protocols with and without isoproterenol in children with unexplained syncope.

Head‐up tilt testing with or without isoproterenol is extensively used in the evaluation of patients with unexplained syncope. However, sensitivity and specificity of tilt protocols with and without isoproterenol have not been clarified in children, due to lack of age matched control subjects. This study was designed to assess and to compare the sensitivity and specificity of tilting alone and tilting in conjunction with isoproterenol. Thirty children with unexplained syncope (group I) and 15 age‐matched control subjects (control group I) underwent successive 60° head‐up tilts for 10 minutes during infusions of 0.02, 0.04, and 0.06 μg/kg/min of isoproterenol, after a baseline tilt to 60° for 25 minutes. Also, 35 children (group II) with unexplained syncope and 15 healthy control subjects (control group II) were evaluated by head‐up tilt to 60° for 45 minutes without an infusion of isoproterenol. In response to tilt protocol with graded isoproterenol, 23 (76.6%) of the patients in group I and 2 of the 25 (13.3%) control subjects developed syncope. Accordingly, the sensitivity of tilt testing with isoproterenol was 76.6%, and its specificity was 86.7%. Tilt testing without isoproterenol was positive in 17 (48.5%) of the patients in group II but in only 1 of the 15 (6.6%) control subjects. Thus, sensitivity and specificity of tilt testing without isoproterenol were 48.5% and 93.4%, respectively. The mean heart rate and systolic blood pressure decreased significantly (P < 0.001) in all tilt positive patients during syncope. In conclusion, the head‐up tilt test is a valuable diagnostic test in the evaluation of children with unexplained syncope, and isoproterenol is likely to increase the sensitivity of the test without decreasing its specificity.

The role of serotonin re-uptake inhibitors in preventing recurrent unexplained childhood syncope – a preliminary report

AbstractTo assess the efficacy of a serotonin re-uptake inhibitor, sertraline hydrochloride, in preventing recurrent neurocardiogenic syncope, we studied 15 patients (10 female; mean age 12.9 ± 2 years) with positive head-upright tilt test and resistant to standard pharmacotherapy, atenolol or disopyramide. The patients were given 50 mg oral sertraline hydrochloride daily for 6 weeks. Intolerance to the drug was seen in 3 patients and 2 had syncopal episodes during the therapy. A head-upright tilt table test was then repeated in 10 patients. Six were tilt negative and asymptomatic over a mean follow up period of 7 ± 3 months while four remained tilt positive: two experienced marked hypotension and bradycardia, characterized as mixed type syncope, and two had cardiac asystole, lasting >10 s, during tilting, thereby exhibiting a cardio-inhibitory response. Conclusion Sertraline hydrochloride may be useful in preventing recurrent neurocardiogenic syncope resistant to standard pharmacotherapy but careful clinical studies are essential before such a treatment strategy can be recommended since serious asystole could develop.

Causes of syncope in children: a prospective study

We prospectively evaluated 80 patients with syncope, between January 1991 and January 1992 to determine the causes of syncope in children. There were 35 male and 45 female patients, whose mean age was 10.5 years. A single syncopal attack had occurred in 30 patients and multiple attacks in 50. A cardiovascular cause was established in 22 (27.5%) patients and a noncardiovascular cause in 36 (45%). The cause remained unknown in 22 patients (27.5%). Vasovagal syncope was the leading cause of syncope in these patients with an incidence of 32.5%. These findings suggest that every patient who has even one syncopal attack should be promptly investigated since the underlying cause could be a life-threatening one.

Mitral and aortic insufficiency in polyarticular juvenile rheumatoid arthritis.

SummaryValvar heart disease is a rare complication of juvenile rheumatoid arthritis (JRA), the aortic valve being most commonly affected. Reported cases with symptomatic mitral involvement are rare. We describe a 13-year-old boy with seronegative, polyarticular onset of JRA in whom mitral and aortic valve insufficiency was diagnosed by clinical and laboratory investigations. Two-dimensional and continuous-wave Doppler echocardiography confirmed mild pericardial effusion with moderate mitral and mild aortic insufficiency. Cardiac assessment and echocardiogrphic follow-up are recommended in all patients with JRA.

Compatibility of Automatic Threshold Tracking Pacemakers with Previously Implanted Pacing Leads in Children

KUCUKOSMANOGLU, O., et al.: Compatibility of Automatic Threshold Tracking Pacemakers with Previously Implanted Pacing Leads in Children. The Autocapture function controls and optimizes the amplitude of the pacing pulse and saves energy. The manufacturer recommends using a special low polarization, low threshold bipolar Pacesetter lead for the Autocapture function. The purpose of this study was to evaluate the compatibility of Autocapture with previously implanted pacing leads. The study included 15 patients (mean age 13.6 ± 3.4 years) who needed pulse generator replacement and received the VVIR pacemaker Regency SR+ or the DDDR pacemakers Affinity DR or Integrity DR with the Autocapture function. The new pulse generators connected to previously implanted ventricular leads. At the time of implantation the pacing threshold was 1.0 ± 0.35 V at 0.5 ms, the lead impedance was 580 ± 80 Ω, and the spontaneous R wave amplitude was 7.89 ± 4.89 mV. The polarization signal (PS) was 3.8 ± 3.04 mV, and evoked response (ER) was 8.15 ± 4.57 mV at the predischarge testing. Follow‐up telemetry was done at months 1, 3, 6, 12, and 18. The follow‐up duration was 9.4 ± 5 months (range 1–18 months). If the results of PS and ER measurements were acceptable for Autocapture, it turned on at the 1‐month visit. In six (40%) patients the results were found acceptable for Autocapture function. Age, lead impedance, pacing threshold, intrinsic R wave measurement, lead age, fixation mechanism, and ER measurements were not statistically different in Autocapture suitable and not suitable groups. The main reason not to activate Autocapture had been increased PS. Any significant fluctuations were not observed in pacing threshold, lead impedance, ER, and PS during follow‐up. In conclusion, previously implanted pacing leads may be compatible with the Autocapture function.

Heart Rate Variability and Autonomic Nervous System Changes in Children with Vasovagal Syncope

ALEHAN, D., et al.: Heart Rate Variability and Autonomic Nervous System Changes in Children with Vasovagal Syncope. The aim of this study was to evaluate the HRV at rest and during tilt test (HUTT) in children with a history of vasovagal syncope and to link the HRV indices with the clinical results of the test. HRV indices were assessed in the supine position and during the initial 5 minutes of the 60‐degree HUTT in 49 patients (33 females, 16 males, mean age of 13 ± 2.8 years) who were evaluated for recurrent syncope. The positive to negative results of the test were 21 to 28. The normalized power of high frequency component (npHF) decreased, normalized power of low frequency component (npLF) and the LF:HF ratio increased during HUTT of tilt‐positive patients (P < 0.05 for each parameter). Parallel changes, but to a lesser degree, were observed for similar HRV parameters of tilt‐negative patients. In addition, the HF and all the time‐domain indices decreased significantly (P ≤ 0.05) during HUTT in the latter group. When the tilt‐positive and‐negative patients were compared, the npHF was lower (P = 0.002), npLF and LF:HF ratio were higher (P = 0.01 and P = 0.001, respectively) during the test in tilt‐positive patients, reflecting increased sympathetic tone in this group. A cut‐off point for LF:HF was assigned as 2.7 for differentiating tilt‐negative and tilt‐positive results. The specificity, sensitivity, and positive and negative predictive values of this cut‐off point were calculated as 93%, 52%, 85%, and 41%, respectively. Patients with vasovagal syncope show variations in vagal autonomic tone and appear to be more prone to syncope when their sympathetic tone is elevated at the beginning of the test. LF:HF > 2.7 is a specific marker (specificity 93%) and can correctly predict a positive tilt test in 85% of patients.

Parameters of iron deficiency in children with cyanotic congenital heart disease

A group of 67 children with cyanotic congenital heart disease (CCHD) were studied, and 35 were given iron treatment according to a regimen that gives iron to patients with a hematocrit (Hct) below 60%. The patients were categorized as iron-deficient and iron-sufficient according to their transferrin saturation and ferritin values. The pretreatment hemoglobin (Hb) and Hct values of the groups were similar. The mean Hct was nearly three times as much as the mean Hb in the iron-sufficient group and more than three times as much as the Hb in the iron-deficient group. Excessive erythrocytosis in the iron-deficient group was impressive. Mean corpuscular volume (MCV) values were below 72.7 fl in all of the iron-deficient patients. After treatment the Hb, Hct, transferrin saturation, and ferritin increased significantly in both groups, with the increments greater in the iron-deficient group. Increments in the erythrocyte (RBC) count were significant in the iron-sufficient group but insignificant in the iron-deficient one. Increments of MCV in the iron-deficient group were significant but insignificant in the iron-sufficient group. Our study demonstrated that prediction of Hb, RBC count, and MCV, measurements of which are easy and inexpensive and require little blood, can suffice for the diagnosis of iron deficiency in patients with CCHD without altering systemic perfusion.