Paroxysmal Complete Atrioventricular Block: A Rare Cause of Syncope in Children.

Paroxysmal atrioventricular block (PAVB) is a rare cause of syncope, mostly reported in adults. In the present study, a child with recurrent syncope due to PAVB is reported. A 12-year old boy was admitted due to syncope. Some syncopal episodes were consistent with vasovagal syncope, while others had atypical features. Electrocardiography, echocardiography and 24-hour electrocardiography monitoring were normal. Head-up tilt table test revealed mixed type vasovagal syncope. With beta-blocker treatment, the frequency of syncopal episodes decreased; however, the episodes with atypical features continued. Intracardiac electrophysiological study was normal, but repeated external loop recorder monitoring revealed transient AVB during a syncopal episode. In children with syncope with atypical features, PAVB should be kept in mind. Repeated external loop recorder monitoring may be useful in the diagnosis of such seldom seen arrhythmic causes.

The utility of multidetector computed tomography for evaluation of congenital heart disease.

BACKGROUND: Congenital heart diseases (CHD) are the leading cause of birth defect-related deaths. Multi detector computed tomography (MDCT) plays an important role for imaging CHD in addition to echocardiography and provides a comprehensive evaluation of complex heart malformations for the referring cardiologist. The aim of the study was to evaluate the utility of MDCT in the assessment of CHD. MATERIALS AND METHODS: A 102 patients with CHD were investigated after initial assessment by echocardiography. The information obtained by MDCT and findings of echocardiography were reviewed together by paediatric cardiologists and cardiac radiologists. Perioperative anatomic descriptions, wherever available(n = 34) formed the gold standard for the comparison. RESULTS: The clinical consensus diagnosis defined 154 cardiovascular lesions in the patients. The results were classified in groups. We present the appearance of various congenital cardiac lesions seen in clinical practice. CONCLUSIONS: MDCT provides important information about anatomic details of CHD for the referring cardiologist. The evaluation of different anatomic structures such as heart, great vessels, lungs and abdomen is possible in one acquisition with this technique.

Determination of anomalous pulmonary venous return with high-pitch low-dose computed tomography in paediatric patients.

BACKGROUND: In this study, we aimed to image pulmonary venous return anomalies and associated cardiovascular and pulmonary abnormalities by high-pitch low-dose computed tomography (CT) in children. MATERIALS AND METHODS: Forty-one patients with total or partial anomalous pulmonary venous return anomalous between May 2012 and June 2019 were retrospectively reviewed. The anomalies were determined using high-pitch low-dose CT. The patients' mean age was 3 years (6 months to 15 years), and 24 of them were female. RESULTS: There were 10 patients with total pulmonary venous return anomalies (TPVRA) and 31 patients with partial pulmonary venous return anomalies (PPVRA). Six (60%) patients with TPVRA had the supracardiac type, 2 (20%) had the cardiac type, and 2 (20%) had the mixed type. All patients with TPVRA had a large atrial septal defect (ASD), 1 patient also had patent ductus arteriosus, and 1 patient had right cardiac hypertrophy. Forty cases of PPVRA were found in 31 patients. Twenty-seven (67%) of them were right-sided, and 13 were left-sided (33%). Twenty (65%) patients also had an additional cardiovascular anomaly (ASD in 12 patients, persistent superior vena cava in 4 patients, patent ductus arteriosus in 3 patients, and aortic coarctation in 2 patients). Of the 27 patients with right-sided PPVRA, it drained into the superior vena cava in 19 patients, the right atrium in 5 patients, and the inferior vena cava in 3 patients. In left-sided cases, the anomalous pulmonary vein drained into the left innominate vein in 9 patients, and in 4 patients, there were accessory pulmonary veins that drained into the left innominate vein. Many of the patients had additional lung anomalies, including pneumonic infiltration (n = 12), atelectasis (n = 8), and lobar emphysema (n = 5), and some of these findings coexisted. CONCLUSIONS: Anomalous pulmonary venous drains and associated cardiac and extra-cardiac anomalies can be detected reliably and quickly with high-pitch low-dose CT without sedation in paediatric patients.

Serum carnitine levels during the doxorubicin therapy. Its role in cardiotoxicity.

Doxorubicin is an anthracycline antibiotic with a broad spectrum of antineoplastic activity. Cardiotoxicity is a serious long-term complication of the drug. Simultaneous administration of carnitine has been proposed to prevent cardiotoxicity. We aimed to monitor the serum carnitine levels during the treatment of doxorubicin and to determine a relationship between serum carnitine levels and cardiac dysfunction. Fifteen patients were evaluated prospectively. Measurement of carnitine levels and evaluation of cardiac function were performed prior to treatment, and after cumulative doses of 180 and 300 mg/m2 of doxorubicin. A group of 20 healthy children served as control group to obtain reference values. We found subclinical abnormalities in cardiac function, while the cumulative doses of the doxorubicin was increasing. The mean end diastolic and end systolic left ventricular dimensions of the patient group after completion of the treatment were significantly increased compared with initial values. The ejection and shortening fraction of the patient group after cumulative doses of 300 mg/m2 of doxorubicin were significantly lower than those of the control group. A statistically significant augmentation was observed in mitral A, with a decrease in mitral E/A ratio. There was a trend towards lower serum carnitine levels with higher cumulative doses of doxorubicin, although it was not statistically significant. Our results invite new detailed investigations depending on the measurement of serum and urinary free and acyl carnitine and myocardial carnitine levels to evaluate possible roles of carnitine in the prevention of doxorubicin-induced cardiotoxicity.

Balloon dilation of stenotic nonvalved conduits after Fontan operation.

The Fontan operation is used to supply a ventriculo-arterial connection in patients with tricuspid atresia. An important complication is the obstruction of the conduit that may necessitate reoperation. In these patients balloon dilation of the conduit stenosis has been advocated as a method to relieve the obstruction and postpone surgical replacement. While there are several reports about the balloon dilation of stenotic valved conduits, we do not have enough information about the results of balloon dilation of nonvalved conduits. We performed successful balloon dilations in two patients with tricuspid atresia who underwent the Fontan operation and had stenotic nonvalved conduits. In the first patient, the stenosis was relieved but recurred. A second balloon dilation procedure was performed, and the patient has been symptom free for one year. In the second patient, the stenosis was relieved but recurred. Our preliminary results suggest that balloon dilation is an efficient method to relieve the obstruction in stenotic nonvalved conduits and can be repeated successfully if the stenosis recurs.

Torsade de pointes associated with encephalitis.

Torsade de pointes is a polymorphic ventricular tachycardia. Causes of torsade de pointes are well described. Although intracranial disease can produce dramatic electrocardiographic (ECG) changes, we are not aware of previous cases with torsade de pointes and encephalitis. We report a case with encephalitis who developed torsade de pointes, and was treated with temporary ventricular pacing and magnesium infusion.

Vascular ring formed by right aortic arch with aberrant left subclavian artery and left ligamentum arteriosum: a rare cause of respiratory distress in newborn infants.

Vascular ring, in which the trachea and esophagus are completely surrounded by vascular structures, is one of the causes of respiratory distress in children. Right aortic arch with aberrant left subclavian artery is a common aortic arch anomaly; however, respiratory distress due to vascular ring is seldom associated with this anomaly. We report herein a newborn infant treated surgically because of severe respiratory distress caused by vascular ring formed by right aortic arch with aberrant left subclavian artery and left ligamentum arteriosum. As laryngomalacia was first thought to be the reason for respiratory distress, we suggest that patients with respiratory distress diagnosed with laryngomalacia be evaluated for possible vascular ring.

A case of isotretinoin embryopathy with bilateral anotia and Taussig-Bing malformation.

We report a newborn infant with multiple congenital anomalies (anotia and Taussig-Bing malformation) due to exposure to isotretinoin within the first trimester. In this paper we aim to draw to the fact that caution is needed when prescribing vitamin A-containing drugs to women of childbearing years.

Microdeletion of 22q11 (CATCH 22) in children with conotruncal heart defect and extracardiac malformations.

CATCH 22 is a medical acronym for cardiac defects, abnormal facies, thymic hypoplasia, cleft palate, and hypocalcemia, and a variable deletion on chromosome 22q11. The deletion within the chromosome region of 22q11 may occur in patients with dysmorphologic and cardiological syndromes: DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), and conotruncal anomaly face syndrome (CAFS). In this study, using N25 (D22S75) DiGeorge chromosome region probe. fluorescence in situ hybridization (FISH) analyses were performed on 32 patients with congenital heart diseases. Twenty-nine of 32 patients had conotruncal heart disease. A 22q11 deletion was detected in two patients (6.9%) of the 29 patients with conotruncal heart disease. One of our 22qdel (+) patients had unilateral facial nerve palsy. Although it is not a frequent finding, unilateral facial nerve palsy will be included among the symptoms of CATCH 22 syndrome. After careful clinical evaluation of patients with conotruncal cardiac anomalies, only syndromic cases should be screened for this deletion.

Mycotic pseudoaneurysm of the ascending aorta following purulent pericardial effusion diagnosed by multi-slice computed tomography.

Mycotic pseudoaneurysm of the aorta is an uncommon disease, especially in childhood but has a high mortality due to spontaneous rupture. It is caused by endarteritis following bacteraemia or fungaemia. Due to spontaneous rupture, early diagnosis is very important.

Cardiac multidetector computed tomography (MDCT) of spontaneously closed ventricular septal defect.

PURPOSE: The authors present the findings of contrast-enhanced electrocardiogram (ECG)-gated cardiac computed tomography (CT) in 18 patients with probably spontaneous closure of muscular ventricular septal defect (VSD). MATERIALS AND METHODS: The study included 2,725 consecutive patients referred to our hospitals for multidetector computed tomography (MDCT) coronary angiography. The patients were between the ages of 5 and 78 [mean+/-standard deviation (SD) 59+/-13.86] years, and 1,816 (66.6%) were male. Evaluating the images for coronary artery pathologies revealed pouches or sacs in the central muscular location of the septa of some patients. RESULTS: All patient records were retrospectively reviewed, and 18 patients were found to have pouches or sacs in the interventricular septum location likely to be spontaneous closure of muscular VSD (0.66% prevalence). MDCT findings of these 18 patients correlated with their echocardiographic findings. Of the patients with muscular VSD, 13 were male and five were female. These 18 patients were initially referred due to indications such as chest pain (n=11), risk-factor assessment (n=3), coronary artery anomaly (n=1), suspected aberrant right subclavian artery due to dysphagia (n=1) and coronary artery bypass graft (n=2). CONCLUSIONS: Our study shows that the incidence of spontaneous closure of muscular VSD with central septum location is probably higher than expected. Thus, some patients initially diagnosed with ventricular diverticula with an apical and marginal septum location may actually have spontaneously closed muscular VSD. This finding may affect previously reported rates of both ventricular diverticula and spontaneous closure of muscular VSD.

Carotid intima-media thickness: is it correlated with stroke side?

OBJECTIVE: The objective of the present study was to investigate the possible correlation between the common carotid artery (CCA) intima-media thickness (IMT) and the infarct side. METHOD: The CCA IMTs in patients with atherosclerotic non-lacunar stroke were measured. RESULTS: The mean age of the patients was 64.3 +/- 10.7 years (range 40-83 years) and 42 of 100 patients were male. The infarcts were at the left side in 53 patients and at the right side in 47 patients. The mean CCA IMT was 1.02 +/- 0.18 mm at the infarct side and 0.87 +/- 0.17 mm at the contralateral side. The difference between them was statistically significant (P < 0.01). Although the mean age of the patients with a left-sided infarct was greater than that of the patients with a right-sided infarct, the difference was not statistically significant. CONCLUSION: Our results suggest that CCA IMT may be used in prediction of possible infarct side, and in the prediction of potential risk of stroke by evaluating the IMT of both CCAs separately.

Effectiveness and safety of intravenous amiodarone in drug-resistant tachyarrhythmias of children.

BACKGROUND: Experience with pediatric use of intravenous amiodarone is limited. In this study, our experiences with intravenous amiodarone in children with acute life-threatening or chronic tachyarrhythmias are reviewed. METHODS AND RESULTS: Twelve patients, with a mean age of 3.4 +/- 3.1 years, range 9 months-10 years (two with incessant ventricular tachycardia, one with ectopic atrial tachycardia, two with atrioventricular re-entrant tachycardia (three episodes), four with postoperative or congenital junctional ectopic tachycardia, two with bradycardia-tachycardia syndrome, one with atrial tachycardia) were treated with intravenous amiodarone during 13 tachycardia episodes. Left ventricular systolic functions were depressed in six patients. In 11 patients, a median of two drugs (range one-four), including adenosine infusion and in five cases direct current cardioversion were tried without success prior to intravenous amiodarone. The loading dose of amiodarone was 5 mg/kg in all episodes, infused over 1 h. Maintenance infusion was required in 12 episodes. In 10 episodes (77%), amiodarone was considered effective, in one (7.6%) partially effective (junctional ectopic tachycardia) and in two (15.4%) ineffective (sick sinus syndrome, atrial tachycardia). Therapeutic effect was obtained in a median period of 30 h (range 1-103 h). The mean effective maintenance dose was 10 +/- 4.7 micrograms/kg per min (range 5-15 micrograms/kg per min). In one patient, mild hypotension, and in three patients cellulitis occurred, but none of them necessitated termination of treatment. CONCLUSIONS: Intravenous amiodarone is found to be an effective and safe antiarrhythmic agent for children with acute life-threatening and chronic tachyarrhythmias and depressed left ventricular systolic functions.

Comparison of normal sinus rhythm and pacing rate in children with minute ventilation single chamber rate adaptive permanent pacemakers.

Rate adaptive pacemakers are used to achieve a better cardiac performance during exercise by increasing the heart rate and cardiac output. The ideal rate adaptive sensor should be able to mimic sinus node modulation under various degrees of exercise and other metabolic needs. Minute ventilation sensing has proven to be one of the most accurate sensor systems. In this study, alterations in sinus rhythm and pacing rates during daily life conditions in 11 children (median age 11 years, range 6-14 years) with minute ventilation single chamber pacemakers were investigated. Correlation of sinus rhythm with pacing rates was assessed. ECG records were obtained from 24-hour Holter monitoring. Average rates of five consecutive P waves and pace waves were determined every half hour. The average of the two values was then used to determine hourly rates. Correlation coefficients between the sinus rhythm and pacing rates were calculated. In nine patients, pacing rates correlated well to sinus rhythm (range 0.6793-0.9558, P < 0.001 and P < 0.05), whereas in two cases correlation was not sufficient (P > 0.05). Most of the patients, in whom rate response factor (RRF) measurements during peak exercise by treadmill with chronotropic assessment exercise protocol were performed and pacemakers were programmed to these parameters, had more appropriate ventricular rates compared to spontaneous sinus rates. In these patients mean RRF value was 15.3 +/- 2.7 (range 12-20, median 15). This study shows that during daily activities minute ventilation rate adaptive pacemakers can achieve pacing rates well correlated to sinus rhythm that reflects the physiological heart rate in children.

Clinical and genetic correlate in childhood onset Friedreich ataxia.

We analyzed the clinical and genetic aspects of 28 FRDA patients from 20 families. 19 families were consanguineous. The onset was between 4 and 13 1/2 years of age (mean 15.4 +/- 6.2). Three patients presented with cardiomyopathy, one with weakness, and the rest with ataxia. There were two patients with preserved lower-limb deep tendon reflexes. Sensory nerve action potentials were reduced in 14/14 patients. Cardiac echograms were abnormal in 17/19 cases, and this was between 6 and 16 years of age (mean 10.1 +/- 3.5). Four families were multiplex. Clinical intra-familial variability was observed. Increased GAA repeats of the X25 gene were found in 27/28 patients studied, all in a homozygous state. 88.9% of patients had a smaller allele larger than 500 repeats, and 66.7% had more than 700 repeats. The patient who did not have increased GAA repeats in both alleles had peculiar findings. Significant correlation of expansion was obtained for the early onset, and cardiomyopathy as the onset.

Transcatheter closure of patent ductus arteriosus using controlled-release coils.

Controlled-release coils have become available recently for the closure of patent ductus arteriosus (PDA). Transcatheter closure of patent arterial ducts was attempted in 13 patients, ranging in age from 5 months to 15 years, mean 4.1 years. Implantation of controlled-release PDA coils was attempted via the femoral artery through 5 Fr catheters in all cases except one, in whom both the femoral arterial and venous routes were used. The procedure was successful in 10 of the 13 patients. In these, the pulmonary artery systolic pressure ranged between 25 and 42 mmHg and the duct diameter varied from 1.5 to 6 mm at its narrowest point. Six of the patients received a single coil. Two coils were inserted in three patients and three coils in one patient. In three patients the ducts were too large for safe release of the coils, despite attempted implantation of up to three coils simultaneously. These coils were easily withdrawn into the catheter. Immediately at the end of the procedure, the duct was completely occluded in nine of the 10 patients, and in one patient there was a small residual flow. The procedure time varied between 35 min and 2.5 h, mean 81 min and the fluoroscopy time varied from 5 to 78 min, mean 25 min. None of the patients experienced hemorrhage, diminished lower extremity pulse, hemolysis or infection. In one patient, a 5 mm coil embolized into the right pulmonary artery soon after release. It was retrieved with a snare, then 8 mm and a 5 mm coil were implanted satisfactorily in the arterial duct. At follow-up by color Doppler echocardiography, the duct was completely occluded in all patients. Transcatheter closure of patent arterial ducts by controlled-release PDA coils is effective and safe. Even when more than one coil is inserted, it is still cheaper than transcatheter umbrella closure. This method is therefore of great value, particularly in less affluent countries.

Comparison of mid-term clinical experience with steroid-eluting active and passive fixation ventricular electrodes in children.

Although active fixation ventricular leads seem to have advantages over passive fixation leads, this study compares the follow-up results of active and passive fixation leads in children. We evaluated the implantation and follow-up data of 41 children with active (Accufix II DEC, group 1) (n = 20) or passive (Membrane E, group 2) (n = 21) fixation, steroid-eluting ventricular leads. All but one of the patients in group 1 completed the 12-month follow-up. The mean follow-up period in group 2 was 10.4 +/- 2.9 months (range 3-12 months, median 12 months). In both groups the mean pacing threshold was measured as 0.51 +/- 0.09 V versus 0.48 +/- 0.15 V (P > 0.05) at 0.5-ms pulse width, mean R wave amplitude as 9.9 +/- 2.5 mV versus 9.4 +/- 3.2 mV (P > 0.05), and mean impedance as 557 +/- 92 omega versus 664 +/- 160 omega (P < 0.05), respectively, at implantation. After the first week of pacing, mean threshold values in group 1 were significantly lower than those of group 2 (P < 0.01 and P < 0.05, respectively). During the follow-up period, lead impedance measurements did not show a significant difference between the two groups. In one patient from group 1, the lead (by unscrewing) was removed easily because of pacemaker pocket infection. No lead dislodgement or helix deformation occurred in group 1. Nevertheless, in one patient from group 2, the lead was extracted at 4-month postimplantation because of lead displacement. We conclude that the steroid-eluting active fixation lead (Accufix II DEC) have advantages of easier implantation and lower acute and chronic stimulation thresholds compared to the passive fixation lead (Membrane E). Therefore, Accufix II DEC is superior to Membrane E, and it is a better first choice in children with an implanted single chamber ventricular pacemaker.