[Supraventricular tachycardia in infants, children and adolescents: diagnosis, drug and interventional therapy]

Supraventricular tachycardias are the most frequent forms of symptomatic tachyarrhythmias in infants, children and adolescents. Clinical symptoms depend on age and underlying cardiac anatomy. Newborn babies and infants with paroxysmal atrioventricular reentrant tachycardias usually present with signs of congestive heart failure due to rapid heart rate. In older children and adolescents, palpitations are the leading symptom. Patients with chronic-permanent tachycardias (i.e., atrial ectopic tachycardia, permanent form of junctional reciprocating tachycardia) often develop a secondary form of dilated cardiomyopathy, the so-called "tachymyopathy". Adenosine has evolved as the drug of choice in any age group for the termination of atrioventricular reentrant tachycardia of any origin. In addition, it serves as a diagnostic tool in primary atrial tachycardias. Long-term management of atrioventricular reentrant tachycardia in infancy and childhood is age dependent. In newborn babies and infants, pharmacological therapy is advised due to the high spontaneous cessation rate of those tachycardias at the end of the first year of life. In contrast to this, the probability of spontaneous cessation of tachycardia in children > 1 year of age is very low. Therefore, radiofrequency catheter ablation of the anatomical substrate of the tachycardia is a rational alternative to long-lasting antiarrhythmic therapy. Results in children with a structurally normal heart are comparable to those achieved in adults. In patients with congenital heart disease and supraventricular tachycardias, catheter ablation during preoperative cardiac catheterization is recommended. Atrial reentrant tachycardias have been identified as one major risk factor for late postoperative morbidity and mortality in young patients. Pharmacological therapy is often not sufficient to control the tachycardia. In addition, underlying sinus node dysfunction may be aggravated in a considerable portion of the patients affected. Catheter ablation based on conventional endocardial mapping techniques by multipolar electrode catheters with the aim of identifying the critical region of the reentrant circuit is associated with an impaired success rate and a considerable recurrence rate. It may be assumed that, using the modern mapping techniques currently available (electroanatomical mapping and non-contact mapping), results of radiofrequency catheter ablation of atrial reentrant tachycardias after surgical correction of congenital heart disease will be significantly improved within the next few years.

Effects of intracardiac radiofrequency current application on coronary artery vessels in young pigs

INTRODUCTION

Radiofrequency current is widely used in children to ablate accessory AV pathways. Previous data in a pig model demonstrated coronary artery obstruction adjacent to radiofrequency current lesions 48 hours and 6 months after energy delivery. In the present study, the long-term effects (>6 months) of radiofrequency current application on coronary artery vessels in young pigs are assessed.

METHODS AND RESULTS

Radiofrequency current (500 kHz) was delivered over 30 seconds in ten piglets (mean body weight 12.8 kg) using a steerable 6-French catheter with a 4-mm thermistor tip electrode (target temperature 75 degrees C). Lesions were created under fluoroscopic and electrocardiographic guidance at the lateral right atrial (RA) wall above the tricuspid valve orifice, and at the lateral left atrial and left ventricular wall adjacent to the mitral valve orifice. Selective coronary angiography and intravascular ultrasound (IVUS) studies were performed 3, 6, 9, and 12 months after energy application. After 12 months, the lesions were studied pathohistologically. All lesions consisted of compact fibrous tissue. RA lesions extended to the adjacent right coronary artery and led to coronary artery involvement with increased fibrous tissue in the adventitia and media and intimal thickening in three animals. Coronary arterial narrowing was documented by IVUS during follow-up in all three cases 9 months after energy application. Angiography failed to demonstrate coronary pathology in any of the three animals.

CONCLUSION

The risk of late coronary artery lesions must be considered when catheter ablation at the RA wall is planned in children with free-wall accessory AV pathways.

Supraventricular tachycardia in infants, children and adolescents: diagnosis, and pharmacological and interventional therapy

Supraventricular tachycardia is the most frequent form of symptomatic tachydysrhythmia in children. Neonates and infants with paroxysmal supraventricular tachycardias generally present with signs of acute congestive heart failure. In school-aged children and adolescents, palpitations are the leading symptom. Chronic-permanent tachycardia results in a secondary form of dilated cardiomyopathy. Therapy for episodes of tachycardia depends on the individual situation. In severe haemodynamic compromise, or if ventricular tachycardia is suspected, tachycardia should immediately be terminated by external cardioversion during deep sedation. Vagal manoeuvres are effective in patients with atrioventricular reentrant tachycardias. Adenosine is the drug of first choice in any age group for tachycardias involving the atrioventricular node; its advantages include short half-life and minimal or absent negative inotropic effects. Adenosine may also be used in patients with wide QRS complex tachycardia. Intravenous verapamil is contraindicated in neonates and infants because of the high risk of electromechanical dissociation. In older children (>5 years) and adolescents, verapamil may be administered with the same restrictions as in adult patients (wide QRS complex tachycardia, significant haemodynamic compromise). Spontaneous cessation of tachycardia can be expected in most neonates and infants during the first year of life. Prophylactic pharmacological treatment in this age group is advisable because recognition of tachycardia is often delayed until the occurrence of symptoms. Withdrawal of drug treatment should be attempted around the end of the first year. However, in older children, spontaneous cessation of tachycardia is rare. Prophylactic drug therapy is performed on an empirical basis. Digoxin may be administered in all forms of supraventricular tachycardia in which the atrioventricular node is involved, except in patients with pre-excitation syndrome aged >1 year. In patients with atrioventricular reentrant tachycardia, class IC drugs such as flecainide and propafenone are effective. Sotalol is also effective in atrioventricular reentrant tachycardia, as well as in primary atrial tachycardia. Although amiodarone has the highest antiarrhythmic potential, it should be used with caution because of its high rate of adverse effects. In school-aged children and adolescents, radiofrequency catheter ablation of the anatomical substrate is an attractive alternative to drug therapy, with a rate of permanent cessation of the tachycardia of up to 90%. Despite the clear advantages of this procedure, it should be performed only with unquestionable indication; the long term morphological and electrophysiological sequelae on the growing atrial and ventricular myocardium are still unknown.

Strand cleavage of supercoiled DNA by water-soluble peroxyl radicals. The overlooked importance of peroxyl radical charge

It is well established that the peroxyl radicals formed during the thermal decomposition of 2,2'-azobis(amidinopropane), ABAP, in oxygenated water can cleave double-stranded DNA, from which fact it has been concluded that peroxyl radicals, as a general class, can induce DNA strand scission. However, the ABAP-derived radicals are positively charged, and DNA is a negatively charged polyanion. Moreover, the relatively small and, therefore, free to diffuse peroxyl radicals likely to be formed in vivo will generally be negatively charged or neutral. Plasmid supercoiled DNA [pBR 322, 4361 base pairs (bp)] was reacted with known, equal fluxes of two positively charged peroxyl radicals, a negatively charged peroxyl radical, and a neutral peroxyl radical. The two positively charged peroxyl radicals degraded >/=80% of the supercoiled pBR 322 at a flux of 4 radicals/bp, but the negatively charged and neutral peroxyl radicals had no significant effect even at a flux as high as 24 radicals/bp. The same lack of effect on the DNA was also observed with high fluxes of superoxide/hydroperoxyl radicals. Similar results were obtained with another supercoiled DNA, pUC 19, except that pUC 19 is somewhat more sensitive to strand scission by positively charged peroxyl radicals than pBR 322. We conclude that most of the peroxyl radicals likely to be formed in vivo have little or no ability to induce DNA strand scission and that the potential role of electrostatics in radical/DNA reactions should always be considered.

Self-reported needlestick injuries in dental health care workers at Armed Forces Hospital Riyadh, Saudi Arabia

The objective of the present study was to assess the incidence of sharps/needlestick injuries among dental health care workers (DHCWs) at Armed Forces Hospital Riyadh. A questionnaire was distributed among all dental staff, including dentists, hygienists, and dental surgery assistants. Results show that 65 individuals (58%) had sharps/needlestick injuries, and of these, more than half did not report these injuries to the appropriate department. At the time of injury, the majority of the DHCWs were vaccinated or immune, but a few of them were not vaccinated against hepatitis B virus. This study concludes that every DHCW should be immunized against hepatitis B virus to avoid cross-infection from sharps/needlestick injuries, which are quite common in a dental practice. The high frequency of these injuries could be reduced by simple interventions.

[Early postoperative dysfunction of a modified Blalock-Taussig shunt: successful therapy with angioplasty and stent implantation in the subclavian artery]

A newborn with pulmonary atresia with ventricular septal defect and transposition of the great arteries was palliated with a modified Blalock-Taussig shunt at 5 days of age. Three days postoperatively arterial oxygen saturations dropped significantly. Thrombosis of the shunt was suspected. Angiography revealed stenosis of the proximal subclavian artery related to the creation of the shunt. The patient was successfully treated with angioplasty and stent implantation into the stenotic subclavian artery. Follow-up angiography 3 months after stent deployment showed a completely patent subclavian artery and unobstructed blood flow across the modified Blalock-Taussig shunt.

Anterograde double-balloon valvoplasty for treatment of severe valvar aortic stenosis in a preterm baby weighing 1400 grams

We describe our treatment of a premature baby born weighing 1400 g with severe aortic stenosis, with a gradient of 80 mmHg across the valve. Efforts to advance a 6 mm angioplasty catheter into the stenotic aortic valve via the left ventricle failed. Anterograde angioplasty, instead, was performed using two 4 mm coronary angioplasty catheters. Six months subsequent to the intervention, the pressure gradient measured 25 mmHg, and there was no hemodynamically significant aortic insufficiency.

Percutaneous transluminal angioplasty for the treatment of complete arterial occlusion after retrograde cardiac catheterization in infancy

Nine patients with arterial thrombosis were treated with transcatheter recanalization and subsequent balloon dilation of the occluded vessel. Repeat angiography or duplex sonography 3 to 14 months after intervention showed completely patent arteries without restenosis in 7 patients; there was residual narrowing of the vessel in the remaining 2 patients.

Transcatheter closure of atrial septal defect with a new flexible, self-centering device (the STARFlex Occluder)

The purpose of this study was to evaluate the short-term safety and efficacy of the STARFlex Occluder for transcatheter closure of atrial septal defects with difficult anatomy. Transcatheter closure of the defect was attempted and successfully performed in 5 patients; the "stretched" defect diameter ranged from 12 to 24 mm and the implanted devices ranged from 23 to 33 mm.

Instantaneous pressure-flow velocity relations of systemic venous return in patients with univentricular circulation

OBJECTIVE

To assess the pressure and flow velocity relations and respiratory variability of the systemic venous and hepatic venous return in patients with univentricular circulation.

PATIENTS

15 selected patients who had undergone cavopulmonary anastomosis (10) or atriopulmonary anastomosis (5). Mean age at operation was 55.1 months (range 9 to 145). Studies were done at 75.5 (32.6) months (mean (SD)) after the operation.

SETTING

Tertiary referral centre.

METHODS

Patients were studied using simultaneous recordings of ECG, pressure trace, respirometer trace, and pulsed Doppler echocardiography. Mean systemic venous pressure and pulmonary vascular resistance did not differ significantly between the two patient groups.

RESULTS

After total cavopulmonary anastomosis, systemic venous pressure tracings showed a flattened pressure curve without any dependence on cardiac or respiratory cycle. After atriopulmonary anastomosis, right atrial pressure tracings showed a significantly higher "a" wave corresponding to atrial contraction, without any respiratory variability. Pulsed Doppler examination of the superior and inferior caval vein and hepatic vein after total cavopulmonary anastomosis did not show a reverse flow after atrial contraction. The inspiratory to expiratory velocity ratio of antegrade flow revealed a significant dependence of flow on changes in intrathoracic pressure in the intra-atrial tunnel, caval veins, and hepatic vein. During expiration, decrease or cessation of antegrade hepatic venous flow was documented. After an atriopulmonary anastomosis, there was a biphasic antegrade venous flow pattern without significant respiratory variation.

CONCLUSIONS

After total cavopulmonary anastomosis, there was marked respiratory dependence of systemic and hepatic venous return, whereas after an atriopulmonary anastomosis venous flow pattern varied according to cardiac cycle and pressure trace. The effects of total cavopulmonary anastomosis on venous return might counteract its other haemodynamic advantages.

Hepatitis B awareness and attitudes amongst dental health care workers in Riyadh, Saudi Arabia

This study was done to investigate the current awareness and uptake of the hepatitis-B vaccination, as well as any changes in patterns over the years. A questionnaire was distributed among all dental staff, including dental specialists, general dentists, hygienists and dental surgery assistants at the dental department of the Military Hospital, Riyadh. Out of 126 DHCW, 112 (88.2%) responded. Ninety-six (85.7%) completed full course of vaccination, 4 (3.6%) did not intend to, be vaccinated and 10 (8.9%) were naturally immune. Of the 96 vaccinate, 42 (43.8%) did not confirm the vaccine efficacy by serological tests. And 54 vaccinate who had post-vaccination serology test, 26 (48.2%) did not check the results of the test. It is concluded from the study that in spite of greater acceptability of the HB vaccine by the DHCW, still a large proportion of them need further advise on the importance of post-vaccination serological tests.

Idiopathic ventricular tachycardia in infancy and childhood: a multicenter study on clinical profile and outcome. Working Group on Dysrhythmias and Electrophysiology of the Association for European Pediatric Cardiology

OBJECTIVES

The present study intended to evaluate the clinical profile and outcome in a large cohort of pediatric patients with idiopathic ventricular tachycardia (VT).

BACKGROUND

Ventricular tachycardia (VT) without underlying heart disease is rare in childhood. Limited information is available with regard to outcome and indications for long-term antiarrhythmic treatment.

METHODS

A retrospective multicenter study was conducted. Patient data were obtained from the individual centers using a standardized questionnaire.

RESULTS

Ninety-eight pediatric patients with episodes of VT in the absence of structural heart disease were included. Mean age at first manifestation of the arrhythmia was 5.4 years (range 0.1 to 15.1), with 27% of the patients having had VT already in infancy. Clinical symptoms or echocardiographic signs of left ventricular dysfunction were observed initially in 36% of the patients, of which one third (12% of the whole population) presented with severe symptoms (heart failure or syncope). After a mean follow-up of 47 months (range 12 to 182), no patient had died. Twenty-five patients had never been treated with antiarrhythmic drugs. Sixty-three patients were free of VT and did not take antiarrhythmic drugs at last follow-up. Prognosis was better when VT occurred during the first year of life (VT resolution in 89%) compared with VT occurrence beyond the first year of life (VT resolution in 56%: p < 0.01). The clinical profile was more favorable for patients with presumed right VT (VT resolution in 76%, symptoms in 25% of patients) compared with patients with presumed left VT, where VT resolution occurred in 37% and symptoms in 67% of patients (p < 0.01).

CONCLUSIONS

VT in children with a normal heart carried a good prognosis. Outcome was better after onset of VT during infancy and when VT originated in the right ventricle. A restrictive use of antiarrhythmic agents might be justified in a large proportion of these patients.

Transcatheter recanalization and subsequent stent implantation for the treatment of early postoperative thrombosis of modified Blalock-Taussig shunts in two children

Two babies with duct-dependent cyanotic congenital heart disease were palliated with modified Blalock-Taussig shunts. One patient was diagnosed to have tetralogy of Fallot, and the other patient, tricuspid atresia type Ia. Early postoperative arterial oxygen saturations dropped significantly due to shunt thrombosis. Both patients were successfully treated with angioplasty and stent implantation.

Radiofrequency current application on immature porcine atrial myocardium: no evidence of areas of slow conduction after 12-month follow-up

INTRODUCTION

Radiofrequency current (RFC) application is a widely used procedure for treatment of supraventricular arrhythmias. The purpose of this study was to investigate late electrophysiologic sequelae of RFC lesions at immature atrial myocardium in pigs, as they have not yet been systematically investigated in vitro.

METHODS AND RESULTS

RFC application (temperature guided) was performed in seven piglets (mean age 6 weeks) by a steerable 6-French electrode catheter positioned at the lateral aspect of the tricuspid valve annulus. After 12 months, hearts were removed, and lesions with surrounding tissue were isolated. The viable tissue at the border of the specimen was paced with a cycle length of 500 and 600 msec. One hundred fifty impalements were performed on each specimen using capillary microelectrodes to record action potential characteristics from the lesion's surface and the surrounding tissue. In all seven specimens, no transmembrane action potentials from the fibrotic surface of each of the lesions could be recorded. The surrounding viable tissue was sharply demarcated electrically. No areas of slow conduction were detected. Action potential characteristics as mean maximum diastolic transmembrane potential, mean action potential duration at 90% repolarization, and upstroke velocity of phase 0 of the action potential were all normal.

CONCLUSION

No evidence of areas of slow conduction 12 months after RFC application at immature atrial myocardium suggests that this technique is safe regarding occurrence of late atrial tachyarrhythmias after the procedure.

Stepwise interventional approach in a neonate with pulmonary valve atresia and intact ventricular septum

In neonates with pulmonary atresia and intact ventricular septum the aims of therapy are maintenance of pulmonary blood flow and right ventricular decompression in order to achieve right ventricular support of the pulmonary circulation. Recent developments in interventional heart catheterization with pulmonary radiofrequency-assisted balloon valvuloplasty and ductal stent implantation offer an alternative to the classical surgical approach. We report on a neonate with membranous pulmonary atresia and intact ventricular septum, in whom a large interatrial right-to-left shunt via the foramen ovale persisted after radiofrequency-assisted pulmonary balloon valvuloplasty on the 2nd day of life. The interatrial shunt prevented adequate right ventricular filling and antegrade pulmonary perfusion leading to severe cyanosis (transcutaneous oxygen saturation 40%). In order to increase pulmonary blood flow and raise left atrial pressure, the arterial duct was stented. After ductal stenting, prostaglandin was discontinued and the transcutaneous oxygen saturation remained stable around 89%. At follow up after 7 weeks the foramen ovale had decreased in size and only a small left-to-right shunt was present, documenting the effectiveness of this approach.

CONCLUSION

Based on the present case we propose a stepwise interventional approach for the neonate with pulmonary atresia and intact ventricular septum. If cyanosis persists after isolated pulmonary valvuloplasty despite adequate right ventricular function, ductal stent implantation can reduce interatrial shunting and thus improve oxygen saturation.

Oral and dental health status of children with cleft lip and/or palate

OBJECTIVE

To ascertain the oral and dental health status of children with cleft lip and/or palate.

DESIGN

Oral and dental examinations were carried out on 114 selected children with cleft lip and/or palate, using standard criteria and indices.

SETTING

These children were examined at two cleft palate clinics in the United Kingdom.

PATIENTS

All children examined were between the ages of 3 and 18 years.

RESULTS

Sixty one (53.5%) of the subjects exhibited no evidence of previous caries experience, but as many as 20% exhibited active decay. The mean caries experience in the deciduous dentition (dmfs) was 2.3, and that in the permanent dentition (DMFS) was 0.9. Caries experience of the Caucasian children of the sample was lower (mean dmfs 1.9) than that of the Asian children (mean dmfs 5.5). The mean simplified debris index of the sample was 0.9, and the mean gingival bleeding index was 0.4. Children with cleft lip and palate had generally poorer oral and gingival health than those with isolated clefts of the lip or palate.

CONCLUSION

Twenty percent of the sample had active decay. These children had poor oral health in the surgically repaired anterior segment.

Extending the limits of transcatheter closure of atrial septal defects with the double umbrella device (CardioSEAL)

OBJECTIVE

To report initial findings from a selected group of patients with morphological variations of the atrial septal defect who underwent transcatheter closure with a second generation redesigned double umbrella device.

PATIENTS

Two patients with abnormal location of the oval fossa and partial deficiency of the septal rim, three patients with multiple defects, and two patients with a multiperforated aneurysm of the interatrial septum (age range, 3.6-25.5 years).

METHODS

Defects were closed with the double umbrella device (CardioSEAL) consisting of two sets of flexible arms (with central and two mid-arm hinges) covered with sewn Dacron patches. The implantation procedure was monitored by transoesophageal echocardiography.

RESULTS

The diameter of the defect measured during transoesophageal echocardiography ranged from 7-18 mm and the balloon stretched diameter ranged from 13-21 mm. The size of the devices varied from 28-33 mm and the ratio of device size to defect size varied from 1.6-2.1. Two devices (23 and 28 mm) were chosen in a patient with two separated defects. No complications or serious arrhythmias were observed during implantation or follow up (median, 1.8 months). Residual shunting was trivial in three patients and mild in one patient (inferiorly located additional defect).

CONCLUSIONS

To extend the selection critera of an isolated central interatrial defect for transcatheter closure, some modifications of the implantation technique are needed. Using the redesigned double umbrella device, effective closure in patients with multiple or irregularly shaped atrial septal defects was achieved, indicating a broadening of the spectrum of transcatheter closure.

Permanent junctional re-entry tachycardia. A multicentre long-term follow-up study in infants, children and young adults

AIMS

Permanent junctional re-entry tachycardia is a relatively uncommon form of re-entry tachycardia with antegrade conduction occurring through the atrioventricular node and retrograde conduction over an accessory pathway usually located in the postero-septal region. It was the aim of the study to investigate the course of permanent junctional re-entry tachycardia with particular regard to the effectiveness of pharmacological treatment and ablation procedures; evaluation was performed with respect to the patient's symptoms, tachycardia rate, frequency of the tachycardia and left ventricular function.

METHODS AND RESULTS

The long-term follow-up of 32 patients with permanent junctional re-entry tachycardia was evaluated. The first presentation with supraventricular tachycardia occurred between the 27th week of gestation and 27 years. The tachycardia rate ranged from 100 to 250 beats.min-1. During Holter-ECG, permanent junctional re-entry tachycardia was documented as present for over 50% of the time in 24 h in 22 patients (69%). Left ventricular performance was impaired in nine patients (28%) due to a tachycardia-related cardiomyopathy. Symptoms or signs of heart failure were mild to moderate in eight and severe in four patients; 20 patients showed no clinical impairment. Follow-up time was 1 to 31 (mean 10) years; current age of the patients ranged from 1.5 months to 35 (mean = 15 x 3) years. Four patients needed no therapy because of the infrequency of permanent junctional re-entry tachycardia episodes. Twenty-five patients initially received antiarrhythmic drugs, which were effective or partially effective in 14 (56%). Eight of them are still on medical therapy; in five treatment was discontinued because of absence of symptoms. Eleven patients had ablation of the accessory pathway during follow-up, three underwent ablation as a primary procedure.

CONCLUSION

Permanent junctional re-entry tachycardia in our experience is an arrhythmia with a large variety of clinical symptoms. Patients with a slow tachycardia rate and infrequent episodes of tachycardia may never develop symptoms and therefore do not need any therapy. Patients with frequent permanent junctional re-entry tachycardia, a fast tachycardia rate and impaired left ventricular function need effective therapy. In infancy and early childhood medical therapy is recommended as a first option, whereas in older and symptomatic patients catheter ablation is an effective and safe procedure.

Sotalol associated torsades de pointes tachycardia in a 15-month-old child: successful therapy with magnesium aspartate

Torsades de points (Tdp) is a form of ventricular tachycardia, and its occurrence in childhood is very rare. In adult patients treated with sotalol, Tdp has been reported to the occur with an incidence of 2%-4%. In children who are treated with sotalol, occurrence of Tdp has been reported in only a single case. A 15-month-old girl with Wolff-Parkinson-White syndrome developed recurrent syncopal attacks. She had been treated with sotalol 1.5 mg/kg daily since shortly after birth because of recurrent episodes of paroxysmal supraventricular tachycardia. ECG monitoring exhibited frequent Tdp tachycardia. Serum electrolyte levels were normal. Echocardiographic analysis excluded a structural heart defect and did not show any signs of myocardial infection. Sotalol treatment was stopped and an infusion with lidocaine was started. Despite this therapy the Tdp continued. Magnesium aspartate was then administered, which immediately stopped the Tdp. As no other reason was evident, Tdp in this child has to be judged as a proarrhythmia related to sotalol therapy.

Safety of oral propafenone in the treatment of arrhythmias in infants and children (European retrospective multicenter study). Working Group on Pediatric Arrhythmias and Electrophysiology of the Association of European Pediatric Cardiologists

This study was designed to assess adverse effects of oral propafenone in a large number of pediatric patients. Retrospective data from 27 European centers covering 772 patients treated with oral propafenone were analyzed. The following arrhythmias were treated: reentrant supraventricular tachycardia in 388 patients, atrial ectopic tachycardia in 66, junctional ectopic tachycardia in 39, atrial flutter in 21, ventricular premature complexes in 140, ventricular tachycardia in 78, and other arrhythmias in 39 patients. Two hundred forty-nine patients (32.3%) had structural heart disease. Significant electrophysiologic side effects and proarrhythmia were found in 15 of 772 patients (1.9%): sinus node dysfunction in 4, complete atrioventricular block in 2, aggravation of supraventricular tachycardia in 2, acceleration of ventricular rate during atrial flutter in 1, ventricular proarrhythmia in 5, and unexplained syncope in 1 patient. Cardiac arrest or sudden death occurred in 5 of 772 patients (0.6%): 2 patients had supraventricular tachycardia due to the Wolff-Parkinson-White syndrome and a normal heart; the remaining 3 patients had structural heart disease. Overall, adverse cardiac events were more common in the presence (12 of 249 patients, 4.8%) than in the absence (8 of 523 patients, 1.5%) of structural heart disease (p <0.01). There was no difference between patients treated for supraventricular and ventricular arrhythmias. Thus, propafenone is a relatively safe drug for the treatment of several pediatric tachyarrhythmias. Proarrhythmic effects seem to be less frequent than those reported for encainide or flecainide and occur predominantly in patients with structural heart disease.

[High frequency catheter ablation in young patients with permanent junctional reentry tachycardia and ectopic atrial tachycardia]

Ten young patients with a median age of 10.5 (range: 6 to 31) years suffering from the permanent form of junctional reciprocating tachycardia (PJRT; n = 7) and ectopic atrial tachycardia (AET; n = 3) were treated by transcatheter radiofrequency current application. Indications for interventional therapy were failure of medical therapy after a median of 3 antiarrhythmic drugs in all patients, syncope in 1, and impaired left ventricular function in 4 patients (PJRT n = 3, AET n = 1). The intervention was primarily successful in all patients. Median fluoroscopy time during the ablation procedure was 17 (10 to 70) minutes. A median of 3 (1 to 14) radiofrequency (500 kHz) pulses was delivered at a target temperature of 70 degrees C or with 30 W for 30 s. One patient had a recurrence of PJRT and was successfully treated by a repeat ablation. After a median follow-up of 14 (2 to 61) months, all patients are free of drug treatment and in normal sinus rhythm. Left ventricular function has normalized in patients with follow-up > 6 months. Radiofrequency catheter ablation was a safe and effective therapy in young patients with drug-resistant forms of chronic-permanent supraventricular tachycardia.

[Mechanical recanalization of venous thrombosis and pulmonary embolism with the Clotbuster thrombectomy system in a 12-year-old boy]

The treatment of patients with deep vein thrombosis and pulmonary embolism with contraindications for a thrombolytic therapy is a therapeutic challenge. We report on a 12 year old patient who was treated for large cell lymphoma according to NHL-BFM 95: Block AA protocol. During his therapy, he developed a thrombosis of his right femoral vein and pulmonary embolism affecting the left segments 4, 5, 8, and 9. Because of cerebral metastasis a fibrinolytic therapy was contraindicated. Therefore, we performed a mechanical thrombectomy using the Amplatz thrombectomy device. The postinterventional scintigraphy showed a markedly improved pulmonary perfusion; dopplersonography 4 months postinterventionally showed a patent right femoral vein.

[Percutaneous transcardiac intraluminal balloon angioplasty for reopening an arterial thrombosis after percutaneous arterial heart catheterization in a 19-month-old patient with tetralogy of Fallot]

Cardiac catheterization is a common cause of arterial thrombosis in children. Besides heparin therapy, fibrinolysis plays a major role in the therapeutic approaches to arterial thrombosis while surgery is rarely performed in pediatric patients. We report on a 19 month old patient with tetralogy of fallot, who developed thrombosis of the right femoral artery after a retrograde interventional cardiac catheterization. We performed an antegrade balloon angioplasty of his thrombosed femoral artery using a transvenous, transcardial approach via a ventricular septal defect. There were no complications. Doppler sonography showed no residual stenosis after 4 months.

Early and late atrial dysrhythmias after modified Fontan operation

Occurrence of supraventricular tachycardia and sinus node dysfunction was investigated pre- and postoperatively by serial ECG and Holter monitors in 63 consecutive patients with univentricular circulation after modified Fontan operation (total cavopulmonary connection 39 patients, atriopulmonary connection 24 patients). Mean age at operation was 7.2 (0.1-20.3) years. Of the 63 patients, 14 (22%) had early (< 14 d) supraventricular tachycardia or sinus node dysfunction, which was not related to the type of operation. None of 9 patients with a preoperative mean right atrial pressure < or = 2.5 mm Hg had early supraventricular tachycardia or sinus node dysfunction in contrast to 16/54 patients (30%) with a preoperative mean right atrial pressure > 2.5 mm Hg. 6/63 patients died during the early (< 14 d) postoperative period. In only 1 child, death was related to a dysrhythmia (junctional ectopic tachycardia). During a mean follow-up of 2.5 years, 15/57 long-term survivors (21%) had late supraventricular tachycardia or sinus node dysfunction. Early supraventricular tachycardia/sinus node dysfunction was a predictor or late atrial dysrhythmias, as it occurred in 8 of the surviving 14 patients with early dysrhythmias in contrast to 4 children without early atrial dysrhythmias (p < or = 0.001). After creation of an atriopulmonary connection, 10/22 patients (45%) had late supraventricular tachycardia/sinus node dysfunction, but only 2/35 patients (6%) with a total cavopulmonary connection had late atrial dysrhythmias (p < 0.001).

CONCLUSIONS

Early atrial dysrhythmias after the Fontan operation were related to preoperative hemodynamics. Early supraventricular tachycardia/sinus node dysfunction and the atriopulmonary type of Fontan connection were significant risk factors for late atrial dysrhythmias.

[A German version of the Eating Disorder Inventory EDI-2]

The paper presents a German version of the second revised edition of the Eating Disorder Inventory EDI-2 (Garner 1991). The EDI-2 is a self-rating inventory (self-report measure) with 91 items and 11 subscales designed for the assessment of attitudinal and behavioural dimensions relevant to anorexia and bulimia nervosa. It consists of the eight original subscales: drive for thinness, bulimia, body dissatisfaction, ineffectiveness, perfectionism, interpersonal distrust, interoception and maturity fears, and the three new subscales: asceticism, impulse regulation and social insecurity. The German EDI-2 was given to 71 patients with anorexia or bulimia nervosa, 30 patients with binge eating disorder, a control group of 186 women and a further control group of 102 men. In comparison to the female control group, patient groups showed significantly elevated means on all subscales. Item analysis revealed sufficient internal consistencies for all subscales except subscale 9 (asceticism) with Cronbachs alpha ranging from 0.58 to 0.90. Twelve of the 91 items showed poor item total scale correlations below 0.40. Factor analysis supported a six-factor-structure. Hence, the reliability and validity of the three new subscales was confirmed only partially. The use of the EDI-2 in therapy research and clinical practice is critically discussed.

[Severe stenosis of the right coronary artery in a 15-year-old girl with type IIa hypercholesterolemia: successful treatment with stent implantation]

Coronary artery stenosis with need for therapy is rarely seen in childhood. A 15-year-old girl with hypercholesterinaemia type II a was undergoing lipid aphereses therapy (once or twice a week) since she was 6 years old. The girl was seen in our hospital with stenocardia and depression of the ST-segment in the inferior ECG leads at rest. Myocardial scintigraphy with technetium 99 showed an ischemia of the infero-lateral left ventricular myocardium. During selective coronary angiography a 90% stenosis of the proximal right coronary artery over a distance of approximately 5 mm close to the ostium was found. Post stenotic dilatation of the vessel was obvious. In addition a diffuse 10% stenosis in the proximal and middle part of the right coronary artery was found. The left coronary artery appeared angiographically normal. After balloon dilatation, stent implantation was performed without complications with a 6 mm microstent. Reduction of the stenosis from 90% to 40% could be achieved. Ticlopidin 2 x 250 mg was started for thrombocyte aggregation inhibition. During the following 12 months the patient has been free of symptoms. Lipidaphareses has been continued as before. Stent implantation seems to be a successful treatment for coronary artery stenosis also in young patients.

Coronary artery involvement early and late after radiofrequency current application in young pigs

Radiofrequency current (500 kHz) was delivered by temperature guidance (75 degrees C) over a 30-second period in 10 young piglets with a steerable 6F electrode catheter equipped with a thermistor at the 4 mm tip electrode. Lesions were created at the right atrial aspect of the tricuspid valve anulus, at the left ventricular myocardium under the lateral mitral valve anulus, and at the left ventricular apex. After 48 hours, five animals were randomly sacrificed. Lesions in the five animals appeared as transmural gray-white coagulation necrosis. Lymphocytic infiltration around the right atrial lesions extended into the layers of the right coronary artery in four of five animals. After 6 months, lesions consisted of compact fibrous tissue in the remaining five animals. Right atrial lesions extended to the layers of the right coronary artery in four of five pigs. In two animals the lumen of the right coronary artery was narrowed because of intimal thickening by 25% and 40%, respectively. No increase in the lesion size was observed with the growth of the animals. Effects on the right coronary artery as a late sequela after radiofrequency current application may also be possible in human beings and should be considered when radiofrequency current ablation procedures are proposed in infants and young children.

Adenosine: an effective and safe antiarrhythmic drug in pediatrics

Adenosine is an effective, safe drug for the diagnosis and treatment of paroxysmal tachycardias in adult and pediatric patients. A starting dose of 0.05-0.10 mg/kg as a rapid bolus injection is recommended for infants and children. An electrophysiologic effect can be expected within 20 seconds after injection. Dosage may be increased up to 0.3 mg/kg in steps of 0.05-0.10 mg/kg or until conversion to sinus rhythm is reached. Due to its basic electrophysiologic properties of slowing conduction in the atrioventricular (AV) node, which may result in transient AV block, adenosine is almost always effective in terminating supraventricular tachycardias in which the AV node forms a critical part of the reentrant circuit (i.e., AV nodal reentrant tachycardia and AV reciprocating tachycardia). Based on its properties, adenosine is also advocated as a useful diagnostic tool for unmasking primary atrial tachycardias by inducing transient high grade AV block. Advantages over other antiarrhythmic agents include the agent's short half-life (<2 seconds) and minimal or no negative influence on blood pressure. Because of its short half-life, however, early recurrence of the tachycardia is observed in up to one-third of patients treated. Based on rare but serious unwanted side effects, patients with known or suspected irritable airways and sinus node dysfunction and those who have undergone orthotopic cardiac transplantation should probably not be given adenosine. Adenosine may be recommended as the drug of choice for treatment of paroxysmal tachycardia in young patients. Primary success rates range between 85% and 100% of all the tachycardia episodes treated. Termination of the tachydysrhythmia, however, does not always mean that the underlying dysrhythmia was of supraventricular origin with the AV node as a critical part of the tachycardia mechanism. Rare but possible life-threatening side effects (prolonged sinus arrest and complete AV block, atrial fibrillation, acceleration of ventricular tachycardia, apnea) necessitate proper monitoring of the patients.

Extracorporeal support for intractable cardiorespiratory failure due to meningococcal disease

BACKGROUND

Meningococcal disease is still associated with considerable mortality, despite the use of early antibiotics and management in specialised intensive care units, due principally to early refractory myocardial depression and hypotension as well as severe acute respiratory distress syndrome. Extracorporeal membrane oxygenation (ECMO) is a complex technology that uses a modified "heart-lung" machine to provide temporary cardiac and respiratory support. We reviewed the UK and Australian experience of the use of ECMO in patients with refractory cardiorespiratory failure due to meningococcal disease.

METHODS

The records from all 12 known patients supported with ECMO for meningococcal disease in the UK and Australia since 1989 were reviewed.

FINDINGS

12 patients (aged 4 months to 18 years, median 26 months) with meningococcal disease received ECMO over 8 years. In seven patients, ECMO was required early for cardiac support for intractable shock within 36 h of admission to intensive care. In the other five patients, ECMO was indicated for respiratory failure due to severe adult respiratory distress syndrome, which tended to occur later in the disease. The paediatric risk of mortality score ranged from 13 to 40 (median 29, median predicted risk of mortality 72%). Six of the 12 patients required cardiopulmonary resuscitation before ECMO and the other six were deteriorating despite maximal conventional therapy. Overall, eight of the 12 patients survived, with six leading functionally normal lives at a median of 1 year (range 4 months to 4 years) of follow-up.

INTERPRETATION

ECMO might be considered to support patients with intractable cardiorespiratory failure due to meningococcal disease who are not responding to conventional treatment.

New antiarrhythmic drug in pediatric use: sotalol

Sotalol is a noncardioselective beta-blocking agent with additional class III antiarrhythmic properties (action potential duration prolongation). These combined electrophysiologic effects make it a valuable drug for treating various arrhythmias. Its effectiveness for suppressing supraventricular reentrant tachycardias in children is well documented. Atrial flutter in children can be effectively managed in a high percentage of those treated. Ventricular arrhythmias in children can be adequately controlled by the administration of oral sotalol. Side effects are those typically seen during the course of treatment with a beta-blocker and lead to discontinuation of the drug in 3-6% of children. Proarrhythmia is another concern after sotalol administration. Increased ventricular ectopy, impairment of atrioventricular conduction, and suppression of sinus node activity with exacerbation of bradycardia (especially in children with sinus node dysfunction) may be found in a considerable number of treated patients, usually within a few days of sotalol initiation. Sotalol is an effective antiarrhythmic drug, but its potential side effects warrant inpatient treatment initially and close electrocardiographic monitoring.

Generic database design for patient management information

Patient management information tracks general facts about the location of the patient and the providers assigned to care for the patient. The Clinical Data Repository at Columbia Presbyterian Medical Center employs a generic schema to record patient management events. The schema is extremely simple, yet can support several different views of patient information, as required by different applications: a longitudinal view of patient visits, including both inpatient and outpatient encounters; a visit-oriented view, to record facts related to a current encounter; a location-based view to provide a census of a nursing ward; and a provider-based view to give a list of the patients currently being cared for by a given clinician. All of these views can be supported in a highly efficient manner by the use of appropriate indexes.

[Coronary sinus defects: rare form of interatrial communication]

A coronary sinus defect results in a communication of variable size between the coronary sinus (CS) and the left atrium (LA). It is in most cases associated with a persistent left superior vena cava (l-SVC) and an atrial septal defect of the coronary sinus type and often part of a more complex cardiac malformation. If the CS to LA fenestration is the single cardiac defect, this anomaly provides the basis of an unusual form of interatrial communication, which may cause diagnostic difficulties. Two patients with this rare anomaly are reported. A 9-year-old boy presented with history of mild cyanosis pronounced after physical activity (SaO2 < 90%) since the age of 3. Comprehensive pulmonary and cardiological diagnostic procedures in the referring hospital yielded normal findings. Finally, a 1-SVC draining into a mildly dilated coronary sinus could be demonstrated echocardiographically. Contrast echocardiography revealed a right-to-left-shunt at atrial level. Diagnosis of a partially unroofed coronary sinus was subsequently confirmed during cardiac catheterization. The second patient was primarily diagnosed echocardiographically to have an atrial septal defect of the primum type (ASD I) in the first year of life. After pulmonary vascular markings on chest-x-ray had increased, she was assigned to our hospital for cardiac catheterization. Slight arterial desaturation (SaO2 88%) was present due to a large l-SVC anomalously draining into the LA, the innominate vein was missing. The roof of the coronary sinus was predominantly absent. Combined with a large atrial septal defect of the coronary sinus type, this resulted in significant left-to-right-shunt and right-to-left-shunt at atrial level due to a pure unroofed coronary sinus.

CONCLUSION

A coronary sinus defect with partial or complete unroofing of the CS and a persistent l-SVC should be considered in the differential diagnosis of an otherwise unexplained systemic desaturation and in patients with both left-to-right-shunt and right-to-left-shunt at atrial level.

Lack of evidence of areas of slow conduction early after radiofrequency current application at porcine atrial myocardium

Electrophysiological sequelae after creation of atrial myocardial lesions by radiofrequency current (RFC) application have not been studied in vitro. During general anesthesia, a steerable 6 French electrode catheter, equipped with a thermistor at the 4-mm tip electrode, was positioned at the lateral atrial aspect of the tricuspid valve annulus in 5 piglets (German Landrace, mean body weight 12.5 kg). Temperature-guided (75 degrees C) RFC (500 kHz) was delivered over 30 seconds. Forty-eight hours later, the hearts were removed and placed in ice-cold Turner's solution. The right atria were dissected, and the RFC lesions with surrounding tissue were cut out and transferred to an organ bath according to Steiert. Preparations were superfused with Turner's solution at 37 degrees C. Pacing of the viable tissue at the border of the preparations was accomplished at a cycle length of 500 ms. Whole atrial preparations were impaled (76 to 150 impalements per specimen) with KCl capillary microelectrodes containing 3 MKCl. In the surrounding viable tissue of the five preparations, mean maximum diastolic transmembrane potential ranged from -61.3 to -63.7 mV, mean action potential duration at 90% repolarization ranged from 135.2 to 156.1 ms, and mean maximum upstroke velocity of phase 0 of the action potential was between 104.7 and 112.9 V/sec. Statistical analysis revealed no significant differences among all 3 variables. No intracellular action potential was recorded from the surface of all 5 lesions. The surrounding tissue was sharply demarcated, with unaltered transmembrane action potential characteristics in the vicinity of the lesions. Areas of slow conduction were not observed. Lack of evidence of areas of slow conduction after RFC application to the atrial myocardium may imply that this technique is safe regarding occurrence of atrial tachyarrhythmias.

Enhanced release of nitric oxide causes increased cytotoxicity of S-nitroso-N-acetyl-DL-penicillamine and sodium nitroprusside under hypoxic conditions

S-Nitroso-N-acetyl-DL-penicillamine (SNAP) and sodium nitroprusside (SNP), both of which are known to release nitric oxide (.NO), exhibited cytotoxicity against cultivated endothelial cells. Under hypoxic conditions 5 mM SNAP and 20 mM SNP induced a loss in cell viability of about 90% and 80% respectively, after an 8 h incubation. Under normoxic conditions, cell death was only 45% and 42% respectively within the same time period. Concentrations of .NO liberated from SNAP and SNP were measured by the oxyhaemoglobin method and by two of the recently developed nitric oxide cheletropic traps (NOCTs). The .NO concentrations from SNAP and SNP increased from 74 microM and 28 microM to 136 microM and 66 microM respectively within 15 min of hypoxic incubation, and then decreased to 36 microM and 28 microM. In the respective normoxic incubations the .NO levels from SNAP and SNP remained in the region of about 30 microM and 20 microM respectively. In contrast, spermine/NO adduct (spermineNONOate) was shown to be more toxic under normoxic than under hypoxic conditions. Under either of these conditions, the concentration of .NO liberated from 2 mM spermineNONOate was about 20 microM. The results demonstrate that the cytotoxicity of SNAP and SNP, but not of spermineNONOate, is significantly enhanced under hypoxic compared with normoxic incubations. Studies on the .NO-releasing behaviour of these compounds indicate that the increased toxicity of SNAP and SNP under hypoxic conditions is related to the influence of O2 on the chemical processes by which .NO is produced from the precursors, rather than to an increased sensitivity of the hypoxic cells towards .NO.

[Permanent ventricular tachycardia in a 12-year-old boy: curative therapy by high frequency current ablation]

A 12-year old boy from Armenia presented with chronic permanent ventricular tachycardia (150/min) and reduced left ventricular shortening fraction (< 30%). Tachycardia was present > 20 h/day on several 24-h Holter monitorings. Diagnosis of ventricular tachycardia could be established on surface ECG by identification of atrioventricular dissociation and a right bundle branch block pattern with a R/S ratio < 1 in lead V6. Antiarrhythmic therapy with mexiletine and sotalol alone or in combination did not influence the presence of the dysrhythmia. During electrophysiological study, the dysrhythmia could not be terminated by administration of adenosine, ventricular extrastimuli, overdrive stimulation or direct current cardioversion. Endocardial mapping identified a region on the left ventricular surface of the anterior upper interventricular septum as the origin of the dysrhythmia. At this location stimulation at a cycle length shorter than the tachycardia produced a QRS complex nearly identical to the tachycardia QRS complex. Local ventricular electrogram preceded the onset of the tachycardia QRS complex on surface ECG by 23 ms. Radiofrequency current application with 30 W for 30 s resulted in permanent termination of the tachycardia. No complications occurred. Six months after the intervention, the boy is still in normal sinus rhythm. Left ventricular function normalized.

CONCLUSION

Radiofrequency catheter ablation should be considered in young patients with drug-refractory chronic permanent ventricular tachycardia.

[Intermediate and long-term outcome after percutaneous balloon dilatation of valvular pulmonary stenoses in childhood]

Pulmonary balloon valvuloplasty was performed in 52 patients aged 7 days to 19 years (mean 5.5 years). Mean balloon/anulus ratio was 1.24. Mean right ventricular outflow tract (RVOT) systolic pressure gradient was 79.9 +/- 37.3 (x +/- SD) mm Hg before valvuloplasty and 37.2 +/- 29.6 mm Hg (p < 0.001) immediately after the procedure. 33 patients had residual RVOT-gradient < or = 36 (22 +/- 7) mm Hg, 19 patients had gradients > 36 (67.1 +/- 35.6) mm Hg. During intermediate follow-up (< 2 years) RVOT gradient assessed by catheterization or Doppler echocardiography improved without any additional intervention in 10/19 patients with RVOT gradient > 36 mm Hg early after valvuloplasty. 6/19 patients required additional reduction of RVOT gradient by repeated valvuloplasty (51 +/- 19 to 29 +/- 5 mm Hg; p < 0.01). 3/19 patients needed surgical resection of extremely thickened dysplastic valves. 49 patients had a mid- to long-term follow-up by echocardiography (mean 4.3, max. 9 years); the RVOT gradient decreased from 25.7 +/- 12.8 mm Hg during intermediate follow-up to 18.0 +/- 7.0 mm Hg during long-term follow-up. If pulmonary regurgitation was present after dilatation (n = 38), it was hemodynamically not significant and did not change during follow-up. Percutaneous balloon valvuloplasty was a safe and effective treatment for pulmonary valve stenosis in infancy and childhood. Long-term results confirm the value of this method.

[Atrial flutter in young patients after corrective operation of congenital heart defects: therapy by high frequency catheter ablation]

Radiofrequency catheter ablation has been used successfully in adult patients for treatment of atrial flutter. Three young patients (mean age 14.6 years) with common type atrial flutter (n = 2) and uncommon type atrial flutter (n = 1) underwent electrophysiologic study. Cardiac diagnoses included tricuspid atresia after Fontan operation, status after closure of an atrial septal defect of secundum type, and status after surgical valvotomy for valvular pulmonary stenosis, respectively. Indication for ablation were syncopal episodes in one and presyncopal episodes in two patients. Flutter cycle length ranged from 280 to 320 ms. Right atrial endocardial mapping revealed areas with local electrograms preceding the onset of the flutter-P-wave by 70 to 80 ms. In these regions pace mapping was performed with the intention to produce an identical P-wave morphology and short stimulus to P-wave interval. Radiofrequency current application (500 kHz) with 30 W for 30 s at theses sites terminated atrial flutter and prevented reinduction in all three patients. No complications were observed. Follow-up (7 to 11 months) revealed recurrence of uncommon type of atrial flutter in one patient who previously had had common type. The remaining two patients are in stable sinus rhythm.

CONCLUSION

Radiofrequency catheter ablation appears to be an effective treatment of atrial flutter after surgery for congenital heart defects in young patients.

Periodontal diseases of children and adolescents. An update

Plaque related periodontal diseases in children and adolescents have long been recognized, but recent studies have highlighted their prevalence and presentation. The aim of this article is to highlight the current classification of periodontal diseases of children and adolescents and to review the diagnosis and treatment of these diseases. This will help dental practitioners to diagnose and treat their juvenile and young adult patients suffering from different types of periodontal diseases.

Familial idiopathic atrial fibrillation with bradyarrhythmia

A 10-year-old boy is reported who presented with idiopathic atrial fibrillation and bradyarrhythmia. After history of intrauterine and postnatal bradycardia, atrial fibrillation was first documented electrocardiographically at 16 months of age. An underlying structural heart disease was not evident. At the age of 10 years, implantation of a permanent ventricular demand pacemaker was indicated after syncope due to severe bradyarrhythmia. The family history revealed five persons of four generations with bradyarrhythmias. Idiopathic atrial fibrillation known since childhood was documented in three close relatives. A high grade AV block resulting in bradyarrhythmias and the occurrence of ST-T-changes in precordial leads could be demonstrated in all affected family members suggesting a diffuse general conduction abnormality in these patients. In this family, idiopathic atrial fibrillation seems to be transmitted as an autosomal dominant trait.

CONCLUSION

Atrial fibrillation without underlying heart disease is extremely rare in children. Careful electrocardiographic follow-up of these patients and the evaluation of ECG recordings of all family members is recommended.

Total cavopulmonary anastomosis in patients less than three years of age

BACKGROUND

As young age at modified Fontan operation was thought to be a preoperative risk factor for poorer survival, we studied early and intermediate outcome in our young patient group.

METHODS

Results in children less than 3 years of age (group I; n = 26; age range, 7 to 35 months) were compared with those in older patients (group II; n = 46; age range, 36 to 219 months). For both groups there was no significant difference with regard to preoperative pathology and hemodynamics.

RESULTS

With an overall mortality of 9.7% (7/72) there was no significant difference for both groups. Group I (n = 23) and group II (n = 42) survivors did not differ with respect to early postoperative incidence of atrial dysrhythmias, duration and volume of pleural effusion, or incidence of reoperation. Results on intermediate follow-up (group I, 31 +/- 14 months; group II, 44 +/- 20 months) demonstrated a relatively low incidence of late atrial dysrhythmias (12.3%; 8/65). Late atrioventricular valve insufficiency was significantly more frequent in group I patients.

CONCLUSIONS

With similar preoperative anatomic and hemodynamic parameters including 68% of patients with complex univentricular heart, total cavopulmonary anastomosis could be performed in patients less than 3 years of age with good clinical and hemodynamic results, as achieved in older patients.

[Q-fever associated myocarditis in a 14-year-old boy]

A 14-year-old boy presented with the symptoms and clinical signs of myocarditis. Ventricular arrhythmias were the main manifestation. Dilated left ventricle with slightly impaired contractility and spongy appearance of the myocardium were also noted. Laboratory signs of an acute infectious disease were absent, but a significant rise in the complement fixation titer for Coxiella burnetii was observed. Treatment with oral tetracycline for 6 months resulted in improvement of ventricular arrhythmias and normalization of left ventricular dimensions and structure over the following months. Cardiac involvement in Q fever is rare, and with it endocarditis is usually seen as a chronic form of the disease. Myocarditis associated with Q fever has been reported only in some rare cases but not in children. The case reported here illustrates that the diagnosis of Q fever should also be considered in a case of myocardial involvement in an infectious disease of unknown etiology.

Efficacy and proarrhythmia of oral sotalol in pediatric patients

OBJECTIVES

This study sought to assess the efficacy of oral sotalol for various arrhythmias in pediatric patients and to evaluate the incidence of proarrhythmia and systemic side effects.

BACKGROUND

Sotalol is a beta-adrenergic blocking agent with additional class III antiarrhythmic properties. Experience in pediatric patients is limited. Data concerning the incidence of proarrhythmia in children are lacking.

METHODS

Seventy-one pediatric patients (mean age 7.3 years) with various supraventricular and ventricular tachyarrhythmias were treated with oral sotalol. All the patients were admitted to the hospital for initiation of sotalol therapy. Antiarrhythmic and proarrhythmic effects of sotalol were assessed by daily surface electrocardiograms (ECGs) during the in-hospital phase and by serial Holter monitoring.

RESULTS

Sotalol was either completely (27 [66%] of 41 patients) or partially effective (11 [27%] of 41) in 38 (93%) of 41 patients with supraventricular reentrant tachycardias. In patients with atrial flutter predominantly after operation for congenital heart disease, sotalol was effective in 84% of patients (completely in 9 of 19 and partially in 7 of 19). Ventricular tachycardia was completely (3 of 11) or partially (4 of 11) controlled in 64% of children. Proarrhythmia occurred in seven patients (10%) and consisted of symptomatic bradycardia from sinoatrial block and high grade atrioventricular (AV) block, respectively, in two children; asymptomatic high grade AV block in one; torsade de pointes in one; and relevant increased ventricular ectopic activity in three. Proarrhythmia required drug discontinuation in four patients. Mean duration of treatment for all patients was 18 months (range 1 to 40).

CONCLUSIONS

Sotalol was an effective antiarrhythmic drug for a wide range of pediatric tachyarrhythmias. The considerable number of patients with proarrhythmic effects indicates the need for initiation of treatment on an inpatient basis and close monitoring by serial Holter electrocardiography.

[Sotalol-induced torsade de pointes tachycardia in a 15-month-old infant]

Torsade de pointes (tdp) is a form of ventricular tachycardia whose occurrence in childhood is very rare. In adults treated with sotalol (Sotalex), tdp has been reported to have an incidence of 2-4%. There have been no reports of its occurrence in children treated with sotalol. We report about a 15-month-old girl with Wolff-Parkinson-White syndrome who developed recurrent syncopal attacks. She had been treated with sotalol at 1.5 mg/kg daily since being a newborn because of recurrent episodes of paroxysmal supraventricular tachycardia. Electrocardiogram exhibited frequent tdp tachycardia. Serum electrolyte levels were normal. Echocardiography excluded a structural heart defect and showed no signs of myocardial infection. After sotalol was ceased, infusion with lidocain was started. Despite this therapy the tdp continued. Magnesium aspartate (Magnesiocard) was then administered, and this finally stopped the tdp. As no other cause was evident, tdp in this child must be judged as a proarrhythmia related to sotalol therapy.