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Biomedical subjects

T Paul

Publications and source records attributed to T Paul.

At least 91 records · Page 5Linked to original sources

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.

Child, Preschool↗

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.

Administration, Oral↗

Transcatheter ablation of incessant ectopic left atrial tachycardia using radiofrequency current.

Catheter ablation of ectopic atrial tachycardia has been previously reported in a small number of patients in whom the ectopic focus was predominantly located in the right atrium. We report on a 51-year-old patient with atrial automatic tachycardia originating in the left atrium, in whom successful radiofrequency catheter ablation was performed via a transseptal puncture. The patient had suffered incessant atrial tachycardia for several years, refractory to antiarrhythmic drug treatment and DC-cardioversion. Radiofrequency ablation terminated left ectopic atrial tachycardia and, therefore, should have been attempted before resorting to open heart surgical ablation.

Catheter Ablation↗

[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.

Anti-Arrhythmia Agents↗

[Therapeutic efficacy and diagnostic potential of adenosine in infants and children].

In an open study a total of 53 episodes of supraventricular reentrant tachycardia in 31 infants and children were treated with intravenous adenosine at two centers. Adenosine was given as a rapid intravenous bolus injection beginning with a dose of 0.1 mg/kg. If there was persistence of the dysrhythmia dosage was increased in 0.05 mg/kg-steps up to a maximum dose of 0.3 mg/kg if necessary. The median dose required for successful termination of the tachycardias was 0.15 mg/kg. In 26 patients with 48 episodes of regular narrow-QRS-complex tachycardia adenosine was used as the therapeutic agent of first choice. In all patients a shortlasting atrioventricular block occurred within seconds after the administration of adenosine. In 42 of 48 episodes of tachycardia (87%) the dysrhythmias were converted to a stable sinus rhythm. In six episodes (13%) recurrence of the tachycardia was observed immediately. In five children adenosine was used for diagnostic purpose: in three children with wide-QRS-complex tachycardia successful termination with adenosine proved the supraventricular origin of the dysrhythmia. In two children with suspected atrial flutter adenosine-induced atrioventricular block allowed identification of flutter waves in one patient while in the other patient no effect of adenosine was seen. Side-effects such as flush, chest-pain or abdominal pain were frequent but mild and only of a few seconds' duration. No influence of adenosine on blood pressure was noted. Only in one child with previously unknown sinus node dysfunction was a relevant electrophysiologic side effect seen: a prolonged sinus arrest with asystole of 12 seconds' duration occurred after adenosine administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

[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.

Adolescent↗

[Nitric oxide in therapy of pulmonary hypertension after correction of congenital single atrium].

We report on a 19-month-old boy with congenital single atrium. Cardiac catheterization preceding the surgical repair revealed an elevated pulmonary artery pressure of 60/15 mmHg (mean pressure 40 mmHg). Pulmonary flow was 8.4 l/min.m2 and systemic flow was 5.5 l/min.m2. Pulmonary arteriolar resistance was elevated to 4.2 U.m2 with 64% left-right shunt and 25% right-left shunt. Arterial O2-saturation varied around 90%. After surgical repair (insertion of a Goretex patch), the patient required mechanical ventilation with 100% oxygen for adequate oxygenation. Cardiac catheterization was repeated on the first postoperative day. No residual shunts were found. The pulmonary artery pressure was 66/40 mmHg (mean pressure 50 mmHg), systemic arterial pressure was 85/62 mmHg (mean pressure 68 mmHg). Cardiac index was 2.8 l/min.m2, pulmonary vascular resistance was 12 U.m2. After administration of prostacyclin a significant decrease of pulmonary artery pressure was observed, but without changing the ratio between pulmonary and systemic pressure. The AaDO2 varied between 400 and 580 mmHg and the oxygenation-index (PaO2/FiO2) was less than 1.0. In this situation, an attempt with inhaled nitric oxide (NO) was performed. After adding 20 ppm NO to the inspired gas, the AaDO2 decreased significantly from 580 to 270 mmHg and the oxygenation-index (OI) rose from 0.9 to 1.5. The inspired fraction of oxygen could be reduced quickly to 60%. During the next days, the concentration of NO was reduced stepwise to 1 ppm. Finally, the AaDO2 was within the normal range (25-65 mmHg) and the OI rose to a level about 4.0. The FiO2 could be reduced to 30% and nitric oxide therapy could be stopped and the child could be extubated.

Administration, Inhalation↗

[Results of oral sotalol therapy in children with supraventricular and ventricular arrhythmias].

Experience with oral sotalol, a beta-blocker with class III-antiarrhythmic properties, is limited in the pediatric population. Sotalol was administered to 32 patients with a mean age of 8.7 years (range 1 day-19.9 years). Mean dosage was 4.6 (1.5-9.4) mg/kg or 122.1 (52-306) mg/m2, respectively. In 27/32 patients, at least 1 antiarrhythmic agent had failed to control the dysrhythmia before sotalol was started. Cardiac diagnoses included normal heart (n = 16), status after correction of congenital heart disease (n = 13), and cardiomyopathy (n = 3). Success (based on symptoms and 24-h electrocardiogram) was achieved in 16/18 patients with reentry supraventricular tachycardia, in 7/8 patients with atrial flutter, and in 4/6 patients with ventricular tachycardia. During a mean follow-up of 15.6 (2-78) months, proarrhythmia occurred in five (16%) patients (symptomatic bradycardia n = 2, QT-prolongation and ventricular extrasystoles n = 1, ventricular extrasystoles n = 1, 2 degrees av-block n = 1), requiring dosage reduction (n = 3), cessation of treatment (n = 1) and pacemaker implantation in one patient, respectively. Symptomatic hypotension was noted in two patients, in whom therapy had to be stopped. Sotalol was a very effective agent for the treatment of various pediatric cardiac dysrhythmias. However, incidence of proarrhythmic effects warrants close electrocardiographic monitoring.

Administration, Oral↗

Atrial baffle procedures for complete transposition of the great arteries: natural course of sinus node dysfunction and risk factors for dysrhythmias and sudden death.

359 patients after the Mustard (275) or Senning (84) operations for transposition of the great arteries were followed-up for a mean of 103.7 (range 0.4 to 204) months. 259 patients had postoperative 24-h Holter recordings. In 129 Mustard children serial (mean 4.4) postoperative Holter recordings were available for evaluation. Criteria based on Holter and scalar electrocardiograms at normal sinus node functions were used for rhythm analysis. Postoperative dysrhythmias appeared in 70% of the patients: sinus node dysfunction in 62.8%, second or third degree atrioventricular block in 3.2%, sustained atrial tachycardia or atrial flutter in 4.5%, and significant ventricular arrhythmia (Lown 2-5) in 21.4%. The prevalence of sinus node dysfunction increased slightly from 50.8% during the first 2 postoperative years to 64.4% in patients more than 10 years postoperatively. Fifteen patients (4.2%) died suddenly during follow-up. By multivariate analysis severe tricuspid regurgitation and/or right ventricular dysfunction and uncontrolled supraventricular tachydysrhythmias were identified as the two significant risk factors for sudden death.

Adolescent↗

[Ablation of permanent left atrial ectopic tachycardia by high-frequency energy].

Catheter ablation of ectopic atrial tachycardia has been previously reported in a small number of patients in whom the ectopic focus was predominantly located in the right atrium. We report on a 53-year-old patient with atrial automatic tachycardia originating in the left atrium, in whom successful radiofrequency catheter ablation was performed via a transseptal puncture. The patient presented a permanent atrial tachycardia for several years, refractory to antiarrhythmic drug treatment and DC-cardioversion. Radiofrequency ablation terminated left ectopic atrial tachycardia and, therefore, should be attempted before resorting to open-heart surgical ablation.

Cardiac Pacing, Artificial↗

[Malignant hyperthermia in swine during isoflurane anesthesia].

A case of porcine malignant hyperthermia (MH) is reported, which occurred during a cardiological animal experiment under general anaesthesia using isoflurane as inhalational anaesthetic. Initially, tachycardia (238 bpm) and a sudden increase of end-exspiratory pCO2 were noticed. Discontinuation of isoflurane followed by administration of dantrolene (7 mg/kg body weight) led to a rapid recovery. Two days later, no difference in clinical state was apparent in comparison with the remaining swine. After regular euthanasia, acute muscle necrosis was seen macroscopically in back and glutaeal muscles, which was confirmed by histological examination. The rise of end-tidal pCO2 was the striking symptom thus allowing the detection of the incipient malignant hyperthermia. Early onset of dantrolene therapy is shown to be sufficient in termination of this hyperacute complication, and may prevent its deleterious outcome. Therefore, the administration of dantrolene should be taken into account in case of porcine MH, especially in time-consuming and costly series of animal experiments.

Anesthesia, Inhalation↗

Usefulness of propafenone for supraventricular arrhythmias in infants and children.

The relation between propafenone dose, serum level, electrocardiographic parameters, antiarrhythmic drug efficacy and adverse effects was studied in 47 children with symptomatic supraventricular arrhythmias aged 1 day to 10.3 years (median 2.2 months) with a mean follow-up of 14.3 months. Propafenone trough serum levels were measured using gas chromatography. Oral propafenone (mean dose 353 mg/m2/day) was effective in 41 of the 47 patients (87.2%). Serum levels did not differ between patients responding and not responding to propafenone (0.45 +/- 0.40 vs 0.36 +/- 0.41 mg/liter). PR interval and QRS complex duration increased more significantly with propafenone dose increments (p < 0.001), than with propafenone serum levels (p < 0.05). At successful treatment PR interval and QRS complex were prolonged by a mean of 19.2 and 20.5% compared with pretreatment status. Five patients exhibited unexpected marked QRS complex prolongation (50 to 200%) despite low propafenone dosage (< 300 mg/m2/day) and level ranging from 0.05 to 1.33 mg/liter. Three patients (6.1%) were suspected of being "poor" metabolizers of propafenone. Mild chronic elevation of serum liver enzymes was observed in 5 patients treated with a larger dose (mean 448 mg/m2/day, p < 0.001). No proarrhythmia was noted on serial Holter monitors. One patient with Wolff-Parkinson-White syndrome and a normal heart had cardiac arrest after aspiration. Serial monitoring of PR interval and QRS complex duration was more useful for proper dosage adjustment than propafenone serum levels. Serum liver enzymes should be closely monitored when using higher propafenone doses. Malignant proarrhythmia could not be excluded in the 1 patient with cardiac arrest.

Administration, Oral↗

[The automatic implantable cardioverter-defibrillator for prevention of sudden heart death in children and adolescents].

Little experience exists with the automatic implantable cardioverter-defibrillator in the pediatric population. Since 1990, an automatic implantable cardioverter defibrillator was implanted in four young patients (mean age 15.8 years, mean body weight 53.3 kg) with life-threatening ventricular tachyarrhythmias at our institution. In three patients, a cardiac anomaly was evident (dilated cardiomyopathy, status post Rastelli operation for complex transposition of the great arteries, status post atrial switch for transposition of the great arteries), the last patient had a normal cardiac anatomy. Indications for implantation were resuscitation from documented hypotensive ventricular tachycardia in one patient and recurrent syncope of suspected cardiac origin in the remaining three patients. At preimplantation electrophysiological study, all four patients had inducible ventricular tachycardia and/or ventricular fibrillation. At implantation of the cardioverter defibrillator in the operating theatre, the ventricular tachyarrhythmias were again induced and terminated reliably by the device. After a mean follow-up of 13 months, three of the four patients had appropriate discharges without syncope or resuscitation. The automatic implantable cardioverter-defibrillator appears to be a feasible and effective therapy also in pediatric patients for prevention of sudden cardiac death due to ventricular tachyarrhythmias.

Adolescent↗

[Atrial arrhythmias after modified Fontane operation: effect of preoperative hemodynamics and the kind of operation (atriopulmonary vs. total cavopulmonary anastomosis)].

UNLABELLED: Between October 1986 and March 1992, 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 nine 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 > or = 2.5 mm Hg. 6/63 patients died during the early (< 14 d) postoperative period. In only one child death was related to a dysrhythmia (junctional ectopic tachycardia). During a mean follow-up of 2.5 years, 12 patients (21%) had late supraventricular tachycardia or sinus node dysfunction. Early supraventricular tachycardia/sinus node dysfunction was a predictor of late atrial dysrhythmias, as it occurred in eight of the surviving 14 patients with early dysrhythmias, in contrast to four children without early atrial dysrhythmias (p < 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.

Adolescent↗

[Therapy of postoperative ectopic junctional tachycardia by surface hypothermia].

Postoperative junctional ectopic tachycardia is associated with a poor prognosis in patients after open-heart surgery. This dysrhythmia has been shown to be resistant to medical treatment as well as to epicardial pacing and external cardioversion. Successful therapy with surface hypothermia in an infant with junctional ectopic tachycardia (ventricular rate 210-230 bpm) after repair of tetralogy of Fallot is presented. Hypothermia (rectal temperature 32-34 degrees C) was effective in decreasing the ventricular rate of the dysrhythmia (< 170 bpm). After spontaneous cessation of the tachycardia, sinus rhythm resumed, resulting in stable hemodynamics.

Combined Modality Therapy↗

[Emergency 12-hour transesophageal stimulation in a 21-month-old infant].

In a 21-month-old child with complex cyanotic congenital heart disease an aortopulmonary shunt was created as preparation for a modified Fontan operation. During the early postoperative period low cardiac output with right atrial pressures of 20 mm Hg developed due to a slow ventricular tachycardia (ventricular rate 135 bpm). Pharmacological interventions (isoprenaline 0.01 mg/kg hourly and lidocaine 1 mg/kg hourly were without any effect. As epicardial pacing leads had not been implanted during surgery, atrial pacing was performed via the transoesophageal route using a 9.5-F bipolar electrode catheter with an interelectrode distance of 15 mm. Atrial capture could be established with an impulse width of 9.9 ms and 10 mA output at a rate of 150 bpm. With restoration of atrioventricular synchronicity, right atrial pressure finally decreased to 10 mm Hg with consecutive stabilization of the cardiovascular status. After 12.5 h transoesophageal pacing could be stopped without any problems due to spontaneous cessation of ventricular tachycardia. No clinical signs of oesophageal injury were noted. It is concluded that transoesophageal pacing is a practical, safe and effective method for emergency cardiac pacing.

Cardiac Output, Low↗