Medical research at the Faculty of Medical Sciences, UWI, Mona Campus, 1960-1990.
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Bibliometrics↗
Biomedical subjects
T Paul
Publications and source records attributed to T Paul.
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.
Cardiac Catheterization↗
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.
Angiography↗
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.
Adolescent↗
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.
Blood Flow Velocity↗
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.
Attitude of Health Personnel↗
Sudden death due to low-energy chest-wall impact (commotio cordis)
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Animals↗
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.
Administration, Oral↗
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.
Angioplasty, Balloon, Coronary↗
[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.
Angioplasty, Balloon↗
[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.
Angiography↗
[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.
Adolescent↗
Stepwise interventional approach in a neonate with pulmonary valve atresia and intact ventricular septum.
UNLABELLED: 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.
Angioplasty, Balloon, Coronary↗
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.
Adolescent↗
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.
Anti-Arrhythmia Agents↗
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.
Action Potentials↗
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.
Adolescent↗
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.
Adolescent↗