Left coronary artery arising from the non-coronary sinus: a rare congenital coronary anomaly.

Anomalous origin of the left coronary artery is a cause of sudden death in adolescents and young adults. Most commonly, it originates from the right coronary sinus or the pulmonary artery. Origin of the left main coronary artery from the non-coronary sinus of Valsalva is extremely rare. We report a case of a child with anomalous origin of the left main coronary artery from the non-coronary sinus diagnosed during the evaluation of a ventricular arrhythmia.

Ultrasound-assisted cannulation of the right internal jugular vein during electrophysiologic studies in children.

Percutaneous access of the right internal jugular vein for coronary sinus cannulation in pediatric patients undergoing electrophysiologic studies may be technically difficult. We report the use of an ultrasound-guided technique for obtaining jugular venous access. Forty-five pediatric patients who underwent electrophysiologic study were analyzed. Access was obtained in 100 % of the patients using this technique with no major complications. Ultrasound guidance for access of the internal jugular vein for coronary sinus cannulation during electrophysiologic studies in pediatric patients, may increase the success rate and prevent the development of complications.

Bulboventricular foramen resection: hemodynamic and electrophysiologic results.

BACKGROUND: The two major surgical approaches to the relief of bulboventricular foramen (BVF) obstruction in patients with single left ventricle (LV) are the Damus-Kaye-Stansel (DKS) procedure or direct BVF resection. Theoretical advantages of the DKS include better out-flow gradient relief, lower potential incidences of postoperative heart block and lower incidences of reoperation. Potential disadvantages of this approach include increased semilunar valvar insufficiency, lack of feasibility when attempting septation-type operations for univentricular hearts, and a technically more difficult operation. We report the results of direct surgical BVF resection. METHODS: From June 1990 to June 1999, 9 patients had direct BVF resection performed at our institution. The median age at surgery was 16.5 years (range 1 month to 27 years). Diagnoses in these patients were [S,L,L] single LV (n = 8) and [S,D,D] single LV tricuspid atresia (n = 1). Eight of 9 patients had pulmonary artery bands placed either before BVF resection or at the same time as this procedure. Three patients required reoperation for reobstruction at the BVF (12 total operations in 9 patients). RESULTS: Median preoperative peak systolic gradient across the BVF measured at cardiac catheterization was 47 mm Hg (range 10 to 63 mm Hg). The median peak gradient measured by Doppler echocardiography was 44 mm Hg (range 5 to 125 mm Hg). Eight of 9 patients survived the operation to discharge from the hospital and 7 of 9 are alive at follow-up. At a median follow-up of 22 months (range 5 to 76 months), 8 of 8 surviving patients had an unobstructed BVF as determined by qualitative two-dimensional echocardiography and Doppler color flow imaging. There was one perioperative and one late death 5 months postoperatively (secondary to fungal sepsis). No patient developed new or worsened aortic insufficiency after BVF resection. Eight of 9 patients had no change in AV nodal conduction after surgery. One patient developed Mobitz II heart block requiring postoperative implantation of a pacemaker. CONCLUSIONS: Direct resection of an obstructive BVF can be performed with total relief of obstruction although reoperation may be required. Atrioventricular nodal function can be preserved in most patients with this operative approach, including those with [S,L,L] segmental anatomy.

Torsade de pointes in a child with acute rheumatic fever.

Ventricular arrhythmias are uncommon in acute rheumatic carditis. We report the case of a child who presented with rheumatic carditis, prolonged corrected QT interval, and torsade de pointes. The episodes of torsade were controlled with beta-blockade and cardiac pacing. The child subsequently died as a result of brain injury; the autopsy revealed classic findings of acute rheumatic carditis.

Continuous intravenous diltiazem infusion for short-term ventricular rate control in children.

Intravenous diltiazem was administered to 10 pediatric patients with primary atrial tachyarrhythmias with rapid ventricular response. Rapid, consistent, and safe temporary ventricular rate control was obtained in all patients given this medication.

Radiofrequency ablation of an accessory pathway in a surgically created atrioventricular Fontan anastomosis: case report and review of previous published cases.

Supraventricular tachyarrhythmias following the Fontan procedure can be life-threatening. Though most are commonly due to intraatrial reentry, orthodromic reentrant tachycardia may also be present. Atrioventricular accessory pathways may develop across suture lines following right atrial to right ventricular anastomosis in patients with tricuspid atresia. We report a case of a patient who underwent this type of Fontan who developed orthodromic reentrant tachycardia and heart failure. An electrophysiological study revealed the presence of an atrioventricular accessory pathway traversing the Fontan anastomosis suture line. Successful radiofrequency ablation of the accessory pathway led to control of the tachyarrhythmia and improvement of heart failure.

Noninvasive prediction of pulmonary artery pressure in patients with isolated ventricular septal defect.

Management of patients with isolated ventricular septal defect (VSD) requires information regarding pulmonary artery pressure (PAP). The purpose of this study was to evaluate the individual predictive value of noninvasive methods for assessment of PAP and to determine if any combination of techniques significantly improved their predictive power. We reviewed the clinical history, electrocardiogram, and echocardiogram of 31 patients (age 1.9 +/- 1. 73 years) who underwent catheterization for isolated VSD. Noninvasive data were compared for patients with mean PAP <20 mmHg (group 1) and those with mean PAP > or =20 (group 2) at catheterization. Fourteen (45%) patients were in group 1 and 17 (55%) in group 2. Doppler estimation of VSD gradient, right ventricular hypertrophy by echocardiogram, interventricular septal orientation, and VSD size had predictive value for elevated mean PAP (p < 0.01). All patients (n = 6) with normal findings in all four variables had normal PAP. All patients (n = 12) with at least three of four abnormal findings had elevated PAP. Six patients in group 1 had at least one variable that incorrectly predicted high PAP, whereas 3 patients with normal findings on three of the four variables nevertheless had elevated PAP. No single noninvasive variable accurately predicted PAP in all cases. However, normal findings for all four significant variables did predict normal PAP and suggest that cardiac catheterization is unnecessary in that setting. However, any other combination of normal and abnormal findings for the four significant variables did not reliably predict PAP and such patients may require catheterization to directly measure PAP.

Serial echocardiographic measurements of the pulmonary autograft in the aortic valve position after the Ross operation in a pediatric population using normal pulmonary artery dimensions as the reference standard.

Serial echocardiographic measurements of the annulus and sinus were obtained in children before the Ross operation, and early and late postoperatively. Values were compared with normal standards for the aorta and pulmonary artery (PA). There was no significant difference between PA annulus measurements before surgery and the corresponding autograft immediately afterward (1.73 +/- 0.60 cm preoperatively; 1. 63 +/- 0.58 cm postoperatively, p = NS). Late after surgery the mean annulus diameter was enlarged compared with the normal aorta (DeltaZ 1.9 +/- 2.4), but remained relatively unchanged compared with the normal PA (DeltaZ 0.7 +/- 1.1, p <0.01). In contrast, the autograft sinus was dilated early after surgery (1.83 +/- 0.58 cm preoperatively; 2.18 +/- 0.73 cm postoperatively, p <0.01). Mean sinus Z score further increased compared with both the aorta (DeltaZ 1.3 +/- 1.7) and PA (DeltaZ 1.3 +/- 1.6). Use of standard PA measurements may be important in the assessment of autograft enlargement. Minimal change in autograft Z scores over time suggests that annulus enlargement is mainly due to somatic growth. In contrast, the autograft sinus showed an immediate and continued disproportionate increase in size over time, suggesting that sinus enlargement is largely due to passive dilation.

Catheter ablation of atrioventricular junction via retrograde route in a patient with single ventricle.

Radiofrequency catheter ablation of the atrioventricular junction (AVJ) was performed by the retrograde route in a 19-year-old woman with atrial fibrillation and single ventricle following the bidirectional Glenn procedure. Two energy applications resulted in complete atrioventricular block and dependence on an epicardial ventricular pacemaker.

Progressive tricuspid valve disease in patients with congenitally corrected transposition of the great arteries.

BACKGROUND: The outcome of patients with corrected transposition of the great arteries (CTGA) is variably affected by associated intracardiac defects, tricuspid valve competence, and systemic right ventricular (RV) function. The relative importance of these factors in long-term outcome has not been evaluated. METHODS AND RESULTS: Since 1958, 40 patients with CTGA were studied to determine risk factors for poor outcome, including age, open heart surgery, tricuspid insufficiency (TI), cardiac rhythm, pulmonary overcirculation, and RV dysfunction. Follow-up ranged from 7 to 36 years (mean 20 years). Intracardiac repair was performed in 21 patients; 19 were unoperated or had closed heart procedures. For the purposes of this study the designation TI(S) refers to at least moderately severe TI as delineated by echocardiogram and/or angiography. TI(s) was the only independently significant factor for death (P=0.01), and in turn, only the presence of a morphologically abnormal TV predicted TI(s)(P=0.03). Twenty-year survival without TI(S)was 93%, but only 49% with TI(S). Poor long-term postoperative outcome was due to TI(S) in all but 1 patient; 20-year survival rates for operated patients with and without TI(s)were 34% and 90%, respectively (P=0.002). Similarly, 20-year survival rates for unoperated patients with and without TI(s)were 60% and 100%, respectively, whether or not attempts to repair the TI were made (P=0.08). CONCLUSIONS: TI(S)represents the major risk factor for CTGA patients; RV dysfunction appears to be almost always secondary to long-standing TI. Decisions related to surgical interventions with or without associated lesions must be strongly influenced by the status of the tricuspid valve.

Cardiac pacing in children.

Indications for cardiac pacing in pediatric patients continue to expand. In addition to its traditional use in sinus and atrioventricular nodal disease, applications for cardiac pacing now include treatment of tachyarrhythmias after repair of congenital heart disease, reduction of left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and prevention of sudden death in the congenital long QT syndrome. Whereas many benefits have been well documented in adults, they remain anecdotal in children. Programmable features such as rate-response and antitachycardia pacing contribute to pacemaker versatility and facilitate the achievement of normal hemodynamics in children requiring long-term pacing therapy.

Blade balloon atrial septostomy in patients with severe primary pulmonary hypertension.

BACKGROUND: Patients with severe primary pulmonary hypertension have a poor prognosis, but those with a patent foramen ovale may survive longer. A few reports of clinical improvement after blade balloon atrial septostomy in patients with severe pulmonary vascular disease have appeared. The purpose of this study was to systematically evaluate the effects of blade balloon atrial septostomy on clinical signs and symptoms, hemodynamics, and survival in patients with severe primary pulmonary hypertension. METHODS AND RESULTS: Blade balloon atrial septostomy was performed on 15 children and young adults with severe primary pulmonary hypertension. Despite maximal medical therapy, prior to septostomy all patients had recurrent syncope and 8 had severe right heart failure. Thirteen patients survived the procedure. After blade balloon atrial septostomy, no patient experienced further syncope, and signs and symptoms of right heart failure improved in all New York Heart Association Class IV patients. Within 24 hours after the procedure and at follow-up catheterization 7 to 27 months after septostomy, there was a significant increase in cardiac index, resulting in an increase in systemic oxygen transport. There was improved long-term survival in the 13 patients who survived blade balloon atrial septostomy compared with similar groups of primary pulmonary hypertension patients who received standard therapy (P < .05). CONCLUSIONS: Blade balloon atrial septostomy resulted in clinical and hemodynamic improvement and improved survival in selected patients with severe primary pulmonary hypertension.

Arrhythmias in pediatric heart transplant recipients: prevalence and association with death, coronary artery disease, and rejection.

To ascertain the prevalence and types of arrhythmias occurring after heart transplantation in children, all available 24-hour ambulatory ECGs (mean, 1.5/patient), and 12-lead surface ECGs (mean, 27/patient) obtained from 59 orthotopic pediatric heart transplant recipients (mean age, 9.7 +/- 5.9 years) were examined. Correlation of the appearance of arrhythmias with the occurrence of rejection, coronary artery disease, or death was investigated. Of the 59 patients, 24 (41%) were found to have arrhythmias including chronic sinus tachycardia (eight patients), sinus bradycardia (four patients), supraventricular tachyarrhythmias (nine patients), significant ventricular premature depolarization (seven patients), and nonsustained ventricular tachyarrhythmias (seven patients). The occurrence of arrhythmias was not significantly associated with the number of rejections per patient month of survival. However, a significant proportion of patients with supraventricular (seven of nine patients; p = 0.006) and ventricular (six of seven patients; p = 0.02) tachyarrhythmias experienced a rejection episode in association with the onset of the rhythm abnormality. The presence of coronary artery disease was significantly associated with the presence of ventricular tachyarrhythmias (p = 0.03). Graft survival was significantly lower in those patients with arrhythmias as compared with the arrhythmia-free group (58% versus 86%, p = 0.02). The results suggest that the appearance of arrhythmias in a pediatric heart transplant recipient should prompt a search for the presence of rejection and/or coronary artery disease.

Chronotropic and dromotropic actions of acetylcholine on the developing fetal heart.

We studied the effect of acetylcholine (ACh), 1 x 10(-8) to 5 x 10(-7) M, on electrophysiologic characteristics of the isolated (Langendorf), perfused fetal canine heart. ACh induced concentration-dependent decreases in sinoatrial (SA) rate and recovery from overdrive pacing and in atrioventricular (A-V) conduction. These effects of ACh were greater in mid-gestation than late-gestation hearts. The effects of ACh were potentiated by inhibition of acetylcholinesterase by neostigmine, 1 x 10(-7) M, in the late- but not the mid-gestation fetal heart. Decreasing the pH of the perfusion solution from 7.3 to 6.8 potentiated the response to ACh of SA rate and A-V conduction more in mid- than in late-gestation hearts. The response to ACh of the late-gestation fetal canine heart is more sensitive to cholinesterase inhibition whereas the response of the mid-gestation heart is more sensitive to the action of ACh in the presence of acidosis.

Transcatheter ablation of ectopic atrial tachycardia in young patients using radiofrequency current.

BACKGROUND: Ectopic atrial tachycardia (EAT) is a reversible cause of cardiomyopathy but may be quite difficult to control with conventional therapy. Transcatheter ablation with radiofrequency current was tested as an alternative to medical or surgical treatment of this condition. METHODS AND RESULTS: Twelve young patients (aged 10 months to 19 years) with drug-resistant EAT were treated with direct transcatheter ablation of the ectopic focus using radiofrequency (RF) energy. All had depressed left ventricular contractility by echocardiographic criteria, involving shortening fractions of 10-26% (median, 20%; normal, 28-35%). The EAT was mapped to the left atrium in seven cases and to the right atrium in five. Local atrial activation at the ectopic site preceded the onset of the surface P wave by 20-60 msec (median, 42 msec). Tachycardia terminated 0.5-13.0 seconds (median, 2.0 seconds) into a successful RF application. The ablation effectively eliminated EAT in 11 of 12 patients (92%), all of whom were discharged in sinus rhythm without medications after a median hospital stay of 48 hours. Ablation was unsuccessful in one patient with diffuse dysplasia of the anterior right atrium, who eventually did well after surgical resection of abnormal atrial tissue. Transient depression of sinus node function was noted in one patient who had successful ablation of an EAT focus in close proximity to the sinus node, although normal sinus node function returned within 72 hours. No other complications were encountered. During follow-up (3-21 months; median, 13 months), one patient had recurrence of a slower and less-sustained EAT that was successfully eliminated at a second ablation session. All others remained in sinus rhythm, and all 12 subjects recovered normal ventricular function. CONCLUSIONS: RF ablation appears to be a safe and effective therapeutic option for drug-resistant ectopic atrial tachycardia and may be the preferred first-line therapy for those patients with depressed ventricular function.

Transvenous pacemakers in children: relation of lead length to anticipated growth.

Although transvenous pacing is feasible in infants and children, uncertainty remains as to how to allow for future growth at the time of lead insertion. Accordingly, we retrospectively reviewed the relation between age and transvenous lead length. Standard posteroanterior chest roentgenograms were reviewed for 26 patients with transvenous pacemakers inserted at Babies Hospital and Presbyterian Hospital between 1985 and 1989. Sixteen of these were children (age range, 0.75 to 15 years) and 10 were adults (age range, 27 to 90 years). The intravascular length of right ventricular pacing leads was measured as projected on the roentgenogram. In 10 children, the presence of lead loops in the right atrium required the lead length that would have resulted from conventional placement to be estimated. Results for right ventricular pacing lead lengths were correlated with age using linear regression analysis. Average uncorrected lead length measured on the roentgenogram was 345 +/- 35 mm (standard deviation) in adults and 222 +/- 51 mm in children. The use of right atrial loops increased implanted lead length by an estimated 79 mm, from 188 +/- 26 to 267 +/- 43 mm. The difference between lead length in children and adults was analyzed. Approximately 190 mm of additional right ventricular pacing lead in infants and 100 mm in 10-year-old children was needed for growth to adult size. We conclude that an 80-mm right atrial lead loop will allow 6 to 12 years (mean, 8 years) of growth in infants and children without the need for reoperation to adjust lead length.

Acute pulmonary embolism in pediatric patients awaiting heart transplantation.

Acute pulmonary embolism with infarction can delay urgently needed heart transplantation and increase the postoperative pulmonary complications. Few data are available concerning pulmonary embolization in the pediatric patient with end-stage congestive heart failure. Sixty-two consecutive pediatric patients awaiting heart transplantation were monitored for evidence of acute pulmonary embolism. Acute pulmonary infarction was documented by ventilation-perfusion scan, pulmonary angiography or pathologic examination in six patients. The prevalence differed by diagnosis; 5 of 36 patients with dilated cardiomyopathy and 1 of 20 patients with congenital heart disease developed acute pulmonary embolism with infarction. No significant difference in age at the time of transplantation evaluation, duration of congestive heart failure, presence of cardiac arrhythmias or degree of cardiac dysfunction was seen between patients with and without pulmonary embolism. Two-dimensional echocardiography failed to detect the presence of an intracardiac thrombus in four of the six patients. Two patients who developed acute pulmonary infarction are alive after successful heart transplantation. The remaining four patients died within 6 weeks of initiation of anticoagulant therapy before transplantation could safely be performed. In summary, pediatric patients with end-stage congestive heart failure are at risk for acute pulmonary embolism. No specific clinical factor identified those patients who developed acute pulmonary infarction. Anticoagulant therapy is strongly recommended in the pediatric patient with poor ventricular function awaiting heart transplantation.

Developmental changes in the effects of lidocaine and quinidine on the canine heart.

We studied the developmental changes that occur in the use-dependent effects of lidocaine and quinidine on the intact canine heart. At comparable intravenous dosages, adults showed higher total and free plasma lidocaine concentrations than young dogs, whereas for quinidine, the total and free levels were comparable. Lidocaine demonstrated a use-dependent depressant effect on intraventricular conduction in adults that was significantly greater than that in the young, and it significantly accelerated repolarization (QT interval) in the adult. In contrast, comparable effects of quinidine were seen on conduction in adult and young dogs, while repolarization was prolonged more in the young. These effects on conduction and repolarization in the adult and young hearts were explained by our earlier cellular electrophysiologic studies. Our findings indicate the following: (a) developmental changes in the cellular electrophysiologic effects of specific antiarrhythmic drugs are predictive of the effects in the in situ heart; (b) these effects are further modified by developmental differences in drug metabolism and protein binding; (c) developmental changes in the effects of one antiarrhythmic local anesthetic are not necessarily predictive of those for another; and (d) the effects of drugs on the adult heart may be, but are not necessarily, predictive of those in the young.