Sudden Death in the Young: Information for the Primary Care Provider.

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

Cost-effectiveness of treating infantile haemangioma with propranolol in an outpatient setting.

BACKGROUND: Infantile haemangioma is one of the most commonly known benign vascular tumours of infancy and childhood, having an incidence of 3-10%. Most lesions regress spontaneously; however, some may require treatment owing to their clinical and cosmetic effects. Propranolol has become the treatment of choice for infantile haemangioma, but treatment protocols are largely institutional based without any specific consensus guidelines. Our aim was to evaluate the cost-effectiveness of propranolol use as inpatient versus outpatient therapy. METHODS: A decision tree model was created depicting alternate strategies for initiating propranolol treatment on an inpatient versus outpatient basis combined with the option of a pretreatment echocardiogram applied to both strategies. Cost analysis was assumed to be based on treatment of haemangioma in patients who were born at term, had no chronic illnesses, a non-life-threatening location of the haemangioma, and those who were not taking any other medications that could potentiate the side effects of propranolol. A sensitivity analysis was performed to evaluate the probability of side effects. RESULTS: The average cost incurred for inpatient treatment of infantile haemangioma was approximately $2603 for a single hospital day and increased to $2843 with the addition of an echocardiogram. The expected cost of treatment in the outpatient setting was $138, which increased to $828 after the addition of an echocardiogram. CONCLUSION: Treating infantile haemangioma with propranolol is more cost-effective when initiated on an outpatient basis.

Tilt table testing to diagnose pseudosyncope in the pediatric population.

OBJECTIVE: Pseudosyncope can be difficult to distinguish from true syncope. Often, pediatric patients with pseudosyncope undergo multiple tests and referrals before the appropriate diagnosis is reached. The purpose is to describe the utility of the head-up tilt table test to elicit the diagnosis of pseudosyncope in the pediatric population. DESIGN: Retrospective chart review from November 2012 to December 2015 of patients age ≤23 years referred for 30-minute, 80-degree tilt table test. Pretest probability for pseudosyncope was high if there was no response to traditional management, atypical episodes, occurrence during undesirable exercise, or prolonged episode duration. Inductive techniques were utilized to persuade patients of the likelihood of experiencing an episode during the procedure. Pseudosyncope was confirmed when a patient had normal vital signs during their event and had reflex responses to disruptive maneuvers. RESULTS: Tilt table testing was performed on 89 patients [median age 16 years (5-23); 26% male] with the majority (60%) being negative for pseudosyncope, including 51 true negatives and 2 false-negatives. Of the 36 patients with syncope during tilt table testing, 28 were diagnosed with vasovagal syncope and 8 with pseudosyncope [median age 16 years (15-21); 38% male]. Pseudosyncope episodes were observed immediately in 2 patients. All patients with late-onset pseudosyncope required inductive techniques prior to the recorded episode. CONCLUSIONS: Pseudosyncope can be identified during tilt table testing if inductive techniques are utilized in patients with a high index of suspicion. Disruptive maneuvers are excellent adjunctive methods to confirm the diagnosis. Tilt table testing is an effective means to identify pseudosyncope and allow appropriate diagnosis and treatment.

Isolated Left Subclavian Artery, Complete Atrioventricular Block, and Tricuspid Atresia in a Neonate.

Isolated left subclavian artery is one of the rarer aortic arch anomalies. It has been associated with other congenital heart diseases, typically tetralogy of Fallot, double-outlet right ventricle, and atrial and ventricular septal defects. Its significant clinical implications include a left-to-right shunt from the vertebrobasilar system, which causes pulmonary overcirculation and subclavian steal. We present an unusual case of a premature infant who was diagnosed prenatally with congenital complete atrioventricular block and tricuspid atresia and was found to have an isolated left subclavian artery postnatally. The patient underwent implantation of a permanent single-chamber epicardial pacing system. To our knowledge, this combination of lesions has not been reported-and in our case, it influenced our surgical planning.

Induction of atrial fibrillation with adenosine during a transesophageal electrophysiology study to risk stratify a patient with asymptomatic ventricular preexcitation.

An asymptomatic adolescent male athlete was incidentally found to have ventricular preexcitation on electrocardiogram during a sports preparticipation physical. A transesophageal electrophysiology study (TEEPS) was performed after an exercise stress test failed to delineate the patient's risk of sudden cardiac death. The TEEPS was favored in this case over a transvenous electrophysiology study due to reduced invasiveness. The goal of the TEEPS was to place the patient into atrial fibrillation (AFib) and evaluate the shortest preexcited RR interval during AFib, thereby assessing the risk of his accessory pathway. Conventional pacing modalities were unable to induce AFib. During atrial burst pacing, adenosine was then administered, which successfully induced AFib. This case highlights adenosine's potential to induce atrial fibrillation during transesophageal electrophysiology studies when atrial pacing alone was unable to do so.

Intermittent cyanosis years after a Mustard repair for dextro-transposition of the great arteries.

A 28-year-old woman, who as an infant had undergone the Mustard atrial switch procedure for dextro-transposition of the great arteries, presented with a baffle leak and consequent intermittent cyanosis. In addition, an occlusive thrombus had formed in the systemic venous baffle after a failed attempt to remove infected pacemaker leads. Corrective surgery was successful. In addition to the case of our patient, we discuss long-term sequelae of the atrial switch procedure that present challenges in patient care.

A newborn with congenital complete atrioventricular block, lissencephaly, and skeletal abnormalities: a case of suspected cytomegalovirus infection.

We present a case of congenital complete atrioventricular block in a preterm microcephalic male with multiple additional congenital anomalies, including spinal and rib abnormalities. The heart was structurally normal, and maternal tests for autoimmune disorders were negative. The brain had an immature lissencephalic appearance, suggestive of an insult early in gestation. Genetic testing was normal, virtually excluding chromosomal disorders that are known to cause lissencephaly. Viral studies were suggestive of cytomegalovirus infection during early gestation, and we believe that the patient's clinical presentation was most likely the result of an early cytomegalovirus infection. The finding of complete atrioventricular block in a patient with presumed cytomegalovirus infection would represent a very rare complication. "Isolated" complete atrioventricular block in a fetus should be considered an incentive for an extensive work-up in search for a possible etiology, rather than accepted as a final diagnosis.

Postoperative ventricular tachycardia in patients with congenital heart disease: diagnosis and management.

Ventricular tachycardia (VT) after palliative repair of congenital heart disease is relatively rare. Despite this rarity, VT is a known cause of early, intermediate and late morbidity and mortality in these patients. A number of factors have been linked to the development of VT in this unique patient population. The purpose of this article is to provide a concise overview regarding the etiology, diagnosis and treatment of VT in patients with congenital heart disease. In-depth information will be provided to aid diagnosis and the treatment of early postoperative VT. The use of additional diagnostic methods such as echocardiography, cardiac catheterization and electrophysiology studies to risk assess patients with postoperative VT will also be discussed. In addition, I examine the long-term management strategies for VT in these patients, from medical management and cardiovascular surgery to implantation of cardioverter-defibrillators.

Can pediatric electrophysiologists safely perform electrophysiology studies on adults with congenital heart disease?

INTRODUCTION: Adults with congenital heart disease (ACHD) are known to have arrhythmias. The purpose of this study was to review the safety and efficacy of a pediatric electrophysiologist performing electrophysiology studies (EPS) on ACHD. METHODS: All ACHD >18 years of age who underwent an EPS performed by a pediatric electrophysiologist between 1995 and 2004 were included. Patient records were reviewed for demographics, cardiac diagnosis, surgery, arrhythmia, and catheterization issues such as vascular access, fluoroscopy time, complications, procedure performed, and success rates. RESULTS: The study identified 70 patients who underwent 93 EPS: 42 with ventricular tachycardia (VT) and 28 with supraventricular tachycardia (SVT). With respect to safety, vascular access was obtained in 100% of patients, fluoroscopy time averaged 34.2 minutes, and complications occurred in 3 patients (4%) including permanent (1) or transient (1) atrio-ventricular node injury and coagulum on the catheter (1), but no deaths. With respect to efficacy, 30 patients had an attempted radiofrequency ablation that was successful in 21 of 28 (75%) with SVT and 1 of 2 (50%) with VT. CONCLUSIONS: (1) ACHD can safely undergo an electrophysiology study performed by pediatric electrophysiologists, with low fluoroscopy times and few complications. (2) Success rates for ablation in this patient population approach 75%.

Stent implantation as a stabilization technique in supracardiac total anomalous pulmonary venous connection.

A 6-week-old male presented in-extremis with obstructed supra-cardiac total anomalous pulmonary venous connection. Balloon dilation and stent implantation in the stenotic segment of the vertical vein relieved the obstruction until the patient was stable enough to undergo surgical repair. An unusual form of extrinsic vertical vein compression was found at surgery.

Early postoperative arrhythmias after pediatric cardiac surgery.

OBJECTIVE: Early postoperative arrhythmias are a known complication of cardiac surgery; however, little data exists specific to pediatrics. The purpose of this study was to determine the incidence and risk factors associated with the development of arrhythmias immediately after surgery in a pediatric population. METHODS: Data were collected in a prospective observational format from pediatric patients undergoing cardiac surgery between September 2000 and May 2003. This format included age, anatomy, surgical repair, and serum magnesium and calcium levels, as well as cardiopulmonary bypass and aortic crossclamp times. Patients were continuously monitored, and hemodynamically significant arrhythmias were recorded. RESULTS: Arrhythmias occurred in 28 of the 189 patients enrolled (15%) including 16 with junctional ectopic tachycardia, 7 with complete atrioventricular block, 4 with ventricular tachycardia, and 1 with re-entrant supraventricular tachycardia. Significant differences were found between the arrhythmia and nonarrhythmia groups with regard to age (22 vs 45 months), cardiopulmonary bypass time (189 vs 109 minutes), and aortic crossclamp time (105 vs 44 minutes); P < .05. Magnesium and calcium levels were not significantly different between the groups. Two repairs carried an increased risk: complete atrioventricular septal defect repair, 8 of 11 patients (72%), and the arterial switch 5 of 8 patients (62.5%); P < .05. Atrioventricular septal defects had an even higher incidence when controlled for age, bypass time, and crossclamp time (odds ratio = 7.65). CONCLUSIONS: Hemodynamically significant postoperative arrhythmias are a frequent complication of pediatric cardiac surgery. Younger age and longer bypass and crossclamp times are risk factors for arrhythmia. In addition, the repair of atrioventricular septal defects carries an independent risk of arrhythmias.

Intraoperative radiofrequency ablation of the atrium: effectiveness for treatment of supraventricular tachycardia in congenital heart surgery.

BACKGROUND: Supraventricular tachycardia (SVT) is common in surgical patients with congenital heart disease. Ablation and maze operations have been shown to be effective in treating SVT, but these procedures can be complex and time-consuming because of variable anatomy and a thickened right atrium. To simplify and shorten these procedures, we used a long, flexible radiofrequency probe capable of producing long ablation lines quickly and effectively. We report the initial results with this procedure. METHODS: Six patients aged 6 weeks to 40 years with refractory SVT were referred for reoperation for repair of complex congenital heart disease (transposition of the great vessels, Ebstein's anomaly, single ventricle, tetralogy of fallot). Intraoperative radiofrequency ablation was performed in the right atrium for refractory SVT as an adjunct to surgical reconstruction (redo Fontan, right atrial reduction plasty, right ventricular outflow tract reconstruction, tricuspid repair). Lesions were made with a radiofrequency probe using temperatures of 70 degrees C for 60 seconds. Lesions were placed between the coronary sinus and the tricuspid valve, between the tricuspid valve and the inferior vena cava, between the atrial septal defect and the superior and inferior vena cava in patients with intraatrial reentry tachycardia/atrial flutter, and at the location of the accessory pathway in a patient with Wolff-Parkinson-White syndrome. The long, flexible probe has multiple independently controlled segments allowing ablation lesions that conform to the atrial morphology. RESULTS: An average of five intraoperative radiofrequency ablation lesions per patient were made. Average time for ablation was 14 minutes. With up to 25 months' follow-up, 5 patients are in sinus rhythm, and 1 is in a paced atrial rhythm. The patient with Wolff-Parkinson-White syndrome showed no preexcitation after operation. No complications resulting from intraoperative radiofrequency ablation were encountered. CONCLUSIONS: Intraoperative radiofrequency ablation in the atrium is a safe, effective, and expeditious procedure for control of SVT in patients undergoing reoperation for congenital heart disease with refractory SVT.