Sinus node dysfunction masquerading as complete atrioventricular block in the setting of atrial parasystole after heart transplantation.

Heart transplantation is the gold standard for treatment of end stage heart failure. Atrial parasystole (AP), defined as the presence of an additional dissociated atrial pacemaker on a surface electrocardiogram, has been described to be seen after heart transplantation using biatrial surgical technique. AP may pose a challenge in diagnosing underlying rhythm disturbances in these patients. Here, we report a rare phenomenon of junctional escape rhythm with sinus node dysfunction, mimicking as complete atrioventricular block due to the presence of an AP, in a heart transplant recipient.

Development of paediatric electrophysiology standards for Florida Children's Medical Services.

The Florida Children's Medical Services (CMS) has a long-standing history of ensuring that providers of multiple paediatric subspecialties abide by the highest standards. The cardiac sub-committee has written quality standard documents that participating programmes must meet or exceed. These standards oversee paediatric cardiology services including surgery, catheterisations, and outpatient services. On April, 2012, the cardiac sub-committee decided to develop similar standards in paediatric electrophysiology. A task force was created and began this process. These standards include a catalogue of required and optional equipment, as well as staff and physician credentials. We sought to establish expectations of procedural numbers by practitioner and facility. The task force surveyed the members of the Pediatric and Congenital Electrophysiology Society. Finding no consensus, the task force is committed to generate the data by requiring that the CMS participating programmes enrol and submit data to the Multicenter Pediatric and Adult Congenital EP Quality (MAP-IT™) Initiative. This manuscript details the work of the Florida CMS Paediatric Electrophysiology Task Force.

A high school-based voluntary cardiovascular risk screening program: issues of feasibility and correlates of electrocardiographic outcomes.

Risk factors for adult cardiovascular events can be identified from the prenatal period through childhood. We performed a cardiovascular risk-screening program in students from grades 9-12 in 7 high schools in Hillsborough County, FL. We obtained blood pressure (BP) measurements and calculated body mass index (BMI) as risk factors for future cardiovascular events as well as obtained an electrocardiogram (ECG) for the purposes of detecting possible life-threatening arrhythmias. Of ~14,000 students contacted, 600 (4 %) participated in the screening. Of these, 517 (86 %) were diagnosed with normal, 71 (12 %) with borderline, and 12 (1 %) with abnormal ECGs. Although no participant had any cardiac history, two of the abnormal ECGs indicated a cardiac diagnosis associated with the potential for sudden cardiac death. Both systolic and diastolic BP increased as the ECG diagnosis moved from normal (115.6/73.8) through borderline (121.0/75.9) to an abnormal (125.0/80.7) diagnosis (all P ≤ .0016). An increase in BMI was only observed when an ECG diagnosis was abnormal (P = .0180). Boys had a greater prevalence (18.97 %) of borderline or abnormal ECGs compared with girls (6.75 %), whereas no discernible differences were seen in ECG diagnosis between white and nonwhite individuals (15.09 and 12.26 %, respectively). Although participation rates were low, a high school-based cardiovascular risk-screening program including ECG is feasible. Although ECG diagnosis tended to be related to other known cardiovascular risk factors (BP, BMI), the utility of an abnormal ECG in adolescence as a predictor of future cardiovascular risk will require further evaluation in more controlled settings.

Low recurrence rate in treating atrioventricular nodal reentrant tachycardia with triple freeze-thaw cycles.

BACKGROUND: Cryoablation is an alternative to radiofrequency ablation in treating atrioventricular nodal reentrant tachycardia (AVNRT). However, its long-term effectiveness is in question when compared to radiofrequency ablation. We reviewed the results of cryoablation in children with AVNRT at our institute. METHODS: We performed a retrospective single-center chart review of consecutive patients ≤18 years of age with AVNRT who underwent cryoablation between January 2007 and August 2009. During cryoablation, a 6-mm-tip cryocatheter was used with temperature set to -80°C. Test lesions were performed at the presumed slow pathway location based on combined anatomic and electrophysiologic approach. If successful, ablation was then continued with triple freeze-thaw cycles (FTC) of 4 minutes each. RESULTS: A total of 53 patients (age range: 6.1-18.4 years, mean: 13.6 years, median: 13.2 years) underwent slow pathway modification with cryoablation. Acute success was achieved in 51 (96.2%) cases. Transient atrioventricular block was seen in 19 cases. The block occurred during FTC in eight patients (15%). The number of FTC was three in 47 (92.2%) patients. Less than three FTC were given in two patients due to transient heart block and four FTC were given in two patients with suspected catheter movement. Procedure duration was 177 ± 56 minutes; fluoroscopic time was 14 ± 11 minutes. Mean follow-up was 30.7 ± 10 (range 12-52, median 31) months. Recurrence of supraventricular tachycardia was seen in only one (1.96%) patient. CONCLUSIONS: Triple FTC cryoablation lesions resulted in a low recurrence rate comparable to RF ablation in treating AVNRT without increased complications.

Ciprofloxacin-induced Q-T interval prolongation.

PURPOSE: A case of Q-T interval prolongation in a pediatric patient with no known risk factors for the development of a long Q-T syndrome is reported. SUMMARY: A 16-year-old boy arrived at a children's hospital reporting mucous diarrhea that had lasted two weeks, light-headedness with two blackouts on the day before his arrival to the hospital, and a 4.3-kg weight loss over the previous three weeks. He had a 3.5-year history of Crohn's disease and had been hospitalized for two months with a diagnosis of colitis with cryptitis. He was admitted for the treatment of an acute flare of Crohn's disease and a perirectal abscess. The patient was started on i.v. ciprofloxacin 400 mg twice daily and metronidazole 500 mg every six hours. The selected agents provided adequate empirical coverage of the suspected organisms and would not be contraindicated with the patient's allergy to penicillin. Within 48 hours of administration of ciprofloxacin, the patient became bradycardic. The cardiology service was consulted, and an electrocardiogram showed a mildly prolonged Q-T interval (corrected Q-T interval, 486 msec) and low heart rate (42 beats/min). Antimicrobial therapy was changed to ampicillin and then to linezolid. The patient's Q-T interval normalized within seven days of ciprofloxacin discontinuation. The patient had no further cardiac anomalies. Two weeks later, he was discharged on linezolid and aztreonam for the treatment of his abscess and was responding to treatment. CONCLUSION: A pediatric patient with Crohn's disease and colitis with cryptitis developed a prolonged Q-T interval within 48 hours of treatment with ciprofloxacin.

Transthoracic echocardiographic guidance of transcatheter atrial septal defect closure.

This study examines the safety and efficacy of transthoracic echocardiographic (TTE) guidance of atrial septal defect (ASD) device closure. We evaluated 74 patients for TTE-guided ASD closure. Fifty-six patients had successful device implantation using TTE guidance. Twelve patients were referred for surgical ASD closure on the basis of TTE evaluation. Five patients with multiple ASDs or poor transthoracic acoustic windows had ASD device closure guided by transesophageal echocardiography (TEE).