Background
Successful slow pathway (SP) ablation sites for atrioventricular nodal reentrant tachycardia (AVNRT) are usually located inside the Koch's triangle (KT). This study aimed to determine the ...ablation site of SP using the coronary sinus (CS) ostium (CSO) as the reference and to evaluate the efficacy of the CSO‐guided SP ablation.
Methods
A regional geometry around the KT was constructed by 3D mapping in 52 consecutive patients under age 18 with AVNRT. SP cryoablation was performed. If initial cryoablation was unsuccessful or cryoablation was deemed not suitable, then radiofrequency (RF) ablation was performed. The successful ablation site direction relative to the CSO was expressed as o'clock with the CSO viewed as a clock.
RESULTS
Cryoablation was used as the primary energy source in 40 patients. Of which, 32 were successful and eight required additional RF ablation. Direct RF ablation was performed in 11 patients. Using the CSO as reference, the successful site with cryoablation was at its 2.2 ± 0.6 o'clock; the RF ablation success site was at CSO 2.7 ± 0.5 o'clock (P = .006). During a median follow‐up of 12 month, there was 98% success of SP ablation in these patients, with one patient with RF ablation had a tachycardia recurrence.
Conclusions
Using CSO as reference, the cryoablation site at its 2:00 o'clock and RF ablation at its 3:00 o'clock are highly efficacious for SP ablation with good short‐term outcomes, and may be a useful tool in guiding the ablation target for AVNRT.
Ablation success sites in cryoablation group and RF ablation group: Using CS ostium as reference and viewed as a clock, the median (solid line) and mean (dashed line) directional location of the successful cryoablation group (green) and RF ablation group (blue) are depicted in an illustrated Koch's triangle in a right anterior oblique view.
BACKGROUND Wearable smartphone-enabled cardiac monitoring devices can aid the diagnosis of asymptomatic tachycardia in neonates and infants. This report is of a rare case of left posterior fascicular ...ventricular tachycardia of Belhassen type detected in a neonate by 'smart sock' cardiac monitoring. CASE REPORT A premature baby boy at 37 weeks gestational age was discharged home after three days without complication, and was given 'smart socks' to wear. He was followed up daily for the management of hyperbilirubinemia, which was treated in the outpatient clinic with a phototherapy blanket. He was admitted to the emergency room (ER) at 6 days of age because his 'smart socks' identified a tachycardia of between 180-200 bpm. His parents reported no fever, cough, nasal congestion, or emesis. On examination in the ER, he was alert with no distress. An electrocardiogram (ECG) showed a sustained monomorphic and wide QRS tachycardia with a heart rate of 200 bpm, right bundle branch block (RBBB), and a superior axis that was compatible with a diagnosis of left posterior fascicular ventricular tachycardia of Belhassen type. The echocardiogram showed a structurally normal heart with normal cardiac function. His tachycardia spontaneously converted to normal sinus rhythm after four hours. He was discharged home three days later without further episodes of tachycardia. Cardiac monitoring using 'smart socks' continued at home, and no further arrhythmias were detected at one year of age. CONCLUSIONS The home use of smartphone-enabled technology to monitor the neonatal and infant cardiac heart rate can identify asymptomatic arrhythmias.
Objectives The purpose of this study was to define the clinical characteristics and long-term follow-up of pediatric patients with short QT syndrome (SQTS). Background SQTS is associated with sudden ...cardiac death. The clinical characteristics and long-term prognosis in young patients have not been reported. Methods This was an international case series involving 15 centers. Patients were analyzed for electrocardiography characteristics, genotype, clinical events, Gollob score, and efficacy of medical or defibrillator (implantable cardioverter-defibrillator ICD) therapy. To assess the possible prognostic value of the Gollob score, we devised a modified Gollob score that excluded clinical events from the original score. Results Twenty-five patients 21 years of age or younger (84% males, median age: 15 years, interquartile range: 9 to 18 years) were followed up for 5.9 years (interquartile range: 4 to 7.1 years). Median corrected QT interval for heart rate was 312 ms (range: 194 to 355 ms). Symptoms occurred in 14 (56%) of 25 patients and included aborted sudden cardiac death in 6 patients (24%) and syncope in 4 patients (16%). Arrhythmias were common and included atrial fibrillation (n = 4), ventricular fibrillation (n = 6), supraventricular tachycardia (n = 1), and polymorphic ventricular tachycardia (n = 1). Sixteen patients (84%) had a familial or personal history of cardiac arrest. A gene mutation associated with SQTS was identified in 5 (24%) of 21 probands. Symptomatic patients had a higher median modified Gollob score (excluding points for clinical events) compared with asymptomatic patients (5 vs. 4, p = 0.044). Ten patients received medical treatment, mainly with quinidine. Eleven of 25 index cases underwent ICD implantation. Two patients had appropriate ICD shocks. Inappropriate ICD shocks were observed in 64% of patients. Conclusions SQTS is associated with aborted sudden cardiac death among the pediatric population. Asymptomatic patients with a Gollob score of <5 remained event free, except for an isolated episode of supraventricular tachycardia, over an average 6-year follow-up. A higher modified Gollob score of 5 or more was associated with the likelihood of clinical events. Young SQTS patients have a high rate of inappropriate ICD shocks.
BACKGROUNDPalliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing ...system (PPMv) may be associated with additional adverse long-term outcomes. OBJECTIVESThe goal of this study was to quantify the attributable risk of PPMv in patients with SV, and to identify modifiable risk factors. METHODSThis international study was sponsored by the Pediatric and Congenital Electrophysiology Society. Centers contributed baseline and longitudinal data for functionally SV patients with PPMv. Enrollment was at implantation. Controls were matched 1:1 to PPMv subjects by ventricular morphology and sex, identified within center, and enrolled at matched age. Primary outcome was transplantation or death. RESULTSIn total, 236 PPMv subjects and 213 matched controls were identified (22 centers, 9 countries). Median age at enrollment was 5.3 years (quartiles: 1.5-13.2 years), follow-up 6.9 years (3.4-11.6 years). Median percent ventricular pacing (Vp) was 90.8% (25th-75th percentile: 4.3%-100%) in the PPMv cohort. Across 213 matched pairs, multivariable HR for death/transplant associated with PPMv was 3.8 (95% CI 1.9-7.6; P < 0.001). Within the PPMv population, higher Vp (HR: 1.009 per %; P = 0.009), higher QRS z-score (HR: 1.19; P = 0.009) and nonapical lead position (HR: 2.17; P = 0.042) were all associated with death/transplantation. CONCLUSIONSPPMv in patients with SV is associated with increased risk of heart transplantation and death, despite controlling for increased associated morbidity of the PPMv cohort. Increased Vp, higher QRS z-score, and nonapical ventricular lead position are all associated with higher risk of adverse outcome and may be modifiable risk factors.
Catecholaminergic polymorphic ventricular tachycardia is an uncommon, potentially lethal, ion channelopathy. Standard therapies have high failure rates and little is known about treatment in ...children. Newer options such as flecainide and left cardiac sympathetic denervation are not well validated. We sought to define treatment outcomes in children with catecholaminergic polymorphic ventricular tachycardia.
This is a Pediatric and Congenital Electrophysiology Society multicenter, retrospective cohort study of catecholaminergic polymorphic ventricular tachycardia patients diagnosed before 19 years of age. The cohort included 226 patients, including 170 probands and 56 relatives. Symptomatic presentation was reported in 176 (78%). Symptom onset occurred at 10.8 (interquartile range, 6.8-13.2) years with a delay to diagnosis of 0.5 (0-2.6) years. Syncope (P<0.001), cardiac arrest (P<0.001), and treatment failure (P=0.008) occurred more often in probands. β-Blockers were prescribed in 205 of 211 patients (97%) on medication, and 25% experienced at least 1 treatment failure event. Implantable cardioverter defibrillators were placed in 121 (54%) and was associated with electrical storm in 22 (18%). Flecainide was used in 24% and left cardiac sympathetic denervation in 8%. Six deaths (3%) occurred during a cumulative follow-up of 788 patient-years.
This study demonstrates a malignant phenotype and lengthy delay to diagnosis in catecholaminergic polymorphic ventricular tachycardia. Probands were typically severely affected. β-Blockers were almost universally initiated; however, treatment failure, noncompliance and subtherapeutic dosing were often reported. Implantable cardioverter defibrillators were common despite numerous device-related complications. Treatment failure was rare in the quarter of patients on flecainide. Left cardiac sympathetic denervation was not uncommon although the indication was variable.
We aimed to compare New York Heart Association (NYHA) functional class in adult congenital heart disease (ACHD) patients with objectively measured cardiopulmonary exercise testing (CPET) parameters. ...This study included retrospective review of ACHD patients who underwent a CPET between August 2014 and April 2018 at our center. Patients were grouped according to severity of CHD, and NYHA class as recorded in their medical record or estimated from the clinical narrative. A total of 175 ACHD patients (mean age 30 ± 11 years) with NYHA class I-III enrolled in the study. The NYHA functional class was II or III in most complex CHD. There was a strong inverse relation between NYHA class and peak oxygen consumption, oxygen uptake efficiency slope, and the double product at peak exercise (product of heart rate and systolic blood pressure) (p<0.0001). There was no relation between NYHA class and ventilation efficiency slope (p = 0.37). In conclusion, NYHA functional class correlates with objective measures of CPET, however there is wide variability in measured exercise capacity in each NYHA classification. Therefore, whereas NYHA class of patients is a simple measure for assessment of functional status, CPET is an important tool to identify the source of exercise limitation in ACHD patients.
BACKGROUND Priapism is rarely reported as a potential complication after the cardiac ablation procedure. We report the case of a teenager admitted for atrial flutter ablation who developed priapism ...following the procedure. CASE REPORT A 16-year-old male with episodic atrial flutter came to our hospital for an electrophysiological study and catheter ablation. During the procedure, he was given IV propofol for anesthesia and IV heparin for anticoagulation. After the procedure, nursing noted that he had an erection, which persisted for 5 h, with complaints of discomfort. There was no known history of sickle cell disease or trauma to the perineum, nor did he endorse any prior prolonged erections. On physical examination, he had a circumcised phallus with rigid and non-tender corpora cavernosa. He was given 5 mg terbutaline PO, without improvement. Three hours later, a second dose of terbutaline was given. In addition, a penis corporal venous blood gas was taken, and the result was consistent with an ischemic priapism. He had detumescence 1-2 min later. The total duration of his priapism was 8 h. There was no swelling, pain, or any sequelae after detumescence. CONCLUSIONS Although priapism rarely occurs as a complication following catheter ablation procedures due to propofol use, prolonged priapism can result in corporal fibrosis and cause future erectile dysfunction. Recognition and treatment of priapism in the postoperative period may be delayed due to a patient's hesitance to express concerns. To prevent future erectile dysfunction, signs of priapism should be included in routine postoperative evaluation in male patients.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an ion channelopathy characterized by ventricular arrhythmia during exertion or stress. Mutations in RYR2-coded Ryanodine Receptor-2 ...(RyR2) and CASQ2-coded Calsequestrin-2 (CASQ2) genes underlie CPVT1 and CPVT2, respectively. However, prognostic markers are scarce. We sought to better characterize the phenotypic and genotypic spectrum of CPVT, and utilize molecular modelling to help account for clinical phenotypes.
This is a Pediatric and Congenital Electrophysiology Society multicentre, retrospective cohort study of CPVT patients diagnosed at <19 years of age and their first-degree relatives. Genetic testing was undertaken in 194 of 236 subjects (82%) during 3.5 (1.4-5.3) years of follow-up. The majority (60%) had RyR2-associated CPVT1. Variant locations were predicted based on a 3D structural model of RyR2. Specific residues appear to have key structural importance, supported by an association between cardiac arrest and mutations in the intersubunit interface of the N-terminus, and the S4-S5 linker and helices S5 and S6 of the RyR2 C-terminus. In approximately one quarter of symptomatic patients, cardiac events were precipitated by only normal wakeful activities.
This large, multicentre study identifies contemporary challenges related to the diagnosis and prognostication of CPVT patients. Structural modelling of RyR2 can improve our understanding severe CPVT phenotypes. Wakeful rest, rather than exertion, often precipitated life-threatening cardiac events.
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.
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