The Safety and Efficacy of Transcatheter Pulmonary Valve Replacement Combined with Electrophysiology Procedures.

The objective of this study was to evaluate the safety and efficacy of combining transcatheter pulmonary valve replacement (TPVR) and electrophysiology (EP) procedures. A retrospective review was undertaken to identify TPVR and EP procedures that were concomitantly performed in the cardiac catheterization laboratory at University of Iowa Stead Family Children's Hospital from January 2011 to October 2019. Procedural and follow-up data were compared between patients who underwent TPVR and EP procedures in the same setting to those who received TPVR or EP procedure separately and that were similar in age and cardiac anatomy. A total of 8 patients underwent combined TPVR and EP procedures. One patient was excluded due to lack of adequate control, leaving seven study subjects (57% female; median age at time of procedure 16 years). The median follow-up time was 11.5 months (range 2-36 months). Patients who received combined TPVR and EP had shorter recovery times (combined: median 18.9 h; IQR 18.35-19.5 vs separate: median 27.98 h; IQR 21.42-39.25; p-value 0.031), shorter hospital length of stay (combined: median 27.5 h; IQR 26.47-31.4 vs separate: median 38.4 h; IQR 33.42-51.50; p-value 0.016), and a 51% reduction in total hospital charges (combined: median $171,640; IQR 135.43-219.22 vs separate: median $333,560 IQR 263.20-400.98; p-value 0.016). There were no significant differences in radiation dose or procedure time between the combined and control groups. The median radiation time for those who had the combination procedure was 30.5 min [IQR 29.6-47.9], and the median dose area product was 215 mGy [IQR 158-935]. In conclusion, combining TPVR and EP procedures is feasible, safe, and economically advantageous.

Difficulties with invasive risk stratification performed under anesthesia in pediatric Wolff-Parkinson-White Syndrome.

BACKGROUND: Children with Wolff-Parkinson-White Syndrome (WPW) are at risk for sudden death. The gold standard for risk stratification in this population is the shortest pre-excited RR interval during atrial fibrillation (SPERRI). OBJECTIVE: The purpose of this study was to determine how closely measurements made in the electrophysiology laboratory in patients with WPW compared to SPERRI obtained during an episode of clinical pre-excited atrial fibrillation (Clinical-SPERRI). METHODS: This was a subgroup analysis of a multicenter study of children with WPW. Subjects in our study (N = 49) were included if they had Clinical-SPERRI measured in addition to 1 or more of 3 surrogate measurements: SPERRI obtained during electrophysiological study (EP-SPERRI), accessory pathway effective refractory period (APERP), or shortest pre-excited paced cycle length with 1:1 conduction (SPPCL). RESULTS: Seventy percent of electrophysiological measurements were made with patients under general anesthesia. Clinical-SPERRI moderately correlated with EP-SPERRI (r = 0.495; P = .012). However, 24% of our patients with Clinical-SPERRI ≤250 ms would have been misclassified as having a low-risk pathway based on EP-SPERRI >250 ms. Clinical-SPERRI did not correlate with APERP or SPPCL (r < 0.3; P >.1). Mean EP-SPERRI, APERP, and SPPCL all were greater than Clinical-SPERRI. CONCLUSION: Electrophysiology laboratory measurements of pathway characteristics made with patients under general anesthesia do not correlate well with Clinical-SPERRI. Of APERP, SPPCL, and EP-SPERRI, only EP-SPERRI had moderate correlation with Clinical-SPERRI. This study questions the predictive ability of invasive risk stratification with patients under general anesthesia, given that 24% of patients with high-risk Clinical-SPERRI (≤250 ms) had EP-SPERRI that may be considered low risk (>250 ms).

Cost analysis of combining congenital cardiac catheterization and electrophysiology procedures in an outpatient setting.

BACKGROUND: Patients with congenital heart disease require multiple procedures over their lifetime. These procedures increase cost and time commitment. Previous studies in the field of medicine have shown that combining procedures is an effective method to reduce cost and time. There has been no such study to evaluate the cost and efficiency of combining pediatric cardiac procedures. OBJECTIVE: The objective of this study was to compare the cost and time commitment of combined cardiac catheterization (cath) and electrophysiology (EP) outpatient procedures against separate cath and EP procedure. METHODS: Outpatient combination procedures performed in the pediatric cardiac cath lab from 2013 to 2016 were matched to a control population of two or three similar single outpatient procedures from 2009 to 2016 for patients of similar age and cardiac anatomy. Procedure duration, recovery duration, length of stay, equipment charges, physician charges, all other hospital charges, and total admission charges were analyzed. The two groups were compared using an unpaired t-test. RESULTS: A total of 92 subjects, 32 study subjects and 60 control subjects, were included in this study. Study group procedures had a significantly shorter recovery duration (P = 0.04) and length of stay (P = 0.01). Study group procedure duration trended shorter on average but statistically insignificant (P = 0.20). The total median savings for patients undergoing combined procedures in the study group was $13,181 (interquartile range $423.8-$26710). CONCLUSIONS: Combining cath and EP outpatient procedures reduces the time commitment and provides some economic advantage.

Voltage mapping for slow-pathway visualization and ablation of atrioventricular nodal reentry tachycardia in pediatric and young adult patients.

Voltage guidance for the ablation of the slow pathway in atrioventricular nodal reentry tachycardia (AVNRT) is a dramatic shift from the traditional anatomy-guided approach within the triangle of Koch. The use of voltage gradient mapping has been evaluated in adults as an aid to identification of the slow pathway guiding placement of ablation applications. This study aimed to evaluate this technique of voltage-guided ablation of AVNRT in pediatric and young adult patients, who have a smaller, more compact triangle of Koch. A retrospective cohort study evaluated patients 20 years of age or younger with AVNRT who underwent voltage mapping. Using NavX, three-dimensional voltage maps of the right atrium were created during sinus rhythm, focusing primarily on the triangle of Koch. The voltage map gradients were adjusted to uncover a "voltage bridge" of lower voltage signals. This bridge was used as a surrogate of the slow pathway to guide cryoablation at this site. Of the 31 patients who underwent voltage mapping, three were excluded from the study due to inadequate mapping. All the patients experienced procedural success. In 86 % of the patients, there was an adequate voltage bridge to allow guided ablation. The successful ablation site was within the first three lesions for 60 % of the patients. Two patients experienced recurrence during a median follow-up period of 14 months. It appears that voltage-guided ablation of a voltage bridge in AVNRT can be used effectively and safely in the pediatric population.

Successful transcatheter cryoablation in infants with drug-resistant supraventricular tachycardia: a case series.

PURPOSE: Drug-resistant supraventricular tachycardia can cause hemodynamic instability, especially in infants. There are no case-series reports of transcatheter cryoablation treatment for infants with drug-resistant supraventricular tachycardia. Our purpose is to report our experience with transcatheter cryoablation in three infants with drug-resistant supraventricular tachycardia. METHODS: We reviewed clinical and electrophysiologic data from infants who underwent cryothermal ablation for drug-resistant supraventricular tachycardia (SVT) at our institution. RESULTS: Three patients (age 10-42 days) underwent transcatheter cryothermal ablation over a 1-year period. None had arrhythmia suppression on medical management, and all had hemodynamic instability from persistent SVT episodes. Cryothermal mapping (-30 C) localized the suspected foci. All foci were adjacent to the AV node. Cryoablation lesions were delivered at and around mapped foci. In one patient, cryothermal energy application eliminated the SVT but resulted in transient right bundle branch block that resolved later. Two patients had hemodynamically insignificant episodes of SVT in the immediate post-ablation period that resolved with standard antiarrhythmic treatment. One died of sepsis but remained SVT free for 10 days after the procedure without antiarrhythmic medications. Neither of the two surviving patients had SVT recurrence at 6-month follow-up off medications. CONCLUSIONS: In our series, transcatheter cryoablation was an effective treatment for drug-resistant SVT in infants. We encountered some early nonsustained post-procedure SVT; however, such episodes did not predict procedural failure.

Transcatheter cryoablation with 3-D mapping of an atrial ectopic tachycardia in a pediatric patient with tachycardia induced heart failure.

Atrial ectopic tachycardias (AET) are often resistant to medical management and can lead to a significant reduction in cardiac function. Transcatheter cryoablation, a definitive therapy, to our knowledge has yet to be described in the pediatric population. A three-year-old male presented with AET induced heart failure which persisted despite medical management. Management was complicated by worsening heart failure and propylene glycol intoxication. He underwent transcatheter cryoablation using a 3-D navigation system with an initially successful elimination of the arrhythmia. After a late recurrence (15 months) of the AET he underwent epicardial transcatheter ablation using cryotherapy with successful elimination of the arrhythmia.

Transcatheter cryothermal ablation of junctional ectopic tachycardia in the normal heart.

BACKGROUND: Junctional ectopic tachycardia in the normal heart is rare and often is resistant to pharmacologic management. Transcatheter ablation using radiofrequency energy places the AV node at risk. OBJECTIVES: The purpose of this study was to report our experience with transcatheter cryothermal ablation using three-dimensional mapping in six patients with junctional ectopic tachycardia. METHODS: A review of clinical and electrophysiologic data was performed on all patients with structurally normal hearts who underwent cryothermal ablation for treatment of junctional ectopic tachycardia at two institutions. RESULTS: Six patients (age 7.7-36.5 years) underwent attempted transcatheter cryothermal ablation using three-dimensional mapping. Only one patient had achieved arrhythmia suppression on medical management. Cryothermal mapping (-30 degrees C) localized the junctional focus while normal conduction was monitored. The junctional focus was high in the triangle of Koch in four patients and was low in one patient. The sixth patient had only one run of junctional ectopic tachycardia during the procedure and therefore received an empiric cryoablation (-70 degrees C) lesion. Subsequent cryoablation lesions were delivered at and around the junctional focus. In one patient, cryomapping eliminated the junctional focus but resulted in transient complete AV block; therefore, cryoablation was not performed. All patients who received the cryoablation lesions had elimination of their junctional ectopic tachycardia at 6-week follow-up. The patient who did not receive a cryoablation lesion remained in a slower junctional rhythm at follow-up. CONCLUSION: Cryoablation of junctional ectopic tachycardia is safe and effective. Nonetheless, proximity to the His-Purkinje system may preclude success. Empiric cryoablation can be effective; cryotherapy may not yield immediate success, but a delayed salutary effect can follow.