Radiofrequency ablation of supraventricular arrhythmias after orthotopic heart transplantation: Long-term follow-up of a single-center experience.

BACKGROUND: Supraventricular arrhythmias (SVAs), commonly managed with radiofrequency ablation (RFA), may occur after orthotopic heart transplantation (OHT). METHODS: We retrospectively assessed 514 consecutive patients (pts.) undergoing OHT between January 1990 and July 2016 in a single-center. Patients with SVAs managed with RFA were included. Mechanisms of genesis of SVAs, association with surgical techniques and outcomes, were analyzed. RESULTS: Of 514 pts undergoing OHT, 53% (272 pts.) were managed with bicaval (BC) technique and 47% (242 pts.) with biatrial (BA) technique. Mean follow-up 10 ± 8.4 years. Nine pts. (1.7%) developed SVA requiring RFA. The BC technique was performed in 4 pts., 3 pts. presented cavotricuspid isthmus-dependent atrial flutter (CTI AFL), and 1 pt. double loop AFL. Five pts. were managed with BA technique, 4 pts. presented CTI AFL, and 1 pt. atrial tachycardia (AT). Mean time between OHT and SVA occurrence was 6.6 ± 5.5 years. The procedure was successful in 89% (8 pts.). Arrhythmia recurrence was seen in 3 pts (37%), all with BA technique. CONCLUSION: Supraventricular arrhythmias in heart transplantation may be associated with the surgical scar. Identifying the mechanism is vital to choose the appropriate treatment with radiofrequency ablation.

Terapia de resincronización cardíaca. Incidencia y mecanismos involucrados en la reducción de la insuficiencia mitral funcional / Cardiac Resynchronization Therapy. Incidence and Mechanisms Involved in the Reduction of Functional Mitral Regurgitation

RESUMEN Introducción: La insuficiencia mitral funcional (IMF) es común en pacientes con insuficiencia cardíaca (IC). La IMF moderada/ grave (M/G) se asocia a peor pronóstico. Objetivo: Describir la prevalencia de IMF y los mecanismos involucrados en su reducción en respondedores a la terapia de resincronización cardíaca (TRC) a los 6 meses comparados con 12 y 24 meses. Métodos: Entre 2009 y 2018 fueron tratados 338 pts. Respondedores: reducción de CF NYHA ≥1 grado o aumento de la fracción de eyección ventricular izquierda (FEVI) ≥5% (absoluto). La IMF se graduó en 4 puntos: No-IMF, leve, M y G, y se la relacionó con las mediciones ecocardiográficas. Características Basales: edad 64 ±10 años, hombres 71%, CF-NYHA IIIII 92%, bloqueo de rama izquierda (BRI) 67%, QRS ≥150 ms 75%, diámetro diastólico del VI (DDVI) 68 ± 9 mm, diámetro sistólico del VI (DSVI) 52 ± 12 mm, FEVI 24 ± 7%. Resultados: La prevalencia de IMF fue del 92,6%. A los 6 meses, 86% fueron respondedores y 23% de ellos mejoraron de IMF-M/G a IMF-Leve/No-IMF. Hubo un fuerte remodelado inverso: DDVI 68 ± 10 vs 63 ± 11 mm, (p = 0,0001), DSVI 55 ± 12 vs 50 ± 13 mm, (p = 0,0006) y FEVI 25 ± 11 vs 33 ± 10%, (p = 0,00001). Comparando 6 con 12 meses 89,4% fueron respondedores, 8% mejoraron de IMF-M/G a IMF-Leve/No-IMF. Comparando 6 con 24 meses 88% fueron respondedores, 14,6% mejoraron de IMF-M/G a IMF-Leve/No-IMF. Entre 6 y 12 y 6 y 24 meses no hubo remodelado inverso significativo. Conclusiones: La prevalencia de IMF fue elevada. El mayor remodelado inverso y reducción de la IMF se observaron a los 6 meses, siendo el primero el principal mecanismo en la reducción de la IMF. Esta mejoría se sostuvo a los 12 y 24 meses.

ABSTRACT Background: Functional mitral regurgitation (FMR) is common in heart failure, and moderate/severe (M/S) FMR is associated with worse prognosis. Objective: The aim of this study was to describe the prevalence of FMR and the mechanisms involved in its reduction in responders to cardiac resynchronization therapy (CRT) at 6 months compared with 12 and 24 months. Methods: Between 2009 and 2018, 338 patients received CRT. Patients showing NYHA functional class (FC) reduction ≥1 or left ventricular ejection fraction (LVEF) absolute increase ≥5% were considered responders. Functional mitral regurgitation was graded using a 4-point scale into none-, mild-, M- and S-FMR, and was related to echocardiographic measurements. Baseline patient characteristics were: age 64±10 years, men 71%, NYHA FC II-III 92%, left bundle branch block (LBBB) 67%, QRS ≥150 ms 75%, LV diastolic diameter (LVDD) 68±9 mm, LV systolic diameter (LVSD) 52±12 mm, and LVEF 24±7%. Results: The prevalence of FMR was 92.6%. At 6 months, 86% were responders, 23% improved from M/S-FMR to mild/none-FMR and there was strong reverse remodeling: LVDD 68±10 vs. 63±11 mm, (p=0.0001), LVSD 55±12 vs. 50±13 mm, (p=0.0006) and LVEF 25±11 vs. 33±10%, (p=0.00001). Comparing 6 with 12 months, 89.4% were responders and 8% improved M/S-FMR to mild/none-FMR. Comparing 6 with 24 months, 88% were responders and 14.6% improved M/S-FMR to mild/none-FMR. Between 6 and 12 and 6 and 24 months, there was no significant reverse remodeling. Conclusions: The prevalence of FMR was high. The highest reverse remodeling and FMR reduction was observed at 6 months, the former being the main mechanism of FMR reduction. This improvement persisted at 12 and 24 months.