Impact of weight adjusted high frequency low tidal volume ventilation and atrial pacing in lesion metrics in high-power short-duration ablation: Results of a pilot study.

INTRODUCTION: Lesion size index (LSI) was introduced with the use of Tacticath™ and as a surrogate of lesion quality. The metric used to achieve the predetermined values involves combined information of contact force (CF), power and radiofrequency time. Rapid atrial pacing (RAP) and high-frequency low-tidal volume ventilation (HFLTV) independently or in combination improve catheter stability and CF and quality of lesions. Data of the impact of body weight adjusted HFLTV ventilation strategy associated with RAP in the lesion metrics still lacking. The study aimed to compare the results of high-power short-duration (HPSD) atrial fibrillation ablation using simultaneous weight adjusted HFLTV and RAP and standard ventilation (SV) protocol. METHODS: Prospective, nonrandomized study with 136 patients undergoing de novo ablation divided into two groups; 70 in RAP (100 ppm) + HFLTV with 4 mL/kg of tidal volume and 25 breaths/min (group A) and 66 patients with SV in intrinsic sinus rhythm (group B). Ablation using 50 W, CF of 5-10 g/10-20 g and 40 mL/minute flow rate on the posterior and anterior left atrial wall, respectively. RESULTS: No procedure-related complications. Group A: Mean LSI points 70 ± 16.5, mean total lower LSI 3.4 ± 0.5, mean total higher LSI 8.2 ± 0.4 and mean total LSI 5.6 ± 0.6. Anterior and posterior wall mean total LSI was 6.0 ± 0.4 and 4.2 ± 0.3, respectively. Mean local impedance drop (LID) points were 118.8 ± 28.4, mean LID index (%) 12.9 ± 1.5, and mean LID < 12% points 55.9 ± 23.8. Anterior and posterior wall mean total LID index were 13.6 ± 2.0 and 11.9 ± 1.7, respectively. Recurrence in 11 (15.7%) patients. Group B: Mean LSI points 56 ± 2.7, mean total lower LSI 2.9 ± 0.7, mean total higher LSI 6.9 ± 0.9, and mean total LSI 4.8 ± 0.8. Anterior and posterior wall mean total LSI was 5.1 ± 0.3 and 3.5 ± 0.5, respectively. Mean LID points were 111.4 ± 21.5, mean LID index (%) 11.4 ± 1.2, and mean LID < 12% points 54.9 ± 25.2. Anterior and posterior wall mean total LID index were 11.8 ± 1.9 and 10.3 ± 1.7, respectively. Recurrence in 14 (21.2%) patients. Mean follow up was 15.2 ± 4.4 months. CONCLUSION: Weight adjusted HFLTV ventilation with RAP HPSD ablation produced lower recurrence rate and better LSI and LID parameters in comparison to SV and intrinsic sinus rhythm.

Comparison between weight-adjusted, high-frequency, low-tidal-volume ventilation and atrial pacing with normal ventilation in high-power, short-duration atrial fibrillation ablation: Results of a pilot study.

Background: Better contact force (CF) and catheter stability (CS) during atrial fibrillation (AF) ablation are associated with higher success rate. Changes in CF and CS are observed during respiratory movements and cardiac contraction. Previous studies have suggested that rapid atrial pacing (RAP) and high-frequency, low-tidal-volume ventilation (HFLTV) independently or in combination improve CS and CF and quality of lesions. Data from a body weight-adjusted HFLTV strategy associated with RAP in AF high-power, short-duration (HPSD) ablation are still lacking. Objective: This study aimed to compare the results of HPSD AF ablation using simultaneous weight-adjusted HFLTV and RAP and standard ventilation (SV) protocol. Methods: This was a prospective, nonrandomized study with 136 patients undergoing de novo ablation were divided into 2 groups: 70 in RAP (100 ppm) + HFLTV with 4 mL/kg of tidal volume and 25 breaths/min (group A) and 66 patients with SV in intrinsic sinus rhythm (group B). The ablation used 50 W, CF of 5 to 10 g and 10 to 20 g, and 40 mL/min flow rate on the posterior and anterior left atrial walls, respectively. Results: There were no procedure-related complications. In group A, left atrial and total ablation times were 53.5 ± 8.3 minutes and 67.4 ± 10.1 minutes, respectively. Radiofrequency time was 19.7 ± 5.7 minutes, radioscopy time was 3.4 ± 1.8 minutes, 62 (88.6%) patients had first-pass isolation, 23 (33.3%) patients had elevation of luminal esophageal temperature, and 7 (10%) patients had recurrence. In group B, left atrial time was 56.7 ± 10.8 minutes, total ablation time was 72.4 ± 11.5 minutes, radiofrequency time was 22.4 ± 6.2 minutes, radioscopy time was 3.6 ± 3 minutes, 58 (87.9%) patients had first-pass isolation, and 20 (30.3%) patients had luminal esophageal temperature elevation. Conclusion: Weight-adjusted HFLTV with RAP in comparison with SV and intrinsic sinus rhythm in HPSD ablation is safe with no CO2 retention. The approach produced significantly reduced radiofrequency, left atrial, and total ablation times and better CF and local impedance drop indexes.

Registro brasileiro de estimulação fisiológica da sociedade brasileira de arritmias cardíacas - SOBRAC / Brazilian registry of physiological stimulation of the brazilian society of cardiac arrhythmias - SOBRAC

INTRODUÇÃO: Resultados favoráveis foram relatados com estimulação direta do sistema de excito-condutor cardíaco, o que tem motivado a inclusão desta técnica em recomendações e diretrizes atuais. Entretanto, não há dados disponíveis dessa prática no Brasil. OBJETIVOS: Descrever as características demográficas, eletrocardiográficas e ecocardiográficas assim como os achados intra e peri-operatórios dos pacientes submetidos a estimulação fisiológica no Brasil. MÉTODOS: Trata-se de um registro multicêntrico realizado em 15 centros no Brasil. A técnica cirúrgica utilizada seguiu a rotina dos centros participantes. RESULTADOS: 180 pacientes (64,9% homens, 74,8±12,5 anos) foram incluídos na análise entre maio e setembro de 2021. Características clínicas: 82,7% eram hipertensos, 33,5% diabéticos, 51,9% tinham antecedente de sincope, 23,2% DAC e 0,7% doença de Chagas; 76,7% apresentavam-se em CF-NYHA I ou II. A cardiopatia subjacente e o motivo do implante estão ilustrados na figura 1. Em 13,5% dos pacientes, o CDI foi concomitantemente indicado. Quanto aos achados eletrocardiográficos, 89,2% dos pacientes apresentavam-se em ritmo sinusal e 10,8% em FA/flutter atrial. O QRS basal médio era de 131±32ms; 28,1% dos pacientes apresentavam BRE e 31,4% BRD. A FEVE média foi de 54,14±16,66%. Todos os centros reportaram sucesso do implante. O tempo médio de fluoroscopia foi de 17,6±14,5min e a duração média do procedimento 81,8±43,8. Dispositivo bicameral foi predominante na maior parte dos casos (figura 2). Em 75,1% dos casos, o eletrodo ventricular foi posicionado no RE/septo profundo (LVAT médio 77,7±10,7ms, potencial de RE reportado em 25,7%) enquanto o feixe de His foi a posição escolhida em 24,9% dos casos. Em 6,6% dos pacientes procedeu-se HOT/LOT-CRT. A onda R média foi 9,8mV e o limiar de captura 1,17V x 1,0ms. A duração média do QRS final foi 107,46 ± 18,6ms. As taxas de complicações foram baixas (figura 3). CONCLUSÕES: O implante de marcapasso fisiológico é factível e seguro. As características dos pacientes incluídos nesse registro brasileiro, a preferência quanto ao tipo de estimulação (RE) e os resultados intra e pós operatórios precoces estão alinhados com as publicações internacionais mais recentes.

Initial Experience with Fractionation Mapping in the Identification of Vagal Ganglionated Plexus During Cardioneuroablation

This is a series case report of five symptomatic patients presented with diagnosis of sinus bradycardia, first and second degrees atrioventricular (AV) blocks, that were referred to pacemaker implantation. During the screening, a functional cause for the bradycardia and AV blocks were documented by treadmill stress test, 24-hour Holter monitoring and atropine test. After the confirmation of the diagnosis, patients were submitted to cardioneuroablation on an anatomical basis supported by a tridimensional electroanatomical fractionation mapping software. The technique and the acute and short-term results of the cardioneuroablation are described.