Ablación exitosa con radiofrecuencia a través de la cúspide coronariana derecha de un complejo ventricular prematuro parahisiano / Successful radiofrequency ablation through the right coronary cups of a parahisian premature ventricular complexes

Resumen Los complejos ventriculares prematuros (CVP) son hallazgos frecuentes en individuos con o sin enfermedad estructural cardiaca. Los CVP cuyo origen se localiza en la región parahisiana son poco frecuentes y su manejo a través de ablación con catéter de radiofrecuencia es un reto, pues su localización favorece un alto riesgo de desarrollo de bloqueo aurículo-ventricular. Se describen dos casos de pacientes con CVP parahisianos llevados a ablación con catéter de radiofrecuencia.

Abstract Premature ventricular complexes (PVC) are common findings in patients with or without structural heart disease. Parahisian PVC are uncommon and their management through radiofrequency catheter ablation remains a challenge, since their location favors a high risk for developing atrioventricular block. Two cases of patients with parahisian PVC undergoing radiofrequency catheter ablation are described.

Ablação por Cateter de Taquicardia Atrial Focal com Ativação Precoce Próxima ao Feixe de His, a Partir da Cúspide Aórtica não Coronária / Catheter Ablation of Focal Atrial Tachycardia with Early Activation Close to the His-Bundle from the Non Coronary Aortic Cusp

Resumo Fundamento A ablação da taquicardia atrial (TA) com local de ativação mais precoce próxima ao feixe de His é um desafio, devido ao risco de bloqueio de AV completo por sua proximidade ao sistema de His-Purkinje (SHP). Uma alternativa para minimizar esse risco é posicionar o cateter na cúspide não coronária (CNC), que é anatomicamente contígua à região para-Hissiana. Objetivos O objetivo deste estudo foi fazer uma revisão de literatura e avaliar as características eletrofisiológicas, a segurança e o índice de sucesso de aplicação de radiofrequência (RF) por cateter na CNC para o tratamento de TA para-Hissiana em uma série de casos. Métodos Avaliamos retrospectivamente dez pacientes (Idade: 36±10 anos) que foram encaminhados para ablação de taquicardia paroxística supraventricular (TPSV) e haviam sido diagnosticados com TA focal para-Hissiana confirmada por manobras eletrofisiológicas clássicas. Para a análise estatística, um P valor d <0.05 foi considerado estatisticamente significativo. Resultados A ativação atrial mais precoce na posição His foi de 28±12ms da onda P, e a CNC foi 3±2ms antes da posição His, sem evidência de potencial His em todos os pacientes. Foi aplicada RF à CNC (cateter de ponta de 4-mm; 30W, 55°C) e a taquicardia foi interrompida em 5±3s sem aumento no intervalo PR ou evidência de um ritmo juncional. Os testes eletrofisiológicos não induziram novamente a taquicardia em 9/10 pacientes. Não houve complicações em nenhum procedimento. Durante o período de acompanhamento de 30 ± 12 meses, nenhum paciente apresentou recorrência de taquicardia. Conclusão O tratamento percutâneo de TA para-Hissiana por meio de CNC é uma estratégia segura e eficiente, tornando-se uma opção interessante para o tratamento de arritmia complexa. (Arq Bras Cardiol. 2021; 116(1):119-126)

Abstract Background Atrial tachycardia (AT) ablation with earliest activation site close to the His-Bundle is a challenge due to the risk of complete AV block by its proximity to His-Purkinje system (HPS). An alternative to minimize this risk is to position the catheter on the non-coronary cusp (NCC), which is anatomically contiguous to the para-Hisian region. Objectives The aim of this study was to perform a literature review and evaluate the electrophysiological characteristics, safety, and success rate of catheter-based radiofrequency (RF) delivery in the NCC for the treatment of para-Hisian AT in a case series. Methods This study performed a retrospective evaluation of ten patients (Age: 36±10 y-o) who had been referred for SVT ablation and presented a diagnosis of para-Hisian focal AT confirmed by classical electrophysiological maneuvers. For statistical analysis, a p-value of <0.05 was considered statistically significant. Results The earliest atrial activation at the His position was 28±12ms from the P wave and at the NCC was 3±2ms earlier than His position, without evidence of His potential in all patients. RF was applied on the NCC (4-mm-tip catheter; 30W, 55ºC), and the tachycardia was interrupted in 5±3s with no increase in the PR interval or evidence of junctional rhythm. Electrophysiological tests did not reinduce tachycardia in 9/10 of patients. There were no complications in all procedures. During the 30 ± 12 months follow-up, no patient presented tachycardia recurrence. Conclusion The percutaneous treatment of para-Hisian AT through the NCC is an effective and safe strategy, which represents an interesting option for the treatment of this complex arrhythmia. (Arq Bras Cardiol. 2021; 116(1):119-126)

Research progress of His bundle pacing / 心血管康复医学杂志

His bundle pacing is a new treatment for bradyarrhythmias .Its electrical excitement download along nor-mal heart conduction system ,keeps normal or near normal ventricular electrical excitement order and ventricular contraction synchronization ,which is a relative physiological pacing mode .For patient with heart failure ,left bun-dle branch block etc .that are indicated for cardiac resynchronization therapy ,His bundle pacing possesses same sig-nificance as dual ventricular pacing .The present article made a review on anatomical structure of His bundle ,defini-tion ,current research outcome and clinical indications of His bundle pacing .

Transcatheter radiofrequency ablation of atrial tachycardia originating from the side of the bundle of His / 介入放射学杂志

Objective To investigate the electrophysiological characteristics of atrial tachycardia (AT) originating from the side of the bundle of His, and to analyze the efficacy and safety of transcatheter radiofrequency ablation via the right side of the bundle of His and left noncoronary sinus of aorta for the treatment of AT. Methods A total of 12 patients with AT originating from the side the bundle of His, which was confirmed by conventional electrophysiological study and atrial activation patterns, were included in this study. The patient’s age ranged from 12 to 64 years old with a mean of (47.4±14.6) years. The mapping was carried out at the right side of the bundle of His and radiofrequency ablation was performed. When the ablation procedure failed, or the junction zone rhythm or atrioventricular block occurred, ablation via the left noncoronary sinus of aorta was employed. Results Atrial stimulation could repeatedly induce and terminate AT in all the 12 patients, the average cycle length was (327±76) ms. TA was terminated within 10 seconds after the start of ablation in 10 patients during their AT attacks. Ablation was unsuccessful in 2 patients. Ablation via the right side of His bundle was successfully accomplished in 2 patients, and the ablation via the left noncoronary sinus of aorta was successfully carried out in 8 patients. The average follow-up time was 1-6 years, and no recurrence of AT was observed. Conclusion Atrial tachycardia originating from the side of the bundle of His has certain electrophysiological characteristics, and transcatheter radiofrequency ablation is safe and effective for its treatment. Ablation via the left noncoronary sinus of aorta should be considered as a strategy of priority.

Supraventricular Tachycardia and Sinus Rhythm with Contralateral Bundle Branch Block Patterns

A contralateral bundle branch block (BBB) aberration during tachycardia with a preexisting BBB strongly suggests the presence of ventricular tachycardia. We report on a middle-aged, female patient presented with wide QRS tachycardia. The patient had orthodromic atrioventricular tachycardia with a left BBB aberration in the presence of a preexisting right BBB due to an abnormal His-Purkinje system. We learned that the contralateral BBB aberration with supraventricular tachycardia could be seen when the His-Purkinje system was abnormal.

Catheter Ablation of Parahisian Premature Ventricular Complex

Catheter ablation is performed in selected patients with a symptomatic premature ventricular complex (PVC) or PVC-induced cardiomyopathy. Ablation of PVC from the His region has a high risk of inducing a complete atrioventricular block. Here we report successful catheter ablation of a parahisian PVC in a 63-year-old man.

Estimulación paraseptal permanente: Indicaciones y seguimiento / Permanent Para-Hisian Pacing: Indications and Follow-Up

Introducción Se ha demostrado que la estimulación definitiva en el ápex del ventrículo derecho provoca disincronía ventricular izquierda y eventualmente deterioro contráctil y ello ha llevado a la búsqueda de otros sitios alternativos de estimulación. Las indicaciones y los resultados de la estimulación septal, así como las dificultades técnicas del implante, se encuentran actualmente en estudio. Objetivos Analizar la indicación, la factibilidad y el seguimiento en un grupo de pacientes con estimulación septal parahisiana. Material y métodos Se evaluaron 22 pacientes con edades entre 27 y 68 años, con complejo QRS angosto sin trastorno de conducción intraventricular, con indicación de marcapasos. Se utilizaron catéteres comunes para la aurícula con fijación activa y catéteres con vaina deflectable para la estimulación septal. Durante el implante y el seguimiento se midieron los umbrales y la amplitud de la onda R. Resultados Los umbrales durante el implante fueron menores de 2 voltios/0,50 mseg y la onda R mayor de 5 m V. El tiempo de implante promedio de los catéteres convencionales fue de 30 ± 10 min y el de los catéteres especiales, de 15 ± 5 min. El seguimiento promedio fue de 24 meses. Los umbrales crónicos fueron de 2,5 ± 1,5 voltios con una amplitud de onda R media de 5 ± 2 voltios. Hubo un desplazamiento durante el seguimiento. Conclusiones La estimulación septal parahisiana presentó un índice bajo de complicaciones. El uso de catéteres y vainas especiales redujo el tiempo de implante. La ubicación parahisiana se caracterizó por umbrales más altos y amplitud de la onda R menor que en la comunicada durante estimulación convencional. La estimulación septal parahisiana sería una alternativa válida para evitar la disincronía producida por la estimulación del ventrículo derecho en pacientes sin trastornos de la conducción intraventricular.

Background It has been demonstrated that permanent right ventricular apical pacing produces left ventricular dyssynchrony and decreases contractile function. For this reason other sites of stimulation have been explored. The indications, outcomes and technical difficulties of para-hisian pacing are currently under investigation. Objectives To analyze the indications, feasibility and follow-up in a group of patients undergoing para-hisian pacing. Material and Methods A total of 22 patients between 27 and 68 years with indication of permanent pacing, narrow QRS complexes and preserved intraventricular conduction were evaluated. Activefixation atrial leads and ventricular leads with a deflectable sheath for parahisian stimulation were used. Pacing thresholds and R-wave amplitude were measured during implantation and follow-up. Results During implantation, pacing thresholds were <2 V/0.50 ms and R-wave amplitude was >5 m V. The average duration of placement of conventional leads and special leads were 30±10 min and 15±5 min, respectively. Mean follow-up was 24 months. Chronic thresholds were 2.5±1.5 Volts, and mean R-wave amplitude was 5±2 Volts. One lead displacement was reported during follow-up. Conclusions Para-hisian pacing presented a low rate of complications. The use of special leads and sheaths reduced the implantation time. Compared to conventional pacing, para-hisian pacing presented higher thresholds and lower R-wave amplitude. Para-hisian pacing would be a valid option to avoid ventricular dyssynchrony related to right ventricular pacing in patients with preserved intraventricular conduction.

His bundle pacing and atrio-ventricular nodal ablation guided by intracardiac echocardiography / 中华超声影像学杂志

Objective To develop an in vivo procedure f or His bundle pacing (HBP) and radio-frequency (RF) ablation of the atrio-ventricular node (AVN) guided by intracardiac echocardiography (ICE) and tissue Doppler imaging (TDI). The procedure included a custom designed bipolar active fixation pacing lead and steerable delivery catheter, and a commercial RF generator and ablation catheter. Methods Six anesthetized- closed-chest canines were tested. The anatomy in the His bundle and AVN regions, and the onset of myocardial electro-mechanical activation were identified using ICE and TDI. The lead and RF ablation catheter were navigated using an ICE catheter (for local detailed imaging) and fluoroscopy (for global imaging). Surface QRS morphologies were recorded to confirm HBP and third degree block post-ablation. Results Direct His bundle pacing was achieved in one canine, and His + ventricular septal pacing in the remaining five. QRS width in sinus rhythm and HBP were ( 59.7-? 5.3-)ms and ( 82.8-? 16.6-)ms separately (P= 0.02-). The increased QRS width for HBP was due to early septal activation. HBP thresholds were ( 3.0-? 1.0-) volts at 0.5 ms (N=5 due to a late exit block). The mean procedure durations were: HBP 40 minutes (3 to 81 minutes), AVN ablation 3 minutes (2 to 5 minutes), and total X-ray exposure 13 minutes (1 to 55 minutes). Post-mortem analysis of the lead and ablation lesions confirmed correct anatomic localization for HBP and AVN ablation. Conclusions ICE provides precise anatomic guidance of HBP lead implantation and AVN ablation and can significantly reduce exposure to fluoroscopy.

Effect of cardiac pacing with a His bundle lead on cardiac electrophysiological and haemodynamical action in dogs / 中国病理生理杂志

AIM: To evaluate the effect of cardiac pacing with a His bundle lead on cardiac electrophysiological and haemodynamical action in dogs and the experience of location technique with His bundle pacing lead. METHODS: With opening chest operation in general-anesthetized dogs, a special lead was located at His bundle based on a typical "H" wave and narrow duration of the QRS wave recorded in ECG; Platinum leads were fixed at the epicardium of the right ventricular apex (RVA) respectively, forming HisB- VVI pacing,RVA- VVI pacing. Cardiac electrophysiological and haemodynamical parameters were compared in sinus rhythm and the different pacing models. RESULTS: The threshold of HisB pacing is similar to that of RVA pacing. Cardiac output(CO)is increased about 18.81% in HisB- VVI pacing than self. It is decreased about 5.41% in RVA- VVI pacing. SV is similar to self,but it is 25.59% higher in HisB- VVI than RVA- VVI . LVSW and RVSW in His B- VVI pacing is superior to that in RVA- VVI . CONCLUSION: His bundle pacing significantly improves cardiac function compared with the RVA- VVI pacing because it can maintain normal physiological electronic activation sequence and systolic synchrony and have a better haemodynamics effect.neral-anesthetizeddogs,as