A Case of Left Ventricular Noncompaction Accompanying Fasciculo-Ventricular Accessory Pathway and Atrial Flutter

Left ventricular hypertrabeculation/noncompaction (LVHT) is an uncommon type of genetic cardiomyopathy characterized by trabeculations and recesses within the ventricular myocardium. LVHT is associated with diastolic or systolic dysfunction, thromboembolic complications, and arrhythmias, including atrial fibrillation, ventricular arrhythmias, atrioventricular block and Wolff-Parkinson-White syndrome. Herein, we describe a patient who presented with heart failure and wide-complex tachycardia. Echocardiography showed LVHT accompanied with severe mitral regurgitation. The electrophysiologic study revealed a fasciculo-ventricular accessory pathway and atrial flutter (AFL). The AFL was successfully treated with catheter ablation.

The automaticity of Mahaim fibre and its response to effective ablation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Typical accessory pathways (APs) of Wolf-Parkinson-White syndrome have been widely discussed in recent decades. However, the characteristics of the special AP, Mahaim fibre, are not so clear. It is known that these fibres have antegrade conduction only, long conduction time, decremental node-like conduction and automaticity properties. This study was to elucidate the automaticity of Mahaim fibre and its response to effective ablation.</p><p><b>METHODS</b>Thirteen patients with Mahaim fibre (ten atrioventricular and three atriofascicular accessory pathways) were subjected to electrophysiological study and radiofrequency ablation via catheter. The incidence and characteristics of anautomatic rhythm originating from Mahaim fibre were observed during the whole procedure, especially during radiofrequency current delivery.</p><p><b>RESULTS</b>Repetitive and short-run automatic rhythm (rate: 65-72 beats per minute), with a QRS morphology similar to that of clinical pre-excited atrioventricular re-entrant tachycardia (AVRT), occurred in two patients during sinus rhythm. Conduction via Mahaim fibre was successfully eliminated by radiofrequency current. Fourteen applications of RF were associated with irregularly accelerated automatic tachycardia of Mahaim fibre (with a sensitivity of 78%), lasting for 1.2-14 seconds. However, such automatic tachycardia of Mahaim fibre did not occur during 54 failed applications of radiofrequency current.</p><p><b>CONCLUSIONS</b>Mahaim fibre has the function of automaticity. The accelerated automatic tachycardia of Mahaim fibre occur red during radiofrequency catheter ablation can be used as a predictor for successful procedure.</p>

Ablaçäo por cateter de fibras atriofasciculares de Mahaim guiada pelo potencial de ativaçäo / Catheter ablation of atriofascicular Mahaim fibers guided by the activation potential

OBJECTIVE: To determine whether recording of the activation potential may be used as an isolated criterion to guide catheter ablation of atriofascicular Mahaim fibers. METHODS: We studied 6 patients (5 females, mean age of 26±7.3 years) with paroxysmal tachycardias with a wide QRS complex, whose electrophysiological study diagnosed atriofascicular Mahaim fibers. Mapping and catheter ablation were performed in sinus rhythm, guided only by the recording of the activation potential of the fiber. RESULTS: Efficacy in ablation was achieved in all patients. The fibers were located in the right lateral region of the tricuspid ring in 3 patients, right posterolateral region in 2, and right anterolateral region in 1. A mean of 5.3±3 radiofrequency applications was performed. The mean fluoroscopy time was 46.6±25 minutes, and the mean duration of the procedure was 178.6±108 minutes. No complication occurred. In a mean 20-month follow-up, all patients were asymptomatic and receiving no antiarrhythmic drugs. CONCLUSION: Catheter ablation of Mahaim fibers may be performed with good safety and efficacy by mapping the activation potential of the tricuspid ring in sinus rhythm

Tratamiento no farmacológico de vías accesorias atrioventriculares en la anomalía de ebstein / No pharmacological treatment of accessory atrioventricular pathways in Ebstein's anomaly

Se estudiaron en forma consecutiva 16 pacientes con anomalías de Ebstein con taquicardias supraventriculares, que involucran una vía accesoria. Encontramos una vía accesoria en 9 (56 por ciento) pacientes, y múltiples vías en 7 (44 por ciento), incluyendo 5 fibras de Mahaim atriofasciculares. Veintitrés vías fueron manifiestas y sólo dos ocultas. El 96 por ciento (24/25) se localizaron en el lado derecho: en la región lateral 36 por ciento (9/25), posterolateral 24 por ciento (6/25), poseroseptal 20 por ciento (5/25). Hubo otras localizaciones 16 por ciento (4/25) y lateral 4 por ciento (1/25). Los pacientes fueron sometidos a tres modalidades de tratamiento según la gravedad del padecimiento. Diez (62 por ciento) con 13 vías se sometieron a ablación con radiofrecuencia por vía percutánea, 3 (19 por ciento) con 7 vías a ablación transoperatoria y 3 (19 por ciento) con 5 vías a sección quirúrgica. La técnica de mapeo para la identificación y localización de la vía accesoria no fue diferente a los criterios actuales. Se obtuvo un éxito del 100 por ciento y sin recurrencia en las vías sometidas a sección quirúrgica (4/4) y ablación con radiofrecuencia (6/6) transoperatoria. El éxito primario fue de 86 por ciento (6/7) en ablación percútanea de una vía, con un fracaso y una recurrencia, y de 67 por ciento (4/6) en múltiples vías con dos fracasos y dos recurrencias. Estos pacientes no han sido sometidos a un segundo intento y se han controlado con antiarrítmicos. El éxito total con los tres procedimientos fue del 88 por ciento (22/25), 12 por ciento (3/25) fracasos, 12 por ciento (3/25) recurrencias, sin mortalidad y sin complicaciones mayores. En conclusión, en la anomalía de Ebstein, la ablación con radiofrecuencia por vía percutánea es el tratamiento de elección en pacientes sin deterioro hemodinámico que no requiere cirugía, y la ablación transoperatoria en aquellos que serán sometidos a corrección quirúrgica de su patología y defectos asociados. La sección quirúrgica de la vía debe considerarse un procedimiento histórico frente a la ablación con radiofrecuencia

Síndrome de pré-excitaçäo por fibras nodofasciculares (Mahaim): relato de dois casos / Pre-excitement syndrome by nodofascicular (Mahaim)fibers: report of 2 cases

A participaçäo de vias anômalas nodofasciculares ou de Mahaim no circulo de taquicardia clínica ou entäo no aspecto do eletrocardiograma (ECG) basal é descrita, respectivamente, em 2 pacientes. No caso 1, com crises recorrentes de taquicardia paroxística, o ECG basal näo mostrava qualquer forma de pré-excitaçäo e o QRS era normal. Durante a taquicardia, o QRS apresentava aspecto de bloqueio completo do ramo esquerdo (BCRE) e a freqüência cardíaca era de 180 bpm. Durante o estudo eletrofisiológico, demonstrou-se a presença de dupla via nodal, estando o início da taquicardia clínica na dependência de bloqueio da via rápida e conduçäo pela via lenta, induzido por extra-estímulos atriais. A transiçäo de conduçäo para a via lenta coincide com o encurtamento do intervalo HV e com o aparecimento de morfologia de BCRE. Quando se atinge intervalo crítico de alongamento da conduçäo pela via lenta nodal, a taquicardia clínica é disparada. Os componentes anterógrado (via lenta nodal - via nodofascicular) e retrógrado (porçäo proximal do ramo direto - tronco do feixe de His - via nodal rápida) podem ser estudados e a açäo benéfica do verapamil demonstrada. No caso 2, o paciente näo tinha taquicardia e o ECG basal mostrava sinusal intervalo PR = 0,18 e QRS com morfologia de BCRE. A presença de vias nodofasculares no determinismo da imagem de BCRE demonstrada pela presença de intervalo HV = 0 e pela normalizaçäo do QRS com estimulaçäo do feixe de His