Unusual variants of pre-excitation: From anatomy to ablation: Part I-Understanding the anatomy of the variants of ventricular pre-excitation.

The famous quotation of Winston Churchill, made in his radio broadcast of 1939 regarding Russia's next move, specifically "A riddle wrapped up in a mystery, inside an enigma," perfectly fits the current understanding of unusual accessory atrioventricular pathways, including the variants producing ventricular pre-excitation. It was many decades after their original descriptions that we came better to begin to understand most of their structure-function relationships. Their mysterious pathophysiology was sometimes unveiled after invasive treatments, such as surgical ablation of the atrioventricular conduction axis instead of the accessory pathway itself. Speculations made on this basis have largely been validated by subsequent clinical experience. Most of the names suggested for description of the pathways have stood well the test of time. For some of them, however, this is not the case, with the initial names becoming confusing. In a series of reviews, we re-visit those accessory pathways producing ventricular pre-excitation other than classical Wolff-Parkinson-White syndrome. To set the scene, in this initial review, we describe the development and anatomy of the normal atrioventricular conduction axis, along with the insulating tissues of the atrioventricular junctions. We have sought to illustrate our explanations by using virtual dissection of computerized tomographic datasets, since they retain the intact heart within the setting of the body. These images illustrate well the value of attitudinally appropriate terminology. Thereafter, we discuss the electrophysiological manifestations of the abnormal anatomical pathways which provide the potential for both accessory atrioventricular and intraventricular conduction.

Fasciculoventricular pathways: clinical and electrophysiologic characteristics of a variant of preexcitation.

UNLABELLED: Fasciculoventricular Fibers. INTRODUCTION: Fasciculoventricular tracts are considered a rare form of ventricular preexcitation. Few fasciculoventricular pathways have been reported, and none have been linked to a reentrant tachycardia. METHODS AND RESULTS: Four patients with fasciculoventricular bypass tracts underwent electrophysiologic evaluation. Two patients had a single fasciculoventricular pathway, one that inserted anteroseptally and the other in the left ventricle. Two patients also had an AV bypass tract, with anterograde conduction over the fasciculoventricular pathway during orthodromic AV reentrant tachycardia. After ablation of the AV pathways, the ECG during sinus rhythm and the electrophysiologic study showed ventricular preexcitation due to a fasciculoventricular bypass tract inserting into the right ventricle. Adenosine triphosphate was helpful in the diagnostic process. CONCLUSION: Electrophysiologists should be able to make the differential diagnosis between a fasciculoventricular bypass tract and an anteroseptal accessory pathway to preclude potential harm to the AV conduction system if a fasciculoventricular pathway is targeted for catheter ablation.

[The clinico-electrocardiographic classification of the early ventricular repolarization syndrome]. / Kliniko-élektrokardiograficheskaia klassifikatsiia sindroma rannei repoliarizatsii zheludochkov.

Based on an analysis of 4980 ECGs of patients, the authors could distinguish and classify the clinico-electrocardiographic versions of the early ventricular repolarization syndrome (EVRS): permanent, occurring for the first time, suddenly disappearing, intermittent with a gigantic T wave; with a negative T wave, with a short-term T wave inversion, marked by the combination with Wolff-Parkinson-White syndrome, and additional chordae of the left ventricle. The clinico-electrocardiographic classification of the EVRS is of paramount importance for practitioners owing to an assumption that the EVRS is not only a version of the normal ECG but also can be a marker of CHD. The authors view the EVRS as an independent version of the preexcitation syndrome along with Wolff-Parkinson-White and CLK syndromes, with the manifestations of which it may combine.

Los electrocardiogramas: métodos sistemáticos para su lectura / Electrocardiograms: a systematic method of reading them

Lectura e interpretación del electrocardiograma en diversaspatologías. Guía simple y metódica con muy buena ilustración para llegar al diagnóstico, pautas para la interpretación metódica de las distintas afecciones y de las modificaciones del ritmo cardiaco, de la desviación del eje, de la onda P, intervalo P-R, onda Q, complejo QRS, seguimiento S-T y onda T. Cambios del electrocardiograma por condiciones extracardíacas o "artefactos" que puedan dar errores de interpretación

Los electrocardiogramas: métodos sistemáticos para su lectura / Electrocardiograms: a systematic method of reading them

Lectura e interpretación del electrocardiograma en diversaspatologías. Guía simple y metódica con muy buena ilustración para llegar al diagnóstico, pautas para la interpretación metódica de las distintas afecciones y de las modificaciones del ritmo cardiaco, de la desviación del eje, de la onda P, intervalo P-R, onda Q, complejo QRS, seguimiento S-T y onda T. Cambios del electrocardiograma por condiciones extracardíacas o "artefactos" que puedan dar errores de interpretación