The Wolff-Parkinson-White syndrome can rarely present with pre-excited atrial fibrillation. In this condition the short refractory period of the accessory pathway can lead to rapid atrioventricular conduction. There is then a danger that at high heart rates the irregular broad complex tachycardia that results can deteriorate into ventricular fibrillation. The initial management of patients pres...

A case of isolated atrioventricular discordance in situs solitus is described. The importance of a well defined situs and of the presence of both ventricles in making this diagnosis is underlined and previous published reports reviewed. It is suggested that the haemodynamic concept of isolated atrioventricular discordance cannot be described only by the spatial relation between the ventricles (...

Ablation of accessory tracts in the posteroseptal region can be challenging, as illustrated by these 2 cases. Familiarity of the anatomy of this region and recognition of the ECG patterns can help identify the AP origin and potentially improve success rates of ablation. The isoelectric initial preexcited QRS complex with rSR’ pattern in lead V1 of the surface ECG but not the relatively earlier ...

The journal presents critical pathways for specific diagnoses -complete with evidence-based rationales -and publishes studies of these protocols' effectiveness. Critical Pathways in Cardiology translates evidence into practice, giving clinicians the tools to determine the best, most cost-effective patient management plans. This peer-reviewed quarterly journal provides the latest details of new ...

The atriofascicular accessory pathway (AP), known as the Mahaim pathway, is a rare form of pre-excitation, comprising less than 3% of all APs. Mahaim AP is characterized by decremental, anterograde-only conduction, and antidromic tachycardia with left bundle branch morphology. Prevalence of Mahaim AP in Ebstein's anomaly is significantly high. In addition, combination of Wolff-Parkinson-White (...

Electrophysiologic study was performed in a 52-year-old man with type A ventricular preexcitation. An accessory atrioventricular pathway with no ventriculoatrial conduction was localized to the posteroseptal region. "Fatigue phenomenon," defined as suppression of atrioventricular conduction following rapid pacing, was observed to be provoked by atrial pacing in a rate- and duration-dependent ma...

1 wo previous reports have demonstrated dual AV nodal pathways as the causative mechanism of spontaneous SVT termination in the WPW syndrome. Westveer et al’ reported a patient with WPW and non-sustained antidromic SVT, where SVT termination was related to retrograde dual AV nodal pathways. Retrograde conduction of the SVT occurred over the slow retrograde AV nodal pathway with concealment into...

A 31-year old male presented with atrial fibrillation and ventricular preexcitation that was positive in leads V1-V4, negative in lead II, and positive in lead AVR. The patient was cardioverted and invasive electrophysiologic study was performed. Based on the ECG findings, the coronary sinus and its branches were interrogated during orthodromic atrioventricular reentrant tachycardia. The earlie...

Drosophila seminal proteins have an unusually high rate of molecular sequence evolution, suggesting either a high rate of neutral substitution or rapid adaptive evolution. To further quantify patterns of polymorphism and divergence in genes encoding seminal proteins, also called accessory gland proteins (Acp's), we conducted a sequencing survey of 10 Acp genes in samples of Drosophila melanogas...