Inapparent atrial flutter due to atrial dissociation.

Percutaneous and surgical procedures intended to potentially cure atrial fibrillation require creating lines of conduction block in specific locations throughout the atrial chambers. In patients presenting with recurrent atrial fibrillation, repeat procedures are often performed, resulting in more extensive regions of conduction block and the potential for regions of dissociated atrial rhythms. The present case describes a patient post-multiple ablation procedures who presented with a symptomatic atrial arrhythmia, the mechanism of which was hidden by the presence of extensive atrial dissociation. Electrophysiologic study revealed the appropriate mechanism and a beneficial ablative procedure was then successfully accomplished.

Traversing and dilating venous collaterals: a useful adjunct in left ventricular electrode placement.

In patients receiving cardiac resynchronization therapy (CRT), the left ventricular electrode cannot always be positioned in the preferred lateral or posterolateral locations due to technical factors and anatomic variations in the coronary sinus. Recent reports also suggest that CRT outcomes are improved by pacing the site of latest dyssynchrony and accessing these regions is not always possible. We report the utility of applying a technique described in the interventional literature over the past 3 years, effectively traversing and dilating collateral channels. Our patients demonstrated either no venous targets in the optimal location, or problems accessing this location using a antegrade approach. Subsequently, collaterals supplying this region were traversed with a guidewire using a retrograde approach and dilated with a balloon catheter. In the first case, the pacing electrode was then advanced in similar fashion and successfully positioned in an ideal lateral location. In the second case, the retrograde guidewire was captured with a vascular snare and pulled into a second guiding catheter, allowing appropriate dilatation and stenting of a problematic proximal venous stenosis with resultant facile placement of the pacing electrode. This technique offers a potential alternative to patients with challenging venous anatomy as a method to facilitate optimal CRT outcomes.