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Wolff-Parkinson-White (WPW) syndrome is a pre-excitation syndrome wherein aberrant conduction is present between atrium and ventricle. Slurring of initial portion of QRS complex along with short PR interval are the hallmarks of this condition. In some patients, concomitant reciprocating tachycardia and atrial fibrillation (AF) occur. The effects of cocaine on AV conduction in patients with pre-excited atrial fibrillation is not well described. We report a case of a patient with such a scenario.
A 45-year-old male presented with pre-syncope followed by syncope. Initial rhythm was an irregular wide complex tachycardia consistent with WPW with AF. Following administration of diltiazem by EMS, he felt worse and had nausea and vomiting. This intense vomiting then led to conversion to normal sinus rhythm with obvious pre-excitation. Troponin on admission was elevated. Left heart catheterization and 2D echo were unremarkable.
His rhythm strip while in pre-excited AF showed shortest pre-excited R R interval (SPERRI) of less than 250 milliseconds (ms). Due to high risk nature of this pathway, he was taken for electrophysiology study. This revealed a left posterolateral accessory pathway with an effective refractory period of 280 ms, while being sedated during the EP study. Since his pathway already proved to be high risk on presentation, we successfully performed ablation through a trans-septal approach. Interestingly he also had dual AV node physiology, however AV node reciprocating tachycardia was not inducible on isoproterenol and so we deferred slow pathway ablation. In clinic follow up one month later, he denied having any recurrent dizzy spells or syncope, which he reports having frequently prior to ablation.
It is difficult to tell what role, if any the cocaine or administration of diltiazem played in the acute setting of pre-excited AF. The combination of diltiazem and cocaine may have helped to unmask the high-risk nature of this accessory pathway. A SPERRI < 250 ms, as well as the presentation of syncope are high risk features and probably warrant intervention even in the setting of cocaine use and diltiazem.
Poster Hall, Hall F
Monday, March 18, 2019, 9:45 a.m.-10:30 a.m.
Session Title: FIT Clinical Decision Making: Arrhythmias and Clinical EP 5
Abstract Category: Arrhythmias and Clinical EP
Presentation Number: 1316-196
- 2019 American College of Cardiology Foundation