INTERMITTENT WOLFF-PARKINSON-WHITE SYNDROME: A CASE REPORT WITH LITERATURE REVIEW

Abstract

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: An uncommon form of cardiac preexcitation, Wolff-Parkinson-White (WPW) syndrome results in an abnormal QRS complex that is generated as a result of normal conduction over the atrioventricular conduction pathway in conjunction with the accessory conduction pathway. WPW is classically characterized by the presence of short P-R interval (<120 ms), widened QRS interval (>110 ms) with slurred upstroke known as the delta wave on EKG and symptomatic tachycardia(1). Among patients in the United States less than 50 years of age there is a prevalence of 0.36/1000(2). Intermittent preexcitation in WPW is described as the loss of delta waves with prolongation of the P-R interval. The following case report presents a rare form of intermittent preexcitation with WPW syndrome. CASE PRESENTATION: A healthy 34-year-old man presented with a complaint of 1-2 episodes per week of palpitations, each lasting a few seconds. Initial EKG was remarkable for classic findings of WPW syndrome. His cardiac workup was relatively unremarkable, except for the exercise stress test which showed the disappearance of delta waves with HR >144 bpm in Stage 4 of the Bruce protocol. Serial EKGs revealed a pattern of intermittent preexcitation with WPW syndrome. DISCUSSION: Individuals with intermittent preexcitation may have a longer refractory period of the accessory pathway with poor conduction(3). Such unpredictable conduction in intermittent preexcitation via the accessory pathway is clinically relevant in asymptomatic to minimally symptomatic patients. The accessory pathway of WPW syndrome is also associated with reentrant supraventricular tachycardia and sudden cardiac death depending on the characteristics of conduction across the accessory pathway. Current treatment guidelines for WPW syndrome with intermittent preexcitation recommends no intervention in asymptomatic patients with an unremarkable diagnostic workup. With persistent preexcitation, pharmacologic therapy to slow the ventricular heart rate or to prevent the arrhythmia and the non-pharmacological therapy of catheter ablation of the accessory pathway are available. CONCLUSIONS: Cases of WPW syndrome with intermittent preexcitation range from asymptomatic to life-threatening. Such cases dictate careful review of electrocardiograms and close monitoring with ambulatory follow-ups. This case with low-risk features exemplifies the lack of need for further invasive testing in asymptomatic clinical scenarios of WPW syndrome with intermittent preexcitation. REFERENCE #1: 1. Iqbal AM, Ghazni MS, Mubarik A, Zubair N, Jamal SF. The Conversion of Wolff-Parkinson-White (WPW) Pattern into WPW Syndrome in the Presence of Ischemia: A Case Report. Cureus. 2019;11(2):e4147. Published 2019 Feb 27. doi:10.7759/cureus.4147 REFERENCE #2: 2. Lu CW, Wu MH, Chen HC, Kao FY, Huang SK. Epidemiological profile of Wolff-Parkinson-White syndrome in a general population younger than 50 years of age in an era of radiofrequency catheter ablation. Int J Cardiol. 2014;174(3):530-534. doi:10.1016/j.ijcard.2014.04.134 REFERENCE #3: 3. Klein GJ, Gulamhusein SS. Intermittent preexcitation in the Wolff-Parkinson-White syndrome. The American Journal of Cardiology. 1983 Aug;52(3):292-296. DOI: 10.1016/0002-9149(83)90125-x. DISCLOSURES: No relevant relationships by Ajay Agarwal, source=Web Response No relevant relationships by Akruti Patel, source=Web Response