Life Threatening Severe QTc Prolongation in Patient with Systemic Lupus Erythematosus due to Hydroxychloroquine.

John P O’Laughlin,Parag H Mehta,Brian C Wong

doi:10.1155/2016/4626279

John P O’Laughlin, Parag H Mehta + Show 1 more

Open Access

https://doi.org/10.1155/2016/4626279

Copy DOI

Abstract

We present a case of a syncopal episode resulting from significant QT interval prolongation in a patient on hydroxychloroquine for the treatment of systemic lupus erythematosus and end stage renal disease. The patient had been treated with hydroxychloroquine for two years prior to presentation. After thorough workup for secondary causes of QT interval prolongation hydroxychloroquine was discontinued and the patient's QT interval shortened. The patient was treated with mexiletine to prevent sudden ventricular arrhythmias, which was unique compared to other documented cases in which lidocaine was used. The patient was noted to have mild prolongation of the QT interval on electrocardiogram prior to initiation of hydroxychloroquine therapy which was exacerbated by its use and may have been caused due to toxicity from underlying renal failure.

Highlights

QT interval prolongation is the result of abnormal repolarization of the ventricular myocardium resulting in lengthening of the QT interval on electrocardiogram [1,2,3]
Torsades de Pointes (TdP) is a form of polymorphic ventricular tachycardia with a heart rate greater than 100 beats per minute with characteristic twisting around the isoelectric baseline every 5–20 beats [7, 8]
We present a unique case of severe QT interval prolongation in a patient with systemic lupus erythematosus (SLE) and end stage renal disease (ESRD) on chronic HCQ therapy which lead to a life threatening complication of syncope and resultant head trauma

Summary

Introduction

QT interval prolongation is the result of abnormal repolarization of the ventricular myocardium resulting in lengthening of the QT interval on electrocardiogram [1,2,3]. Patient’s ECG from two years prior showed a baseline prolonged QTc interval of 500 (Figure 2) She was evaluated for reversible causes of QT interval prolongation including electrolyte derangements, medications, and SLE flare. After further discussion with the patient’s Cardiologist and Rheumatologist she had been noted to have a prolonged QTc interval of approximately 500 ms while on therapy with HCQ She was trialed off the medication for two months without resolution of the QT interval abnormality, possibly due to undiagnosed underlying SLE cardiomyopathy. At three-month follow-up the patient remained off HCQ as after discussion with her Rheumatologist the risks related to syncope and possible intracranial bleed while on anticoagulation treatment greatly outweighed the benefits of HCQ therapy She continues to be closely monitored for SLE flares, and treatment decisions are to be strategized as clinical issues arise. The subcutaneous implantable defibrillator is providing secondary prevention of sudden cardiac death due to prolonged QT interval

Findings

Discussion

Conclusion