Acquired long QT syndrome from stress cardiomyopathy is associated with ventricular arrhythmias and torsades de pointes

Abstract

Background: Stress cardiomyopathy (SCM) is a syndrome of transient ventricular dysfunction triggered by severe emotional or physical stress, likely resulting from catecholamine-mediated myocardial toxicity. Repolarization abnormalities associated with other hyperadrenergic states can cause QT prolongation and lethal arrhythmia including torsades de pointes (TdP). Despite the development of repolarization abnormalities and QT prolongation in SCM, little is known about the risk of ventricular fibrillation (VF) and TdP.

Objective: The aim of this study was to assess the prevalence and clinical predictors of ventricular arrhythmias in a cohort of patients with SCM.

Methods: Data from a registry of consecutive patients with SCM from 2 institutions were reviewed. Patients who developed VF or TdP were identified. Clinical characteristics and outcomes were analyzed and compared with a control group of patients with SCM without VF/TdP.

Results: Of 93 patients with SCM, 8 (8.6%) experienced VF/TdP. Of these 8 patients, 2 presented with VF and were subsequently diagnosed with SCM. Six other patients experienced pause-dependent TdP or VF after SCM diagnosis in the setting of substantial QT prolongation. Prolongation of the corrected QT interval (QTc) was significantly associated with the occurrence of ventricular arrhythmia (odds ratio 1.28 for each 10 ms increase in QTc, 95% confidence interval 1.10 to 1.50).

Conclusion: SCM can be associated with life-threatening ventricular arrhythmia in over 8% of cases. SCM should be recognized among the causes of acquired long QT syndrome and can be associated with a risk of TdP.