Elsevier

Heart Rhythm

Volume 3, Issue 8, August 2006, Pages 924-929
Heart Rhythm

Original-clinical
Refractory ventricular tachycardia secondary to cardiac sarcoid: Electrophysiologic characteristics, mapping, and ablation

https://doi.org/10.1016/j.hrthm.2006.03.031Get rights and content

Background

Cardiac sarcoidosis is a recognized cause of ventricular tachycardia (VT) and sudden death that has not been well studied.

Objectives

The purpose of this study was to describe the clinical characteristics of a consecutive series of eight patients with recurrent monomorphic VT due to cardiac sarcoidosis and to define the electrophysiologic characteristics of the VT and its electrophysiologic substrate.

Methods/results

Of 98 patents with nonischemic cardiomyopathy and VT referred for ablation over a 7-year period, sarcoid was the etiology in 8%. Mean age was 42 ± 8 years, and all but one patient had a reduced left ventricular ejection fraction (mean 34% ± 15%). VT was the initial manifestation of sarcoid disease in 5 of 8 cases based on retrospective analysis. All patients had not responded to therapy with multiple antiarrhythmic drugs (mean 2.5 ± 1). Cardiac biopsy initially was negative in 3 of 7 patients, and in 2 patients the diagnosis was not made until posttransplant examination of the heart. Two patients (25%) had a previous presumptive diagnosis of arrhythmogenic right ventricular dysplasia. Electrophysiologic study revealed evidence of scar-related reentry with multiple monomorphic VTs induced (4 ± 2 VTs per patient) with both right bundle branch block and left bundle branch block QRS configurations. Areas of low-voltage scar were present in the right ventricle in all 8 of 8 patients, in the left ventricle in 5 (63%) of 8 patients, and in the epicardium in 2 patients undergoing epicardial mapping. Ablation abolished one or more VTs in 6 (75%) of 8 patients, but other VTs remained inducible in all but one patient. Postablation, some form of sustained VT recurred in 6 of 8 patients within 6 months. However, at longer follow-up (range 6 months to 7 years), 4 of 8 patients currently are free of VT with antiarrhythmic drugs and immunosuppression. Cardiac transplantation eventually was required in 5 of 8 patients because of either recurrent VT (n = 4) or heart failure (n = 1).

Conclusion

Sarcoid is an important diagnostic consideration in scar-related VT. Sarcoid can be misdiagnosed as idiopathic or arrhythmogenic right ventricular cardiomyopathy. Arrhythmia control can be difficult, although ablation can be helpful in some patients.

Introduction

Although myocardial involvement occurs in at least 25% of patients with systemic sarcoidosis, it most often involves a small portion of heart and is clinically silent.1 A small fraction of patients develop overt cardiac involvement that can lead to arrhythmic manifestations, including impaired AV conduction, ventricular arrhythmias, and sudden death.2, 3, 4 Although most patients with systemic sarcoid have preserved ejection fraction, advanced cardiac involvement also can lead to reduced systolic function. In patients with cardiac sarcoid, ventricular tachycardia (VT) is associated with significant morbidity and is an independent predictor of mortality.5 Current management for VT might include immunosuppressive therapy, defibrillator implantation, and transplantation, but outcomes are not well defined. This observational study describes the clinical characteristics of a consecutive series of eight patients with recurrent monomorphic VT due to cardiac sarcoidosis and defines the electrophysiologic characteristics of the VT and its electrophysiologic substrate.

Section snippets

Methods

All cases with a diagnosis of nonischemic cardiomyopathy referred to Brigham and Women’s Hospital for catheter ablation of recurrent monomorphic VT from August 1997 to August 2004 were reviewed. Of 98 patients, 8 (8%) were determined to have cardiac sarcoidosis. The diagnosis of sarcoid was based on the pathologic identification of cardiac noncaseating granulomas via either endomyocardial biopsy or examination of the explanted heart in 7 of 8 patients. The remaining patient had a prior

Results

Of 98 patients with sustained monomorphic VT and a diagnosis of cardiomyopathy not due to coronary artery disease, 8 (8%) had cardiac sarcoidosis (Table 1). Mean age was 42 ± 8 years at the time of referral; 7 of 8 patients had recurrent VT despite therapy with multiple antiarrhythmic drugs (mean 2.5 ± 1). All but one patient also had a reduced left ventricular ejection fraction (mean 34% ± 15%). The median time from symptomatic cardiac arrhythmia to ablation was 5 months (range 3–48 months).

Discussion

This series shows that cardiac sarcoid is an important diagnostic consideration in patients with nonischemic heart disease and VT. The differential diagnosis in this population includes other forms of nonischemic dilated cardiomyopathy, arrhythmogenic right ventricular dysplasia, and giant cell myocarditis. Establishing the diagnosis requires a tissue biopsy demonstrating the characteristic noncaseating granulomas. Our patients illustrate several important points. VT can be the presenting event

References (17)

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