Hydroxychloroquine Cardiotoxicity and Sarcomeric Hypertrophic Cardiomyopathy

Tauben Averbuch; Jeffrey Shaw; Kristin Lyons; Yinong Wang; James A White; Omid Kiamanesh

doi:10.1016/j.jaccas.2025.103683

Hydroxychloroquine Cardiotoxicity and Sarcomeric Hypertrophic Cardiomyopathy

JACC Case Rep. 2025 Jun 11;30(14):103683. doi: 10.1016/j.jaccas.2025.103683.

Authors

Tauben Averbuch¹, Jeffrey Shaw², Kristin Lyons², Yinong Wang³, James A White², Omid Kiamanesh⁴

Affiliations

¹ Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada.
² Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada; Broderick Cardiomyopathy Program, University of Calgary, Calgary, Alberta, Canada.
³ Alberta Precision Laboratories, Department of Pathology and Laboratory Medicine, University of Calgary, Alberta, Canada.
⁴ Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada; Broderick Cardiomyopathy Program, University of Calgary, Calgary, Alberta, Canada. Electronic address: omid.kiamanesh@ucalgary.ca.

Abstract

Background: Hydroxychloroquine cardiotoxicity is a rare cause of dilated or restrictive cardiomyopathy.

Case summary: A 50-year-old male with a prior clinical diagnosis of hypertrophic cardiomyopathy presented with monomorphic ventricular tachycardia. Cardiac magnetic resonance imaging (CMR) revealed biventricular hypertrophy and systolic dysfunction, with diffuse nonischemic fibrosis. Endomyocardial biopsy (EMB) revealed myocyte hypertrophy and interstitial fibrosis, consistent with hypertrophic cardiomyopathy, and vacuolated myocytes and myeloid bodies, consistent with hydroxychloroquine cardiotoxicity. Genetic testing found a heterozygous pathogenic MYBPC3 intronic variant, confirming the diagnosis of sarcomeric hypertrophic cardiomyopathy.

Discussion: Hydroxychloroquine is an underrecognized cause of cardiotoxicity, particularly in patients with a preexisting cardiomyopathy. In the setting of preexisting cardiomyopathy with clinical deterioration and suspicion of a superimposed process, CMR, EMB, and genetic testing can provide diagnostic clarity and facilitate cascade screening.

Keywords: genetic cardiomyopathy; hydroxychloroquine cardiotoxicity; hypertrophic cardiomyopathy.

Publication types

Case Reports