Anti-malarial Induced Cardiomyopathy Masquerading as an Apical Hypertrophic Cardiomyopathy

Description of Clinical Presentation: 70/F with systemic lupus erythematosus (SLE) since 1978 treated with hydroxychloroquine for 25-30 years had an ECG and echocardiogram that demonstrated left ventricular hypertrophy (LVH). Cardiovascular magnetic resonance (CMR) was ordered to assess the cause of LVH with initial study in 2023 suggesting apical hypertrophic cardiomyopathy (HCM). Given a trend of chronic mild elevation in troponin and subsequent echocardiography imaging not classic for apical HCM, the patient’s rheumatologist requested a repeat CMR with a question of anti-malarial induced cardiomyopathy (AMIC).

Diagnostic Techniques and Their Most Important Findings: CMR October 2023: Normal left ventricular ejection fraction (LVEF) of 65%, apical left ventricle (LV) hypertrophy of 12mm, suggestive of apical HCM. Mild non-ischemic late gadolinium enhancement (LGE) at the apex.

Echocardiogram November 2024:
Normal LV and right ventricle (RV) size and systolic function.
Loss of normal apical LV tapering and thickening of the lateral apical wall.

CMR July 2025:
Normal biventricular size and function (LVEF 60% and RVEF 53%). Mild increase in apical LV wall thickness (maximally 9-10mm) with India ink artifact on steady-state free precession (SSFP) cines at the distal septum and lateral wall and basal inferior wall (suggestive of fat). Extensive mid-myocardial LGE at the mid to apical interventricular septum, basal inferior-lateral, and anterior-lateral walls. Diffuse increase in native T1 values (1293 to 1442 ms on 3T Siemens magnet) with mild elevation of native T2 values (46 to 51 ms also on 3T) outside the areas of fat seen on SSFP cines. In the clinical context, overall findings are suggestive of AMIC.

Learning Points from this Case:

• AMIC is an under-recognized cardiomyopathy related to chloroquine and hydroxychloroquine toxicity.


• It commonly presents with left ventricular hypertrophy, usually concentric in type.


• In tissue characterization, AMIC can mimic Fabry disease, as both result from the intracellular accumulation of glycosphingolipids; however, the underlying processes are different.


• The most common location of LGE is at the basal to mid inferolateral wall segment with mid-myocardial distribution.


• Native T1 map values may be low due to glycosphingolipid accumulation in individuals on longer treatment, while increased values represent progression to fibrosis.


• CMR can serve as an alternative to endomyocardial biopsy for diagnosis, especially if clinical suspicion is high.

A: Focused apical 4-chamber view in systole shows thickened apical septal and lateral walls demonstrating lack of basal to apical tapering (white arrows). B: 4-chamber view SSFP image demonstrates subtle India ink artifacts at the apical septal and lateral walls, suggestive of intramyocardial fat. C-D: 2-chamber and 3-chamber view cine SSFP images in diastole again demonstrate apical tapering, characteristic in apical type of hypertrophic cardiomyopathy.
Top row (A-C): Short-axis PSIR images done last 2023 initially showed subtle low intensity mid-myocardial LGE involving the interventricular septum and sub-epicardial distribution at the lateral wall extending to the apical LV walls. Bottom row (D-F): Short-axis PSIR images from the recent study show progression of LGE with extensive involvement in a mid-myocardial and sub-epicardial pattern.
Left to right: Short-axis T1 map images from base to apex show similar distribution of elevated map values following LGE. Quantitatively, elevation of native T1 map values ranged from 1293 to 1442 ms at 3T.