{Reference Type}: Case Reports {Title}: Severe Hypertrophic Cardiomyopathy Associated With Hydroxychloroquine in a Young Woman With Systemic Lupus Erythematosus: A Case Report and Review of the Literature. {Author}: Brown B;Joseph C;Talanki V;Budzikowski AS;McFarlane SI;John S; {Journal}: Cureus {Volume}: 16 {Issue}: 5 {Year}: 2024 May 暂无{DOI}: 10.7759/cureus.61452 {Abstract}: The use of the antimalarial drug hydroxychloroquine is a standard treatment in patients with systemic lupus erythematosus. It helps reduce disease-associated damage, prevents disease flare, and improves overall survival. The mechanism of action of hydroxychloroquine includes interference with lysosomal degradation of cells leading to the accumulation of vacuoles. Retinopathy is a well-described adverse effect of hydroxychloroquine, thus requiring screening with an ophthalmologist after prolonged use. Although rarely reported, cardiac adverse effects of hydroxychloroquine can also occur. In this report, we present a case of a 23-year-old woman with systemic lupus erythematosus on hydroxychloroquine who presented with stroke possibly due to Libman-Sacks endocarditis and was found to have severe hypertrophic cardiomyopathy on transthoracic echocardiogram.