Critical heart failure associated with beta-blocker-induced cardiac phospholipidosis: a case report.

Background: Drug-induced phospholipidosis (DIPL) is an acquired lysosomal storage disorder characterized by the accumulation of lamellar bodies and phospholipids, typically associated with the use of cationic amphiphilic drugs (CADs). Over 200 marketed CADs, including widely prescribed β-blockers, have the potential to induce phospholipid deposition in various organs. In rare cases, DIPL may lead to secondary cardiomyopathy. Case summary: We report the case of a 70-year-old man with a history of hypertension, permanent atrial fibrillation, and Stanford type B aortic dissection. The patient presented with a 2-week history of worsening dyspnoea. Examination revealed cardiomegaly, elevated B-type natriuretic peptide, and left ventricular dysfunction with an ejection fraction of 24%. Despite intensive medical treatment, the patient developed severe pulmonary congestion and died on Day 35. Post-mortem examination revealed vacuolar degeneration and lamellar body accumulation in the myocardium, consistent with DIPL. The most likely causal agent was bisoprolol, one of the patient's prescribed CADs. Discussion: While β-blockers are commonly used for the treatment of hypertension and heart failure, their potential to induce phospholipid deposition in the heart is rare but significant. This case underscores the need for awareness of DIPL as a potential adverse effect, especially in patients receiving CADs.