Work

Hypertrophic Cardiomyopathy With Evolution to a Mixed Hypertrophic Noncompaction Phenotype

Year: 2026

Type: article

Abstract: BACKGROUND: Noncompaction cardiomyopathy (NCCM) and hypertrophic cardiomyopathy (HCM) are both attributed to pathogenic sarcomere variants. Although a mixed HCM-NCCM phenotype has been described, temporal expression is not well understood. CASE SUMMARY: We present a 28-year-old male with findings suggesting a mixed, transitional HCM-NCCM phenotype. The patient was diagnosed with HCM in adolescence, requiring septal myectomy at age 20. Subsequent echocardiograms demonstrate evolving predominant features of NCCM. DISCUSSION: Although mixed HCM-NCCM phenotypes have been documented in a minority of patients, the concept of a transitional phenotype with progressive findings of noncompaction is unique. This case suggests that HCM may obscure initial evidence of noncompaction. Some cases of NCCM diagnosed later in life could represent a transitional phenotype. The management and prognostic implications of this overlap are not established. TAKE-HOME MESSAGE: A mixed, transitional HCM-NCCM phenotype may be more prevalent than previously recognized, requiring further investigation into its clinical and prognostic significance.

Source: JACC Case Reports

DOI: 10.1016/j.jaccas.2026.107743

Authors: Neelia E. Abadi, Christopher A. Abadi

Institutions: University of Vermont, SouthCoast Health

Language: English

Topic: Cardiomyopathy and Myosin Studies

Subfield: Cardiology and Cardiovascular Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $850