Resumo:
Background: Apical hypertrophic cardiomyopathy (ApHCM), also known as
Yamaguchi syndrome, is a rare phenotypic variant characterized by predominant
hypertrophy of the left ventricular distal segments. Despite a generally favorable
prognosis, its diagnosis remains a clinical challenge due to its heterogeneous presentation.
Objective: To describe the clinical, genetic, and phenotypic characteristics of patients
with ApHCM followed at a reference center in Bahia, Brazil. Methods: A descriptive
case series of patients followed at the Arrhythmia Outpatient Clinic of the Professor
Edgard Santos University Hospital (HUPES/UFBA), who underwent clinical evaluation,
electrocardiography, multimodal imaging, and expanded genetic panel testing. Results:
Five cases were analyzed (institutional prevalence of 0.19%), with a male predominance
and a mean age of 58 ± 10,7. years old. The clinical course was predominantly stable
(NYHA I-III), with no reports of syncope or major ventricular arrhythmias. The
electrocardiogram (ECG) revealed giant negative T-waves (≥10 mm) in 40% of the
sample. Cardiac magnetic resonance (CMR) confirmed the "ace-of-spades" morphology
and identified late gadolinium enhancement (LGE/fibrosis) in 80% of the patients, with
a modest magnitude (4% to 11%). Molecular analysis revealed variants of uncertain
significance (VUS) in the TNNT2 and MYBPC3 genes, with no detection of classic
pathogenic mutations. Conclusion: The results reinforce the heterogeneous nature and
the generally benign clinical course of ApHCM in the studied population. CMR and
genetic evaluation are indispensable tools for precise phenotypic characterization and risk
stratification, contributing to the proper management of this frequently underdiagnosed
entity in the Brazilian scenario.
