Late Gadolinium Enhancement and Electrocardiographic Associations in Hypertrophic Cardiomyopathy.

Background: Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging is a well-established indicator of myocardial fibrosis in hypertrophic cardiomyopathy (HCM). However, its association with electrocardiographic (ECG) abnormalities and the risk of atrial fibrillation (AF) remains uncertain.

Objective: To investigate the association between the presence and burden of LGE with ECG characteristics, including precordial voltage, depolarization and repolarization abnormalities, and the incidence of AF in adults with HCM.

Methods: We conducted a retrospective cohort study of 144 adults with HCM with CMR and 12-lead ECG within 30 days of each other. LGE was quantified as a percentage of LV mass and categorized as absent, < 5%, or ≥ 5%. ECG parameters, including QRS voltage, repolarization abnormalities, and LVH criteria, were analyzed. Incident AF was assessed during a median follow-up of 6.6 years.

Results: LGE was present in 96 (67%) patients, with 21 (22%) having ≥ 5% LGE. There were no significant differences in precordial voltage between patients with and without LGE across Sokolow-Lyon, Cornell, and Romhilt-Estes criteria. However, T-wave inversion was more common in leads I (41% vs. 19%, p = 0.009), aVL (50% vs. 31%, p = 0.033), and V4 (41% vs. 23%, p = 0.035) in patients with LGE. Patients with ≥ 5% LGE had a significantly lower median LVEF (64% vs. 74%, p = 0.003). Additionally, LGE presence was not associated with an increased risk of incident AF (HR 1.8, 95% CI 0.6-5.3, p = 0.308).

Conclusions: In contrast to pediatric HCM, LGE is associated with specific ECG repolarization abnormalities, particularly T-wave inversion in lateral leads, but does not significantly affect precordial voltage in adults.