In this cross-sectional cohort, both nonobstructive and obstructive HCM had greater LA enlargement and dysfunction than controls, with the largest abnormalities in obstructive HCM, and greater LVOT obstruction severity was associated with higher LAVImin and lower LASr.
Both HCM groups had greater LA enlargement and dysfunction than healthy controls, with the largest abnormalities in obstructive HCM.
In the primary adjusted model, LVOTO was associated with higher minimum indexed LA volume (LAVImin).
In the primary adjusted model, LVOTO was associated with lower LA reservoir strain (LASr).
The associations of LVOTO with LAVImin and LASr persisted in sensitivity analyses using continuous LVOT gradient and a higher threshold.
Estimated filling pressure markers E/e' and tricuspid regurgitation velocity (TRV) were not significantly associated with LVOTG in sensitivity analyses.
Greater obstruction severity was associated with greater LA remodeling and reduced reservoir function, but the cross-sectional design limits inference about outcomes.
This study compared the left atrium (the heart's upper-left chamber) in 50 healthy people and 90 people with hypertrophic cardiomyopathy (HCM), a condition where the heart muscle thickens. Patients were grouped by whether blood flow out of the left ventricle was blocked (obstructive, 40 patients) or not (nonobstructive, 50 patients). Researchers used 3D ultrasound to measure atrial size and strain imaging to measure how well the atrium stretches and functions. Both HCM groups had larger and less well-functioning left atria than healthy people, and the changes were greatest in those with obstruction. After statistical adjustment, obstruction was associated with a larger minimum atrial volume and lower atrial reservoir strain. The links held when obstruction was measured as a continuous gradient and when a stricter cutoff of 50 mmHg was used. Two common ultrasound estimates of filling pressure were not significantly linked to the gradient. This research suggests that outflow obstruction in HCM is tied to worse atrial remodeling and function. Because the study captured a single point in time, it cannot show that obstruction causes these changes or that these measures predict patient outcomes. The authors call for prospective studies to test that.
Lin W, Zhong R, Que Q, Lin W, Zhu R, Cai F. (2026). Association of Left Ventricular Outflow Tract Obstruction with Left Atrial Remodeling and Dysfunction in Hypertrophic Cardiomyopathy: A Three-Dimensional Echocardiography and Left Atrial Strain Study.. Echocardiography (Mount Kisco, N.Y.). https://doi.org/10.1111/echo.70653