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Isolation of Atrial Myocytes from Adult Mice
Published on: July 25, 2019
Left atrial function and phenotypes in asymmetric hypertrophic cardiomyopathy
Yukari Kobayashi1,2, Matthew Wheeler1,2, Gherardo Finocchiaro1,2
1Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA, USA.
Echocardiography (Mount Kisco, N.Y.)
|April 4, 2017
Summary
Left atrial (LA) function is impaired in hypertrophic cardiomyopathy (HCM) patients, even with nonobstructive disease. Obstructive HCM phenotypes show further declines in total and passive LA function, impacting cardiac health.
Area of Science:
- Cardiology
- Cardiovascular Imaging
- Cardiac Physiology
Background:
- Few studies have investigated left atrial (LA) function changes across different hypertrophic cardiomyopathy (HCM) phenotypes.
- Understanding these changes is crucial for managing HCM, a condition characterized by asymmetric thickening of the heart muscle.
Purpose of the Study:
- To assess and compare left atrial (LA) function and left ventricular (LV) strain in patients with obstructive and nonobstructive hypertrophic cardiomyopathy (HCM) versus healthy controls.
- To determine the association between specific HCM phenotypes and the degree of LA dysfunction.
Main Methods:
- Retrospective analysis of the Stanford Cardiomyopathy Registry.
- Echocardiography to evaluate LA function (emptying fraction, strain) and LV strain in 35 nonobstructive HCM, 35 obstructive HCM, 35 obstructive HCM with therapy, and 50 healthy controls.
- Age- and sex-matched participant selection.
Main Results:
- Left atrial (LA) volume index increased progressively from controls to nonobstructive and obstructive HCM groups (P<.05).
- All measures of LA function were impaired in HCM patients compared to controls.
- Total and passive LA function worsened with increasing obstruction (HCM 2/3 vs. HCM 1), while active LA function remained similar across HCM groups.
- Septal longitudinal strain was significantly reduced in all HCM groups compared to controls (P<.05).
Conclusions:
- Left atrial (LA) function impairment is present even in minimally symptomatic, nonobstructive hypertrophic cardiomyopathy (HCM).
- Obstructive HCM phenotypes exhibit more pronounced deficits in total and passive LA function.
- These findings highlight the progressive nature of LA dysfunction in HCM and its correlation with disease severity.
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