Characterization of Left Atrial Mechanics in Hypertrophic Cardiomyopathy and Essential Hypertension Using Vector...

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• Systemic hypertension (HTN) and hypertrophic cardiomyopathy (HCM) can cause left atrial (LA) dilation.
• The distinct impact of HTN and HCM on LA mechanical function remains unclear.
• This study aimed to characterize LA mechanical changes in HTN and HCM using vector velocity imaging (VVI).

Purpose of the Study:

• To differentiate left atrial (LA) mechanical abnormalities in systemic hypertension (HTN) and hypertrophic cardiomyopathy (HCM).
• To investigate the relationship between LA function and disease severity in HTN and HCM.
• To assess the utility of vector velocity imaging (VVI) in characterizing LA dysfunction.

Main Methods:

• VVI was used to assess longitudinal LA function in 76 HCM patients, 33 HTN patients, and 30 controls.
• Measurements included peak atrial longitudinal strain (ɛsys), and strain rates during systole (SRsys), early diastole (SRe), and late diastole (SRa).
• These parameters correspond to LA reservoir, conduit, and contractile functions, respectively, with similar assessments for left ventricular (LV) function.

Main Results:

• Left ventricular (LV) mass and LA volume index were elevated in both HCM and HTN groups compared to controls.
• LA reservoir and conduit functions were significantly more impaired in HCM patients than in HTN patients and controls.
• In HTN, only conduit function was deteriorated, and LA dysfunction was linked to advanced disease; in HCM, LV function predicted LA dysfunction.

Conclusions:

• Left atrial (LA) mechanics respond differently to hypertrophic stimuli in HCM and HTN.
• HCM is associated with more significant impairment of LA reservoir and conduit functions, correlating with disease severity.
• In HTN, conduit function is primarily affected, and LA dysfunction suggests a more advanced stage of the disease.