Assessment of left ventricular longitudinal function in cats with subclinical hypertrophic cardiomyopathy using...

Area of Science:

• Veterinary Cardiology
• Echocardiography
• Cardiovascular Physiology

Background:

• Hypertrophic cardiomyopathy (HCM) in cats causes left ventricular (LV) hypertrophy and impaired cardiac function.
• Tissue Doppler imaging (TDI) has shown variable reference ranges in feline HCM, limiting its diagnostic utility.
• Two-dimensional speckle tracking echocardiography (STE) is effective in human HCM but its role in cats is unclear.

Purpose of the Study:

• To evaluate global and segmental LV myocardial function using STE in cats with HCM.
• To compare STE findings with conventional echocardiography and TDI in feline HCM.
• To identify sensitive echocardiographic parameters for early diastolic dysfunction in feline HCM.

Main Methods:

• Echocardiography, TDI, and STE were performed on 35 cats (22 HCM, 13 controls).
• HCM cats were categorized into segmental (S-HCM) and diffuse (D-HCM) hypertrophy groups.
• STE assessed global and segmental LV function, focusing on longitudinal strain rate during early diastole.

Main Results:

• The longitudinal strain rate during early diastole was significantly decreased in both S-HCM and D-HCM groups.
• This decrease was observed even in segments without hypertrophy in the S-HCM group.
• STE parameters were more sensitive than TDI in detecting early diastolic dysfunction in feline HCM.

Conclusions:

• STE is a sensitive tool for detecting early myocardial diastolic dysfunction in cats with HCM.
• STE can identify subtle cardiac functional changes missed by conventional TDI, even in unaffected segments.
• STE offers valuable insights into feline HCM pathophysiology and aids in early diagnosis.