Non-invasive assessment of cardiac function in a mouse model of renovascular hypertension

Area of Science:

• Cardiology
• Hypertension Research
• Medical Imaging

Background:

• Hypertension is a major cause of cardiovascular morbidity and mortality.
• Early detection of myocardial effects is crucial for effective management.
• Understanding hypertension's impact on cardiac function requires robust preclinical models.

Purpose of the Study:

• To assess the feasibility of in vivo longitudinal evaluation of cardiac function in a mouse model of renovascular hypertension (RVH).
• To characterize early changes in left ventricular (LV) systolic and diastolic function using non-invasive imaging.
• To correlate in vivo findings with ex vivo myocardial tissue analysis.

Main Methods:

• Renovascular hypertension (RVH) induced in male mice (n=9).
• Longitudinal assessment using M-mode, pulsed-wave Doppler, and tissue Doppler echocardiography at baseline, 2, and 4 weeks.
• Ex vivo analysis of myocardial tissue for cellular morphology, fibrosis, extracellular matrix, and inflammation.

Main Results:

• RVH induced significant increases in systolic blood pressure.
• LV end-diastolic volume decreased, ejection fraction increased, and cardiac output was preserved.
• Abnormal diastolic function profile observed, including shortened E velocity deceleration time and increased E/e' and E/A ratios.
• Ex vivo analysis showed increased myocyte size and extracellular matrix deposition.

Conclusions:

• Non-invasive high-resolution ultrasonography is feasible for assessing diastolic function in a small animal model of RVH.
• RVH leads to significant alterations in cardiac function and myocardial structure.
• These findings underscore the utility of this model for studying early hypertensive cardiac effects.