Left Ventricular Impaired Relaxation and Interstitial Myocarditis Identified in Sepsis-Associated Cardiac...

Area of Science:

• Cardiology
• Pathology
• Animal Models

Background:

• Sepsis is a systemic response to infection, with left ventricular (LV) diastolic dysfunction contributing to mortality.
• Animal models are crucial for studying sepsis-induced cardiac dysfunction, controlling for clinical confounders.
• Endotoxemia models offer insights into sepsis-associated cardiac pathology.

Purpose of the Study:

• To evaluate an endotoxemia (LPS) rodent model for left ventricular (LV) diastolic dysfunction using echocardiography and tissue Doppler.
• To assess histopathological changes in the myocardium following LPS administration.
• To correlate structural and functional cardiac alterations in sepsis.

Main Methods:

• Male Sprague-Dawley rats were randomized to LPS or saline (control).
• Echocardiography with tissue Doppler assessed LV diastolic function.
• Mean arterial blood pressure (MAP) was monitored.
• Histopathology and immunohistochemistry examined myocardial tissue post-mortem.

Main Results:

• LPS administration induced hypotension (MAP 81.86±31.67 mmHg vs. 124.29±20.16 mmHg).
• Impaired LV relaxation was observed (early diastolic velocity [e'] 0.06±0.02 m/s vs. 0.09±0.02 m/s).
• Histopathology revealed interstitial myocarditis, including hydropic changes and inflammation.

Conclusions:

• The LPS rodent model demonstrated both LV diastolic dysfunction and interstitial myocarditis.
• These findings establish a link between structural and functional cardiac changes in sepsis.
• This model facilitates further investigation into the mechanisms and treatments for sepsis-associated cardiac dysfunction.