Myocardial collagen changes and edema in rats with hyperdynamic sepsis

Area of Science:

• Cardiovascular Physiology
• Sepsis Pathophysiology
• Myocardial Remodeling

Background:

• Sepsis is a life-threatening condition characterized by a dysregulated host response to infection.
• Sepsis is frequently associated with myocardial dysfunction, affecting both systolic and diastolic function.
• The role of myocardial collagen in sepsis-induced cardiac dysfunction remains incompletely understood.

Purpose of the Study:

• To investigate alterations in myocardial collagen content during sepsis.
• To correlate changes in myocardial collagen with myocardial compliance and contractility in sepsis.
• To elucidate the contribution of collagen remodeling to sepsis-associated cardiac dysfunction.

Main Methods:

• A prospective, randomized, controlled animal study was conducted using male Sprague-Dawley rats.
• Sepsis was induced via cecal ligation and perforation, with interventions assessed at 24 and 48 hours.
• Myocardial collagen content and interstitial space were quantified using polarized light microscopy and video densitometry.

Main Results:

• Sepsis groups exhibited significantly increased heart rate and cardiac index, and decreased systemic vascular resistance index compared to sham groups.
• A significant reduction in myocardial collagen content was observed in sepsis groups at both 24 and 48 hours post-surgery.
• Interstitial space within the myocardium was significantly increased in sepsis groups compared to sham controls.

Conclusions:

• Sepsis is associated with significant decreases in myocardial collagen content and increased myocardial edema.
• These myocardial structural changes, particularly collagen alterations, likely contribute to systolic and diastolic dysfunction in sepsis.
• The observed ventricular dilation in sepsis may be partly explained by these collagen and interstitial space modifications.