Myocardial collagen changes and edema in rats with hyperdynamic sepsis.

OBJECTIVE

To determine if sepsis, which is accompanied by both systolic and diastolic myocardial dysfunction, involves changes in myocardial collagen, as myocardial collagen changes can affect both myocardial compliance and contractility.

METHODS

Prospective, randomized, controlled study.

METHODS

Animal laboratory at a university-affiliated hospital.

METHODS

Male Sprague-Dawley rats, weighing 310 to 396 g.

METHODS

Cecal ligation and perforation (to induce sepsis) for 24 (n = 9) or 48 hrs (n = 9); sham laparotomy for 24 (n = 10) or 48 hrs (n = 9) with saline fluid resuscitation or normal control (n = 5) groups.

RESULTS

Collagen content and interstitial space were determined, using polarized light microscopy and a computer video densitometry system. At 24 and 48 hrs post surgery, heart rate and cardiac index were increased, and systemic vascular resistance index was decreased significantly in the sepsis vs. the sham rats. Collagen content was decreased significantly in the sepsis vs. the sham groups both at 24 and 48 hrs following surgery (1.83 +/- 0.79 [SD] % [24 hrs], 1.76 +/- 0.31% [48 hrs] vs. 2.83 +/- 0.73% [24 hrs], 2.25 +/- 0.72% [48 hrs]; p < .01). Interstitial space was increased significantly in the sepsis vs. the sham groups (13.9 +/- 3.5% [24 hrs], 15.6 +/- 5.2% [48 hrs] vs. 8.6 +/- 4.2% [24 hrs], 9.9 +/- 4.8% [48 hrs]; p < .01).

CONCLUSIONS

Sepsis is accompanied by changes in myocardial collagen content and myocardial edema. These changes may contribute to the systolic and diastolic myocardial dysfunction, and particularly to the ventricular dilation, observed in sepsis.