Cardiovascular function time course in a rodent model of burn injury

Abstract

Severe burn injury may attenuate cardiovascular function with the diminished function contributing to morbidity and mortality. Male rats were randomly divided into sham (N = 8) or burn (N = 12) groups. Dorsal burns (30% surface area) were induced by immersion in 100°C water for 25 sec. Fluid resuscitation with Lactated Ringers (4ml/kg bodyweight/% burn, i.p.) was administered over 24hrs. Echocardiography assessed left ventricular (LV) structure and function 2, 4, and 7 days after burn. At day 7, LV function was measured with pressure volume catheterization, and serum collected to measure cardiac biomarkers. Echocardiography revealed a progressive increase in cardiac output (CO) secondary to an increase in stroke volume (SV) and LV dilation in burn animals. At day 7, burn animals had greater end diastolic volume (P = 0.01) and CO (P = 0.04), with a trend toward greater SV (P=0.06). Burn animals also had greater LV contractility (+dP/dt: 11319±1013 vs. 8336±411) and rate of relaxation (Tau: 7.9±0.3 vs. 9.4±0.6 msec). Cardiac myosin binding protein‐C was slightly elevated in burn animals (8.30±1.93 vs. 3.23±0.68ng/ml, P = 0.10). These preliminary studies in a rat model demonstrate that a full thickness burn leads to a sustained increase in cardiac function, which parallels the hyperdynamic state previously reported by others. If continued this effect may lead to cardiomyopathy. Funding: USAMRAA W81XWH‐10‐2‐0172.