Left Ventricular Function Changes Induced by Moderate Hypothermia Are Rapidly Reversed After Rewarming—A Clinical Study

OBJECTIVES: Targeted temperature management (32–36°C) is used for neuroprotection in cardiac arrest survivors. The isolated effects of hypothermia on myocardial function, as used in clinical practice, remain unclear. Based on experimental results, we hypothesized that hypothermia would reversibly impair diastolic function with less tolerance to increased heart rate in patients with uninsulted hearts. DESIGN: Prospective clinical study, from June 2015 to May 2018. SETTING: Cardiothoracic surgery operation room, Oslo University Hospital. PATIENTS: Twenty patients with left ventricular ejection fraction greater than 55%, undergoing ascending aorta graft-replacement connected to cardiopulmonary bypass were included. INTERVENTIONS: Left ventricular function was assessed during reduced cardiopulmonary bypass support at 36°C, 32°C prior to graft-replacement, and at 36°C postsurgery. Electrocardiogram, hemodynamic, and echocardiographic recordings were made at spontaneous heart rate and 90 beats per minute at comparable loading conditions. MEASUREMENTS AND MAIN RESULTS: Hypothermia decreased spontaneous heart rate, and R-R interval was prolonged (862 ± 170 to 1,156 ± 254 ms, p
Source: Critical Care Medicine - Category: Emergency Medicine Tags: Online Clinical Investigations Source Type: research