Midazolam and Dexmedetomidine Sedation Impair Systolic Heart Function

Background: Sedation is an essential part of clinical practice. Despite this fact, we still lack data describing the exact impact of sedation on heart function.

Purpose: To compare the changes in heart function, induced after sedation with either midazolam or dexmedetomidine, using cardiac magnetic resonance imaging (MRI).

Methods: A total number of 30 volunteers were randomized into two groups: 15 participants in the midazolam group (MID) and 15 participants in the dexmedetomidine group (DEX). Every participant underwent a one-session cardiac MRI before and after sedation onset. The following parameters were recorded: left and right ventricle stroke volume (Ao-vol and Pul-vol resp.) and maximum flow velocity through the mitral valve during early (E-diast) and late diastole (L-diast). A monitor recorded values of mean blood pressure (MAP), pulse (P) and blood oxygen saturation (SpO2) in 5-minute intervals.

Results: Dexmedetomidine led to a statistically significant decrease in Ao-vol (p = 0.006) and Pul-vol (p = 0.003), while midazolam decreased E-diast (p = 0.019) Ao-vol (p = 0.001) and Pul-vol (p = 0.01). The late diastolic filling was not influenced by the sedation technique.

Conclusion: Both sedation regimens worsened the systolic function of both ventricles. Midazolam moreover attenuated early diastolic filling of the left ventricle (Tab. 3, Fig. 4, Ref. 19).