Changes in left ventricular electromechanical relations during targeted hypothermia.

Background: Targeted hypothermia, as used after cardiac arrest, increases electrical and mechanical systolic duration. Differences in duration of electrical and mechanical systole are correlated to ventricular arrhythmias. The electromechanical window (EMW) becomes negative when the electrical systole outlasts the mechanical systole.

Left Ventricular Function During Epinephrine Stimulation and Hypothermia: Effects at Spontaneous and Paced Heart Rates in a Porcine Model.

Postcardiac arrest patients treated with hypothermia, frequently require vasopressors and inotropic medication. The aim of this experimental study was to investigate the effect of epinephrine on left ventricular (LV) function during hypothermia. In an open-chest porcine model, seven animals were equipped with LV micromanometer and epicardial ultrasound transducers to provide LV pressure, , and wall thickness and thickening velocities in systole (S') and early diastole (e').

Left Ventricle Function During Therapeutic Hypothermia with Beta-Adrenergic Receptor Blockade.

Therapeutic hypothermia is an established treatment in patients resuscitated from cardiac arrest. It is usually well-tolerated circulatory, but hypothermia negatively effects myocardial contraction and relaxation velocities and increases diastolic filling restrictions. A significant proportion of resuscitated patients are treated with long-acting beta-receptor blocking agents' prearrest, but the combined effects of hypothermia and beta-blockade on left ventricle (LV) function are not previously investigated.

Systolic left ventricular function is preserved during therapeutic hypothermia, also during increases in heart rate with impaired diastolic filling.

Background: Systolic left ventricular function during therapeutic hypothermia is found both to improve and to decline. We hypothesized that this discrepancy would depend on the heart rate and the variables used to assess systolic function.

Methods: In 16 pigs, cardiac performance was assessed by measurements of invasive pressures and thermodilution cardiac output and with 2D strain echocardiography.

Effects of therapeutic hypothermia on left ventricular function assessed by ultrasound imaging.

Background: Therapeutic hypothermia is used after cardiac arrest. The aim of this study was to investigate the effects of therapeutic hypothermia on left ventricular (LV) function assessed by ultrasonic imaging.

Methods: In 10 pigs, LV volumes, ejection fractions, and longitudinal strain were measured using two-dimensional echocardiography.