A novel echocardiographic parameter considering left ventricular afterload during V-A ECMO support

Area of Science:

• Cardiovascular Physiology
• Echocardiography
• Critical Care Medicine

Background:

• Left ventricular stroke work index (LVSWI) and cardiac power index (CPI) are crucial prognostic markers in cardiogenic shock.
• Accurate non-invasive measurement of LVSWI and CPI during veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is challenging due to extracorporeal circulation interference.

Purpose of the Study:

• To evaluate the novel Pressure-Strain Product (PSP) echocardiography parameter in an ovine model of cardiogenic shock.
• To determine if PSP correlates with pressure-volume catheter-derived LVSWI and CPI.
• To assess the load-independence of PSP during V-A ECMO flow variations.

Main Methods:

• Nine Dorset-cross ewes were subjected to induced cardiogenic shock and V-A ECMO support.
• Simultaneous measurements of echocardiographic parameters and pressure-volume catheter data were performed at varying ECMO flows.
• PSP was calculated using global circumferential or radial strain multiplied by mean arterial pressure.

Main Results:

• PSPcirc demonstrated a significant correlation with LVSWI (CC=.360) and CPI (CC=.283) compared to other echocardiographic parameters.
• PSPcirc showed higher predictability for LVSWI (AUC .82) and CPI (AUC .80).
• No significant differences in PSPcirc were observed between different ECMO flow rates, suggesting load independence.

Conclusions:

• The novel echocardiographic parameter, PSP, shows potential for non-invasively predicting LVSWI and CPI in cardiogenic shock patients on V-A ECMO.
• PSP may provide a load-independent assessment of hemodynamic parameters in this critical setting.
• This parameter could enhance the monitoring and management of patients supported by V-A ECMO.