Key Points
- To assess the accuracy and reliability of Doppler echocardiographic indexes of left ventricular performance compared to invasive hemodynamic measurements under varied loading and inotropic states.
- Studied N=6 open-chest dogs under altered preload (intravenous nitroglycerin), controlled heart rate (atrial pacing), and varied inotropic states (dobutamine at 5 and 10 mcg/kg/min; propranolol at 1 mg/kg).
- Compared invasive measurements (electromagnetic ascending aorta flow probe and left ventricular pressure transducer for dP/dt) to continuous-wave Doppler measurements at the aortic arch (peak velocity, mean acceleration, time to peak velocity, and systolic velocity integral).
- Doppler peak aortic velocity differed significantly across inotropic conditions (p < 0.01) and correlated strongly within animals with maximum aortic flow (r = 0.96), maximum flow acceleration (r = 0.95), and maximum dP/dt (r = 0.92).
- Mean Doppler acceleration varied across inotropic states (p < 0.05) and correlated closely with conventional indexes but exhibited greater interobserver variability, whereas time to peak velocity and systolic velocity integral showed weaker hemodynamic correlations.
Structured PICO
Does continuous-wave Doppler echocardiography accurately assess left ventricular performance compared to invasive hemodynamic indexes in an open-chest dog model?
PPopulation6 open-chest dogs studied under various conditions (preload varied by nitroglycerin, heart rate by atrial pacing, inotropic state by dobutamine and propranolol)
IInterventionContinuous-wave Doppler echocardiography applied to the aortic arch
CComparatorInvasive hemodynamic measurements (electromagnetic flow probe and high-fidelity pressure transducer)
OOutcomeCorrelation between Doppler echocardiographic indexes and invasive hemodynamic indexes of left ventricular performancesurrogate
Doppler echocardiography provides accurate, non-invasive assessment of left ventricular performance, correlating closely with invasive hemodynamic measurements in an experimental model.