Previous animal studies have suggested the feasibility of echocontrastographic cardiac output evaluation applying the principles of dye-dilution theory. The present study was undertaken in order to verify the feasibility of cardiac output evaluation in humans using a sonicated albumin transpulmonary echocontrast agent (Infoson®). Thirty-seven patients, with a mean age of 57 ± 10 years, who underwent a complete invasive hemodynamic evaluation for clinical reasons, were studied. Infoson® at the dosage of 0.20 ml/kg was administered intravenously to all patients immediately after the hemodynamic study, and the apical 4-chamber view was visualized and recorded on a videotape during contrast injection. The echocardiographic images were subsequently off-line digitized and videodensitometrically analyzed, using a dedicated system (TomTec-Freeland), in order to obtain the time-intensity curve of the left ventricular opacification. After a γ-variate fitting, the following parameters were obtained from the time-intensity curve: the area under the curve, the area under the washout phase, the maximal videointensity, the duration of the curve, the slope of the washout phase and the half-time decay of the curve. After the correlation of each of these parameters with thermodilution cardiac output and cardiac index were separately tested, a multiple regression analysis was performed entering all the videodensitometric parameters and heart rate. Finally, a stepwise multiple regression analysis was performed. Both for cardiac output and cardiac index, only the half-time decay and duration of the curve, and heart rate were retained in the final predictive equation. Our results confirm the existence of a significant correlation between some videodensitometric parameters of the left ventricular opacification time-intensity curve obtained by echocontrastography and the thermodilution cardiac output and suggest the feasibility of cardiac output estimation by means of left ventricular opacification videodensitometry using peripheral venous administration of Infoson®.
|Number of pages||4|
|Publication status||Published - 1997|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Radiology Nuclear Medicine and imaging