TY - GEN
T1 - Assessment of cardiac function during mechanical circulatory support
T2 - 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2011
AU - Ferreira, Antonio L.
AU - Wang, Yajuan
AU - Gorcsan, John
AU - Antaki, James F.
PY - 2011
Y1 - 2011
N2 - A new index to assess left ventricular (LV) function in patients implanted with continuous flow left-ventricular assist devices (LVADs) is proposed. Derived from the pump flow signal, this index is defined as the coefficient (k) of the semiloga-rithmic relationship between pseudo-ejection fraction (pEF) and the volume discharged by the pump in diastole, (V d). pEF is defined as the ratio of the pseudo-stroke volume (pSV) to V d. The pseudo-stroke volume is the difference between V d and the volume discharged by the pump in systole (V s), both obtained by integrating pump flow with respect to time in a cardiac cycle. k was compared in-vivo with others two indices: the LV pressure-based index, M TP, and the pump flow-based index, I Q. M TP is the slope of the linear regression between the triple-product and end-diastolic pressure, EDP. The triple-product, TP LV SP.dP/dt max. HR, is the product of LV systolic pressure, maximum time-derivative of LV pressure, and heart rate. I Q is the slope of the linear regression between maximum time-derivative of pump flow, dQ/dt max, and pump flow peak-to-peak amplitude variation, Q P2P. To test the response of k to contractile state changes, contractility was altered through pharmacological interventions. The absolute value of k decreased from 1.3540.25 (baseline) to 0.6850.21 after esmolol infusion. The proposed index is sensitive to changes in inotropic state, and has the potential to be used clinically to assess contractile function of patients implanted with VAD.
AB - A new index to assess left ventricular (LV) function in patients implanted with continuous flow left-ventricular assist devices (LVADs) is proposed. Derived from the pump flow signal, this index is defined as the coefficient (k) of the semiloga-rithmic relationship between pseudo-ejection fraction (pEF) and the volume discharged by the pump in diastole, (V d). pEF is defined as the ratio of the pseudo-stroke volume (pSV) to V d. The pseudo-stroke volume is the difference between V d and the volume discharged by the pump in systole (V s), both obtained by integrating pump flow with respect to time in a cardiac cycle. k was compared in-vivo with others two indices: the LV pressure-based index, M TP, and the pump flow-based index, I Q. M TP is the slope of the linear regression between the triple-product and end-diastolic pressure, EDP. The triple-product, TP LV SP.dP/dt max. HR, is the product of LV systolic pressure, maximum time-derivative of LV pressure, and heart rate. I Q is the slope of the linear regression between maximum time-derivative of pump flow, dQ/dt max, and pump flow peak-to-peak amplitude variation, Q P2P. To test the response of k to contractile state changes, contractility was altered through pharmacological interventions. The absolute value of k decreased from 1.3540.25 (baseline) to 0.6850.21 after esmolol infusion. The proposed index is sensitive to changes in inotropic state, and has the potential to be used clinically to assess contractile function of patients implanted with VAD.
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U2 - 10.1109/IEMBS.2011.6090041
DO - 10.1109/IEMBS.2011.6090041
M3 - Conference contribution
C2 - 22254290
AN - SCOPUS:84861940272
SN - 9781424441211
T3 - Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS
SP - 223
EP - 226
BT - 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS 2011
Y2 - 30 August 2011 through 3 September 2011
ER -