Patent ID: 8626278

Claim:
A method for assessing hemodynamic stability, comprising: providing a lead assembly including at least one intra-cardiac (IC) electrode, an extra-cardiac (EC) electrode and a subcutaneous remote-cardiac (RC) electrode, the IC electrode configured to be located within the heart, the EC electrode configured to be positioned proximate to at least one of a superior vena cava (SVC) and a left ventricle (LV) of a heart, the RC electrode configured to be located remote from the heart; analyzing intra-cardiac electrogram signals from the at least IC electrode to identify a potential atrial arrhythmia; measuring extra-cardiac impedance along an extra-cardiac impedance (ECI) vector between the EC and RC electrodes to obtain ECI measurements, the ECI vector extending through at least a portion of the greater vessels, the ECI measurements having a respiratory component and a cardiac component; filtering the ECI measurements to remove the respiratory component; determining a EC hemodynamic performance based on the filtered ECI measurements; and declaring the potential atrial arrhythmia to be an atrial arrhythmia based on the EC hemodynamic performance determined from the ECI measurements.