QUANTIFYING SYSTOLIC AND DIASTOLIC CARDIAC PERFORMANCE FROM DYNAMIC IMPEDANCE WAVEFORMS

摘要

The present invention is related to implantable cardiac devices such as pacemakers and defibrillators that deliver cardiac resynchronization therapy (CRT), and to a method of optimizing acquisition of multi-vector impedance signals from electrodes present on implanted lead systems. Acquired impedance signals associated with dynamic intracardiac impedance are related to specific time frames of the cardiac cycle as to derive indices representative of systolic and diastolic cardiac performance. The impedance signals are further adjusted by non-dynamic or static impedance signals associated with pulmonary impedance as to derive composite indices representative of cardiac performance and pulmonary vascular congestion. The pulmonary impedance signals are preferably obtained during relative periods of apnea in a patient.