Importance

Loading Importance Indicators...

Abstract

The apparatus for pacing a heart in accordance with the heart rate needed to produce a required cardiac output while the person is exercising, comprises a pacer adapted to be implanted in a human body and having a pulse generator and control circuitry (e.g. including a microprocessor) therein, a pacing lead adapted to be implanted in a right ventricle in a heart and having a distal electrode adapted to engage and supply pacing pulses to the apex of the right ventricle and a pressure sensor or impedance sensing electrode mounted in or on the lead. An algorithm and routine utilizing same are stored in the control circuitry (microprocessor) and are adapted to (a) relate right ventricular pressure to duration of contraction to determine ejection time and changes in ejection time or (b) to relate impedance and changes in impedance to blood volume or changes in volume, to relate blood volume and changes in blood volume to opening and closing of the pulmonary valve and to determine each time period between each opening and closing to determine ejection time and changes in ejection time and to correlate ejection time or changes in ejection time with the required heart rate needed to supply a desired cardiac output and to cause the pacer to pace the heart at the required heart rate when the heart is not naturally paced.

Loading the Abstract Image...

First Claim