Four-chamber pacing system for optimizing cardic output and determining heart condition

A pacing system for pacing a left side of a patient's heart, comprising:

• first means for obtaining indications of mechanical contractions of the right ventricle, said first means comprising an impedance measuring circuit for obtaining an impedance signal representative of impedance and processing means for processing said impedance signal;
• left ventricular pacing means or pacing the left ventricle;
• and
• LV control means for controlling the timing of said left ventricular pacing relative to indicated right ventricular mechanical contractions, comprising left atrial pacing means for pacing the patient's left atrium, left AV control means for controlling the left AV delay between pacing the left-atrium and the left ventricle, cardiac output means for measuring left heart output as a function of said left AV delay, wherein said left AV control means further comprises maximizing means for adjusting said left AV delay to maximize left cardiac output;
• LA means for determining the timing of left atrial depolarization;
• CO means for measuring cardiac output from the patient's left heart;
• wherein said control sync means further comprises LAVD means for controlling said pacing means to deliver pacing pulses to said patient's left ventricle at a left atrio-ventricular delay following left atrial depolarizations, and adjusting means for adjusting said left atrio-ventricular delay to correspond to maximum measured cardiac output.