Method and apparatus for treating hemodynamic disfunction

A method for effecting simultaneous contraction of both left and right ventricles of a heart for improving hemodynamic efficiency comprising the steps of:

• separately sensing for the presence of cardiac depolarization signals from both left and right ventricles;
• determining whether said cardiac depolarization signals are simultaneously present in both the left and right ventricles;
• and
• stimulating at least one ventricle substantially simultaneously with the contraction of at least one other ventricle in the event that said cardiac depolarization signals are determined not to be simultaneously present in both ventricles.

A method of increasing the cardiac output of a sick heart comprising the steps of:

• (a) implanting a pacing lead having at least two sensing/pacing electrodes in the body such that one of said sensing/pacing electrodes is in or on the right ventricle and the other of said sensing/pacing electrodes is in or on the left ventricle;
• (b) sensing depolarization signals picked up by said sensing/pacing electrodes upon their occurrence;
• (c) determining whether the depolarization signals sensed in step (b) fail to occur within a predetermined time interval of one another and, if so;
• (d) applying an electrical stimulating pulse to the sensing/pacing electrode associated with the ventricle not producing a depolarization signal within said time interval at the conclusion of said time interval.

A bi-ventricular pacemaker, comprising:

• (a) sense means for sensing ventricular depolarization signals originating in or on the right and left ventricles;
• (b) means coupled to said sense means for initiating a time delay of a predetermined length which is short compared to the period of a QRS complex upon detection of a ventricular depolarization signal in one of said right or left ventricles;
• and
• (c) pulse generator means operative upon the termination of said time delay for producing a ventricular simulating pulse and applying same to the other of said right or left ventricles unless a ventricular depolarization signal occurs in said other of said right of left ventricle prior to the expiration of said time delay.