Feedback control in the management of cardiac arrhythmias.

We have devised a computer technique for the control of drug therapy in the management of cardiac arrhythmias. In our system the computer monitors the electrocardiogram in real time, determines the percent of premature ventricular beats (PVBs) using a correlation coefficient technique, and compares it to a desired rhythm. If the measured rhythm departs from the setpoint, an antiarrhythmic drug is infused by the computer. Based upon the pharmacokinetics of the drug, the infusion is delivered so as to attain an immediate change in the blood drug concentration utilizing an exponential infusion technique. The control algorithm is a modified proportional controller. Closed-loop control experiments have been performed in canines with an induced myocardial infarction. The antiarrhythmic agent disopyramide phosphate was used to correct the resulting arrhythmias. Our results suggest that computer control of drug therapy can profitably be applied to the management of cardiac arrhythmias in the coronary care unit.