Avoiding Drive Circuit Saturation in an ECG System

An Electrocardiography (ECG) system configured to produce an ECG output signal of a patient includes a plurality of electrodes, a monitoring circuit, a drive circuit, a lead circuit, and a control module. The electrodes form a plurality of leads. The monitoring circuit is configured to monitor a voltage differential on the leads and produce the ECG output signal. The drive circuit is configured to deliver a current to the electrodes based on a measured voltage at the electrodes. The lead fault detection system comprises one or more current sources configured to produce a current to deliver to the electrodes. The control module is configured to vary the current produced by the current sources based on a measured parameter at one or more of the electrodes.