The Medical Intensive Care Unit at St. Marys, which opened in December 1964, was designed to care for the critically ill medical patient. Since it was expected that a good many of the patients admitted to the unit would be suffering from some type of heart ailment it was decided to install monitoring equipment in three rooms, which would instantly inform medical personnel at the nursing station or at the patient’s bedside of development of cardiac emergency.
By means of small electrodes placed on the patient’s chest the ECG (electrical activity of the heart) was observed both on the small round screen in the bedside unit and on the large 17-inch screen in the central monitor which carried simultaneously ECG recordings from six patients.
The heart rate was read on meters in both the central and bedside monitors. Increase or decrease of the rate beyond a pre-determined level sounded an alarm at the nurses’ station.
Provision was also made for a pacemaker to give electrical stimulation to the heart. This stimulation was instituted automatically if the heart rate slowed below a pre-determined level or stops. A defibrillator (to stop certain dangerous irregularities in heart action), was operated at the bedside or synchronized with the ECG so that a particular wave pattern triggered its operation.
ECGs on six patients were recorded continuously on magnetic tape. This tape was erased except when an acute situation occurred which caused the alarm to sound. The recorder then automatically replayed the previous minute of ECG so that the tracing made just prior to and during the acute episode was available.
Two surveys (one of the first four weeks of operation of the unit, the second of the following twelve weeks) showed that 41 patients were “on monitor” over sixteen weeks. During the twelve-week period, the diagnosis on admission in 83 of 144 patients was some type of heart ailment.