A multiple sensor recording pacemaker for diagnosis and research

In an attempt to allow the recording of selective intracardiac waveforms, whilst at the same time administering pacing therapy, a temporary external diagnostic pacemaker system has been developed. This device provides VDD pacing when appropriate and monitors and records electrical and haemodynamic signals from within the right chambers of the heart. The recorded electrocardiogram provides information on the cardiac rhythm whilst the haemodynamic record can be used to infer data on cardiac function. Specifically this latter record contains real time waveform measurements of intracardiac pressure and impedance which are stored for subsequent analysis and display. All waveforms are recorded over a period both leading up to and during an arrhythmic event and pacing can be suppressed for a short duration to permit detection of bradycardias and cardiac pauses. The system consists of a diagnostic control unit incorporating a microcontroller and a standard Vitatron DDD3 pacemaker hybrid together with a single lead incorporating a pressure transducer and sensing and pacing electrodes. The lead is positioned in the right side of the heart with two electrodes in the atrium and two in the ventricle. Intracardiac impedance can be measured between any pair of electrodes and the pressure transducer can be used to determine the blood pressure waveform in the right ventricle