Cardiac electrophysiological studies: computer analysis using a digitiser and interactive visual display unit.

Recording of localised intracardiac electrical potentials provides useful and important information on conduction disease in man. Analysis of intracardiac recordings involves measurement of large numbers of timing intervals representing the sequence of activation of the various part of the cardiac conduction system. In this paper we describe a semi-automatic computer based analysis system tailored to the specific requirements of cardiac electrophysiological measurement. A digitising tablet is used in conjunction with a visual display oriented data handling package to input data directly to computer memory for sorting and further analysis. Particular attention is paid to providing the user with a system that is simple to learn yet is robust and flexible in use. The computer software is written entirely in the high level FORTRAN language. It is modular in design and is therefore easily adapted for the changing needs of a research oriented department.