Multisource comparative QRS-wave analysis of premature ventricular beats and monomorph ventricular tachycardia

The authors describe a system for storage and display of QRS morphologies of ventricular arrhythmias from different sources. A substantial reduction of data is achieved by the generation of a so-called morphology atlas, containing only representative QRS complexes. An algorithm is described that groups the different morphologies into families. The hardware configuration of the system consists of a digitizer (resolution 0.1 mm), a personal computer, and a printer/plotter. The PC is connected to the central database computer by a serial RS232 line, using the program Kermit for communication. The PC is used as a virtual terminal for the database and controls the digitizer and graphic display. The setup was tested on 24 patients, each with spontaneous monomorphic sustained ventricular tachycardia (VT) late after myocardial infarction, ventricular premature beats (VPBs) recorded on a 5-channel Holter ECG, and (non)-sustained VT induced during programmed electric simulation. The system performed automatic grouping of morphologies rather well in case of (non)-sustained VTs. The correlation threshold of 60% confirmed the diagnoses of three independent observers. In case of VPBs no threshold could be determined