[Computer-assisted long-term ECG analysis in patients with artificial trial pacemaker (AAI) (author's transl)]

Control of AAI-function is limited. To investigate the efficacy of AAI-stimulation, a computer-assisted analysis system for long-term ECG records was developed using "Multipass-Scanning I". 12 patients (5 females, 7 males, 33--78 years old with AAI) underwent Holter-monitoring for 24 hours continuously. THe ECGs of 5 among the collective with heart rate programmable AAI were recorded three times each with different AAI stimulation rates (50--80 b.p.m.). The number of AAI-induced heart beats in relation to the total number of QRS-complexes (AAI-QRS%) was 43 +/- 37% mean. AAI-QRS% during day showed a significantly lower distribution (35 +/- 38%, p less than 0.01) than during night (58 +/- 40%, p less than 0.001). Using an AAI-stimulation frequency of 50 b.p.m., only 9% of the heart beats were AAI-induced during day. Whereas AAI-QRS% increased to 72% during night in patients with AAI-stimulation frequency of 70 b.p.m. The interval between the PM-spike (S) and the following answer of the heart, i.e. SR-interval, demonstrated also a circadian behaviour: SR max occurred between 10 p.m. and 2 a.m. It was significantly prolonged to the SR min. (9--31%, m 20%, p less than 0.0001), which occurred between 9 a.m. and 4 p.m. So the presented computer-assisted long-term ECG analysis system for AAI-pacemakers is able to evaluate the efficacy of AAI with regard to different AAI-stimulation rates. The quantity of AAI-induced heart beats is dependent on patient's heart rate, its circadian behaviour and the stimulation rate of the AAI. The SR-interval also demonstrated a significantly circadian pattern, which can be related to the vagus-influenced PQ- and also AH-interval.