[Functional late potential analysis in the 24-hour electrocardiogram].
BACKGROUND
It has not been investigated, whether repeated late potential analysis within 24 hours provides the recognition of functional changes and could be superior to a single analysis.


METHODS
Therefore we performed late potential analysis from the 24 hour Holter-ECG after validation of the method using a standard analysis system (Predictor((R))) and investigated, whether late potential appearance varied over the day and funtional changes were associated with ventricular arrhythmias. Holter tape recordings in 120 post-infarction patients were analyzed. 40 patients had venticular tachycardia (cylce length >230 ms) in the chronic phase after myocardial infarction (VT-group), 40 patients were resuscitated from ventricular fibrillation (VF-group) and 40 patients had no ventricular arrhythmias after myocardial infarction (ØVT/VF-group). The recordings were subdivided in 24 segments of 60min duration. In each segment late potentials in the time domain and the average RR-interval together with its standard deviation (SDNN) were determined.


RESULTS
Investigation with the standard analysis system showed late potentials in 78% of the patients in the VT-group, in 30% in the VF-group and in 15% in the ØVT/VF-group. These late potentials were found analysing the Holter tape recordings in 70% of the VT-group, in 13% of the VF-group and in 5% of the ØVT/VF-group consistently in all 60min-segments. In 85% of the patients of the VF-group, compared to only 20% in the ØVT/VF-group at least in one 60min-segment within the 24hour period late potentials could be found. In patients in the VT-group, only transitory recognizable late potentials were detected predominantly during heart rate accelerations during day time and in phases of reduced heart rate variability.


CONCLUSIONS
Repeated late potential analysis from Holter tape recordings allows the recognition of functional changes and could therefore improve noninvasive risk stratification, particularly of post-infarction patients to ventricular fibrillation.
Steinbigler
P
P
Medizinische Klinik I der Universität München, Marchioninistr. 15, 81366, München.
Haberl
R
R
Vogel
J
J
Schmücking
I
I
Spiegl
A
A
Steinbeck
G
G