[Alternative methods of microvolt T wave alternans measurements in patients with left ventricular cardiac dysfunction].
BACKGROUND
The presence of a microvolt T wave alternans (MTWA) is linked with increased risk of malignant arrhythmias and overall mortality. The most common method used for MTWA detection is a bicycle exercise test (BET). Method has still several limitations.


OBJECTIVE
To confirm that comparable MTWA results may be obtained by atrial and ventricular pacing during electrophysiology. To identify an anticipated relation between MTWA and malignant arrhythmia occurrence, or a death.


METHODS
We obtained MTWA during BET and consequently during atrial and ventricular pacing. All patients underwent a routine electrophysiology testing prior to prophylactic ICD implantation. The results were compared. The occurrence of malignant arrhythmias and death were registered during follow-up.


RESULTS
The group consisted of 39 patients. The results of MTWA obtained by BET, atrial and ventricular pacing did not show a significant difference. No difference was found among the three methods in the number of positive leads, and onset heart rate. Ventricular pacing increases the magnitude of MTWA comparing to the remaining two methods. No relation between MTWA results and occurrence of malignant arrhythmias or death was found.


CONCLUSIONS
Atrial and ventricular pacing lead to comparable MTWA results as BET and may be used as alternative methods in patients where BET is not feasible.
Fakultní nemocnice Brno, Interní kardiologická klinika. lkrivan@fnbrno.cz
Lubomír
L
Krivan
Petr
P
Lokaj
Milan
M
Kozák
Milan
M
Sepsi
Pavel
P
Trcka
Jitka
J
Vlasínová
Lucie
L
Buresová
Jindrich
J
Spinar
D001145:Arrhythmias, Cardiac / Q000150:complications; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*