Atrial Arrhythmias in long-QT syndrome under daily life conditions: a nested case control study.
BACKGROUND
The long-QT syndromes (LQTS) are inherited electrical cardiomyopathies characterized by prolonged ventricular repolarization and ventricular arrhythmias. Several genetic reports have associated defects in LQTS-causing genes with atrial fibrillation (AF). We therefore studied whether atrial arrhythmias occur in patients with LQTS under daily-life conditions.


METHODS
We systematically assessed atrial arrhythmias in LQTS patients and matched controls using implanted defibrillators or pacemakers as monitors of atrial rhythm in a nested case-control study. Twenty-one LQTS patients (3 male; 39 +/- 18 years old; 18 on beta blocker, ICD therapy duration 6.3 +/- 2.7 years; 4 LQT1, 6 LQT2, 2 LQT3) were matched to 21 control subjects (13 male; 50 +/- 19 years old; 3 on beta blocker; pacemaker therapy duration 8.5 +/- 5.5 years; 19 higher-degree AV block, 2 others). LQTS patients were identified by a systematic search of the LQTS patient databases in Münster and Munich.


RESULTS
One-third (7 of 21) of the LQTS patients developed self-terminating atrial arrhythmias (atrial cycle lengths <250 ms). Only one control patient developed a single episode of postoperative AF (P < 0.05 vs LQTS).


CONCLUSIONS
LQTS patients at high risk for ventricular arrhythmias may develop short-lasting atrial arrhythmias under daily-life conditions, suggesting that prolonged atrial repolarization may contribute to the initiation of AF.
Zellerhoff
Stephan
S
Department of Cardiology and Angiology, Hospital of the University of Münster, Germany.
Pistulli
Rudin
R
Mönnig
Gerold
G
Hinterseer
Martin
M
Beckmann
Britt-Maria
BM
Köbe
Julia
J
Steinbeck
Gerhard
G
Kääb
Stefan
S
Haverkamp
Wilhelm
W
Fabritz
Larissa
L
Gradaus
Rainer
R
Breithardt
Günter
G
Schulze-Bahr
Eric
E
Böcker
Dirk
D
Kirchhof
Paulus
P
D000203:Activities of Daily Living; D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000235:genetics* / Q000517:prevention & control; D016022:Case-Control Studies; D002648:Child; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005260:Female; D005858:Germany; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications / Q000188:drug therapy / Q000235:genetics* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D000319:Adrenergic beta-Antagonists