Heart rate dynamics at the onset of ventricular tachyarrhythmias as retrieved from implantable cardioverter-defibrillators in patients with coronary artery disease.
BACKGROUND
The recent availability of implantable cardioverter-defibrillators (ICDs) that record 1024 R-R intervals preceding a ventricular tachyarrhythmia (VTA) provides a unique opportunity to analyze heart rate variability (HRV) before the onset of VTA.


RESULTS
Fifty-eight post-myocardial infarction patients with an implanted ICD for recurrent VTA provided 2 sets of 98 heart rate recordings in sinus rhythm: (1) before a VTA and (2) during control conditions. Three subgroups were considered according to the antiarrhythmic (AA) drug regimen. A state of sympathoexcitation was suggested by the significant reduction in HRV before VTA onset compared with control conditions. beta-Blockers and dl-sotalol enhanced HRV in control recordings; nevertheless, HRV declined before VTA independent of AA drugs. A gradual increase in heart rate and decrease in sinus arrhythmia at VTA onset were specific findings of patients who received dl-sotalol.


CONCLUSIONS
The peculiar heart rate dynamics observed before VTA onset are suggestive of a state of sympathoexcitation that is independent of AA drugs.
Pruvot
E
E
Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland. etienne.pruvot@chuv.hospvd.ch
Thonet
G
G
Vesin
J M
JM
van-Melle
G
G
Seidl
K
K
Schmidinger
H
H
Brachmann
J
J
Jung
W
W
Hoffmann
E
E
Tavernier
R
R
Block
M
M
Podczeck
A
A
Fromer
M
M
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D003327:Coronary Disease / Q000150:complications*; D017147:Defibrillators, Implantable; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D013015:Sotalol / Q000627:therapeutic use; D017180:Tachycardia, Ventricular / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D013015:Sotalol