Arterial thromboembolism in patients with sick sinus syndrome: prediction from pacing mode, atrial fibrillation, and echocardiographic findings.
OBJECTIVE
To evaluate whether thromboembolism in sick sinus syndrome can be predicted by pacing mode, atrial fibrillation, or echocardiographic findings.


METHODS
Patients were randomised to single chamber atrial (n = 110) or ventricular (n = 115) pacing. They were divided into subgroups with and without brady-tachy syndrome at time of randomisation. The occurrence of atrial fibrillation and thromboembolism during follow up were investigated and compared with echocardiographic findings.


RESULTS
The annual risk of thromboembolism was 5.8% in patients with brady-tachy syndrome randomised to ventricular pacing, 3.2% in patients without brady-tachy syndrome randomised to ventricular pacing, 3% in patients with brady-tachy syndrome randomised to atrial pacing, and 1.5% in patients without brady-tachy syndrome randomised to atrial pacing. In atrial paced patients without brady-tachy syndrome at randomisation and without atrial fibrillation during follow up, the annual risk of thromboembolism was 1.4%. Left atrial size measured by M mode echocardiography was of no value in predicting thromboembolism.


CONCLUSIONS
Arterial thromboembolism in patients with sick sinus syndrome is very common and is associated primarily with brady-tachy syndrome at randomisation and with ventricular pacing. The risk of thromboembolism is small in atrial paced patients in whom atrial fibrillation has never been documented.
Andersen
H R
HR
Department of Cardiology, Skejby Sygehus, Aarhus University Hospital, 8200 Aarhus N, Denmark.
Nielsen
J C
JC
Thomsen
P E
PE
Thuesen
L
L
Pedersen
A K
AK
Mortensen
P T
PT
Vesterlund
T
T
D000368:Aged; D000369:Aged, 80 and over; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D004452:Echocardiography; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012804:Sick Sinus Syndrome / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy; D013923:Thromboembolism / Q000209:etiology* / Q000628:therapy
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D001241:Aspirin