subclinical atrial fibrilation and the risk of stroke.pptx

8/10/2019 Subclinical Atrial Fibrilation and the Risk of Stroke.pptx

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Subclinical Atrial Fibrilatio

and the Risk of Stroke

Tegar MW

Dokter Pembimbing: dr. Zulfahmi Sp.PD, FIN



Background

One quarter of strokes are of unknown cause, and subfibrillation may be a common etiologic factor.

Pacemakers can detect subclinical episodes of rapid awhich correlate with electrocardiographically documefibrillation.

We evaluated whether subclinical episodes of rapid atdetected by implanted devices were associated with arisk of ischemic stroke in patients who did not have othof atrial fibrillation



Methods

We enrolled 2580 patients, 65 years of age or older, withypertension and no history of atrial fibrillation, in whompacemaker or defibrillator had recently been implante

We monitored the patients for 3 months to detect subctachyarrhythmias (episodes of atrial rate >190 beats pemore than 6 minutes) and followed them for a mean o

the primary outcome of ischemic stroke or systemic em



Results

By 3 months, subclinical atrial tachyarrhythmias detectimplanted devices had occurred in 261 patients (10.1%

Subclinical atrial tachyarrhythmias were associated witincreased risk of clinical atrial fibrillation (p<0.001) and ostroke or systemic embolism (p=0.007)

Of 51 patients who had a primary outcome event, 11 hsubclinical atrial tachyarrhythmias detected by 3 monthad had clinical atrial fibrillation by 3 months.



Conclusions

Subclinical atrial tachyarrhythmias, without clinical atrioccurred frequently in patients with pacemakers and wassociated with a significantly increased risk of ischemsystemic embolism



Studies have indicated that, depending on the prograpacemaker, the detection of such episodes of rapid atcorrelates well with electrocardiographic documentatfibrillation.

There are more than 400,000 pacemakers and implantcardioverter – defibrillators (ICDs) implanted each year

America.

Subclinical episodes of rapid atrial rate are detected inthese patients



METHODS

Patient Population

Patients were eligible for inclusion in the study if they weof age or older, had a history of hypertension requiring therapy, and had undergone their first implantation of Medical dual-chamber pacemaker or ICD (for any indthe preceding 8 weeks.



Study Procedure

After providing written informed consent, patients had pacemaker or ICD programmed according to protocosettings

At a clinic visit 3 months later, the devices were interrogorder to classify patients according to whether a subcltachyarrhythmia had occurred or had not occurred sinof enrollment.



RESULTS

Study patients

During the period from December 2004 through Septemtotal of 2451 patients with a newly implanted pacemapatients with a newly implanted ICD were enrolled in 2

Between the time of enrollment and the 3-month visit, aatrial tachyarrhythmia was detected by an implanted patients (10.1%).



Atrial Tachyarrhythmias during the Follow up Period

Patients were subsequently followed for a mean of 2.5 which time 14 patients (0.5%) were lost to follow-up

Clinical atrial tachyarrhythmias on surface electrocardoccurred in 41 of the 261 patients who had had subclintachyarrhythmias before the 3-month visit (15.7%)



Stroke or Systemic Embolism

During the follow-up period, 11 of the 261 patients (4.2%subclinical atrial tachyarrhythmias had been detectedmonths had an ischemic stroke or systemic embolism

The population attributable risk of ischemic stroke or sysembolism associated with subclinical atrial tachyarrhyt

13%



Discussion

A major finding of this study is that among patients 65 yor older with a history of hypertension who had undergimplantation of a pacemaker or ICD and were free froatrial fibrillation, there was a substantial incidence of suatrial tachyarrhythmias



The second major finding of the study is that subclinicatachyarrhythmias were independently associated with by a factor in the risk of ischemic stroke or systemic em

The population attributable risk of ischemic stroke or sysembolism associated with subclinical atrial tachyarrhyt3 months was 13%, which is similar to the attributable ris

associated with clinical atrial fibrillation reported by theFramingham investigators.



The results of our study suggested that the riskwas higher when episodes of subclinical atrialtachyarrhythmias were of longer duration



Thank you

subclinical atrial fibrilation and the risk of stroke.pptx

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