American Stroke Association: Implanted Cardiac Monitor Better Identifies Stroke Risk
An implantable cardiac monitor (ICM) that is implanted under the skin is said to be 6-7 times more likely to detect atrial fibrillation, an abnormal heart rhythm that’s a risk factor for stroke, according to a report presented at the American Stroke Association’s International Stroke Conference 2014. The ICM can be helpful in identifying up to 30% of ischemic strokes that have no cause or origin. Ischemic strokes are generally caused by a clot in a blood vessel in or occur in close proximity to the brain.
Atrial fibrillation is known to be difficult to detect as it is intermittent nature and often asymptomatic. In cases where a stroke is unexplained it is critical to determine if A Fib was a factor and the treatment used.
Most people who have a stroke caused by a blood clot are given aspirin or similar drugs, such as clopidogrel, anticoagulants, such as warfarin, or the newer anticoagulants, to prevent stroke. These medications are generally not given when patients are NOT diagnosed with A Fib. Thus detecting A Fib can play a vital role in the management of patient that are suceptable to stroke or other complications.
There were results from a new study called CRYSTAL-AF (CRYptogenic STroke And UnderLying Atrial Fibrillation) that provided some useful information for clinicials relating to atrial fibrillation and unexplained (cryptogenic) stroke. The study included 441 patients who had 24 hour Holter Monitoring within 90 days of the stroke, and half were tracked with the insertable monitor, which can provide data for up to three years. At the 6 month mark, atrial fibrillation had been found in 8.9 percent of patients with an ICM compared to only 1.4 percent of those who had standard ambulatory ECG studies. A year later, the condition had been detected in 12.4 percent of patients with the insertable monitor, compared with 2% of the others. After 3 years, that gap was 30% with the ICM compared to just 3% percent for standard testing.
The device is slipped under the skin of the chest via a small incision, using local anesthetic in a brief outpatient procedure. The monitor has two electrodes to monitor heart rhythm, and can detect various heart irregularities. It stores a log of when and how long each event occurred and the heart rate. The ICM device has the capability to transmit an cardiac abnormalities via wireless transmission to an external device. The gathered information can easily be sent to the doctor for review.
The ICM is a very safe procedure with only 2.4% removed in the study from complications. The results are proven to very useful to the cardiology community as it reveals (no pun intended) patient that are potentially at a higher risk of disabling stroke because they the proper medical management is not employed.
Source: American Stroke Association – Clarksville Online
