Atrial fibrillation raises stroke risk five-fold

People who experience frequent atrial fibrillation are at an elevated risk for stroke, and need to be identified early and treated, say experts.

Atrial fibrillation occurs when electrical signals misfire and cause the atria to contract in a fast and irregular manner. This causes blood to pool in these chambers and can result in blood clot formation which can travel through the bloodstream and block blood flow to the brain.

People with atrial fibrillation are five times more likely to have stroke than those without the condition. Up to three million people worldwide have stroke-related atrial fibrillation each year.

Furthermore, the Framingham study showed that atrial fibrillation-related strokes tend to be more severe, disabling and fatal than other kinds of stroke. [Circulation 2006;114:e257-354, Global burden of stroke, WHO. www.who.int/cardiovascular_diseases/en/cvd_atlas_15_burden_stroke.pdf Accessed on 25 October, Stroke 1996;27:1760-4, 1991;22:983-8]

Atrial fibrillation-related stroke exerts a huge burden on families and national healthcare services. According to the European guidelines, the death rate is doubled, stroke rate increased and left ventricular function reduced among patients with atrial fibrillation. [Circulation 2006;114:e257-354]

Dr. Razali Omar, a consultant cardiologist and electrophysiologist at the National Heart Institute, said recognizing the symptoms of atrial fibrillation early and referring the patient to hospital can help prevent ischemic stroke.

“Many people with atrial fibrillation have no symptoms. However, some with high heart rates may have symptoms such as palpitations, dizziness, chest pain and breathlessness. These patients are given medication to help normalize their heart rate. Selected patients may be treated with electrical cardioversion to shock the heart to normal sinus rhythm,” Razali added.

According to the European Society of Cardiology guidelines, after diagnosing patients with atrial fibrillation, their risk for stroke should be assessed and treated with an anticoagulant eg, warfarin, before they are treated for atrial fibrillation, said Razali. [Eur Heart J 2010;31:2369-429]

Conditions and lifestyle factors that are known to trigger atrial fibrillation include high blood pressure, diabetes mellitus, heart failure, smoking, obstructive sleep apnea, overactive thyroid and binge alcohol drinking. atrial fibrillation is also more common in people aged 65 and above, he added.

Preventing stroke by advising high-risk patients to lead a healthy lifestyle, especially incorporating regular physical activity, and recognizing the symptoms of stroke and quickly referring the patient to the nearest hospital with a stroke unit is vital in reducing, even reversing, the brain damage caused by ischemic stroke, said Professor Hamidon Basri, of the Neurology and Rehabilitation Unit at Universiti Putra Malaysia, and president of the Malaysian Society of Neurosciences (MSN). (Box 1)

If patients with ischemic stroke are treated with recombinant tissue plasminogen activator (r-tPA) within 30 to 60 minutes, the risk of disability is greatly reduced, Hamidon stressed.

Razali and Hamidon were speaking to journalists at the media launch of 1 Mission 1 Million – Getting to the Heart of Stroke global disease awareness campaign. It is supported by leading health experts and patient organizations in atrial fibrillation, including the World Heart Federation, Atrial Fibrillation Association, AntiCoagulation Europe and the Stroke Association for Europe, and is sponsored by Boehringer Ingelheim. In Malaysia, the campaign is supported by the Society of Pacing and Cardiac Electrophysiology (SOPACE) and MSN.

The campaign invites healthcare professionals, professional and patient organizations, and individuals to submit project ideas on education about AF and stroke risk. The deadline for submissions is 31 December.

Source: Medical Tribune