Loss of brain function caused by blood clots that develop in the heart and travel to the brain.

Alternative Names

Stroke secondary to atrial fibrillation.

Causes, incidence, and risk factors

Stroke involves loss of brain functions (neurologic deficits), caused by a loss of blood circulation to areas of the brain. The specific neurologic deficits vary depending on the location, extent of the damage, and cause of the disorder. Strokes secondary to cardiogenic embolism are caused by moving blood clots ( emboli ) that develop in the heart. These clots travel through the bloodstream and become stuck in small arteries in the brain. This type of stroke typically occurs suddenly, with immediate maximum loss of brain functions ( neurologic deficit ). It is not associated with activity levels and can occur at any time. Heart arrhythmias (which include atrial fibrillation and others) are commonly seen with this disorder, and are often the cause of the embolus. A heart muscle that is not beating strongly or regularly may result in blood stagnating in the heart, causing a clot to form. This may then dislodge and travel upwards to the brain. Risks for stroke secondary to cardiogenic embolism include the following:

a history of heart

valve replacement

arrhythmias (especially

atrial fibrillation )

infective endocarditis

acute MI

mitral valve prolapse

other heart valve disorders

ischemic cardiomyopathy

blood clots anywhere in the body

Signs and tests

A person's medical history may indicate a risk for systemic emboli (clots that travel through the bloodstream from another location in the body). An examination may include neurologic, motor and sensory testing to determine the specific neurologic deficits present because they often correspond closely to the location of the injury to the brain. The examination may show the following:

changes in vision

or

visual fields

clots in the

retina of the eye

changes in reflexes including abnormal reflexes or abnormal extent of "normal" reflexes

abnormal eye movements

muscle weakness

decreased sensation

The

pulse may be irregular. Abnormal sounds may be heard by listening to the heart with a stethoscope. There may be signs of emboli ( splinter hemorrhages , etc.). Tests include:

Head CT scan

MRI of head

, MRA of the head

ECG

showing

arrhythmia , such as atrial fibrillation

Echocardiogram

to determine other heart disorders

Transcranial doppler (ultrasound of the head)

Treatment

Stroke is an acute , serious condition. Immediate medical attention is required, which is why some physicians now call stroke a "brain attack." In all cases, the sooner treatment is given, the better the likely outcome and the lower the chance of permanent disability or death. Treatment varies depending on the severity of symptoms. For virtually all strokes (including this kind), there is a need for hospitalization, possibly including intensive care and life support. When the person is seen quickly, thrombolytic therapy may be appropriate in many cases for this kind of stroke. This involves use of a medication that breaks clots and is meant to restore normal blood flow. It is imperative that thrombolytic medication be given within 3 hours of symptoms onset, which is why it is important to get to the hospital quickly. However, there are strict criteria for eligibility to receive this medication as it also has some risks of significant side effects. If the stroke was caused by bleeding in the brain, and not a clot, this medication can be harmful. Most patients will be admitted to an intensive care unit for close monitoring. If treatment with thrombolytic therapy is successful, there may be complete resolution of symptoms. There is no known cure for stroke if someone is not a candidate for this treatment. Treatment is essentially rehabilitation based on the symptoms presented. Treatment is also aimed at prevention of future strokes. Recovery may occur as other areas of the brain take over functioning for the damaged areas. The goal of treatment is to prevent spread (extension) of the stroke and to maximize the ability of the person to function. The underlying heart disorder should be treated as appropriate, including medications to control the heartbeat.

Expectations (prognosis)

Stroke is the third leading cause of death in developed countries.

About one-fourth of people who have a stroke die as a result of the stroke or its complications.

About one-half have long-term disabilities.

About one-fourth recover most or all function.

Complications

See stroke .

Calling your health care provider

Go to the emergency room or call the local emergency number (such as 911) if you have any reason to suspect a stroke may be occurring.

Prevention

Atrial fibrillation or other arrhythmias should be treated to prevent clot formation. TIA ( transient ischemic attack ) should be treated.