How are stroke and heart disease related? Stroke is often due to sudden loss of blood
supply to a region of the brain which usually results in paralysis of a part of the body.
Stroke could also be due to bleeding into a part of the brain.
Strokes and heart disease are linked together in various ways. In general, risk factors
for stroke and some forms of heart disease are similar. Strokes due to blocks in blood
vessels, can be seen along with blocks in blood vessels of the heart.
Stroke can occur after a heart attack as well. Heart attack damages a part of the heart muscle.
This can lead to damage of the inner lining of the heart in that region. A blood clot
can form on the inner surface of the heart as a consequence.
These clots can break away into the circulation and get lodged into a blood vessel of the
brain. The clot thus blocks a blood vessel of the brain and causes a stroke. Similar
clot formation can also occur when there is obstruction to a heart valve.
Another type of heart disease which leads to stroke is an abnormal rhythm of the heart
known as atrial fibrillation. In atrial fibrillation, there is a fast irregular rhythm originating
in the upper chambers of the heart. Illustration of fast irregular rhythm originating
in the upper chambers, with fast irregular heart rate. Rate in the upper chambers is
much higher than that in the lower chambers in atrial fibrillation. The rhythm is so fast
that effective contractions of the upper chambers cease. This leads to stagnation of blood in
certain parts of the left atrium (upper chamber of the heart), where a blood clot can form.
These clots can get dislodged and travel to blood vessels of the brain and block them,
producing a stroke. Another reason for stroke is high blood pressure.
When the blood pressure goes very high suddenly, small blood vessels in the brain may break
leading to a bleed into the brain matter. This form of stroke (hemorrhagic stroke) is
generally more dangerous than a stroke due to blockage of a blood vessel.
Even without a bleed, brain function can be altered due to high blood pressure, causing
alteration in the level of consciousness. But then that is not a stroke but called as
hypertensive encephalopathy (brain disease due to high blood pressure)