What is Takayasu Arteritis?
Takayasu Arteritis or Pulseless Disease is the term used to describe an inflammation in the aorta, the largest artery that carries blood from heart to various parts of the body and the aorta’s primary branches. Apart from inflammation, high blood pressure and pain in the chest or arm are caused by this condition.
The condition was described for the very first time by Dr. Mikito Takayasu in the year 1908. “A peculiar wreath-like appearance of the blood vessels in the back of the eye (retina)” was the description given by him to this condition. Because wrist pulses were absent in patients with this condition due to narrowing of blood vessels that supply the arm region, it is also known as Pulseless Disease.
It falls under the category of one of the types of vasculitis, a group of diseases in which inflammation of blood vessels occurs. It may narrow the arteries by blocking them in a condition known as stenoses. Aneurysm is the condition in which the arteries bulge out in an abnormal manner.
It is a rare condition which affects 2 or 3 people per a million people per year. Women are more prone to this disease than men. Women and girls below the age of 40 are usually affected. Asian and African women are more affected.
What Causes Takayasu Arteritis?
Unfortunately, the exact cause of this disease is not known. It could be an autoimmune disease; the immune system may attack patient’s own arteries treating them as foreign parts. Evidence also suggests that it could be the result of an infection (bacterial or viral or other).
Symptoms of Takayasu Arteritis:
The symptoms associated with this disease are usually the complications that occur as a result of the damage caused to the blood vessels due to inflammation.
This condition has been divided into 2 phases taking into consideration the symptoms that occur.
- Systemic Phase – This phase is characterized by signs and symptoms associated with any active inflammatory condition. Symptoms include fatigue, fever, non- weight loss. Elevated levels of erythrocyte sedimentation rate and tenderness of the affected arteries are seen in some patients.
- Occlusive Phase – In this phase, symptoms associated with narrowing of blood vessels begin to appear. Symptoms include:
- Pain in the calves during walking or pain in the arm while using a handsaw, the repetitive activities that are performed on a daily basis or regularly.
- Visual disturbances, headaches and feeling dizzy while standing.
- The extent of severity of the narrowing of blood vessels may reach the stage during which the normal pulse in the wrist, elbow, neck and lower extremities cannot be felt. In this stage, a harsh ‘whooshing’ sound made by the blood flowing through the abnormally narrowed blood vessels can be heard using a stethoscope.
- Although high blood pressure is common, blood pressure reading taken in the arms may be false if the artery got narrowed high up in the arm.
- In some patients with Takayasu Arteritis, difference in blood pressure readings in their arms is seen.
- Pulmonary (lung) arteries may be affected.
- In severe cases of the condition, abnormalities in blood vessels are observed with the help of ophthalmoscope by the doctors.
How is Takayasu Arteritis Diagnosed?
According to physicians, diagnosing this condition is very difficult as no specific symptoms are experienced by the patients until it advances to a major complication such as extremely decreased blood flow to one of the legs or an arm, ballooning of the aorta or a stroke in the brain due to high blood pressure in the blood vessels of the brain.
Diagnostic tests such as angiogram, CRP or C-reactive protein, arteriogram, ESR or erythrocyte sedimentation rate, CBC or complete blood count, MRI or magnetic resonance imaging, chest X-ray, ECG or electrocardiogram, ultrasonography and MRA or magnetic resonance angiography are performed to detect abnormalities associated with this condition.
Angiogram – In this diagnostic procedure, a catheter (thin, flexible tube) is inserted into the blood vessel followed by the injection of a special dye into the catheter. As the dye fills up the catheter, X-rays of arteries and veins are taken. The images show any abnormalities in the blood flow due to any blockage or interruption.
MRA or Magnetic Resonance Angiography – In this test, without the usage of X-rays or catheters, detailed images of blood vessels can be obtained. With the help of radio waves in a strong magnetic field the data is generated, which is converted into images by the computer.
Ultrasonography or Doppler ultrasound – A sophisticated version of the normal ultrasound, this one can generate high resolution images of some arteries like subclavian and carotid. It has the ability to identify even a small change in them. Moreover, this ultrasound clearly presents the difference between atherosclerosis (cholesterol particles accumulate in the arteries) and Pulseless Disease.
Treating Takayasu Arteritis:
- Medications – A vast majority of the patients respond very well to the drug prednisone. Although the starting dosage accounts for approximately 1 mg per kg of body weight per day, due to side effects of long term usage, the dose is gradually reduced. Azathioprine, Cyclophosphamide and Methotrexate can be used for long term treatment.
- Surgery – In people whose arteries are blocked or narrowed, this option becomes necessary to unblock the arteries to allow an uninterrupted blood flow. Stenting, Bypass surgery and percutaneous angioplasty are the surgical options.
Although this condition is considered fatal, a combination of medications and surgery has decreased the death rates dramatically.