Ankle Brachial Index

For most of us, low blood pressure, high blood pressure and the likes is not unheard of, but did you know that blood pressure in the area of our legs near the ankle can reflect a lot about your health? Yes sir, seems a bit hard t o believe, but that is true. In fact, the blood pressure we normally calculate by fixing the apparatus on the arms, is not the same as compared to the blood pressure in the legs! This is called Ankle Brachial Index (ABI).

ABI is a reading of the ratio of blood pressure in lower legs to the blood pressure in arms. A slight drop in the blood pressure in the legs can be an indicator of peripheral vascular disease. Peripheral vascular disease refers to blockage of arteries. Basically, as compared to the arms, low blood pressure in the lower part of legs is can be an indicator of a serious health problem. However, the questions like how and why do you do it and when you do it still linger. Therefore, the following text will answer all these questions.

Ankle Brachial Pressure Index

Ankle Brachial Index Test
The apparatus used for this test is a doppler ultrasound. It is typically called the doppler wand or doppler probe. Now this is used to record the peripheral pulse and at the same time, the usual tool with which blood pressure is measured, sphygmomanometer (blood pressure duff) is fixed over the artery, at the point where an appendage joins the body (in this case doppler probe) till the pulse stops. After that, the cuff is made devoid of all the air and the respective sphygmomanometer pressure at the very moment the pulse is regained is the systolic blood pressure reading. Now the blood pressure in each of the foot's posterior tibial artery and dorsalis pedis artery are calculated with the higher of the two values is used as ABPI for the leg. The formula is to divide P arm by P leg. Here, P (leg) is the systolic blood pressure of the lower leg and P (arm) is the highest between the left and right arm systolic blood pressure. It is believed that ABPI is an effective method for a non invasive assessment of peripheral vascular disease.

Interpretation of the Ankle Brachial Test
In normal circumstances, the blood pressure in the lower leg area is a bit more than that at the elbow. As we know, ABI is the ratio of the maximum ankle pressure to brachial artery pressure. An ABPI greater than 0.9 is supposed to be normal and holds no risk of peripheral vascular disease. If the ABPI value is more than 1.3, it is an indicator of severe peripheral vascular disease. That will involve calcification of the walls of the arteries and incompressible vessels. The other interpretations are as such:

• ABPI value under 0.5 - Severe arterial disease
• ABPI value between 0.5 to 0.8 - Moderate arterial disease
• ABPI value between 0.8 to 0.9 - Slight arterial problem
• ABPI value between 0.9 to 0.10 - Acceptable and normal
• ABPI value between 1.0 to 1.2 - Normal range
• ABPI value more than 1.2 - concrete indicator of peripheral vascular disease.

There are other health conditions related to Ankle Brachial Index where vessels are non compressible like diabetes mellitus, end storage renal disease, diffused arterial calcifications, and so on.

There are 2 more tests which are normally suggested by doctors to confirm any kind of cardio vascular disease. Regular check ups are advised after a certain age to ensure that there is no such health problem. Take Care!