2014年5月26日月曜日
Arterial Stiffness
The Arteriograph is a diagnostic instrument which is able to measure the severity of arteriosclerosis. This is the condition of arterial blockage caused by inflammation or damage within arteries followed by an over production of a compound known as plaque created by the body to repair the damage. Plaque is made up of cholesterol, minerals such as calcium, specialised red blood cells known as platelets and other clotting factors.
The Arteriograph is a simple and painless, non invasive investigation that can diagnose arteriosclerosis at an early stage .
Symptoms of arterial blockage include chest pain from blocking heart arteries, or the loss of sensation, numbness, or cramp in the lower limbs as the leg arteries block. These symptoms tend not to occur until a considerable amount of an artery is blocked and other arteries are no longer able to offer effective collateral circulation. Symptoms of cardiovascular disease leading to heart attacks and strokes usually appear only in the last and late stages and so arterial disease remains unrecognised through most of its development. The importance of identifying diseased arteries is clear.
Conventional testing
Current investigations are not designed to detect early occlusion of blood vessels. The Gold Standard exercise or stress ECG (where an individual is placed on a running track with leads on their chest attached to the ECG), will not necessarily change until 70% of a coronary (heart) artery is blocked. More sensitive investigation such as angiography are invasive and demand radiation through x-rays and the injection of a 'dye' to show up the arteries. About 1 in 500 angiographies cause serious or even fatal events and this figure is even higher if you take patients who have chest symptoms. These methods of investigation are effective only in diagnosing late stage disease and can carry risks.
The results of the Arteriograph closely correlate to the invasive tests specifically the Coronary Calcium Score and afore mentioned Coronary Angiography with the advantage of avoiding the adverse events.
Statistics involving arterial disease
Arteriosclerosis is the cause of 40% of premature mortality. It is the main cause of heart attacks and strokes and can begin at the age of 20 although the consequences generally appear in our sixth decade. If we were able to diagnose early stage disease we would reduce these negative figures and the Arteriograph, taking only a few minutes and measuring both small and large artery resistance (the medical term for flexibility) is a sensible and valid method of testing the entire arterial system.
Approximately 48,000 people between the age of 30-69 have a heart attack each year here in the UK and 150,000 people suffer a stroke.
The Arteriograph
An individual simply has to avoid food for 3 hours prior to the test and should not drink alcohol for 10 hours nor have any caffeine for 6 hours. You shouldn’t be smoking anyway but that should not happen for at least 3 hours as well! Supplements and drugs that influence blood pressure should not be stopped unless authorised by your GP or prescribing doctor. Most such medication in most people can be stopped for a few days without any longer term risk allowing a clear indication of a patient's arterial status.
After lying down without movement and thinking nice thoughts for a few minutes then a blood pressure cuff is inflated around the upper arm for a few seconds. Other than some tightness no other discomfort is felt.
The specialised computer inflates the cuff two or three times as it establishes the measurements and the nurse will also add in some specific details including the length from your neck to the base of your abdomen – the length of your aorta.
The whole process can take as little as 20 minutess
The doctor reading the results will be able to comment on:
• The resistance (flexibilty) of small arteries
• The resistance (flexibility) of large arteries
• The blood pressure in the aorta – Central Blood Pressure