Collateral circulation or “Natural Bypasses.” The Natural Bypasses help to compensate for any circulation deficiencies that blocked arteries may cause.
Most heart attacks, up to 85%, actually happen as a consequence of a blood clot which lodges in a partially blocked artery. Two thirds of the time such a blood clot happens in an artery that is not even critically blocked, that is, those arteries that are blocked between 40-60%. Stents and bypass surgery are reserved for blockages in the range of 75% or worse but yet most heart attacks happen in these lesser blocked arteries because it is easier for blood clots to lodge in arteries that are blocked in this range.
ECP stands for external counter pulsation , a non-invasive , low risk procedure.that can reduce or eliminate the symptoms caused by coronary artery blockage. ECP recruits and enlarges accessory blood vessels known as collaterals (Nature's own bypass channel) , creating new pathways around blocked arteries in the heart there by increasing blood flow to the atherosclerotic plaque through the blood columns, much like balloon angioplasty (but without puncturing the body). ECP reduces the plaque volume and also causes "Vascular Remodeling " at the site of obstruction
Today's patients are better educated about their disease. They are more aware of treatment option and consequently seek safer and less invasive treatments. They understand that surgery is not free of risk. Even the news surgical treatments , such as trans myocardial (where a laser beam is used to drill tiny holes in the wall of the heart ) suffer the same drawbacks as their predecessors , being invasive , expensive with a high rate of complication
The importance of all this is that as effective as ECP is in helping the heart grow new Natural Bypasses, it does not open up blocked arteries and it does not stop blood clots from forming in already partially blocked arteries.
Consequently, the extra circulation that ECP can provide essentially buys the coronary patient some time to both identify and correct any of the risk factors that caused the blockages to occur in the first place. If an artery blocks off completely whether it be due to a blood clot or not, heart damage may occur. The size of the damage will be determined by how large an area of muscle was being supplied by the artery and how effective the collateral circulation or Natural Bypasses may be. So that though ECP cannot absolutely prevent a heart attack from occurring, its effectiveness can reduce the size of the heart attack that may happen through its ability to at least partially, if not completely, make up for any circulation deficit occurring from the blocked artery itself.
The long term benefit of ECP then will depend upon how effectively a patient has identified and controlled those risk factors, to effectively halt, if not reverse the tendency, for coronary arteries to develop these blockages.
So, can ECP absolutely prevent a heart attack from happening? The answer is... No. The blockages that you had before ECP will still be there and they will still be susceptible to having blood clots form in them or to have the natural sludging process continue slowly. If your ECP treatments have been effective though, as evidenced by an increased exercise toleration and reduced angina frequency, then you can be assured that the extra collateral circulation or “natural bypasses” that have been grown for you will at least minimize the size of any heart attack that you might have if a blood clot should lodge in a partially blocked artery as is the case in about 85% of those heart attacks that occur. That is they occur as a consequence of a blood clot. Another way of thinking about this is that, ECP may be able to get rid of all angina in a patient with an 80% blockage, but may not be adequate to avoid any angina or even a small heart attack, if that 80% blockage becomes 100%, as a result of a blood clot or the progressive slow blockage from cholesterol.
Perhaps an appropriate analogy might be as follows. If a family's house was burning and the fire department was called and was able to save three of the five family members but that two people in spite of their best efforts perished, would the remaining family thank the fire fighters for saving the three or complain bitterly about why they could not save the other two. This is essentially the same dynamic that occurs with ECP. In spite of a heart attack that might have occurred, how much heart muscle was nevertheless saved as a consequence of the effective growth of some of these “natural bypasses,” that like the firefighters would attempt to put out as much of the fire of coronary disease as possible.
If you don’t control the risk factors that caused the blockages to occur in the first place then the gradual sludging of your arteries will eventually overwhelm any benefits from ECP and your angina may return or become worse.
As we have discussed before these risk factors include :
1) High blood pressure
3) No exercise
4) High stress life style
6) Elevated cholesterol
7) Elevated Homocysteine, Fibrinogen, Lipoprotein (a) or C-Reactive protein in your blood. Each of these problems can be treated but you don’t know to treat them unless you are aware that it is a problem for you. So please make sure that you know the results of these tests.
The noninvasive “Total Attack” approach that is recommended then includes ECP, to grow new circulation to compensate for any blockages that might be already present, but must also include an aggressive approach to the risk factors that caused the blockages to occur in the first place. Angioplasties, stents and bypass surgery can then be reserved for those patients that are felt to be too unstable to wait the necessary 7 weeks to complete a course of ECP and to begin the risk factor modification program.
If after a first course of ECP a patient is significantly improved, on the basis of frequency and severity of angina symptoms, as well as improvement on an exercise test, but is still having some angina symptoms or has not normalized his exercise test, then additional time with ECP will be recommended.
The understanding will be that if ECP has gotten rid of 50% or more of a patient’s symptoms but that some symptoms still persist, then let’s stick with what seems to be working and try to get rid of even more angina and perhaps continue to reduce some of the medications necessary to control it.