By Pass Surgery

The bottom line is this: when patients are advised to have a coronary angiogram, chances are eight out of ten that they do not need it. The critical factor in whether a pa‐ tient needs coronary artery by‐ pass surgery or angioplasty is how well the left ventricular pump is working, not the de‐ gree of blockage or the number of arteries affected. The left ventricle (chamber) of the heart is responsible for pump‐ ing oxygenated blood through the aorta (the large artery ema‐ nating from the heart) and to the rest of the body. Bypass surgery is only helpful when the ejection fraction (the amount of blood pumped by the left ventricle) is less than forty percent of capacity. Up to ninety percent of all bypass procedures are done when the ejection fraction is greater than fifty percent, which is ad‐ equate for circulatory need. In other words, as many as 90 % of all bypass procedures may be unnecessary.