It appears that bypass surgery interrupts a self-healing process
that the body will start when it detects that oxygen is not
reaching the heart. Extraordinarily, 75 per cent of heart
patients experience a relief of pain within three to six months
without any medical intervention because the body starts growing
new blood vessels to form a natural bypass of the obstructed
arteries. These 'collateral vessels', as they are known, are
able to keep the blood flowing to the heart, even when a main
artery has completely closed. These vessels usually disappear
after bypass surgery, 'sensing' a new flow of blood to the
heart. Collateral vessels tend to grow when artery narrowing and
blocking is a slow process. A vessel that is only slightly
narrowed, and then suddenly blocks completely, is likely to
cause a myocardial infarction (heart attack) that the body can
do nothing to prevent. 'The common practice of rushing patients
in for emergency or urgent surgery because of a severely
narrowed coronary artery is completely