Cuff during heart attack reduces heart attack size
Ischemic preconditioning is a powerful innate mechanism the body uses to protect all its tissues – not only the heart – from the effects of lack of blood flow. Dr Reddington and Dr Kharbanda developed a method to harness this natural mechanism in 2001 when they found that reducing the blood flow in the arm sends a warning message to the body and the heart and releases substances in the blood that protect the body and the heart from subsequent injury. The SickKids-developed preconditioning method consists of using a regular blood pressure cuff to transiently cut off blood flow to the arm; the cuff was inflated for five minutes, then deflated for five minutes, four times. At the hospital, the patients received routine heart attack treatment including angioplasty (a procedure to mechanically open narrowed or blocked blood vessels to the heart). Compared to the control group, the size of the heart attack was reduced by about 30 per cent overall in patients who were preconditioned. In patients having the largest heart attacks, the size was reduced by about 50 per cent.