When it needs to pump more blood, the heart can grow in a good way in response to exercise and pregnancy, but after a heart attack, swelling of the heart muscles can lead to further complications. Now, Canadian scientists have found that a protein called cardiotrophin 1 (CT1) can essentially trick the heart into the good kind of growth, and reduce the bad kind.

Heart failure is a life-threatening condition where the organ can't adequately pump blood around the body, and often the only treatment is a transplant. It can be caused by a heart attack that damages muscles in the left side of the organ, or by pulmonary hypertension, whereby high blood pressure in the lungs damages the right side.