Heart Muscle Cells (IMAGE) The Ottawa Hospital Caption Cardiotrophin 1 stimulates a good kind of heart muscle growth, generating long healthy fibres (right panel). Heart disease causes an unhealthy kind of heart muscle growth, similar to what is seen with phenylephrine treatment (middle panel). Credit Cell Research Usage Restrictions This image may only be used to accompany stories related to this research License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.