Cardiac fibroblasts play an important role in the function of the myocardium by regulating the extracellular matrix of the heart. Changes in the function of cardiac fibroblasts are a feature of heart failure. A subset of patients with heart failure that receive Left Ventricular Assist Devices, in combination with pharmacological therapy, are able to recover cardiac function to the point that the devices can be explanted. The response of cardiac fibroblasts to a combination of unloading and the pharmacological therapy given to these patients, which includes the Β₂-adrenoceptor receptor (Β₂-AR) agonist Clenbuterol, may play an important role in the reverse remodelling process. This thesis focuses on the response of cultured cardiac fibroblasts to Clenbuterol and mechanical stretch.