Drug-Induced Cardiomyopathies

Heart failure represents one of most important causes of death in Western countries. Its high mortality originates in part from severe complications like cardiac contractile dysfunction and/or sudden cardiac death caused by ventricular arrhythmias (Shin et al. 2007). Unfortunately, significant portion of heart failure stems from use (and misuse) of several drugs and medications. Indeed, the cardiac muscle is widely known as a target of injury for many drugs and many other chemical compounds. Following their cardiotoxic action, these could be divided into two relevant categories: i) drugs and cardiotoxic substances leading to heart failure in terms of abrupt contractile performance, and ii) drugs affecting ion channels or pumps and, in most cases, leading to prolongation of cardiac repolarisation (and QT interval) and to increased risk of severe cardiac arrhythmias (such as Torsades de Pointes) and premature death. In some cases, it is very difficult to divide them in those categories as they have both of actions. Additionally, drug-induced cardiomyopathies not only belong to the serious adverse events of drug actions but they are widely used as experimental models for studying several cardiac conditions and diseases, offering the advantage of precise control of the onset time and can often be studied in a longitudinal fashion. This chapter covers in detail certain drug groups, as for example anthracyclines or some drugs of abuse, which are clearly associated with the development of cardiomyopathy followed by heart failure. Similarly, note is made regarding experimental models of primary or secondary druginduced cardiomyopathies, QT prolonging agents and rhythm disturbances-triggering drugs. It must be noted that some of the mentioned substances are of clinical importance, the others have their use largely limited, but some of them lost their therapeutic use because of their cardiotoxicity.