An ICC comprise of a number of conditions that affect either the heart muscle (cardiomyopathies), or the electrical circuits of the heart (ion channelopathies). ICCs can result in the heart working ineffectively, dangerous arrhythmias and sudden death. The last decade has seen dramatic advances in understanding of the pathology of ICCs. More than 50 ICCs have been recognised and genetics tests are increasingly available. Epidemiological evidence suggests a combined total prevalence for ICCs of about 340,000 in the UK.