Developed over a century ago, the electrocardiogram provides invaluable information about the state of health of the heart, aiding the diagnosis and management of various cardiovascular conditions. Cardiovascular diseases have significant impact on health, quality of life and economics, being the major cause of death and disability worldwide. In Europe, CVDs are the leading cause of death, accounting for 32% of all deceases, with an estimated cost of €210 billion annually. Addressing CVDs through monitoring and prevention is crucial to improve health expectancy and reduce the economic burden of these diseases. It is in this scenario that smart wearable devices fit: they allow self-monitoring of heart rate and activity.