Connected health is a new model for health management. It puts the correct information in the correct hands at the correct time. It allows patients and clinicians to make better decisions and relies heavily on advanced technologies to do so. In the connected health era there is an opportunity to collect a multitude of data about a patient. These may include daily life and behavior, including compliance to interventions or psychological aspects, as well as daily fluctuations of physiological parameters and contextual factors that influence them and can be combined with clinical and biological data available for the patient at different time points. This multitude of data can offer the opportunity to move from evidence-based medicine to knowledge-based medicine, that is, medicine that relies on knowledge about the patient. To achieve this goal, it is worth investigating the path from new technological methods for data acquisition to analysis and new knowledge and the path from patient knowledge to better intervention, as aspects that have gradually been discovered within the connected health domain. Both points would contribute to the impact of wide adoption of connected health technologies (CHT) as parts of new healthcare models. This chapter discusses first the connected health technologies in cardiac care. Basic concepts and building blocks are discussed, such as point-of-care diagnostics and new sensors, big data analytics, health behavior informatics and systems medicine, interventions, and knowledge-based medicine. CHT as a part of an iterative learning cycle for knowledge acquisition and application is presented, and the relevant challenges are discussed.