We have developed real-time cardiac magentic resonance imaging techniques to overcome the conventional sampling limitations of MRI systems. While the acquisition has far less data available, parallel imaging, non-cartesian k-space sampling and iterative reconstruction result in images which allow clear visualization of irregular heart rhythms. Below, we highlight how this enables improved evaluation of patients with arrhtymias. We can visualize each heartbeat enabling assessment of different beat types which occur during arrhtymia. In addition to visualization, we can perform quantification of ventricular function.