Advanced pacing algorithms resembling device malfunction: A comprehensive review

Pacemakers have evolved from old-school demand pacing to providing tailored therapies. Nowadays, sophisticated algorithms adapt to changing pacing thresholds and provide an artificial chronotropic response while reducing ventricular pacing and preventing dangerous external interferences, among other functions. This way, pacing has become more physiological, maximizing battery duration and increasing patient safety and quality of life. However, this rising in complexity has made their electrocardiogram harder to interpret. In many cases, these functions may create unusual pacing patterns that could sometimes be mistaken for a device malfunction, prompting unnecessary use of medical resources and patient anxiety that could be avoided if such patterns were recognized. This review presents and explains those different advanced functions and algorithms, classified by their apparent malfunction, as a reference for the general cardiologist.