The heart contracting as one unit is called a:

1. Cardiac fibres are electrically connected. 2. That connection makes them act together. 3. Cardiac fibers are connected so that the entire heart contracts as one unit, called a syncytium. 4. So the answer is a syncytium. _Source: OpenStax 'Anatomy and Physiology 2e', Ch 10 'Muscle Tissue'_