Final answer:
Heart block is the absence of one or more complete cardiac cycles where the rhythm is interrupted.
Step-by-step explanation:
The absence of one or more complete cardiac cycles where the rhythm is interrupted is referred to as heart block.
Heart block is a condition where there is a disruption in the electrical conduction system of the heart, leading to a delay or complete blockage of the impulses that regulate the heart rhythm. This can result in a slowed or irregular heartbeat.
Heart block is represented by a third-degree block on an electrocardiogram (ECG), where there is no correlation between atrial activity (the P wave) and ventricular activity (the QRS complex).