4.1.7 Heart rate monitors
Heart rate monitors can be useful in some situations, such as measuring heart rate at different levels of exercise. The main factor in determining heart rate at any level of exercise is fitness. However, animals with heart disease may have an inappropriately high heart rate. Because the degree of fitness is so variable in different animals, no precise rate should be expected. However, in animals with heart disease, knowing what level of exercise can be performed before maximal heart rates (usually around 220-240 bpm) are reached, can be helpful. For example, in a horse with AF which fails to respond to treatment, or an animal with valvular disease, the level of exercise which is required to raise the heart rate to an arbitrary level such as 180 bpm, may be a good guide to the amount of work which the animal can safely be expected to perform. Radiotelemetry will also provide this information.