Chronotropic is a term used in physiology to describe something that affects or relates to the heart rate. Some synonyms for the word chronotropic may include cardiac accelerator, tachycardic, pulsatile, and palpitation-promoting. Other alternatives may be heart-relating, pulse-modifying, rhythm-influencing, or beat-modulating. These synonyms are commonly used to describe the effects of medication, exercise, or other stimuli on the heart rate. In general, any term used to describe something that affects the heart rate can be considered as a synonym for the word chronotropic. However, it's important to note that each synonym may have its own nuances and may be more appropriate in certain contexts.