Which substance affects perception of time and reality and can lead to increased heart rate?

Hallucinogens are substances that primarily alter perception, mood, and various cognitive processes, leading to changes in the way individuals perceive time and reality. They can create vivid imaginations, hallucinations, and distortions in sensory experiences. This alteration in perception can make minutes feel like hours or vice versa, significantly impacting an individual's sense of time.

Additionally, some hallucinogens, particularly certain types like LSD or psilocybin, can also lead to physiological effects, including increased heart rate. This effect can be influenced by factors such as users' mental state, environment, and dosage.

While cocaine is known to increase heart rate and energy levels, it primarily affects mood and alertness rather than perception in the same way hallucinogens do. Heroin is an opioid that typically causes sedation and can lower heart rate, and inhalants, while they can cause disorientation, do not primarily affect perception of time and reality in the same profound way as hallucinogens. Hence, the relationship between hallucinogens, time distortion, and increased heart rate solidifies them as the correct answer to the question.