Final answer:
The heart beats faster due to the orthostatic regulatory mechanism which maintains blood pressure when standing up. Patients experiencing irregular heartbeats should be examined further to rule out serious conditions while also being reassured.
Step-by-step explanation:
The heart must beat faster when an individual changes their body position from lying down to sitting, and then to standing, due to a reflex called the orthostatic regulatory mechanism. This mechanism helps regulate blood pressure in response to gravity-induced changes in blood distribution. When a person stands up, blood pools in the lower extremities due to gravity, resulting in decreased venous return to the heart, which can cause a temporary drop in blood pressure. To compensate, the heart increases its rate to maintain adequate blood flow to the brain and other vital organs, ensuring sufficient oxygen delivery and preventing symptoms such as fainting.
In instances where a patient experiences unexpected changes in heart rate, like the heart speeding up sporadically, it could be due to various reasons including stress, stimulants, or an underlying health condition. Confirming to the patient that such occurrences do not necessarily indicate a heart attack is essential. However, it is equally important that Mariah, upon hearing the concerns of the patient, recommends further examinations such as EKG or a stress test to rule out potential cardiac issues. By doing this, Mariah can provide reassurance while also taking appropriate steps to ensure the patient's well-being.