Which device is commonly used to control the heart's rhythm?

A cardiac pacemaker is a medical device specifically designed to regulate and control the heart's rhythm. It achieves this by sending electrical impulses to the heart muscle, prompting it to contract at a normal pace. This device is particularly beneficial for individuals who experience arrhythmias, which are irregular heartbeats that can lead to various health complications. The pacemaker ensures that the heart maintains an appropriate rhythm and can help prevent symptoms such as dizziness, fatigue, and fainting associated with abnormal heart function.

In contrast, the other options mentioned serve different functions and are not related to heart rhythm control. A blood gas analyzer measures the levels of gases, such as oxygen and carbon dioxide, in a sample of blood, which is essential in assessing lung function and not in controlling heart rhythm. A bursa indicator is not a recognized medical device for heart rhythm management; bursae are small fluid-filled sacs that reduce friction between tissues in joints, and their indicators would be related to musculoskeletal conditions rather than cardiac function. A pressure sensor measures pressure changes in various systems but does not specifically aid in the regulation of heart rhythms. Consequently, the specialized role of the cardiac pacemaker makes it the correct response in this context.