Which monitor records the heart's electrical activity during anesthesia?

• A. ECG
• B. EtCO2
• C. SpO2
• D. Temperature

Answer: (A)

The heart’s electrical activity is recorded by the ECG. It detects the electrical impulses that coordinate each heartbeat, giving a real-time tracing of rhythm and rate through multiple body leads. This is crucial during anesthesia because drugs and physiological changes can alter conduction, so continuous ECG helps detect arrhythmias, ischemia, or abrupt changes in heart rhythm early enough to manage them.

Other monitors measure different physiological aspects: end-tidal CO2 reflects ventilation and CO2 elimination, reflecting how well the patient is breathing; SpO2 indicates arterial oxygen saturation; temperature monitors the body's heat. None of these track the heart’s electrical activity, which is why the ECG is the monitor used to assess electrical cardiac function during anesthesia.