What is the graphic representation of the heart's electrical activity?

• A. Electrocardiogram
• B. Electrocardiograph
• C. Holter monitor
• D. Interval

Answer: (A)

The graphic representation of the heart’s electrical activity is the electrocardiogram, an ECG tracing that shows the heart’s rhythm and conduction. The waveform—P wave, QRS complex, and T wave—reflects atrial depolarization, ventricular depolarization, and ventricular repolarization, providing crucial clues about rhythm, rate, and possible conduction abnormalities. The device that records and displays this tracing is the electrocardiograph. A Holter monitor, by contrast, records ECG data continuously over an extended period to capture rhythms during daily activities, producing multiple tracings over time. An interval refers to a specific measured segment on the ECG, not the overall graphic.