What is the significance of the letter P in an ECG?

What is the significance of the letter P in an ECG?
  1. It represents a specific electrical activity of the heart
  2. It represents the heart rate
  3. It represents the heart sound
  4. It represents the cardiac output

Solution

Each peak in the ECG is identified with a letter from P to T that corresponds to a specific electrical activity of the heart.

Asked in: NCERT

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