What is pulse deficit?

What is pulse deficit?

Normally pulse rate and the heart rate are equal. When the pulse rate is less than the heart rate, the difference is known as pulse deficit. It usually occurs in a fast irregular rhythm like atrial fibrillation. In atrial fibrillation, atria are electrically activated at a very fast rate of the order of 450 to 600 per minute. Proper organized contraction of the atria cannot occur at such fast rate and the electrical activity of the atria in atrial fibrillation is highly disorganized.

Hence atria are practically at stand still. When the very fast electrical signals from the atria get conducted to the ventricles, a good number of them are blocked at the AV node situated at the junction between the atria and the ventricles, in the lower part of right atrium. Still a good number of electrical signals reach the ventricle so that they contract at a fast and irregular rate.

When the ventricular rhythm is irregular, during some beats, ventricles get very little time to fill. The following contraction will be less forceful and not enough to open the aortic valve. Hence a pulse will not be felt during some heart beats, leading to the pulse deficit. Ideally both heart rate and pulse rate have to be counted simultaneously to document pulse deficit. An ingenious way in the monitored setting would be to check the difference between the heart rate display from the ECG tracing and that from the pulse oximetry tracing, though it cannot be accepted as a clinical method!