PVC Heart Rate & Pulse Deficit Calculator
Calculate electrical heart rate vs. mechanical pulse rate to determine pulse deficit.
Do You Count PVCs When Calculating Heart Rate?
This is a common question among medical students, nurses, and EMTs analyzing ECG strips. The answer depends on what you are trying to measure: the Electrical Rate or the Mechanical (Pulse) Rate.
1. The Electrical Heart Rate (ECG)
YES, you count PVCs. When calculating the heart rate from an ECG strip, a Premature Ventricular Contraction (PVC) is an electrical event initiated by the ventricles. It represents depolarization and should be included in the total ventricular rate.
For example, if you are looking at a 6-second strip and see 7 normal sinus beats and 3 PVCs, you have 10 total electrical events. The heart rate would be 10 x 10 = 100 beats per minute (BPM).
2. The Mechanical Pulse Rate
USUALLY NO. PVCs often occur early in the cardiac cycle. Because the ventricles contract prematurely, they may not have had enough time to fill with blood (reduced preload). Consequently, the contraction might not be strong enough to open the aortic valve or generate a pressure wave that can be felt at the radial artery.
This creates a phenomenon known as a Pulse Deficit. The monitor might show a heart rate of 100 BPM (counting the PVCs), but when you palpate the patient's wrist, you might only feel a rate of 70 BPM (counting only the perfusing beats).
How to Calculate Heart Rate with PVCs
To use the calculator above manually, follow these standard steps for a 6-second strip:
- Step 1: Count the number of normal QRS complexes (e.g., 7).
- Step 2: Count the number of PVCs (e.g., 2).
- Step 3: Add them together for the Electrical Rate (7 + 2 = 9). Multiply by 10 to get 90 BPM.
- Step 4: For the estimated Pulse Rate, assume PVCs do not perfuse. Use only the normal beats (7). Multiply by 10 to get 70 BPM.