Learning about the different heart blocks is always a challenge for beginning students in cardiac electrophysiology.
- How do they happen?
- How can you tell them apart?
- How do they affect the patient?
These are but a few of the questions surrounding this particular class of ECG rhythm abnormalities.
Basic principles
Electricity in the heart runs through a very predictable pattern. Originating in the right atrium, the electrical impulse follows specialized electrical pathways in order to ensure that the heart’s chambers contract in a very organized manner.
Occasionally the signal gets interrupted somewhere along the way.
One type of interruption is at the atrioventricular junction, of AV junction. This area of the heart normally acts as a gatekeeper to the flow of electricity from the upper atria to the lower ventricles.
If this part of the conduction tissue is injured, the rate of electrical flow can slow or stop altogether. In other words, the signal gets blocked — hence the name, heart blocks.