Palpitations is the feeling that happens when someone feels an abnormality in the normal beating of the heart. These palpitations can be an isolated extra beat, or they can run together and last for prolonged periods of time. Each part of the heart has the potential to be irritable and cause an extra beat to occur. As well, short circuits in the electrical conduction system of the heart can cause “runs” of abnormal firing.
Every muscle cell in the heart has the potential to generate an electrical signal that can spread outside the normal electrical pathways and bundles to try to generate a heartbeat. If the sino-atrial or SA node fails, then other cells in the atrium try to take over. If they fail, then the atrioventricular or AV node can take over but at a lower rate of about 40 beats per minute. And as the final backup, the ventricle itself can generate electricity but at a much slower rate of about 20 beats per minute.
Types of Palpitations
Extra heartbeats are normal and most people are unaware that they have occurred. Every muscle cell in the heart has the potential to generate an electrical signal that can spread outside the normal electrical pathways and bundles to try to generate a heartbeat. Many extra beats are normal variants and can be nothing more than an occasional irritant, but others can be dangerous – either acutely or chronically. Extra beats that originate in the atrium tend not to be as serious as those that come from the ventricle.
Abnormal heartbeats are classified by the location where they originate, if they happen occasionally or if they are clustered in runs, and if they resolve by themselves (self-limiting).
Conditions causing palpitations include:
- Premature atrial contractions (PAC)
- Premature ventricular contractions (PVC)
- Supraventricular tachycardia (SVT)
- Atrial fibrillation and flutter
- Ventricular tachycardia (V tach) and fibrillation
- Specific types of palpitations may be due to structural abnormalities in the heart.
- Women who are pregnant often experience palpitations but usually, no dangerous rhythm disturbance is present.
Many of the substances that we put into our body can cause palpitations by appearing to act like adrenalin on the heart and make it irritable.
Common stimulants include:
- Medication such as pseudoephedrine, which is found in cold remedies
- Illegal drugs.