What is a Heart Arrhythmia?
An electrical system controls the rhythm of heart contraction and relaxation. It has two nodes, the sinoatrial(SA) node at top of the heart’s upper chambers (atria), and the atrioventricular(AV) node at top of the two lower chambers.
The SA node sends out an electrical signal that stimulates the atria, moving blood down the ventricles. The signal slows down for a while in the AV Node before it stimulates ventricles to contract and pump blood to the lungs.
Arrhythmia refers to a disruption in the steady flow of electrical energy through your heart. An injury or disease can cause an arrhythmia. The SA node is the heart’s natural pacemaker.
If there is an interruption in the path that the electrical impulses travel, arrhythmias can also develop. A change in the electrical patterns can make the heart beat faster, slower or in an unpredicted manner.
- Arrhythmias can be caused by:
- Cardiovascular disease
- heart attack
- Heart valve disease
- High blood pressure
- Inadequate electrolytes such as sodium or potassium
- Next, we will discuss the various arrhythmias associated with higher stroke risk.
- Flutter and atrial fibrillation
Arial fibrillation (AFib), the most common arrhythmia worldwide, was reported in more than 3 million cases in 2017. AFib is when the atria beat or quiver in a chaotic manner instead of their normal synchronized rhythm.
AFib and atrial flutter have a similar mechanism. Although atrial flub is associated with a lower risk of stroke than AFib it’s very common to have both AFib and atrial flub. Atrial flutter is treated in the same way as AFib.
Sick sinus syndrome
A variety of arrhythmias that originate in the SA node are known as sick sinus syndrome. Among them are tachycardia-bradycardia syndrome, in which the heart alternates between beating too quickly and then too slowly.
A 2020 study found that patients suffering from sinus node disease (sick sinus syndrome), have a higher chance of experiencing stroke than patients suffering from other cardiac conditions.
Bradycardia refers to a slower than normal heart rate. Bradycardia can be benign in some cases. In others, it can cause fainting from insufficient blood flow to brain. Sudden cardiac arrest, which can be fatal in severe cases, is a concern.
Junctional bradycardia refers to a slow rhythm of the heart that originates at the AV node. A 2016 study showed that certain individuals may be at risk for stroke from junctional bradycardia.
There are also other types of arrhythmias:
- ventricular tachycardia
- ventricular fibrillation
- supraventricular tachycardia
- Atrial Flutter