The sinoatrial (SA) node is the natural pacemaker of the heart. It generates electrical impulses that cause the heart’s chambers to contract, setting the heart rate. The SA node typically generates 60 ...

Adam Taylor is affiliated with the Anatomical Society. Your heart beats around 60 times a minute, delivering nutrients and removing waste from every cell in your body. It has been doing this since you ...

Sick sinus syndrome (SSS) is a heart rhythm problem that affects your heart's natural pacemaker. You may develop symptoms of SSS like dizziness, fainting, and fatigue. Treatment may include lifestyle ...

Having an accelerated junctional rhythm occurs when the atrioventricular node in your heart beats too quickly. It happens as a result of damage to your heart’s primary natural pacemaker. There’s no ...

Dear Doctor: What is sick sinus syndrome? Is a pacemaker the only cure? My grandmother was just diagnosed with it but, at age 94, has refused to even consider a pacemaker. Dear Reader: Sick sinus ...

The heart is a muscular organ composed of four chambers: two upper chambers called atria and two lower chambers called ventricles. These four chambers pump blood through the body in a rhythmic pattern ...

Genetically-engineered heart cells may be able to replace the electronic pacemakers that hundreds of thousands of cardiac patients have transplanted each year, suggests a new study in guinea-pigs. In ...

An arrhythmia (also termed cardiac dysrhythmia) is described as an irregular heartbeat caused by aberrant electrical activity in the heart. There are multiple categories of arrhythmia, each of which ...