The human heart, a little larger than a fist, incessantly pumps blood through the circulatory system. On an average, the heart beats 100,000 times and pumps about 2,000 gallons of blood each day.
Heart Rhythm Disorders (HRD) or Arrhythmia, is a condition in which the heart's rhythm does not function normally.
Skipping a beat occasionally is no reason to worry but if it happens too often, it is something that needs medical attention immediately.
During the normal heart rhythm (or the sinus rhythm) the sinus node functions as a cardiac electric impulse generator. When a Heart Rhythm Disorder occurs, the sinus node fails, causing the heart to beat either too slow or too fast. When the heart fails to beat properly, it does not pump blood effectively. This leads to the failure of the lungs, the brain and all other organs.
When the heart beats too slowly, (also known as bradycardia) and a person shows symptoms such as dizziness, fainting, etc., then a pacemaker is usually needed for treatment.
When the heart beats too fast, (also known as tachycardia) the treatment varies depending on the symptoms and the cause of palpitations.
The heart has four chambers - Two upper chambers called atria, and two lower chambers called ventricles. The heart also has four valves - Tricuspid valve, Pulmonary valve, Mitral valve, and the Aortic valve.
The blood flows only when there's a difference in pressure across the valves. Under normal conditions, these valves open and close to ensure that the blood flow is unidirectional during the contraction of the heart (heart beat).
The heart pumps blood to the lungs and other body organs through a sequence of systematized contractions of the four chambers.
The heart beat or contraction commences when an electrical impulse from the sinoatrial node moves through it. This node is generally referred to as the pacemaker node or the heart's "natural pacemaker" because it initiates impulses for the heart to beat. In a relaxed and fit heart, the pacemaker node generates 60-100 electrical impulses per minute.
The electrical impulses begin in the right atrium and spread all over the atria to the Atrio-Ventricular (AV) node. From the AV node, the electrical signals travel down to all parts of the ventricles through a group of specialized conducting pathways called the His-Purkinje system.
This precise course must be followed for the heart to pump accurately. As long as the electrical impulse is conducted routinely, the heart pumps and beats at an even pace.