Heart

The heart is a muscular organ about the size of a fist, located just behind and slightly left of the breastbone. The heart pumps blood through the network of arteries and veins called the cardiovascular system.
The heart has four chambers:
1. The right atrium receives blood from the veins and pumps it to the right ventricle.
2. The right ventricle receives blood from the right atrium and pumps it to the lungs, where it is loaded with oxygen.
3. The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle.
4. The left ventricle (the strongest chamber) pumps oxygen-rich blood to the rest of the body. The left ventricle’s vigorous contractions create our blood pressure.

Wolff-Parkinson-White syndrome

Wolff-Parkinson-White syndrome, or WPW syndrome, is the presence of an extra, abnormal electrical pathway in the heart that leads to periods of a very fast heartbeat (tachycardia).
The extra electrical pathway of Wolff-Parkinson-White syndrome is present at birth. People of all ages, including infants, can experience the symptoms related to Wolff-Parkinson-White syndrome. Episodes of a fast heartbeat often first occur when people are in their teens or early 20s.