AIMING FOR THE HEART

                          THE HEART
                                   (Wikimedia Commons - Gray's Anatomy)
When the chest of the assaillant is an intended target for stabbing, consider the following intrathoracic anatomy.

The major organs inside the chest are the heart, right and left lungs, lower portion of the trachea with its bifurcation into the right and left bronchi,

the esophagus or food tube connecting the throat to the stomach and

the thoracic vertebrae which contain and protect the thoracic portion of the spinal cord within the vertebral canal.

The entire chest cavity is supported by a bony cage called the rib cage or thoracic cage.

It is composed of the sternum or breast bone in front and the thoracic vertebrae in the back, with the ribs extending in a semi-circular fashion between the sternum and the thoracic vertebrae.

The heart is primarily situated in the middle of the chest behind the breast bone.

It does extend into the left side of the chest as far out as the left nipple.

It is structurally divided into two upper chambers called the right atrium and left atrium and two larger lower chambers called the right ventricle and left ventricle.

Deoxygenated venous blood from the entire body enters the heart at the back of the right atrium through two major veins called the superior vena cava and the inferior vena cava.

The superior vena cava receives deoxygenated venous blood from the head, neck and arms while the inferior vena cava receives deoxygenated venous blood from the chest, abdomen and legs.

After deoxygenated venous blood empties into the right atrium through the superior vena cava and the inferior vena cava, it is propelled into the right ventricle through a valve called the tricuspid valve.

The right ventricle then contracts and sends this unoxygenated blood through the pulmonary valve into another set of blood vessel called the right and left pulmonary arteries, which carry deoxygenated blood to both lungs.

Venous blood is thoroughly reoxygenated within the two lungs and then returned to the left upper chamber or left atrium through the right anf left pulmonary veins.

From the left atrium, oxygenated blood is propelled through the mitral valve into the left ventricle, which in turn contracts and sends oxygenated blood through the aortic valve into the largest and most important artery of the body called the aorta in order to nourish the entire body.

This anatomic explanation of the heart with all the medical terminology may seem confusing.

All you need to remember is that the heart is situated primarily in the midline with extension into about half of the left chest.

Be also aware that there are a number of large blood vessels connected to the heart.

These are the superior vena cava, the inferior vena cava, the right and left pulmonary arteries and veins and the aorta.

If any chamber of the heart is stabbed and lacerated, death is usually instantaneous.

If the blade of the knife misses the heart but lacerates one of the major blood vessels connected to the heart, the result is just as catastrophic and potentially fatal.

Since the entire chest cavity is protected by the rib cage, two different approaches are necessary for penetration of the heart.

In the direct approach, stabbing is made between two lower ribs on the left side of the breast bone or sternum.

In this maneuver, the lower chambers or ventricles will be perforated and lacerated, leading to cessation of heart beat.

Remember to wiggle the knife handle after penetration is complete in order to maximize cardiac injury.

Another way to reach and penetrate the heart is to insert the blade at a point just below the breast bone but aim the tip of the knife toward the left at a 45 degrees angle.

Again the ventricle or lower chamber will be perforated, blood will leak into the membranous envelop of the heart called the pericardium.

Accumulation of blood underneath the pericardium will compress the heart itself, leading to cardiac tamponade and inability of the heart to contract and expand, which is rapidly fatal.

If you stab your attacker between two higher ribs near the left upper portion of the sternum or breast bone, you will miss the heart but instead lacerate major blood vessels such as the superior vena cava, pulmonary arteries, pulmonary veins and the aorta.

The result can be equally fatal.

                                                     THE HEART
                                         (Wikimedia Commons -  Author Ties van Brussel)