Cardiac tamponade, also known as pericardiac tamponade, is a medical emergency that requires immediate intervention. It is characterized by pericardiac effusion, which leads to elevated pressure in the pericardium, compressing the heart and preventing it from filling with blood correctly during the diastolic phase. Without treatment, this will lead to diminished cardiac output: as the pericardium fills with fluids, the heart pumps less and less blood out, causing cardiogenic shock and, in many cases, death.
For this reason, it is important to be able to recognize the signs and symptoms of cardiac tamponade before it is too late. The most common test for its diagnosis is known as Beck’s Triad, named after the American surgeon Claude Beck, who developed the concept. It consists of examining the patient to find three key anomalies: jugular venous dilation, low pulse pressure, and diminished (or even absent) heart sounds upon examining the heart.
In a healthy person, the cardiovascular system functions in this way: non-oxygenated blood circulates through the veins (the major ones being the superior and inferior vena cava) to the heart. It enters into the right atrium where it is pumped through thee tricuspid valve and arrives at the right ventricle. It then passes through the pulmonary valve to the pulmonary artery, arriving at the lungs to obtain oxygen. It returns to the heart through the pulmonary vein and enters in the left atrium. It passes through the mitral valve (also known as the bicuspid valve) and ends up in the left ventricle. Finally, it is pumped through the aortic valve, circulating at a rapid speed to provide oxygenated blood to the entire body. This cycle repeats, starting again in the right atrium.
In patients with heart disease, such as cardiac insufficiency, there is a problem with the heart’s ability to circulate blood sufficiently, and for that reason, the entire cardiovascular system slows down. This detriment causes the jugular veins to dilate, since the blood is not able to pass into the right atrium due to the resistance caused by the heart’s weakness.
In the case of cardiac tamponade, the fluids inside the pericardium compress the heart and this generates the same problem with bloodflow through the body, and it is for this reason that jugular venous distention can be considered a sign of cardiac tamponade.
Pulse pressure is calculated by subtracting the diastolic pressure from the systolic pressure. For example, if a person has a blood pressure of 120/80 mmHg, his or her pulse pressure would be forty (which is a normal and healthy blood pressure). The descent of this number means that the systolic and diastolic pressures are approaching each other, meaning that cardiac output (the amount of blood that the heart pumps in one beat) has diminished. Low pulse pressure, then, can also be a good indicator of cardiac tamponade.