Cardiac tamponade


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Cardiac tamponade

Cardiovascular system

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Pericardial disorders

Pericarditis and pericardial effusion

Cardiac tamponade

Dressler syndrome

Cardiac tumors

Cardiac tumors

Cardiovascular system pathology review

Acyanotic congenital heart defects: Pathology review

Cyanotic congenital heart defects: Pathology review

Atherosclerosis and arteriosclerosis: Pathology review

Coronary artery disease: Pathology review

Peripheral artery disease: Pathology review

Valvular heart disease: Pathology review

Cardiomyopathies: Pathology review

Heart failure: Pathology review

Supraventricular arrhythmias: Pathology review

Ventricular arrhythmias: Pathology review

Heart blocks: Pathology review

Aortic dissections and aneurysms: Pathology review

Pericardial disease: Pathology review

Endocarditis: Pathology review

Hypertension: Pathology review

Shock: Pathology review

Vasculitis: Pathology review

Cardiac and vascular tumors: Pathology review

Dyslipidemias: Pathology review


Cardiac tamponade


0 / 10 complete

USMLE® Step 1 questions

0 / 4 complete

High Yield Notes

8 pages


Cardiac tamponade

of complete


USMLE® Step 1 style questions USMLE

of complete

A 35-year-old woman is brought to the emergency department following a motor vehicle accident. At the scene, she was in severe pain and pointed to her chest. Soon after arrival, the patient loses consciousness. Temperature is 37.0°C (98.6°F), pulse is 120/min, respirations are 22/min, and blood pressure is 75/55 mmHg. On physical examination, there are multiple lacerations over the torso and face. Significant bruising is noted over the chest. Neck veins are distended. On chest auscultation, lung fields are clear bilaterally and heart sounds are weak. Echocardiography is obtained and shows a large pericardial effusion. Which of the following sets of hemodynamic parameters are most likely to be seen in this patient?  

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Beck triad (cardiac tamponade) p. 481, 717

Cardiac tamponade p. 481

aortic dissection and p. 309

jugular venous pulse in p. 294

MI p. 310, 316

pulse pressure in p. 292

shock p. 319

Electrocardiograms (ECGs) p. 312

cardiac tamponade on p. 481

Heart sounds p. 294

cardiac tamponade p. 481, 717


cardiac tamponade p. 481

Pericardial tamponade

labs/findings p. 720


Content Reviewers

Rishi Desai, MD, MPH


Marisa Pedron

Tanner Marshall, MS

The name “cardiac tamponade” can be broken down: “tamponade” refers to pressure which obstructs blood flow, and “cardiac” refers to the heart. So in cardiac tamponade there’s a buildup of fluid in the pericardium, and that fluid puts pressure on the outside of the heart. As a result, the heart is unable to pump normally and blood flow is obstructed.

Normally, the heart sits inside a two-layered pouch or cavity called the pericardium. The outer layer is the fibrous pericardium, which helps keep the heart in place within the chest cavity. The inner layer of the pouch is the serous pericardium, which includes the pericardial cavity; it’s filled with a small amount of fluid that lets the heart slip around as it beats. The cells of the serous pericardium secrete and reabsorb the fluid, so usually there’s no more than 50 milliliters of fluid in the pericardial cavity at any time—that’s about as much as would fit into a shot glass.

A pericardial effusion happens when this normally protective fluid begins to pool in the pericardial space. It can develop into cardiac tamponade depending on how much fluid there is and how quickly that fluid accumulates.

A rapid accumulation of fluid can occur as a result of trauma to the chest. For example, a stab wound can puncture a blood vessel and fill the pericardium with blood. Even blunt trauma like a steering wheel getting pushed into your chest during a car crash can lead to tamponade, because the force of the impact causes the rupture of lots of small blood vessels. Cardiac tamponade can also happen a few days after a myocardial infarction, because the weak, infarcted ventricular wall ruptures when it’s exposed to the high ventricular pressures. It’s a bit like how jeans might tear at the spot where the denim is worn away and already quite weak. A rare cause is heart surgery, where, once again, a weakened muscle can rupture and cause cardiac tamponade days after the operation. Yet another cause is aortic dissection, which is when blood pools in the actual wall of the aorta. If the aortic dissection ruptures through the wall of the aorta and through the fibrous pericardium, blood can spill right into the pericardial cavity, leading to cardiac tamponade. In these situations, even a small volume—as little as 150 ml!—can lead to tamponade, because the pericardium doesn’t have time to stretch and accommodate it.


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