00:00 / 00:00
Bundle branch block
Pulseless electrical activity
Atrioventricular nodal reentrant tachycardia (AVNRT)
Premature atrial contraction
Long QT syndrome and Torsade de pointes
Premature ventricular contraction
Coronary steal syndrome
Coarctation of the aorta
Polycystic kidney disease
Renal artery stenosis
Peripheral artery disease
Subclavian steal syndrome
Superior mesenteric artery syndrome
Human herpesvirus 8 (Kaposi sarcoma)
Chronic venous insufficiency
Deep vein thrombosis
Acyanotic congenital heart defects: Pathology review
Aortic dissections and aneurysms: Pathology review
Atherosclerosis and arteriosclerosis: Pathology review
Cardiac and vascular tumors: Pathology review
Cardiomyopathies: Pathology review
Coronary artery disease: Pathology review
Cyanotic congenital heart defects: Pathology review
Dyslipidemias: Pathology review
Endocarditis: Pathology review
Heart blocks: Pathology review
Heart failure: Pathology review
Hypertension: Pathology review
Pericardial disease: Pathology review
Peripheral artery disease: Pathology review
Shock: Pathology review
Supraventricular arrhythmias: Pathology review
Valvular heart disease: Pathology review
Vasculitis: Pathology review
Ventricular arrhythmias: Pathology review
0 / 10 complete
0 / 4 complete
aortic dissection and p. 309
jugular venous pulse in p. 294
MI p. 310, 316
pulse pressure in p. 292
shock p. 319
cardiac tamponade on p. 481
cardiac tamponade p. 481, 717
cardiac tamponade p. 481
labs/findings p. 720
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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