Cardiac Tamponade

Question 1

What is cardiac tamponade?

Answer 1

Cardiac tamponade = pericardial effusion + low blood pressure.

It is characterized by the accumulation of fluid in the pericardial space, leading to impaired heart function.

Question 2

What determines the presence of cardiac tamponade?

Answer 2

The rate of accumulation of the fluid, not the volume of the fluid.

i.e., a stab wound or
post-MI LV free-wall rupture resulting in fast blood accumulation, even if
smaller volume, might cause tamponade, but cancer resulting in slow, but large,
accumulation might not cause tamponade

Question 3

What are the components of Beck triad associated with cardiac tamponade?

Answer 3

1) Hypotension, 2) JVD, 3) Muffled/distant heart sounds.

Beck triad is crucial for identifying tamponade in clinical scenarios.

Question 4

What is pulsus paradoxus?

Answer 4

A drop in systolic BP >10 mm Hg with inspiration.

It is classically associated with cardiac tamponade.

Question 5

How does ECG appear in cardiac tamponade?

Answer 5

ECG will show electrical alternans and low-voltage QRS complexes.

Electrical alternans refers to the oscillation of the heights of the QRS complexes.

Question 6

What should be the first step in diagnosis if listed for cardiac tamponade?

Answer 6

Choose ECG as the first step.

If ECG is not listed, choose echocardiography to confirm fluid over the heart.

Question 7

What is the next best step in management for cardiac tamponade when the vignette is obvious?

Answer 7

Choose pericardiocentesis or pericardial window.

USMLE will list one or the other, not both.

Question 8

True or False: The volume of fluid in the pericardial space is the primary factor determining cardiac tamponade.

Answer 8

False.

The rate of fluid accumulation is the critical factor.

Question 9

What is a common finding in cardiac tamponade ECG readings?

Answer 9

electrical alternans and low-voltage QRS complexes

Question 10

What is the change in PCWP, right atrial pressure, SVR, and cardiac index during cardiac tamponade?

Answer 10

PCWP (reflection of left atrial pressure) - increased
Right atrial pressure (reflection central venous pressure) - increased
SVR - increased
cardiac index (cardiac output per body surface area) - decreased