Adult heart and pericardium

Question 1

Pericardial effusion, if acute, called:

Answer 1

Cardiac Tamponade

Defined by the pathognomonic* trio of symptoms called Beck’s Triad:

1. muffled heart sounds due to blood insulation, weakened beat
2. Jugular distension due to reduced venous return
3. Low arterial pressure due to reduced stroke volume/cardiac output
   * The symptoms are so characteristic of the pathology that they are essentially diagnostic

Question 2

Pericardial effusion

Answer 2

A slow accumulation of fluid into the pericardial cavity

Question 3

mitral valve prolapse

Answer 3

a condition in which the valve everts into the left atrium and thus fails to close properly when the left ventricle contracts. It may produce chest pain, shortness of breath, palpitations and cardiac arrhythmia

Question 4

Post-MI: 3 physiologic compensatory mechanisms

Answer 4

1. Coronary Artery collateralization (new capillary growth)
2. Reverse blood flow occurs in Thebesian veins under conditions of low perfusion pressure <–(I feel like he might ask a question about this)
3. Endogenous Bypass via vasa vasorum

(remember the vasa vasorum are the small vessels that supply larger vessels with blood)

Question 5

Coronary Artery Bypass Graft (CABG)

-> Graft Options

Answer 5

1. Great saphenous vein (must reverse direction because of valves)
2. Radial artery (where pulse is taken on wrist)
3. Internal thoracic artery
   * Arteries last longer in grafts than veins

Question 6

What happens to the cardiac plexus post heart transplantation?

Answer 6

The cardiac plexus is an aggregation of many small nerves. They are so numerous/tiny that the plexus cannot be reconnected after a heart transplant.

Because of this transplanted hearts have no external (ie sympathetic/parasympathetic) input.

Circulating catecholamines from adrenal will increase HR during exercise but this is delayed, as is the time it takes for the heart to slow back down to resting rhythmn post-exercise

Question 7

What is the Heart’s Achilles Heel?

Answer 7

The Purkinje fibers are located in a location which is very vulnerable to ischemia: directly below the inner (endocardial) surface.

This region is the last to be supplied by blood and the first to become ischemic.