CVS anatomy- anatomy of chest pain

Question 1

How does the autonomic innervation of the heart reach the heart?

Answer 1

Via the cardiac plexus

Question 2

Where do visceral afferent fibres from the heart go?

Answer 2

Pain fibres travel to the spinal cord alongside sympathetic fibres
Visceral reflex afferents (e.g. from baroreceptors) travel mainly in the vagus nerve (some in CN IX)

Question 3

What are the different cervical sympathetic ganglia?

Answer 3

Superior, middle and inferior

Question 4

At which level of the spinal cord do the sympathetic fibres leave?

Answer 4

T1- L2/3 (thoracolumbar)

Question 5

What are the sympathetic nerves to the heart and lungs transmitted in?

Answer 5

The cardiopulmonary splanchnic nerves

Question 6

Is sympathetic innervation of the heart unilateral or bilateral?

Answer 6

Bilateral (but predominantly left sided)

Question 7

How do sympathetic signals from the CNS reach the heart?

Answer 7

They travel inferiorly within spinal cord tracts
They exit the spinal cord in one of the T1- 5 spinal nerves (thoracolumbar nerves), then they travel superiorly in the sympathetic chain and synapse at another ganglion.
The post synaptic fibres are transmitted to the heart in the cardiopulmonary splanchnic nerves (post synaptic fibres from the cervical and upper thoracic sympathetic chains)

Question 8

What does the cardiac plexus contain?

Answer 8

Sympathetic nerves
Parasympathetic nerves
Visceral afferents

Question 9

How do parasympathetic signals reach the heart?

Answer 9

In cranial nerve X (the vagus nerve)

It carries presynaptic fibres which synapse in the walls of the heart.

Question 10

Which nerve fibres to/from the heart travel in the cardiopulmonary splanchnic nerves?

Answer 10

Post synaptic cardiac sympathetic efferent

Visceral afferent

Question 11

Where do action potentials from body sensation arrive in the brain?
What are these signals called?

Answer 11

The postcenetral gyrus of the parietal lobe

Somatosensory

Question 12

Where do action potentials that cause a conscious skeletal muscle contraction originate from in the brain?
What are these signals called?

Answer 12

The precentral gyrus of the frontal lobe

Somatomotor

Question 13

Describe how the pain in shingles (herpes zoster) comes about

Answer 13

Reactivation of dormant virus in posterior root ganglion
• Pain can be felt anywhere in that dermatome
• Pain precedes blisters
• Patient with shingles developing in T4/T5 dermatome may present with central chest pain

Question 14

Where does the left phrenic nerve pass in relation to the lung hilum?

Answer 14

Anterior to it

Question 15

What is the remnant of the ductus arteriosus connecting the pulmonary trunk to the aorta?

Answer 15

Ligamentum artereosum

Question 16

What is radiating pain?

Answer 16

The PAIN is felt BOTH at the actual site of the pathology AND 
ALSO radiating (spreading away from there)

Question 17

Where does pain radiate to from a somatic structure?

Answer 17

Along the affected dermatome

Question 18

Where does pain from the heart radiate to?

Answer 18

the dermatomes supplied by the spinal cord levels at which the cardiac visceral afferents enter the sympathetic chain/spinal cord i.e. BILATERALLY to cervical and upper thoracic dermatomes.

Question 19

Describe visceral radiating pain

Answer 19

it is “visceral” in nature i.e. although it is felt in a dermatomal pattern, it is still dull, aching and poorly localised in nature

Question 20

What is referred pain?

Answer 20

the sensation of pain is “felt” ONLY at a site remote from the actual area of injury or disease
• Otherwise very similar principle to radiating pain

Question 21

What causes referred pain?

Answer 21

Due to afferent (sensory) fibres from soma and afferent
(sensory) fibres from viscera (visceral afferents) entering
the spinal cord at the same levels
• The brain chooses to believe that the pain signals coming from the organ, are actually coming from the
soma

Question 22

Describe cardiac referred pain

Answer 22

in CARDIAC referred pain the brain chooses to believethe pain signals are coming from the upper limbs (especially the left upper limb) or from the back, neck (or jaw).

Question 23

What is a right dominant pattern of coronary artery supply?

Answer 23

When the posterior interventricular artery is a branch of the right coronary artery

Question 24

What is left dominant pattern of coronary artery supply?

Answer 24

When the posterior interventricular artery is a branch of the left coronary artery

Question 25

What is an extreme right dominant pattern of coronary arterial supply?

Answer 25

When all of the branches except the LAD come from the right coronary artery.

Question 26

What are common sites of narrowing/occlusion due to atherosclerosis in the coronary arteries?

Answer 26

1. The anterior interventricular branch of the LCA
2. The right coronary artery
3. The circumflex branch of the LCA
4. The left main stem coronary artery

Question 27

Where are grafts anastamosed in coronary artery bypass grafting?

Answer 27

They are anastamosed proximally to the ascending aorta and to the coronary artery distal to the narrowing

Question 28

What is the blood supply to the SA node in 60% of patients?

Answer 28

A branch from the right coronary artery near its origin

Question 29

What is the blood supply to the AV node in 80% of patients?

Answer 29

A branch from the right coronary artery near the origin of the posterior interventricular artery.

Question 30

What is the arterial blood supply of the interventricular septum?

Answer 30

The LAD and the posterior interventricular artery

Question 31

What can result when parts of the conducting system of the heart are affected by ischaemia of the coronary arteries?

Answer 31

Arrhythmia

Question 32

What is the result of AV node damage?

Answer 32

Complete heart block

Question 33

What is the result of bundle branch damage?

Answer 33

Bundle branch block