ANS Pathophys

Question 1

Which agents will affect a transplanted heart? Which will not?

Answer 1

Epi, isoproterenol, glucagon
(directly stimulate SA node)

will not work: indirect agents
neo, glyco, atropine

Question 2

Why is a transplanted heart not responsive to indirect stimulation of the SA node/indirect agents?

neo, glyco, atropine

Answer 2

heart rate depends on the SA node’s intrinsic rate

no influence from ANS (vagus nerve or cardiac accelerator fibers)

Question 3

T/F:
Neo can cause bradycardia in a transplanted heart.

Answer 3

False
only happens in someone with an intact SNS

Question 4

Expected resting heart rate of a transplanted heart

Answer 4

100-120

(relies on SA node’s intrinsic rate)

Question 5

A transplanted heart will eventually respond to circulating catecholamines. How?

Answer 5

A & B adrenergic receptors are intact

Question 6

Paragangliomas (formerly called glomangiomas)

Answer 6

• neuroendocrine tumors from neural crest cells
• origin similar to pheochromocytoma but also in extra-adrenal locations
• surrounding the aorta, in lung, near the carotid artery, glossopharyngeal nerve, jugular vein, and middle ear

Question 7

Multiple system atrophy (MSA) with autonomic dysfunction predominating

“Shy-Drager syndrome”

Answer 7

degeneration of:

• locus coeruleus,
• intermediolateral (IML) column of the spinal cord,
• peripheral ANS neurons

manifests as orthostatic hypoTN

Question 8

ANS dysfunction in patients with MSA. How do they respond to GA?

Answer 8

compensation for vasodilation and tachycardia from voltailes may be impaired = exaggerated hypoTN

Question 9

transplanted hearts have a fixed HR, so that means the CO is dependent on…

Answer 9

preload

sensitive to hypovolemia!

CO = HR x SV

Question 10

T/F:
transplanted hearts are sensitive to epi

Answer 10

true

Question 11

What happens if you give a transplant heart verapamil?

Answer 11

AV block

Question 12

the transplanted heart will not show reflex tachycardia from these 2 agents

Answer 12

• hydralazine
• nifedipine

Question 13

T/F:
Transplanted hearts are resistant to BBs.

Answer 13

False
more sensitive

Question 14

EKG changes with transplanted heart

Answer 14

two p waves

(intrinsic SA node & transplanted heart)

does not affect cardiac function

Question 15

What cardiac reflex remains intact with transplanted hearts?

Answer 15

bainbridge

the SA node stretch will directly increase its firing rate

Question 16

these 2 maneuvers do not affect a transplanted heart rate

Answer 16

valsava

carotid sinus massage

Question 17

most common cuase of cardiac denervation in non-cardiac surgery patients

Answer 17

diabetic ANS dysfxn

Question 18

giving cholinesterase inhibitors to a transplanted heart

Answer 18

no bradycardia
but
will activate PNS elsewhere so give with anticholinergic

Question 19

derived from neural crest cells

Answer 19

autonomic ganglia
and
chromaffin cells
of the adrenal medulla

Question 20

T/F:
Paraganglioma tumor size determines the signs and symptoms.

Answer 20

false
location

Question 21

Paragangliomas rarely secrete vasoactive substances, but when they do, ___ secretion is the most common (thus mimicking a pheochromocytoma).

Answer 21

norepinephrine (hypertension)

Question 22

paragangliomas

Serotonin or kallikrein secretion can cause carcinoid-like symptoms such as …

Answer 22

bronchoconstriction, diarrhea, headache, flushing, and hypertension.

Histamine or bradykinin release can cause bronchoconstriction and hypotension.

Question 23

can be used to treat carcinoid-like syndrome

Answer 23

Octreotide

bronchoconstriction, diarrhea, headache, flushing, and hypertension.

Question 24

paragangliomas

Anesthetic concern

Answer 24

• Cranial nerve paragangliomas (glossopharyngeal, vagus, and hypoglossal) can impair swallowing, aspiration, airway obstruction.
• if in the IJ, surgical dissection risks air embolism

Question 25

Multiple system atrophy (MSA)

Answer 25

CNS degeneration and dysfunction

(basal ganglia, cerebellar cortex, locus coeruleus, pyramidal tracts, and vagal motor nuclei)

Question 26

Signs and symptoms of MSA with autonomic dysfunction include:

Answer 26

• Urinary retention, Bowel dysfunction
• Impotence
• Postural hypoTN (syncope!)
• Pupillary reflexes may be sluggish
• control of breathing may be abnormal
• Failure of baroreceptor reflexes

Question 27

Why do MSA patients die?

Answer 27

cerebral ischemia a/w prolonged hypoTN

lifespan ~8Y

Question 28

Anesthetic Considerations for the patient with MSA

Answer 28

• beware exaggerated hypoTN
• Bradycardia best treated with atropine or glycopyrrolate
• may be too light (less apparent bc less responsive SNS)
• IV ketamine could potentially accentuate blood pressure increases
• continue antiparkinson meds