216 Cardiovascular Emergencies

Question 1

List the vasculature that branches off the aorta from the base of the aorta, through the ascending aorta and the aortic arch

Answer 1

-R coronary
-L coronary
-brachiocephalic trunk (splits into: R subclavian & R common carotid)
-L common carotid
- L subclavian

Question 2

List the vasculature that branches off the aorta in the descending thoracic aorta

Answer 2

-bronchial
-mediastinal
-esophageal
-pericardial
-superior phrenic
-intercostal and subcostal

Question 3

List the vasculature that branches off the aorta in the abdominal aorta

Answer 3

-inferior phrenic
-celiac (splits into: L gastric, splenic, common hepatic)
-superior mesenteric
-middle suprarenal
-renal
-gonadal (testicular or ovarian)
-inferior mesenteric
-median sacral
-lumbar

Question 4

define aortic dissection

Answer 4

a separation of the layers of the wall of the aorta due to an intimal tear

Question 5

What do the bronchial arteries supply?

Answer 5

bronchi, bronchioles, lung tissue

Question 6

What do the pericardial arteries supply?

Answer 6

pericardium

Question 7

What do the esophageal arteries supply?

Answer 7

esophagus

Question 8

What do the mediastinal arteries supply?

Answer 8

mediastinal structures

Question 9

what do the intercostal arteries supply?

Answer 9

vertebrae, spinal cord, back muscles, body wall, skin

Question 10

What do the superior phrenic arteries supply?

Answer 10

vertebrae, spinal cord, back muscles, body wall, skin, diaphragm

Question 11

What do the inferior phrenic arteries supply?

Answer 11

diaphragm, inferior portion of esophagus

Question 12

What does the left gastric artery supply?

Answer 12

stomach, adjacent portion of esophagus

Question 13

What does the splenic artery supply?

Answer 13

spleen, stomach, pancreas

Question 14

What does the common hepatic artery supply?

Answer 14

Liver, stomach, gallbladder, duodenum, pancreas

Question 15

What does the superior mesenteric artery supply?

Answer 15

pancreas, small intestine, appendix, first 2/3 of large intestine

Question 16

What does the inferior mesenteric artery supply?

Answer 16

last 1/3 of the large intestine

Question 17

What do the suprarenal arteries supply?

Answer 17

Adrenal glands

Question 18

What do the renal arteries supply?

Answer 18

Kidneys

Question 19

What do the gonadal arteries supply?

Answer 19

Testes or ovaries

Question 20

What do the lumbar arteries supply?

Answer 20

Vertebrae, spinal cord, abdominal wall, lumbar region

Question 21

What is a Stanford Type A dissection? Which De Bakey classifications fall into it?

Answer 21

Aortic dissection involving the ascending aorta. May progress to involve aortic arch and thoracoabdominal. De Bakey Type 1 and Type 2 fall into this category. These are always surgical emergencies

Question 22

What is a Stanford Type B dissection? Which De Bakey classifications fall into it?

Answer 22

Aortic dissection involving the descending thoracic or thoracoabdominal aorta distal to the L subclavian artery without involvement of the ascending aorta. De Bakey Type 3a and Type 3b fall into this category. Likely can be managed medically.

Question 23

define De Bakey Type 1 dissection

Answer 23

Involves ascending aorta, aortic arch, descending thoracic aorta and may involve the abdominal aorta

Question 24

define De Bakey Type 2 dissection

Answer 24

Involves the ascending aorta only

Question 25

define De Bakey Type 3a dissection

Answer 25

Involves the thoracic aorta distal to the L subclavian and proximal to the celiac artery

Question 26

define De Bakey Type 3b dissection

Answer 26

Involves the thoracic and abdominal aorta distal to the L subclavian and distal to the celiac artery

Question 27

Describe the pathophysiology of an aortic dissection

Answer 27

An initial tear occurs in the intima of the aorta. Blood at high pressure passes through the tear and separates the intima from thee media and/or adventitia, creating a false lumen which can spread proximally or distally and whatever arteries that branch off the aorta that are affected will often cause associated symptoms.

Question 28

What is the difference between an uncomplicated and complicated Type B aortic dissection?

Answer 28

Considered complicated if there is evidence of poor perfusion, rapid expansion, impending or frank rupture, uncontrolled pain or refractory hypertension (refractory to 3 or more antihypertensives at max dose)

Question 29

What are risk factors for aortic dissection?

Answer 29

HTN, atherosclerosis, prior cardiac Sx, aortic aneurysm, connective tissue disorder (Marfan's, Loeys-Dietz syndromes), bicuspid aortic valve, prior aortic Sx.

Question 30

What are the S/S of aortic dissection?

Answer 30

- sudden onset severe pain to the anterior chest, may radiate to neck, back, abd and may migrate. - comparison of bilat carotid, subclavian or femoral pulses shows different strengths - aortic valve regurg (diastolic murmur) - signs of cardiac tamponade - signs of ischemic stroke, spinal cord ischemia, ischemic neuropathy, hypoxic encephalopathy - ECG: type A can cause coronary ischemia (RCA most common) - CXR: widened mediastinum, unexplained pleural effusion

Question 31

Causes of R axis deviation on ECG

Answer 31

- RVH - Acute RV strain (i.e. PE) - Lateral STEMI - Chronic lung disease (COPD) - HyperK - Sodium-channel blockade (TCA OD) - WPW - Dextrocardia - Ventricular ectopy - L posterior fascicular block (diagnosis of exclusion) - Normal pediatric ECG

Question 32

Causes of L axis deviation on ECG

Answer 32

- LVH - LBBB - Inferior MI - Ventricular pacing/ectopy - WPW - L anterior fascicular block (diagnosis of exclusion)

Question 33

Causes of extreme axis deviation on ECG

Answer 33

- ventricular rhythms - HyperK - severe RVH

Question 34

List the components of the cardiac electrical conduction system

Answer 34

- SA node - AV node - Bundle of HIS - L and R bundle branches - L divides into anterior, septal and posterior fascicles - Purkinje fibres

Question 35

What properties of vasculature will differentiate arteries vs veins on ultrasound?

Answer 35

- veins are compressible - arteries are pulsatile - arteries will have a thicker wall due to the musculature

Question 36

Describe the cardiac action potential

Answer 36

-Phase 0: Rapid depolarization. Cell is brought to threshold, Na+ channels open, Na+ rapidly enters the cell and the cell becomes positively charged around +45mV. Ca2+ channels also open during depolarization but the Ca2+ moves into the cell much slower than the Na+ -Phase 1: Initial repolarization. K+ channels open and K+ moves out of the cell. -Phase 2: Plateau. Ca2+ enters the cell and K+ leaves the cell. -Phase 3: Repolarization. Potassium moves out of the cell and the cell returns to -90mV. -Phase 4: Na+/K+ pump maintains resting membrane potential at -90mV

Question 37

Define preload

Answer 37

the particular stretch of LV myocardial fibers at end-diastole, which is determined by the resting force, myocardial compliance and degree of filling from the LA.

Question 38

Define afterload

Answer 38

The impedance during ejection. (or) The wall stress in the ventricle during contraction. Wall stress is the tension in any one myocyte during contraction.