CARDIO

Question 1

Digoxin MOA

Answer 1

• slows ventricular rate during afib by ENHANCING VAGAL TONE
  
  • leads to inhibition of AV nodal conduction
• positive inotropic effect via INHIBITION of the Na+/K+-ATPase pump=INC intracellular calcium and greater contractility

Question 2

WPW CP

Answer 2

• palpitations
• no CP or dyspnea
• AV conduction tract bypasses the AV node (accessory pathway bypasses AV node and directly connect atria and ventricles)…triad:
  
  • short PR inteval
  • widening of QRS interval
  • slurred and broad upstroke of QRS complex=DELTA WAVE

Question 3

mechanicla complications of acute MI

Answer 3

• RV failure (acute)
  
  • hypoTN, clear lungs, Kussmaul sign
• papillary muscle rupture (3-5days)
  
  • acute, severe pulm edema
  • severe/acute onset MR with flail leaflet
• interventricular septum rupture defect (3-5d)
  
  • hew holosystolic murmur
  • stepped-up oxygen level between right atrium and ventricle
  • L-R shunting
• free wall rupture (5-14d)
  
  • pericardial tamponade (hemopericardium), JVD, distant heart sounds
    
    • tamponade leads to profound hypoTN and shock with rapid progression to pulseless electric activity + DEATH

Question 4

myxomatous changes (with pooling of proteoglycans)

Answer 4

• where? MEDIA layer of LARGE arteries in cystic.MEDIAL.degeneration
• predisposed to aortic dissections and aortic aneurysms
• seen in young indivs with Marfan

Question 5

media action in giant cell arteritis vs. cystic medial degeneration

Answer 5

• cystic medial degeneration: myxomatous changes with pooling of proteoglycans in MEDIA
• GCA: granulomatous inflam of MEDIA and fragmentation of internal elastic lamina

Question 6

PDA + Eisenmenger syndrome

Answer 6

• differential clubbing ad cyanosis (toes) sans blood pressure or pulse discrepancy=LAGE PDA complicated by Eisenmenger syndrome
  
  • Eis=reversal of shunt flow from L-T to R-L
• (severe coarctation of the aorta can cause lower extremity cyanosis)
• R-L shunting in pts with large septal defects and ToF=WHOLE body cyanosis

Question 7

What are the FIVE (5) things on the differential diagnosis for chest pain

Answer 7

1. coronary artery disease (CAD)
   
   • substernal, radiation to arm/shoulder/jaw
2. pulmonary/pleuritic (pleurisy, pneumonia, pericardities, PE)
   
   • sharp stabbing pain, WORSE W/ INSPIRATION
   • pericarditis: worse when lying flat
   • PE, pneumothorax: respiratory distress, hypoxia
3. aortic (dissection, intramural hematoma)
   
   • SUDDEN SEVERE tearing pain radiates to back in old men
4. GI/esophageal: NOCTURNAL pain in upper abdo and substernal; non-exertional
5. CW/musculoskeletal
   
   • persistent, prolonged
   • worse with movement/chang ein position
   • often follows: REPETITIVE ACTIVITY

Question 8

chronic transmural inflamm (AAA) vs. cystic medial necrosis vs. focal intimal tear (FIT)

Answer 8

• chronic transmural inflamm (AAA)
  
  • focal dilation of abdo aorta (infrarenal mc)
  • RF: >60, smoking, HTN, men
  • TRANSMURAL INFLAMM of the aortic wall
    
    • chronically leads to degradation of elastin and collagen by proteases
    • causes LOSS of ELASTIN and loss of smooth mu cells
    • end up with ABNML collagen remodeling and crosslinking
    • final product: weaken and expand aortic wall=ANEURYSM
• cystic medial necrosis
  
  • loss of smooth mu, collage, elastic tissue
  • formation of cystic mucoid spaces in aortic media
  • marfan syndrom: cystic medial degeneration=rf for ascending AA and dissection
• focal intimal tear
  
  • primary event of aortic dissection

Question 9

cardiac tissue conduction velocity

Answer 9

• park at venture avenue
• fastest–>slowest=purkinje, atrial mu, ventricular mu, AV node
• AV node is slowest conductor-delay allows ventricules to completely fill with blood d/r diastole

Question 10

sans significant PERICARDIAL dz what are the most frequent causes of pulsus paradoxus

Answer 10

• asthma and COPD exacerbation
• immediate relief:
  
  • beta-adrenergic agonists cause bronchial smooth muscle relaxation via INC intracellular cAMP

Question 11

RV MI

Answer 11

• general
• CP:
  
  • systemic hypoTN (and shock)
  • elevated JVP
  • clear lungs
• mc occurs in setting of acute inferior wall MI
  
  • d/t occlusion of proximal RCA
• hemodynamic assessment:
  
  • elevated RA and CVP
  • reduced PCWP
  • reduced CO

Question 12

mc primary cardiac neoplasm

Answer 12

• MYXOMAS
  
  • 80% are in LA
  • pedunulated and gelatinous
  • CP: emboli, mid-diastolic rumbling murmur heard best at apex, positional CV s/s (dyspnea, syncope)
  • histo: scattered cells within a mucopolysaccharide stroma
    
    • abnml blood vessels
    • hemorrhaging

Question 13

Pulmonary artery HTN

Answer 13

• definition: pulm arterial pressure >/=25 (nml: =20)
• 2 hit hypothesis
• abnml BM.PR.2 gene predisposes to xs endothelial and smooth mu cell proliferation
• dz process:
  
  • vascular remodeling
  • elevated pulm vascular resistance
  • progressive pulm HTN

Question 14

paradoxical embolization (stroke in the setting of venous thromboembolism)

Answer 14

• PP: conditions that raise RAP>LAP (Valsalva) can produce transient R-L shunt across PFO
• usually: septum primum and septum secundum flaps all up on eachother and fuse cloed
  
  • ASD: missing primum or secundum…less common than PFO in health adults

Question 15

A fib and thromboembolism

Answer 15

• afib is assoc with INC r/o systemic thromboembolism
• LA appendage=mc site of thrombus formation

Question 16

hemodynamics of severe AORTIC stenosis

Answer 16

• impaired LV output
• higher systolic pressures cause LVH
• atrial contraction necessary for filling of stiffened LV
• end up with: hypoTN and pulm edema
• may cause afib, cardioversion indicated

Question 17

coronary sinus and RA

Answer 17

• CS runs transversely in LAV groove on posterior heart, communicates freely with RA
  
  • CS gets dilated by any factor that causes RA dilation
  • mc: secondary to pulm HTN

Question 18

Constrictive pericarditis

Answer 18

• Etiology
  
  • idiopathic or viral
  • cardiac sx or radiation therapy
  • TB (in endemic areas)
• Path:
  
  • thickened, rigid pericardium noncompliant casing a/r heart=limited ventricular expansion d/r diastolic filling
• Hemodynamic signs:
  
  • INC JVP
  • KUSSMAUL
  • pulsus paradoxus
  • pericardial knock knock who’s there?? (early in diastole)

Question 19

Tet of Fallot SVR:PVR

Answer 19

• pulm stenosis and overriding aorta cause low ration of SVR:PVR (systemic and pulmonary vascular resistance)
• low ratio=deoxy RV output take low-resistance route (via LV) to SYSTEMIC circulation=acute hypoxemia (Tet spell)
• fix with SQUAT!
  
  • quickly INC SVR (sans changing PVR)=INC ratio
  • INC SVR=more RV output goes to PULM circulation, oxygenate in pulm cap beds, INC arterial oxygen concentration…yay!