Cardiovascular

Question 1

Fetal circulation

Answer 1

Umbilical v. –> liver (mix of unoxygenated blood in ductus venosus) –> right atrium

Right atrium to pulmonary a:

1. lungs, to L atrium, L ventricle, aorta
2. ductus arteriosis, aorta

Right atrium through foramen ovale to left atrium, to L ventricle, aorta

Question 2

Fetal shunting sites

Answer 2

ductus venosis
foramen ovale
ductus arteriosis

Question 3

Closure of heart shunting in newborn

Answer 3

1st breath decreases intrathoracic pressure
-decreases pulmonary a. resistance = more blood into pulmonary a.

More blood returning to L. atrium leads to LA pressure > RA pressure, closes foramen ovale

High oxygenated aortic blood closes ductus arteriosis

Question 4

3 causes of atrial septal defect

Answer 4

osmium secundum overlaps foramen ovale
absence of septum secundum
neither septum secundum or septum primum develop

Question 5

Maternal conditions causing congenital heart defects

Answer 5

Alcohol use: Tetralogy of Fallot, VSD, ASD, PDA

Pre gestational DM: transposition of great vessels

Lithium use: Ebstein anomaly

Question 6

Infant conditions leading to congenital heart defects

Answer 6

Congenital rubella - PDA, pulmonary a. stenosis

DiGeorge Sn (22q11 del) - tetralogy of Fallot, truncus arteriosis

Turner Sn: coarctation of aorta, bicuspid aortic valve

Trisomy 21: endocardial cushion defect - ASD, VSD

Question 7

Left to Right shunting congenital heart defects

Answer 7

Ventricular septal defect
Atrial septal defect
PDA

Question 8

Right to left shunts

Answer 8

Truncus arteriosus
Transpiration of the great vessels
Tricuspid atresia
Tetralogy of Fallot
Total Anomalous Pulmonary Venous Return

Question 9

L sided HF sx

Answer 9

Left = lung
dyspnea on exertion
cardiac dilation
pulmonary edema
Paroxysmal nocturnal dyspnea
orthopnea

Question 10

Right sided HF sx

Answer 10

peripheral edema - pedal, pre sacral
JVD
Hepatic congestion - HSM, nutmeg liver

Question 11

Drugs improving survival in chronic CHF

Answer 11

ACEI/ARBs
Aldosterone antagonists
metoprolol, carvedilol, bisoprolol
Nitrates + hydralazine (AA w/ mod-severe)

Question 12

Drugs providing sx relief of chronic CHF only

Answer 12

diuretics - loops and thiazides
digoxin
vasodilators (nitrates and hydralazine in everyone else)

Question 13

Acute CHF - decompensated - tx

Answer 13

NO LIP

Nitrates
Oxygen if hypoxic
Loop diuretics
Inotropic drugs
Positioning - sit up w/ legs down

Question 14

Draw out table on page 178

Answer 14

178

Question 15

Ventricle AP ion channel conductance by phase

Answer 15

Phase 0: Na

1: inactivation of Na channels
2: Ca2+ andK+
3: Close of Ca2+, K+ open
4: K+

Question 16

Pacemaker AP ion channel conductance by phase

Answer 16

Phase 4: Funny Na channels
Phase 0: voltage gated L type Ca2+ channels
3: Ca2+ close, K+ open

Question 17

Draw ECG axis

Answer 17

page 195

Question 18

What lead deflections would you expect to see with a left axis deviation?

Answer 18

Positive: I, aVL, aVR (may be isoelectric)
Negative: II, big negative waves in III, aVF

Question 19

What lead deflections would you expect to see with a right axis deviation?

Answer 19

Positive: II, III, aVF
Negative: I, big negative wave in aVL
Isoelectric: aVR

Question 20

Common causes of Left axis deviation

Answer 20

Interior wall MI
Left anterior fascicular block
LVH (sometimes)
LBBB

Question 21

Common causes of right axis deviation

Answer 21

RVH
Acute right heart strain - massive PE
Left posterior fascicular block
RBBB