Cardio

Question 1

Biomarkers - diagnosis of MI

Answer 1

First 6 hours: ECG is gold standard
Troponin I: Rises after 4 hours, peaks at 24 hours, increased for 7-10 days. Most specific
CK-MB: rises after 6-12 hr, peaks at 16-24 hr, not as specific. Diagnosing reinfarction following acute MI

Question 2

1st degree AV block

Answer 2

Prolonged PR interval (>200 ms). Benign and asymptomatic All atrial excitations are eventually conducted.

Question 3

2nd degree AV block, Mobitz Type I

Answer 3

Progressive lengthening of PR interval until a beat is “dropped” ie P followed by no QRS. Usually asymptomatic.

Question 4

2nd degree AV block, Mobitz type II

Answer 4

Just no QRS following nth P wave, with no PR prolongation.
If 4 PR with 3 QRS then call it 4:3 2nd degree block.
If it is a 2:1 block, cannot differentiate mobitz type I from II.

Question 5

3rd degree AV block

Answer 5

Atria and ventricles beat independently. P and QRS not associated. Atrial rate> ventricular rate. Pacemaker. Can be caused by Lyme disease

Question 6

Atrial Natriuretic Peptide

Answer 6

Released from atrial myocytes in response to increased blood vol and atrial P. Causes vasodilation, decreased Na reabs at collecting duct, dilates afferent arterioles and constricts efferent, promoting diuresis and aldosterone escape.

Question 7

Local metabolites of skeletal muscle at rest and during exercise (for autoregulation)

Answer 7

At rest: sympathetic tone

Exercise: Co2, H+, Adenosine, Lactate, K+

Question 8

Local metabolites in heart

Answer 8

Adenosine, NO, CO2, decreased O2.

Question 9

Tetralogy of Fallot

Answer 9

Most common cyanotic congenital heart defect. Incl ventricular septal defect, right ventricular hypertrophy, overriding aorta, and pulmonary artery stenosis (would hear the crescendo decrescendo murmur in systole)

Question 10

Transposition of great vessels

Answer 10

Aorta arises at right ventricle, pulmonary artery arises at left ventricle. Infant must have PDA or patent foramen ovale to be compatible with life.

Question 11

Propranolol

Answer 11

Non selective B1 and B2 receptor antagonist. Leads to decreased CO through decreased HR and contractility. Lower MAP and decreased in Bp - would lower the equilibrium point of the heart.

Question 12

5 Right to left shunts - early cyanosis

Answer 12

1. Truncus arteriosus
2. Transposition of vessels
3. Triscuspid atresia
4. Tetralogy of fallot
5. TAPVR (Total anomalous pulmonary venous return)

Question 13

Coarctation of aorta

Answer 13

Aortic narrowing near insertion of ductus arteriosis (juxtaductal)
Hypertension in upper extremities, weak delayed pulse in lower extremities
Intercostal arteries enlarge (collateral circulation) - notched ribs.

Question 14

STEMI versus non-STEMI MI

Answer 14

STEMI: Transmural infarcts - full thicknss of myocardial wall, STEMI and Q waves
non-stemi: Subendocardial infarcts, especially vulnerable to ischemia. ST depresion on ECG.