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Flashcards in Heart Deck (32):
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3 layers of the Pericardium

1. Visceral layer of serous pericardium

2. Parietal layer of serous pericardium

3. Fibrous pericardium - fuses with the ff:
- adventitia of great vessels superiorly
- central tendon of diaphragm inferiorly
- sternum anteriorly

1

Depends through the mediastinum lateral to fibrous pericardium

Phrenic nerve

Pericardiophrenic artery

2

Recess between the great arteries & pulmonary veins

Transverse sinus

3

Recess of pericardial cavity

Ends in a cul-de-sac surrounded by pulmonary veins

Oblique sinus

4

Fluid compresses the heart because the fibrous pericardium is inelastic

Paradoxical pulse (inspiratory lowering of systolic BP by >10mmHg)

SVC compression --> facial & neck veins engorgement

Cardiac tamponade

5

Beck's triad

Hypotension (that doesn't respond to rehydration)

High venous pressure

Distant heart sounds

6

Pericardiocentesis

STERNAL APPROACH

ICS 5 or 6 left side near sternum

Penetrates the ff:
- skin
- superficial fascia
- Pectoralis major
- external intercostal muscle
- internal intercostals muscle
- transverse thoracic muscle
- fibrous pericardium

Structures at risk:
- internal thoracic artery
- coronary arteries
- pleura

7

Pericardiocentesis

SUBXIPHOID APPROACH

Left infrasternal angle, angled superiorly & posteriorly

Penetrates the ff:
- skin
- superficial fascia
- anterior rectus sheath
- rectus abdominis
- transverse abdominis muscle
- fibrous pericardium
- parietal layer of serous pericardium

Structures at risk:
- diaphragm
- liver

8

Surfaces of the heart

Posterior surface (base): LA

Apex: LV at ICS5, MCL

Sterna surface: RV

Diaphragmatic surface: LV

9

Borders of the heart

R border: RA, SVC

L border: Aortic arch, pulmonary trunk, LA, LV

Inferior border: RV

Superior border: SVC, aorta, pulmonary trunk

10

Frequency of coronary occlusion in descending order

Anterior interventricular artery (L anterior descending artery)

R coronary artery

Circumflex artery

11

R coronary artery

Branches:
- SA nodal artery
- R marginal artery
- AV nodal artery
- Terminal branches
- Posterior interventricular artery
- Septal branches

Structures supplied:
- RA
- RV
- SA node
- AV node
- Interventricular septum

12

L coronary artery

Circumflex artery
- anterior marginal artery
- obtuse marginal artery
- arterial branches
- post marginal artery

Anterior interventricular artery
- anterior diagonal artery
- septal branches

Structures supplied:
- LA
- LV
- Interventricular septum

13

Venous drainage

GREAT CARDIA VEIN
- follows anterior interventricular artery
- drains into coronary sinus

MIDDLE CARDIAC VEIN
- follows posterior interventricular artery
- drains into coronary sinus

SMALL CARDIAC VEIN
- follows right marginal artery
- drains into coronary sinus

ANTERIOR CARDIAC VEIN
- found on anterior aspect of RV
- drains into directly to RA

SMALLEST CARDIAC VEIN
- begin within the wall of the heart
- directly to the nearest heart chamber

14

Heart valves & Auscultation sites

PULMONARY VALVE (semilunar)
- 3 cusps (R,L, & posterior)
- L ICS 2, parasternal

AORTIC VALVE (semilunar)
- 3 cusps (R,L & posterior)
- R ICS 2, parasternal

MITRAL (left AV valve)
- 2 cusps (anterior & posterior) tethered to papillary muscle by chordate tendinae
- cardiac apex, L ICS 5, MCL

TRICUSPID (right AV valve)
- 3 cusps (anterior, posterior & septal) tethered to papillary muscle by chorda tendinae
- ICS 5, over the sternum

15

Conduction system

SA node

AV node

Bundle of His

Left & right bundle

Purkinje fibers

16

Pacemaker, just beneath the pericardium, at the junction of SVC & RA

SA node

17

Just beneath the endocardium

On the R side of interarterial septum

Near the ostium of coronary sinus

AV node

18

Travels in subendocardial layer

On the R side of Interventricular septum

Bundle of His

19

Left bundle further divides into thin anterior & thick posterior division

Left & right bundle

20

As terminal branches

Purkinje fibers

21

Abnormal migration of neural crest cells --> skewed aorticopulmosegment --> R to L shunt --> cyanosis

4 components:
- pulmonary stenosis
- RVH
- overriding aorta
- VSD

Tetralogy of Fallot (TOF)

22

Incomplete fusion of R and L bulbar ridge and AV cushions --> L to R shunt initially --> if uncorrected, ⬆️ pulmonary blood flow --> pulmonary hypertension --> R to L shunt (Eisenmenger complex)

Membranous VSD

23

Ductus arteriosus (DA)

Fails to close (connection between L pulmonary artery & aortic arch) --> L to R shunt

DA normally closes within few hours after birth to form the Ligamentum arteriosum

Premature infants
Maternal rubella during pregnancy

Maintains patency: PG E1, asphyxia

Promotes closure:
- PG inhibitors (indomethacin)
- ACH
- histamine
- catecholamines

Patent ductus arteriosus (PDA)

24

MC cause: atherosclerosis

Precipitated by exertion, relieved by rest, <30mins

Ischemic heart disease

Angina pectoris

25

Mac cause: atherosclerosis

Complications: CHF, arrhythmia (1st 24 hours)

ECG: ST elevation --> Q waves, inverted T waves

Cardiac enzymes: CK (6-12 hours), Troponin (12 hours), LDH (reversed LDH1:LDH2 ratio 24 horus after)

Treatment & rationale:
- sublingual nitroglycerin (vasodilator)
- b-blocker (relieve tachycardia, hypertension)
- tPA/streptokinase (reduce infrared tissue)
- atropine (relieve bradycardia)
- warfarin/heparin (prevent ventricular aneurysm, embolism, DVT)

Acute myocardial infarction

26

RV dilatation caused by pulmonary hypertension

Acute - following a large thrombopulmonary embolism

Chronic - due to prolonged obstruction of pulmonary vasculature (e.g. Emphysema)

Cor pulmonale

27

Fibrous scarring & calcium nodules

MC affects aortic valve

Calcific valve disease

28

Anti-streptococcal antibodies cross-react with heart valves

MC affects mitral valve --> smart, wart-like vegetations (verrucae), " fish mouth or button hole", stenosis

Pathognomonic lesion: Aschoff bodies (perivascular, fibrinoid, necrosis-surrounded inflammatory Aschoff cells)

Rheumatic heart disease

29

ACUTE

- S. Aureus (50%), Strep 35%)
- previously normal valves
- Large friable vegetations --> septic emboli

SSX:
- splinter hemorrhages in nail beds
- Janeway lesions (nontender, palms & soles)


Acute infective endocarditis

30

S. Epidermis, S. Viridans, Enterococcus sp.

Gram negative bacilli

Previously abnormal valves

SSX:
- Rott spots (retinal hemorrhages)
- Osler nodes (tender, fingers & toes)
- anemia, hematuria, splenomegaly

Infective endocarditis (SUBACUTE)

31

Congenital, accessory conduction pathway

Re-entry loop may develop --> supraventricular tachycardia

Wolff-Parkinson-White syndrome