Cardio 2

Question 1

Describe the anatomy of the pericardium

Answer 1

2 layers -
Serous visceral (single cell layer adherent to epicardium)
&
Fibrous parietal (2mm thick) - has fibrous attachments to fix heart in thorax

Question 2

Describe the physiology of pericardium

Answer 2

Has similar properties to rubber - initially stretchy but become stiff @ high tension
Pericardial sac has small reserve vol

Question 3

Describe tamponade physiology

Answer 3

Small amount of vol added to space has a dramatic effect on filling
So does removal of small amount

Question 4

Why does chronic pleural effusion rarely cause tamponade?

Answer 4

Bc chronic accumulation of fluid allows adaptation of parietal pericardium
Reduces effect on diastolic filling
∴ If very slow effusion, rarely causes tamponade

Question 5

When can you make a clinical diagnosis of Acute Pericarditis?

Answer 5

When 2 or 3 of the following :
* Chest pain
* Friction run
* ECG changes (ST saddle elevation)
* Pericardial effusion

Question 6

Describe the mechanism pulsus paradoxus

Answer 6

Caused by ↑ venous return to R heart during inspiration
Bc RV vol is increased, occupies more space within rigid pericardium
∴ Impairs LV filling

Question 7

What is pulsus paradoxus?

Answer 7

A fall in systolic BP > 10mmHg with inspiration

Question 8

What is Beck’s Triad?

Answer 8

1. ↑ JVP
2. ↓ BP
3. Small, quiet heart

Question 9

Risk factors for atherogenesis

Answer 9

Age
Tobacco smoking
High serum cholesterol
Obesity
Diabetes
HTN
Family history

Question 10

Describe the distribution of atherosclerotic plaques

Answer 10

Peripheral and coronary arteries
Focal distribution along artery length

Question 11

What factors might distribution of atherosclerotic plaques be affected by?

Answer 11

Changes in blood flow/turbulence (at bifurcations) - causes artery to adjust wall thickness, ∴ new growth develops

Question 12

Describe the structure of an atherosclerotic plaque

Answer 12

Lipid
Necrotic core
Connective tissue
Fibrous cap

Question 13

What can ECGs identify?

Answer 13

Arrhythmias
MI and infarction
Pericarditis
Chamber hypertrophy
Electrolyte disturbances (hyper/hypokalaemia)
Drug toxicity

Question 14

Name the 3 natural pacemakers of the heart and state their intrinsic pace

Answer 14

Sinoatrial node - dominant pacemaker, 60-100 bpm
Atrioventricular node - back up pacemaker, 40-60 bpm
Ventricular cells - back up pacemaker, 20-45 bpm

Question 15

Describe the route of impulses

Answer 15

1. SAN
2. AVN
3. Bundle of His
4. Bundle branches
5. Purkinje fibres

Question 16

Describe the sections of an ECG and what occurs in each one

Answer 16

P wave - atrial depolarisation
QRS - ventricular depolarisation
T wave - ventricular repolarisation
PR interval - atrial depolarisation and delay in AV junction

Question 17

Why is there a delay at the AV node?

Answer 17

Allows time for atria to contract before ventricles contract

Question 18

Signs / Symptoms of HTN

Answer 18

Asymptomatic unless malignant HTN
May occasional headache - but not massively different to general population

Question 19

When should CCBs be avoided?

Answer 19

HEART FAILURE !!!!!!!!!!!! (except amlodopine)

Question 20

How does ABPM compare to clinical BP?

Answer 20

ABPM is always lower
Should always “add” 12/7 to “convert” to clinical if need to make decisions for Tx