Blood Vessels Of The Heart

Question 1

What does the RCA supply?

Answer 1

Right atrium, SA and AV nodes and posterior part of IVS

Question 2

What does the LCA (left coronary artery) supply?

Answer 2

Left atrium and ventricle
IVS
AV bundle
May supply AV node

Question 3

What is the difference between chronotrophy and inotrophy?

Answer 3

Increased chronotrophy = increased heart rate

Increased inotropy = increased force of contraction

Question 4

Metabolites are more important for insuring adequate perfusion of skeletal and coronary muscle than activation of B2 receptors.
True or false?

Answer 4

True

Metabolite production e.g. Adenosine, potassium, H+ ion conce increases, pCO2 increases which all act on vascular smooth muscle cells to cause relaxation

A lot of relaxation takes place in response to metabolite production

Question 5

Where are the CVS baroreceptors located?

Answer 5

Aortic arch and carotid sinus

Question 6

Which type of receptor does noradrenaline bind to more favourably in vasculature under normal conditions?

Answer 6

B2 receptors

At higher concentrations will also bind to alpha-1 receptors

Question 7

Is B2 in the vessels vasodilatory or vasoconstrictory?

Remember tho: B2 receptors only present in skeletal muscle, myocardium and liver

Answer 7

Vasodilatory

Question 8

How does the baroreceptor reflex work?

Answer 8

Increased mABP is detected by baroreceptors in the carotid sinus and aortic arch.

THese send signals to the medulla the co-ordinating centre

These then causes reduced sympathetic outflow to heart and vessels to cause vasodilation

Question 9

Is the baroreceptor reflex short term or long term?

Answer 9

Short term - moment to moment changes in BP

Question 10

What factors stimulate renin release?

Answer 10

Reduced NaCl to distal tubule
Reduced perfusion pressure in the kidney causes release of renin - detected by baroreceptors in afferent arteriole
Sympathetic stimulation to JGA increases release

Question 11

What cells in the afferent arteriole is renin released from?

Answer 11

Granular cells

Question 12

Bradykinin is a vasodilator. True or false?

Answer 12

True

Question 13

What other action does ACE have that increases vasoconstriction?

Answer 13

Breaks down bradykinin which is a vasodilator

Question 14

What is ADH stimulated by?

Answer 14

Increased plasma osmolarity

Or severe hypovolaemia

Question 15

What does ANP do and how does it work?

Answer 15

Promotes Na+ excretion

Synthesised and stored in atrial myocytes

Released from atrial cells in response to stretch

Low pressure volume sensors in the atria

Reduce effective circulating volume INHIBITS the release of ANP to support BP

Reduced filling of the heart –> less stretch –> less ANP released

Question 16

What is hypertension called when the cause is unknown?

Answer 16

Primary or ‘essential’ HTN

-95% of cases

Question 17

What are some causes of secondary HTN?

Answer 17

Hyperaldosteronism
Cushing’s syndrome
Renovascular disease
Chronic renal disease

Think rx primary cause !

Question 18

What effect does dopamine have on BP?

Answer 18

Causes vasodilation and increased renal blood flow

Dopamine causes reduced reabsorption of NaCl
Inhibits Na H+ exchanger and Na+/K+ ATPase in principal cells of PCT and TAL

Question 19

What is Conn’s syndrome?

Answer 19

Aldosterone secreting adenoma
- hypertension and hypokalaemia

(Quite a fatty rich tumour)

Question 20

What is Cushing’s syndrome?

Answer 20

Excess secretion of glucocorticoid cortisol

At high concentration acts on aldosterone receptors - Na+ and water retention

Question 21

What is the name of a tumour of the adrenal medulla?

Answer 21

Phaeochromocytoma - secretes catecholamines (noradrenaline and adrenaline)

Question 22

Hypertension causes increased afterload (along with arterial damage)

What are the consequences of increased afterload?

Answer 22

Left ventricular hypertrophy - leads t heart failure

Increased myocardial oxygen demand - myocardial ischaemia and MI

Question 23

Hypertension causes arterial damage.

What are the different types of arterial damage it can cause?

Answer 23

Atherosclerosis –> leads to myocardial ischaemia and MI

Atherosclerosis + weakened vessels can cause: 
CVA
Aneurysm
Nephrosclerosis and renal failure
Retinopathy

Question 24

What are the non-pharmacological approaches for treating HTN?

Answer 24

Exercise
Diet
Reduce Na+ intake
Reduce alcohol intake

Question 25

What 2 main things can cause shock?

Answer 25

Fall in cardiac output | Fall in total peripheral resistance

Question 26

What can cause a fall in cardiac output?

Answer 26

Mechanical- pump cannot fill Pump failure Loss of blood volume - haemorrhage and decreased to a point where cardiac output cannot be maintained enough

Question 27

What can cause a fall in peripheral resistance?

Answer 27

Excessive vasodilation

Question 28

What does cardiogenic shock mean?

Answer 28

Ventricles cannot empty properly - pump failure

Question 29

What does mechanical shock mean?

Answer 29

Ventricles cannot fill properly - obstructive

Question 30

What does hypovolaemic shock mean?

Answer 30

Reduced blood volume leads to poor venous return

Question 31

What is an example of mechanical shock?

Answer 31

Cardiac tamponade

Question 32

What type of shock is a pulmonary embolism? What is the mechanism behind this?

Answer 32

``` Embolus concludes a large pulmonary artery Pulmonary artery pressure high Right ventricle cannot empty CVP high Reduced return of blood to the left side Limits filling of left heart Left atrial pressure low Arterial pressure low SHOCK ``` Also chest pain, dyspnoea

Question 33

What is the management of stable angina?

Answer 33

Sub lingual nitrate spray/tablet Prevent episodes: beta blockers, Ca2+ channel blockers, statins, oral nitrates Prevent cardiac events: aspirin, statins, ACE-i Long term: consider re-vascularisation

Question 34

What is the difference between NSTEMI and STEMI?

Answer 34

NSTEMI - non-ST elevation Infarct is not full thickness STEMI- ST elevation Full thickness myocardium damage

Question 35

``` Case one 86 female Shortness of breath Minor ankle oedema AF 130 on ECG T inversion V4 5 6 Scoliosis and calcified costal cartilage on CXR Troponin 160 ``` Diagnosis?

Answer 35

The reason her troponin has gone up She has heart failure Troponin has gone up Myocardial damage due to other primary cause Had this patient came in with a focal episode of symptoms eg. Sweatiness then yes could say plaque rupture mI but doesn't really fit if slow onset

Question 36

``` 71 year Ltd man ETOH many years Poor mobility Difficult history Tachycardia 110 Raised WCC Troponin 400 - significantly raised CXR - difficult to interpret poor inspiration ``` Diagnosis ?

Answer 36

Troponin spills out with pneumonia Diagnosis pneumonia

Question 37

``` 47 year old Man, ex smoker 6 episodes of chest pain intermittently 5 or so minutes at a time over last 2 days One 10 min episode with clamminess, one episode stopped him while walking the dog, others at rest. Pain free now, normal examination. Normal ECG Normal CXR Troponin 80 Diagnosis? ```

Answer 37

Unstable angina

Question 38

``` 67 year old man COPD Peripheral vascular disease SOB, cough, 4 days Mild left sided chest ache for several hours, worse in certain positions Wheezy chest, scattered crackles CRP 30, WCC 15 CXR- chronic changes of COPD Trop 100 ECG sinus tachy, atrial ectopics. Possible short runs of AF Diagnosis? ```

Answer 38

Could be an MI however no speicific plaque rupture | Probably treat as COPD exacerbation

Question 39

``` Severe aortic stenosis, declined TAVI, recent balloon aortic valvuloplasty Severe coronary artery disease CXR -pulmonary venous congestion ECG- LBBB new or old? Troponin 800 Diagnosis? ```

Answer 39

Could be ACS Or could be entirely due to severe aortic stenosis Could be both

Question 40

``` 83 y/o "Collapsed" at church Abdomnal pain and distension BP 110/60 ECG LBBB WCC normal, Hb normal, urea 12, creatinine 130 Trop. 60 Diagnosis? ```

Answer 40

Could be MI but unlikely However later examined on CCU- bladder distended Treated with a urinary catheter

Question 41

What is the main cause of systolic heart failure?

Answer 41

Ischaemic heart disease Other causes include: ``` HTN Dilated cardiomyopathy: bugs, alcohol/drugs/poisoning, pregnancy Valvular heart disease/congenital Restrictive cardiomyopathy e.g. Amyloidosis Hypertrophic cardiomyopathy Pericardial disease High-output heart failure Arrhythmia ```

Question 42

What is diastolic heart failure caused by?

Answer 42

When the muscles in the heart enlarge e.g. To overcome aortic stenosis then the lumen of the ventricle decreases in size (as the muscle mass takes up more room) therefore cannot fill as well and less blood is able to be pumped out as less blood is coming in