CARDIO RECAP Flashcards
Name 3 catecholamines
Dobutamine
Adrenaline
Noradrenaline
What do catecholamines do
Increase HR and force of contraction
Increase O2 consumption of heart
Decrease cardiac efficiency
How do beta blockers help restore sinus rhythm
By decreasing sympathetic drive
What side effects can non-selective beta blockers cause
Hypoglycaemia
Cold Extremities
When can digoxin be used in heart failure
If the patient also has AF
What is the mechanism of constant Nitric Oxide release
Nitric Oxide Synthase (NOS) converts L-arginine to Nitric Oxide which diffuses into SM cells and increases production of cGMP hence causing relaxation
How do ARB’s work
Angiotensin 1 receptor blockers (ARB’s) competitively block Angiotensin II binding to the AT 1 receptor
How do CCB’s work
Block L-type Ca2+ channels
What can thiazide diuretics be used for
Mild Heart Failure
Hypertension
Severe resistant Oedema (with loop agent)
What can loop diuretics be used for
Chronic Heart Failure
Acute Pulmonary Oedema (IV)
What are the two equations to work out MAP (Mean Arterial pressure)
(2D + S) / 3
D + 1/3(D - S)
Where are the two sets of baroreceptors and which cranial nerves do they signal via
Aortic Arch- signal via CN X (Vagus)
Carotid Sinus- signal via CN IX (Glossopharyngeal)
What two components make up total body fluid
Intracellular fluid (2/3) Extracellular fluid (1/3)
What 2 components make up extracellular fluid
Interstitial fluid
Plasma fluid
What 3 cells does the juxtaglomerular apparatus consist of
Granular cells (release renin)
Macula Densa
Extraglomerular mesangial cells
Mixing of arterial and venous blood results in a decreased 02 saturation of arterial blood, what is this called?
Hypoxaemia
What is the rounded indent in the right atrium called
Fossa Ovalis
What is the fossa ovalis a remnant of
A fibrous sheet which covered the foramen ovale (the foramen ovale in the heart, not the skull)
What is another name for the moderator band which carries the papillary muscles
Septomarginal Trabecula
What provides mechanical adhesion between myocytes
Desmosomes
How does calcium-induced calcium release result in the exposure of the myosin
Ca2+ binds with troponin, pulling troponin-tropomyosin complex aside to expose cross-bridge binding site
In cardiac muscle where is the intracellular calcium released from
The Sarcoplasmic Reticulum (SR)
Which branch of the autonomic nervous system doesn’t have much innervation of arterial smooth muscle (and what are the exceptions to this)
There is no significant PARASYMPATHETIC innervation of arterial smooth muscle except in the penis and clitoris
Which three humoral agents cause vasodilation (by arterial smooth muscle relaxation)
Nitric oxide
Histamine
Bradykinin
Which cells continuously release Nitric Oxide
Endothelial cells of arteries and arterioles
For a heart rate of 75bpm, what are the durations of systole and diastole
Systole - 0.3s
Diastole - 0.5s
What is the normal EDV in an adult
130ml
What causes the dicrotic notch in the aortic pressure curve
The vibration of the aortic valve closing
Why does arterial pressure not fall to 0mmHg during diastole
Due to the elastic walls of the arteries rebounding during diastole
What is the investigation for intermittent claudication and which range of values indicates severe claudication
ABPI (Ankle Brachial Pressure Index)
0- 4.5 = severe
What drug is given to PVD patients
Cilostazol (anti-platelet)
Which type of brain tissue is particularly sensitive to hypoxia
Grey matter
Which arteries form the basilar artery
2 vertebral arteries
Which arteries anastomose to form the circle of Willis
Carotid arteries anastomose to form circle of Willis
What kinds of substances is the blood-brain barrier impermeable to (and give examples)
Hydrophilic
Proteins, Catecholamines, Ions)
What is the key phrase to describe an AAA
Pulsatile, expansile mass
What is the investigation for an AAA
Ultrasound
What diameter must an AAA reach in order to warrant surgery
> 5.5cm
What are the 2 parts of a lipoprotein
Hydrophobic core Hydrophilic coat (contains apoprotein)
What is the rate limiting enzyme in de novo cholesterol synthesis
HMG-CoA reductase
Describe reverse cholesterol transport
HDL accepts cholesterol from the plasma membrane of macrophages via CETP (cholesterol ester transfer protein) and transports it back to liver
What are the 4 major lipoproteins
HDL particles (contain apoA1 and apoA2) - GOOD
LDL particles (contain apoB-100) - BAD
Very-low density lipoprotein (VLDL) (contain apoB-100)
Chylomicrons (contain apoB-48)
What do you give to a patient with bradycardia
Atropine
What do you do if a patient who is bradycardic isn’t responding to atropine
temporary pacing wire
How do you recognise a right axis deviation on ECG
- QRS on lead 1
+ QRS on aVF
How do you recognise a left axis deviation on ECG
+ QRS on lead 1
- QRS on aVF
How do you recognise extreme axis deviation on ECG
- QRS on lead 1
- QRS on aVF
