Cardio Flashcards
Which is the only valve that is normally bicuspid?
mitral
What carotid character do you get in aortic stenosis?
Slow rising
Murmur in aortic stenosis
Ejection systolic
Sequelae of aortic stenosis?
Concentric LVH due to higher pressure needed to open valve
Heart failure
Lack of blood to end organs
+turbulent flow
+microangiopathic haemolytic anaemia- haemoglobinuria
3 cardinal symptoms of aortic stenosis
syncope
angina
dyspnoea
Does a mechanical or bio valve last longer?
Mechanical
Alternative to valve replacement in AS?
Balloon valvuloplasty
50% aortic regurg caused by whaT?
Aortic root dilation
What causes aortic root dilation?
Idiopathic
aortic dissection
aneurysm
Syphilis
Marfan’s/ED
Murmur aortic regurg?
Early decrescendo diastolic
What finding do you get in aortic regurg o/e?
Large pulse pressure leading to hyperdynamic circulation
Why do you get a large pulse pressure in aortic regurg?
Blood volume in ventricle is increased so higher SV so systolic BP high
Blood volume in aorta is decreased so in diastole get a low BP
What are the signs of hyperdynamic circulation
waterhammer pulse
bounding pulse
Head bobbing
Quincke’s sign- pulsating fingernail capillary beds
Other sequelae of aortic regurg?
Eccentric LVH
Most common cause of mitral regurg
prolapse of valve
What causes mitral valve prolapse?
Myxomatous degeneration of the papillary muscles (e.g. due to Marfan’s/ED)
Which valve leaflet’s chordae tendinae are most likely to rupture in mitral prolapse
posterior
Symptoms of mitral prolapse
mostly asymptomatic
Murmur of mitral prolapse?
Systolic murmur with a mid systolic click
What manoeuvres can change the mitral prolapse murmur?
Squatting increases venous return so click is later (more space for the valve to move in) and murmur shorter
Standing/valsalva makes the click earlier and murmur longer
What are other causes of mitral regurg?
Damage to papillary muscles post MI
LHF leading to LV dilation
Rheumatic fever
Murmur of (non prolapse) mitral regurg
Pansystolic ‘blowing’ murmur
Sequelae of mitral regurg
LHF- extra work is created for the heart as the blood keeps draining back- LA and LV volume overload - eccentric hypertrophy –> HF
Most common cause mitral stenosis
Rheumatic fever
What is rheumatic fever
antibodies post strep-A throat infection
Commissural fusion of the valve
Murmur in mitral stenosis
Systolic snap and diastolic rumble
Sequelae of mitral stenosis
High pressure can = atrial dilation
Backs up into pulmonary circulation- pul oedema and dyspnoea
Pul HTN- strain on RH –> RVH –> RHF
Increased risk AF and therefore thrombus risk
Can also get dysphagia
Malar flush is sign of which valve disease?
Mitral stenosis
What pulse pressure do you get in AS?
Narrow
Radio-radial and radio-femoral delay are sign of what?
Coarctation of the aorta
Left sided murmurs (M&A) are louder on
Held expiration
Right sided murmurs (T&P) are louder on
Held inspiration
What could a pansystolic murmur indicate
Mitral regurg
VSD
Tricuspid regurg
would a VSD murmur alter on position/breathing?
No
When is a tricuspid regurg louder?
Held inspiration sitting forwards
What sign do you get in tricuspid regurg?
large V waves on JVP
What do large A waves mean on JVP?
Anything that makes blood flow RA to RV more difficult e.g. RVH (due to pulmonary HTN or pulmonary stenosis) or tricuspid stenosis
What do absent A waves mean on JVP
AF
How is heart failure diagnosed?
Framingham criteria- 2 major OR 2 minor + 1 major
What can be used as a measure of prognosis in heart failure?
Ejection fraction
What categories can heart failure be split into?
Normal ejection fraction
Reduced ejection fraction
what is ‘congestive’ heart failure?
Both R and L ventricles
Pulmonary oedema is a sign of which sided heart failure?
Left
Why does LHF lead to RHF?
pulmonary hypertension
What are signs of RHF?
Peripheral oedema
Hepatic congestion
(systemic venous congestion)
What is the role of BNP in heart failure?
To stratify patients in primary care
> 2000 refer to cardio 2ww
400-200 non urgent referral
<400 consider alt dx
What does BNP do physiologically?
body’s natural defence against hypervolaemia- natriuresis, diuresis and vasodilation
Does a normal CXR exclude heart failure?
No
5 xray findings of heart failure?
Alveolar oedema (bat wing)
Kerley B lines
Cardiomegaly
Dilated upper lobe vessels
Pleural effusion
Which heart failure patients get an echo?
All w susp heart failure
How is heart failure classified?
NYHA - how much functional limitation
What is the most common arrhythmia that heart failure patients develop?
AF
What dietary change is made in severe heart failure?
Fluid restriction to <1.5L/day
What are the two main drugs you give in heart failure?
ACEi and beta blocker- start at different times (use clinical judgement about which you start first.)
Mechanism of ACEi in heart failure treatment?
Vasodilation, reduces afterload and fluid retention- slows LV disease progression and improves neuroendocrine abnormalities
Mechanism of beta blockers in heart failure?
reduce afterload + HR (so tackles arrhythmias)
3 cardio C/Is to beta blockers
2/3rd degree heart block
Sick sinus syndrome
Sinus bradycardia
What other drugs could you consider for symptom control in heart failure?
Diuretics for fluid overload. Once improved may be able to maintain euvolaemia with fluid and salt restriction.
Digoxin if refractory to other Rx
Amiodarone if arryth
CCB
Do diuretics improve LT outcome in heart failure?
No only spironolactone does
What type of diuretic is first line in heart failure?
Loop
Which CCBs can you use in heart failure?
Amlodipine only
Which drugs should be avoided in heart failure?
TCAs
Li
NSAIDs
Corticosteroids
QT prolonging Rx
Flecainide (an antiarrhythmic)
Is the treatment for diastolic HF the same?
No - ionotropic effect is the aim
Early CCBs ± B blockers
Avoid diuretics and strong vasodilators
Caution ACEi
What is diastolic heart failure?
AKA preserved ejection fraction
LV is stiff so can’t fill properly in diastole leading to reduced amount of blood going to body.
Symptoms of HF with normal ejection fraction
How does acute heart failure occur and what can it lead to?
Due to e.g. MI/arryth
Lead to cardiogenic shock
Alternative to ACEi if heart failure pt can’t tolerate ACEi?
ARB
Can you give ACEi in valvular heart disease?
Avoid unless specialist input
name the layers of the wall of the heart and pericardium
Endocardium
Myocardium
Epicardium (surface of heart + visceral layer pericardium)
Pericardial space (lubricant)
Parietal layer pericardium
Fibrous pericardium
Where do the coronary vessels drain into?
Coronary sinus in the RA
What prevents backflow in AV valves? (mitral and tricuspid)
Valve leaflets attached to papillary muscles via the chordae tendineae
What has higher resistance systemic or pulmonary circulation?
Systemic
Name the three layers of blood vessels
Tunica intima
Tunica media
Tunica externa
Which layer of the blood vessel contains smooth muscle and elastin?
Media
What additional structure do large blood vessels have in their tunica externa?
Vasa vasorum (own blood vessels)
What layers do capillaries have?
tunica intima ± basement membrane
Blood flow =?
volume/time
Q
Velocity of blood =?
Distance/time
Or flow/area (Q/A)
V
What is mean arterial pressure?
1/3 SBP + 2/3 DBP
What is Reynold’s number?
How laminar/turbulent blood flow is
What are two features unique to skeletal muscle cells?
Multinucleated
Sarcoplasm contains myofibrils
What is in a myofibril?
Sarcomere containing thick myosin filaments and thin actin filaments
CO=?
SVxHR
Normal CO?
about 5L/min
How much blood in a human body?
About 5L
How do you work out SV?
End diastolic vol - end systolic vol
ejection fraction = ?
stroke volume/end diastolic volume
What is normal ejection fraction?
Around 50-65%
Which organ receives the most blood per gram?
Kidneys
cardiac work =?
mean aortic pressure x stroke volume
Does cardiac work correlate well with cardiac output?
No e.g aortic stenosis- lot of work for little output.
What is preload?
Ventricle wall stress at the end of diastole
What is a law not used in practice to determine wall stress?
Law of Laplace
What is a surrogate used for preload?
End diastolic LV volume
What is preload affected by?
Venous pressure and rate of venous return
Atrial contraction
Resistance from valves
Ventricular compliance
HR
What is afterload?
Ventricle wall stress during systole i.e. the amount of resistance ventricles must overcome during systole.
What is afterload affected by?
SVR
Aortic pressure
Valve disease
What cells start the action potential in the heart?
Pacemaker cells
What is special about pacemaker cells?
Autoarrhythmic
Where is the SA node located?
RA
Action potentials move ___ through pacemaker cells and ____ through myocytes (fast/slow)
fast
slow
How does the action potential reach the other atrium?
Atrial internodal tracts (Bachmann’s bundle)
How and why does conduction slow at the AV node?
Smaller diameter of cells and slower ion channels (calcium not sodium)
This delay allows the ventricles to fill
Does the action potential move quickly or slowly through the His-Purkinje system? Why?
Quick so that there is a co-ordinated contraction
What is the firing rate of the SA node
60-100 BPM
What if the SA node fails to fire?
Then other parts of the heart take over pacing- other parts of atria > AV node > ventricular pacemaker cells (each has a slower and slower rate)
(ectopic foci)
Where is the AV node?
RA just inferior to coronary sinus
what is the carotid sinus?
Major baroreceptor site at the base of the internal carotid artery just superior to the bifurcation of the common carotid
How do cardiomyocytes contract?
Small amount of calcium influx from neighbouring cell
Enters T tubules to allow it to go deep into the cell
Binds to ryanodine receptors on sarcoplasmic reticulum
Even more calcium released
Calcium binds to Troponin C which is attached to tropomyosin
(tropomyosin is draped around actin to cover the myosin head binding sites)
When calcium binds this moves the tropomyosin to expose the binding site
Myosin-actin cross bridge formed–> power stroke –> contraction
Big box in ECG = how long?
0.2s
Small box in ECG = how long?
0.04s
How to calculate rate on ECG
300 divided by number big squares
OR
Number of R waves on strip x 6 (strip is 10s)
In which leads is T wave inversion normal?
III, aVR, V1
What ECG change might be seen in stable angina?
Widespread ST depression
What ECG changes are seen in an NSTEMI?
ST depression
T wave inversion
Difference between ischaemia and infarct
Infarct when cell death occurs due to ischaemia
ECG changes in STEMI (transmural infarct)
T wave inversion
Hyperacute T waves
ST elevation
Pathological Q waves
What is the criteria for ST elevation on ECG
> 1mm in 2 adjacent leads except V2 and V3 where must be >2mm
Other causes of ST elevation
Coronary artery vasospasm
LVH
Pericarditis
Pathological Q waves in V1 and V2- infarct location?
Septal
Pathological Q waves in V3 and V4 - infarct location?
Anterior
Pathological Q waves in V3-6, I and aVL - infarct location?
Anterolateral wall
Which lead is not a reliable one to look at for pathological Q waves?
aVR
Causes of pathological Q waves other than STEMI?
LBBB
WPW
How long does it take for each ECG change to resolve post STEMI?
ST elevation days
T wave inversion weeks/months
Pathological Q waves stay for longer
What would a large P wave in V1 and 2 (and II, III, aVF)
RA enlargement
What are the ECG signs of RV hypertrophy?
Dominant R wave in V1 and dominant S wave V5/6
R axis deviation
Narrow QRS (i.e. not due to RBBB)
Main ECG signs LVH
Deep S wave V1 and v big R wave V5/6. Add up to >35mm
Additional ECG signs in LVH
R wave duration longer (>50ms)
ST elevation V1
ST depression V5/6
T wave inversion V5/6
What do bifid P waves in Lead II and biphasic P waves in lead V1 mean?
LA enlargement
What is it called when blood flow to a muscle increases disproportionately due to vasodilation in those blood vessels?
(functional) hyperaemia
What are the two ways total peripheral resistance is controlled
Intrinsic and extrinsic factors
What are the intrinsic controls of total peripheral resistance?
- Level of metabolites in the surrounding tissue- adenosine and CO2 = vasodilation of arterioles
- Autoregulation: BP decrease = arteriole dilation
- Active hyperaemia: increased organ perfusion as required when it is more active
What is the extrinsic control of total peripheral resistance
Sympathetic NS and endocrine system control vascular smooth muscle contraction
What type of blood vessel is the primary site of vascular resistance?
Arterioles
What is the Starling equation (basically)
fluid movement is based on hydrostatic pressure and oncotic pressure
Also includes a filtration co-efficient which = the water permeability of the capillary wall
Left coronary artery splits into which arteries?
Left anterior descending
Left circumflex
Right coronary artery splits into what?
Right marginal
Posterior descending
What are the four cardiac veins?
Great
Middle
Small
Anterior
Which cardiac vein bypasses the coronary sinus and drains straight into the RA?
Anterior
With which artery does the great cardiac vein run?
LAD
With which artery does the middle cardiac vein run?
PDA
With which artery does the small cardiac vein run?
R marginal
With which artery does the anterior cardiac vein run?
right coronary
ST elevation in leads V1-4- where is the infarction and which artery?
Anterior/septal
LAD
ST elevation in leads V5,6 I and aVL- where is the infarction and which artery?
Lateral
Left circumflex
ST elevation in leads II, III, aVF- where is the infarction and which artery?
Inferior
RCA
ST depression in leads V1-4- where is the infarction and which artery?
Posterior
PDA/RCA
Mnemonic to remember reciprocal changes in ST elevation?
PAILS (arrow under the L)
What is R wave progression?
V1 has a deeper S wave and v small R wave, as you move along to V6 there is a more and more dominant R wave and a smaller S wave
Sensitivity/specificity of BNP?
Sensitive but not specific
Useful in ruling out HF but positive can = a lot of things.
If suspect an inferior MI what can you do to check?
Right sided leads ECG
ST elevation in V4R (5th ICS MCL) is high sens and spec for RV MI.
IF suspect posterior MI what can you do to check?
Posterior leads (V7,8,9)