12.11.21 Cardiac
Heart failure basics
Definition
Inability of the heart to provide oxygen requirements of tissue
Or only at the expense of raised LV filling pressure
Causes
50% CAD
Idiopathic 25%
Valve disease 10%
HTN 4%
Alcohol 4%
Survival varies depending on aetiology
But pooled 5-year survival is <50%
Signs
Raised JVP
Hepatojugular reflex
3rd heart sound
Displaced apical impulse
Murmur
CXR
A - Alveolar oedema
B - B lines
C - Cardiomegaly
D - Diversion to upper lobe
E - Effusion
BNP
False positive if old, female, AF, LVH, renal or resp failure, PE ...
Drugs with survival benefit
ACE inhibitor
Beta blocker
Spironolactone
Calcium channel blockers in heart failure
NOT diltiazem or verapamil as they decrease contractility
Dihydropyridines (e.g. nifedipine) are OK as they have peripheral action
Pacing
Can help heart failure
DON'T put pacing leads, or anything else, in the left heart!
cf thrombosis
If you need LV pacing, thread it round the veins, on the outside
Angina
Definition
Chest pain described as constriction/discomfort in chest, +/- radiation
Brought on by exercise or emotion
Relieved by rest or GTN
Not all 3?
Only 2 out of 3 = Atypical angina pain
0 or 1 out of 3 = Non-anginal pain
Most common cause
Atherosclerotic narrowing of coronary arteries
Symptomatic if >70%
Risk factors
Fixed
Age
Male
Genetics
Modifiable
Tobacco
HTN
DM
Hypercholesterolaemia
Depression
Obesity
Treatment options
Lifestyle modification
Pharmacotherapy
PCI
Surgical revascularisation
ECG features
T wave inversion
ST depression
LVH
LBBB
Exercise stress test
Very poor specificity
Therefore only useful when PPV is high
i.e. Previous Hx of CVD
Investigation based on risk
<10% => Consider non-cardiac cause
10-30% => Do CT calcium score
30-60% => Do functional test
Myoperfusion scan
Dobutamine stress echo
Stress MRI
60-90% => Straight to coronary angiogram
CT calcium score interpretation
0 => Consider other causes
1-400 => 64-slice CT coronary angiography
>400 => Invasive angiography as you won't see shit on a CT angiogram
Treatment
Symptoms
Start with a beta blocker
Add a CCB if still symptomatic
Use a non-dihydropyridine (diltiazem, verapamil)
Block the AV node and slow rate
Then add ranolazine if still symptomatic
Sodium channel blocker
Plus PRN GTN
Secondary prevention
B - Beta blocker
A - Aspirin
S - Statin
I - ACEi
C - Control risk factors
Checkups
Glucose
Lipids
Hb
TFTs
U+Es
Indications for surgery over PCI
Disabled
> 65
Complex 3-vessel disease
Left main stem disease
ACS
Subtypes
STEMI
NSTEMI
Unstable angina
The 11 Ps
Pain relief
Morphine + cyclizine
Paralyse the platelets
Aspirin, clopidogrel, LMWH
Pacify the plaque
High-dose statin
Perfuse the myocardium
PCI
Prevent adverse remodelling
ACEi, Beta blocker
Predict risk of sudden death
GRACE, Echo
Protect from sudden death
Aldosterone receptor antagonist (eplerenone)
NB less anti-androgen effects than spironolactone
Promote exercise
Prevent smoking
Praise health
Permit sex after 2 weeks
Other things causing a trop rise
Myocarditis
Tachyarrhythmia
DC cardioversion
Sepsis
Trauma
CPR
Renal failure
Cardiomyopathy
PE
Arrhythmias
Types and causes
Brady
Sinoatrial node disease
Conduction disease
Tachy
AF/flutter
SVT
AVNRT
AVRT
Atrial tachyarrhythmia
VT
VF
Sinus node disease - subtypes
Slow rate
Occasional failure
Exit failure
Tachy-Brady syndrome
LBBB
Supraventricular origin
QRS ≥ 120 ms
QS or rS complex in V1
RsR' wave in V6
Wenkiebach
Progressively longer PR, then dropped beat
Mobitz II
Regular dropped beats
Escape
Infranodal
Broad QRS, as not using normal pathway
High junctional
Uses His-Purkinje system => Narrow QRS
Junctional bradycardia
Retrograde P waves
Weird STs
May see in a paced rhythm
AF
May be coarse or fine
Often originates in areas round the pulmonary vein
Bigger heart => Predisposition to AF
And AF => Bigger heart, so AF BEGETS AF
Atrial flutter
Dependent on a SLOW ZONE for re-entry round the circuit
So can fix by ablation of this zone
Conduction through the AV node may be regular or variable
Atrial tachycardia
Due to enhanced automaticity
With AV block, can look like flutter
AVNRT
Suspect AVNRT if there's an unexplained tachycardia
Dependent on the slow and fast pathways through the AV node
Can set up a self-propagating loop
This then spreads out to the ventricles and sometimes to the atria too
=> Retrograde P waves
P waves may be buried in other stuff, making it all look weird
AVRT
Orthodromic
Normal pathway carries impulse to ventricles
Uses bundle of His => Narrow QRS complexes
Impulse retrogradely re-enters the atrium via the accessory pathway
P waves follow QRS complexes
Antidromic
Accessory pathway carries impulse down into ventricles
Outside of the bundle of His => Wide QRS, maybe with delta wave
Impulse re-enters the atrium retrogradely via the AV node
Pathway: Posterioseptal or right-sided
Pre-excitation
WPW
Delta waves
VT
Types
Polymorphic
Monomorphic
Check the axis to see if it could be coming from the AV node
Broad-complex tachycardia is VT until proven otherwise
Notes
ACS stats
40% of A&E admission are for chest pain
40% of STEMIs die within minutes
LBBB causes
Underlying CVD
Underlying heart muscle disorder
Congenital conduction disorder
Calcific aortic stenosis
Key drugs for management of angina: BETA BLOCKER AND CALCIUM CHANNEL BLOCKER
Normal sinus rhythm vs Atrial premature depolarisations vs SVT
Epsilon wave
Small positive deflection (‘blip’) buried in the end of the QRS complex
Characteristic finding in arrhythmogenic right ventricular dysplasia (ARVD)