Cardio Flashcards
What occurs to blood pressure during exercise?
Systolic increases, diastolic decreases - leads to increased pulse pressure
Why does cardiac output increase during exercise?
Venous constriction, increased venous return, increased myocardial contractibility
Why does systemic vascular resistance fall during exercise?
Vasodilation in skeletal muscles
What are the stages of Valsalva maneouvre?
- Increased intra-thoracic pressure
- Resultant increases in venous and right atrial pressures reduces venous return
- Reduced preload leads to a fall in cardiac output (Frank Starling mechanism)
- When the pressure is released there is a further slight fall in cardiac output due to increased aortic volume
- Return of normal cardiac output
In what conditions are S1 and S2 soft?
S1: soft in MS
S2: soft in AS
When is S3 normal
<30 years or women <50 years
What is a pathological cause of S3?
Left ventricular failure
MR
Constrictive pericarditis
What causes S4?
Atrial contraction against a stiff ventricle
AS, HOCM, Hypertension
What does the left coronary artery turn into?
LAD and circumflex
What does the right coronary artery turn into?
Posterior descending
Which artery supplies the SA node in 60% and AV node in 90%?
Right coronary
What is bicuspid aortic valve associated with?
Left dominant coronary circulation, where the posterior descending artery arises from the circumflex instead of the right coronary
+ Turner’s syndrome, coarctation of the aorta
Which cardiac abnormality is most common in Down’s syndrome?
AVSD
What murmur is heard in ASD?
Ejection systolic, louder on inspiration, fixed split S2
What is ASD associated with?
Ebstein’s anomaly, foetal alcohol syndrome
What is Ebstein’s anomaly?
Tricuspid leaflet dysplasia, apical displacement of the tricuspid annulus, abnormalities of RA and RV
What are the signs of tricuspid regurgitation?
Pansystolic murmur
Prominent V waves in JVP
Pulsatile hepatomegaly
Left parasternal heave
What is a risk factor for Ebstein’s anomaly?
Exposure to lithium in utero
What is Ebstein’s anomaly associated with?
PFO/ASD
WPW
What are the signs of Ebstein’s anomaly?
Cyanosis Prominent a wave in JVP Hepatomegaly TR RBBB --> widely split S1 and S2
What type of coarctation of the aorta is more common in adults?
Postductal (distal to the ductus arteriosus) which occurs after the left subclavian artery branches from the aorta
What are the signs of coarctation of the aorta?
Infancy - heart failure
Adults - HTN
Radiofemoral delay
Midsystolic murmur, maximal over back
Apical click
Notching of inferior border of ribs
Which cardiac enzyme is the first to rise in cardiac damage?
Myoglobin
What is the first line investigation in stable cardiac chest pain?
CT coronary angiography
What 3 other imaging modalities are 2nd line in investigating stable cardiac chest pain, looking for reversible myocardial ischaemia?
MPS with SPECT
Stress echo
MR perfusion
What is the 3rd line investigation in stable cardiac chest pain?
Invasive coronary angiography
What are the indications for exercise tolerance tests?
Assessing patients with suspected angina
Risk stratifying post MI/HOCM
When is exercise tolerance contraindicated?
MI<7 days Unstable angina Systolic BP>180bpm or <90bpm AS LBBB
What artery supplies the lateral aspect of the heart and which leads does this correspond to?
Circumflex
V5, V6, I
What artery supplies the anterior of the heart and which leads does this correspond to?
LAD
V1-V4
Which artery supplies the inferior aspect of the heart and which leads does this correspond to?
Right coronary
II, III, aVF
What is the ECG criteria for STEMI?
ECG changes in 2 or more contiguous leads and persist for >20 minutes:
V2-V3:
Women: 1.5mm STE
Men>40: 2mm STE
Men<40: 2.5mm STE
All other leads:
1mm STE
New LBBB
What is the management of blood glucose in T2DM post MI?
IV insulin
What is the general management of STEMI?
300mg aspirin
Oxygen if SpO2 <94%
Morphine/nitrates
PCI within 120 minutes OR fibrinolysis
What medications are given prior/during PCI?
Prasugrel
Radial access: Unfractionated heparin + bailout GPIIb/IIIa inhibitor
Femoral access: bivalirudin + bailout GPI
What medications are given prior/during fibrinolysis?
Antithrombin
Ticagrelor post procedure
What measures are taken if patient is high bleeding risk?
If having PCI: swap prasugrel to ticagrelor
If being thrombolysed: swap ticagrelor for clopidogrel
What type of stent is used in PCI?
Drug eluting to reduce the risk of restenosis
What type of access if preferred in PCI?
Radial
In the PCI pathway, if a patient is already taking anticoagulation, what changes are made to the drugs?
Aspirin 300mg as normal
Instead of prasugrel, give clopidogrel
What other procedure are performed during PCI?
Thrombus aspiration
Complete revascularisation
What is the general management of NSTEMI?
Aspirin 300mg
Estimate 6 month mortality:
Low risk - ticagrelor, fondaparinux
High risk - PCI
Why are nitrates avoided in RV infarct?
Reduces preload
How is 6 month mortality estimated in NSTEMI?
GRACE
Uses age, HR, BP, cardiac (Killip class), renal function, cardiac arrest of presentation, ECG findings, trop levels
What are 5 differentials for ST elevation?
Pericarditis/myocarditis Normal variant - high take off Left ventricular aneurysm Prinzmetal's angina Takotsubo cardiomyopathy
What is the general management of angina?
Aspirin
Statin
SL GTN spray PRN
What is the first line treatment of angina?
BB or CCB
If CCB monotherapy - rate limiting e.g. verapamil/diltiazem
Increase to max tolerated dose
What is the second line treatment of angina?
BB and CCB
CCB must be dihydropyridine e.g. nifedipine, if combining with BB
What is the third line treatment of angina?
Long acting nitrate
Ivabradine
Nicorandil
Ranolazine
What is the treatment of Prinzmetal’s angina?
Dihydropyridine CCB
What is the most common cause of arrest in MI?
VF
What 2 types of pericarditis occur post MI?
Post 48h
Post 2-6w (Dressler’s syndrome, autoimmune)
What are the signs of LV aneurysm?
Persistent STE and LV failure
No chest pain
How does LV free wall rupture present?
Acute heart failure secondary to cardiac tamponade
Which 2 post MI complications present with acute heart failure and pansystolic murmur?
Acute MR
VSD
Which type of infarction is acute MR more common with?
Infero-posterior infarction
What is the most common cause of secondary hypertension?
Primary hyperaldosteronism
Which drugs cause secondary hypertension?
Steroids MAOs COCP NSAIDs Leflunomide
Define PAH.
Resting mean pulmonary artery pressure >25mmHg
What are the features of pulmonary hypertension?
Progressive exertional dyspnoea
Exertional syncope, chest pain, peripheral oedema
What are the signs of pulmonary hypertension?
RV heave
Loud P2
Raised JVP with prominent a waves
TR
What is the management of PAH?
Acute vasodilator testing (administration of IV epoprostenol/inhaled NO)
+ve (minority): PO CCB
-ve (majority): prostacyclin analogues (iloprost), endothelin receptor antagonists (bosentan), PDE inhibitors (sildenafil)
What are the 8 reversible causes of cardiac arrest?
Hypoxia
Hypovolaemia
HyperK, hypoK, hypoBM, hypoCa
Hypothermia
Thrombosis
Tension pneumo
Tamponade
Toxins
What is the first line treatment of heart failure?
ACEI and BB
One drug started at a time
Which beta blockers are licensed for use in heart failure?
Bisoprolol
Carvedilol
Nebivolol
What is the 2nd line treatment of heart failure?
Aldosterone antagonist
What is the 3rd line treatment of heart failure?
Ivabradine Sacubitril-valsartan Digoxin Hydralazine + nitrate Cardiac resynchronisation therapy
What is the mechanism of sacubitril valsartan?
Prevents degradation of natriuretic peptides such as BNP and ANP
Why is digoxin used in heart failure if it has no affect on mortality?
May improve symptoms due to inotropic properties
What are the indications for CRT?
Wide QRS/LBBB
Ejection fraction<35%
What are 6 causes of increased BNP, except LV failure?
Tachycardia Hypoxaemia Sepsis COPD Diabetes Cirrhosis
What are 6 causes of decreased BNP?
Obesity
Diuretics
ACEI, BB, AA, ARB
What valvular abnormality is seen in William’s syndrome?
Supravalvular aortic stenosis
What are the 2 causes of aortic stenosis?
<65: bicuspid valve
>65: calcification
What are the features of severe AS?
Narrow pulse pressure Slow rising pulse Delayed ESM Soft S2 S4 Thrill LV failure
When is aortic valve replacement indicate?
Symptomatic
Valvular gradient >40
LVSD
What are the signs of mitral stenosis?
Mid-late diastolic murmur, loudest in expiration Loud S1, opening snap Low volume pulse Malar flush AF
What is the management of mitral stenosis?
Severe: percutaneous mitral commissurotomy –> mitral valve replacement
If unsuitable for open surgery - transcatheter mitral valve replacement
What is the treatment of mitral regurgitation?
MV repair
What drugs are used in pharmacological cardioversion in AF?
Amiodarone Flecainide (if no structural heart disease)
To what is electrical cardioversion synchronised to in AF?
The R wave
What happens if shock is delivered during T wave during AF?
This is ventricular repolarisation
Can trigger T on T phenomenon which leads to VF
In non emergency situations, how long duration of anticoagulation is needed before electrical cardioversion for AF?
4 weeks
Why is conservative management recommended in complete heart block following inferior MI?
Ischaemic AV conduction block
Tends to resolve upon successful revascularisation of the infarcted AV nodal tissue
What is the management of 2nd degree/complete heart block following anterior MI?
Temporary pacing wire
May also be a bridging measure to insert PPM
What are the indications for a temporary pacemaker?
Symptomatic/heamodynamically unstable bradycardia, not responding to atropine
Post anterior MI
Trifascicular block prior to surgery
In what condition is variable intensity of S1 seen?
Complete heart block
When are 3 successive shocks prior to CPR indicated?
Witnessed cardiac arrest whilst on monitor
What are the ECG changes of hypokalaemia?
U waves Small/inverted T waves Prolonged PR interval ST depression Long QT
What are the ECG changes of hypothermia?
Bradycardia
J waves
First deg heart block
Long QT
What is the name of the condition where there is a congenital accessory conducting pathway between the atria and ventricles leading to AVRT?
Wolff-Parkinson White syndrome
In WPW, Why can AF degenerate rapidly to VF?
The accessory pathway does not slow conduction
What are the ECG features of WPW?
Short PR
Wide QRS with slurred upstroke (delta wave)
Type B: LAD, no dominant R wave in V1
Type A: RAD, dominant R wave in V1
What is type A and B WPW?
Type A: left sided accessory pathway
Type B: right sided accessory pathway
What are 5 associations of WPW?
HOCM MV prolapse Ebstein's anomaly Thyrotoxicosis Secundum ASD
What is the treatment of WPW?
Amiodarone/flecainide
Sotalol if not AF
Radiofrequency ablation of accessory pathway
What is the atrial rate in atrial flutter?
300bpm
What is the treatment of atrial flutter?
Similar to AF
Medications less effective, cardioversion more effective - lower energy levels
Radiofrequency ablation of the tricuspid valve isthmus
What is the mechanism of action of nicorandil?
Potassium channel activator
Activates guanylyl cyclase with increases cGMP –> vasodilation
What are 3 side effects of nicorandil?
Headache, flushing, ulceration
How does atropine treat bradycardia?
Inhibits vagal tone by modulating the SA node
What is the mechanism of action of amiodarone?
Blocks K channels - inhibits repolarisation and prolongs the AP
Also blocks Na channels
Name 6 side effects of amiodarone
Thyroid dysfunction Corneal deposits Pulm/liver fibrosis Slate grey appearance Prolonged QT Bradycardia
How do ADP receptor inhibitors, such as clopidogrel and ticagrelor work?
Inhibition of P2Y12 receptor which reduces platelet aggregation
ADP is one of the main platelet activation factors
Why does ticagrelor cause dyspnoea?
Impaired clearance of adenosine
How does dipyridamole work?
Inhibits phosphodiesterase, which elevates platelet cAMP which reduces intracellular calcium
How does adenosine work?
Blocks AV node - agonist of A1 receptor in AV node which inhibits adenylyl cyclase –> reducing cAMP –> hyperpolarization by increased K efflux
What are the ECG signs of digoxin toxicity?
Downsloping ST depression
Flattened/inverted T waves
Short QT
AV block/bradycardia
What is the mechanism of action of statins?
Inhibits HMG-CoA reductase which is the rate limiting enzyme in hepatic cholesterol synthesis
What are the risk factors for myopathy in patients who take statins?
Female Older age Low BMI Diabetes Lipophilic statins
What are the indications for statins?
Q risk >10%
Established CV disease
T1DM: diagnosed >10 years, aged >40, or established nephropathy
Why are statins taken at night?
This is when the majority of cholesterol synthesis takes place
What is the pathophysiology of Takotsubo cardiomyopathy?
Apical ballooning like octopus pot due to severe hypokinesis of mid and apical segments, preservation of basal segments
What are the genetics of HCOM?
Mutation in gene encoding beta-myosin heavy chain protein or myosin binding protein C
What is the pathophysiology of HCOM?
LV hypertrophy –> decreased compliance –> decreased cardiac output
Mainly diastolic dysfunction
Myofibrillar hypertrophy + disarray and fibrosis of myocytes
What are the signs of HCOM?
Jerky pulse
Large a waves of JVP
Double apex beat
ESM, increases with Valsalva and decreases on squatting
What is seen on echo and ECG in HCOM?
Echo: asymmetric septal hypertrophy with systolic anterior movement of anterior leaflet of mitral valve
ECG: LV hypertrophy, progressive TWI, deep Q waves
What are 5 poor prognostic features of HCOM?
Syncope FH SCD Young age at presentation Increased septal wall thickness >30mm Abnormal BP change on exercise
What is the management of HCOM?
ABCDE
Amiodarone Betablockers/verapamil for symptoms Cardioverter defibrillator Dual chamber pacemaker Endocarditis prophylaxis
Which drugs should be avoided in HCOM?
Nitrates
ACEIs
Inotropes
Why are nitrates avoided in heart failure?
Vasodilation reduces preload
What are the causes of restrictive cardiomyopathy?
Amyloid Haemochromatosis Loffler's syndrome Sarcoid Scleroderma
How can restrictive cardiomyopathy be differentiated from constrictive pericarditis?
Prominent apical pulse
No pericardial calcification
Enlarged heart
Bundle branch block and Q waves
What is the inheritance of arrhythmogenic right ventricular cardiomyopathy?
Autosomal dominant
What are the ECG changes of arrhythmogenic right ventricular cardiomyopathy?
TWI V1-V3
Epsilon wave in 50% (terminal notch in QRS)
What is the treatment of ARVC?
Sotalol
Catheter ablation to prevent VT
ICD
What is the triad of Naxos disease?
ARVC (AR variant)
Palmoplantar keratosis
Woolly hair
What is the pathophysiology of LQTS?
Defects in alpha subunit of slow delayed rectifier K channel
What are the congenital causes of LQTS?
Jervell-Lange Nielsen (deafness)
Romano-Ward (no deafness)
What are the acquired causes of LQTS?
Drugs: amiodarone, sotalol, SSRIs, TCAs, chloroquine, macrolides, ondansetron, methadone
Low K, Ca, Mg
What is the management of LQTS?
BB
ICD
What is the genetics of Brugada syndrome?
Autosomal dominant
SCN5A gene - encodes myocardial sodium ion channel
What are the ECG changes of Brugada syndrome?
Convex ST elevation >2mm in >V1-V3, followed by TWI
Partial RBBB
Changes more apparent following administration of flecainide or ajmaline
Name 6 causes of pericarditis
Coxsackie virus TB Uraemia Dressler's CTD Malignancy
What are the ECG changes of pericarditis?
Diffuse saddle shaped ST elevation
PR depression
What is the pathophysiology of rheumatic fever?
Strep pyogenes infection (cell wall includes M protein which is highly antigenic)
Activation of innate immune system leading to antigen presentation to T cells
Molecular mimicry (form of T2 hypersensitivity)
Antibodies against M protein cross-react with myosin
What are the major criteria of rheumatic fever?
Erythema marginatum Sydenham's chorea Polyarthritis Carditis/valvulitis SC nodules
What is the treatment of rheumatic fever?
PO penicillin V
Which cause of infective endocarditis is linked to dental work?
Strep viridans (includes strep mitis, strep sanguinis)
Infective endocarditis caused by staph epidermis is most common in what scenario?
Indwelling lines
Prosthetic valve surgery
Strep bovis/gallolyticus endocarditis is associated with what?
Colorectal Ca
Name 4 culture negative causes of endocarditis.
Coxiella burnetti
Bartonella
Brucella
HACEK
What are 4 poor prognostic features of IE?
S.aureus
Prosthetic valve
Culture -ve
Low complement
What is the treatment of IE of prosthetic valves?
Rifampicin + gentamicin + fluclox/vancomycin
What is Eisenmenger’s syndrome?
The reversal of left to right shunt in congenital heart defect due to pulmonary hypertension
What are the signs of Eisenmenger’s syndrome?
Original murmur may disappear Cyanosis Clubbing RV failure Loud S2 Large a waves in JVP
What is the function of BNP?
Vasodilator
Diuretic, natriuretic
Suppresses sympathetic tone and RAAS
Name 2 causes of reduced BNP
ACEIs/ARBs
Digoxin
Which scan measures LVEF accurately and is used before and after use of cardiotoxic drugs?
Multi-gated acquisition scan (MUGA)
What can SPECT imaging do?
Assess myocardial perfusion and viability
What are the 2 methods of assessing IHD in cardiac CT?
Calcium score
Contrast enhanced - visualisation of coronary artery lumen
What is a risk factor for multi-focal atrial tachycardia?
Chronic lung disease
What are the pathways in AVNRT?
Slow (alpha) with short refractory period
Fast (beta) with long refractory period
What is the management of AVNRT?
Vagal maneouvres
IV adenosine 6 –> 12 –> 12
Cardioversion
What is the treatment of AVNRT in asthmatics?
Substitute adenosine for verapamil
Which features suggest VT rather than SVT with aberrant conduction?
QRS>160 Capture and fusion beats AV dissociation Marked LAD History of IHD Lack of response to adenosine/carotid sinus massage Positive QRS concordance in chest leads
What is the treatment of sustained (>30s) VT?
Shock etc: synchronised DC cardioversion
Amiodarone, lidocaine
What are the causes of polymorphic VT?
If prolonged QT: TDP
If bidirectional: digoxin toxicity
What is the pathophysiology of VT caused by digoxin toxicity?
Triggered activity - due to early or late after-depolarisations
What is the pathophysiology of monomorphic VT?
Re-entry
Abnormal automaticity
What is the treatment of TDP?
IV magnesium sulphate