Cardiology Flashcards
What causes atherosclerosis?
Chronic inflammation and activation of the immune system-> lipid deposition-> atheromatous plaques
What do atherosclerotic plaques cause?
- Stiffening of the artery wall (hypertension and heart strain)
- Stenosis + reduced blood flow (angina)
- Plaque rupture + thrombus (ischaemia)
Non-modifiable risk factors for atherosclerosis?
Older age, family history, male
Modifiable risk factors for atherosclerosis?
Smoking, alcohol, diet, low exercise, obesity, poor sleep, stress
Medical comorbidities that increase the risk of atherosclerosis?
Diabetes, HTN, CKD, inflammatory conditions (eg RA), atypical antipsychotics
Primary prevention of CVD?
- When never had CVD before
- QRISK 3 score
- Give atorvastatin 20mg when-> 10% risk or more, CKD, T1DM
When should statins be stopped (in terms of LFT results)?
When ALT/AST rise to more than 3x upper limit of normal
Secondary prevention of CVD?
4A’s-> Aspirin (+clopidogrel for 12 months after event), Atorvastatin 80mg, Atenolol (or bisoprolol), ACE inhibitor (eg ramipril)
Side effects of statins?
- Myopathy
- Type 2 DM
- Haemorrhagic strokes
- Deranged LFTs
- Rhabdomyolysis
What is stable angina?
- When a narrowing of the CAs reduces blood flow to myocardium causing symptoms
- Stable when symptoms relieved by rest or GTN spray
Gold standard investigation for stable angina?
CT coronary angiography
Baseline investigations in stable angina?
Examination, ECG, FBC, U+Es, LFTs, lipid profile, TFTs HbA1C, fasting glucose
General management for stable angina?
RAMP-> refer to cardio, advise about management, medical treatment, procedure/surgery
Medical management of stable angina?
- Immediate relief-> GTN spray, repeat after 5 mins, call 999 if still pain
- Long term-> beta-blocker or CCB, or long acting nitrate, ivabradine, nicorandil etc
- Secondary prevention-> aspirin, atorvastatin, ACE inhibitor
What does primary PCI entail?
- Percutaneous coronary intervention (PCI) with coronary angioplasty (dilate vessel with balloon and/or stent)
- Catheter via brachial or femoral artery
- Contrast injected
What is CABG?
- Coronary artery bypass graft
- Graft vein from leg (eg great saphenous vein) + sew onto CA to bypass stenosis
- Leaves midline sternotomy scar
What does the RCA supply?
RA, RV, inferior of LV, posterior septal area
What does the circumflex artery supply?
LA and posterior LV
What does the LAD artery supply?
Anterior LV + anterior septum
Diagnosis of STEMI?
ST elevation or new LBBB on ECG
Diagnosis of NSTEMI?
- ST depression, T wave inversion or pathological Q waves on ECG
- Raised troponin levels
Diagnosis of unstable angina?
Symptoms but no ECG changes or raised troponin
Symptoms of ACS?
- Central crushing chest pain, sweating, N+V, SOB, palpitations, pain radiating to jaw/arms
- Symptoms usually last 20+ minutes at rest
What is a silent MI?
ACS in a diabetic patient-> might not get typical chest pain
What area of the heart would ECG changes in leads I, aVL and V3-6 suggest?
Left coronary artery (anterolateral)
What area of the heart would ECG changes in leads V1-4 suggest?
LAD (anterior)
What area of the heart would ECG changes in leads I, aVL, V5-6 suggest?
Circumflex (lateral)
What area of the heart would ECG changes in leads II, III, aVF suggest?
RCA (inferior)
When should troponin levels be taken?
Baseline, 6 hours and 12 hours after symptom onset
What might a raised troponin level suggest?
- Myocardial ischaemia
- CKD, sepsis, myocarditis, aortic dissection, PE
Investigations for ACS?
- Bloods-> FBC, U+Es, LFTs, lipid profile, TFTs HbA1C, fasting glucose
- ECG
- CXR
- Echo-> functional damage
- CT coronary angiogram
When is primary PCI an available treatment option for STEMI?
Within 2 hours of presentation
When is thrombolysis an available treatment option for STEMI?
Within 12 hours of symptom onset + PCI not available within 2 hours
What is thrombolysis?
- Use of fibrinolytic medication to break down fibrin + dissolve clot
- Can use streptokinase, alteplase or tenecteplase
Acute treatment of NSTEMI?
BATMAN-> beta-blockers, aspirin 300mg, ticagrelor (or clopidogrel), morphine, anticoagulant (eg fondaparinux), nitrates (eg GTN)
What is the GRACE Score for PCI in NSTEMI?
- 6 month risk of death or repeat MI after NSTEMI
- If medium or high risk (5% risk or more) then considered for early PCI (within 4 days of admission)
Complications of MI?
DREAD-> Death, Rupture of heart septum/papillary muscles, Edema (HF), Arrhythmia, Aneurysm, Dressler’s Syndrome
What is Dressler’s syndrome?
- Localised immune response + pericarditis 2-3 weeks post-MI
- Pleuritic chest pain
- Global ST elevation + T wave inversion on ECG
- Raised inflammatory markers
- Managed with NSAIDs + steroids + sometimes pericardiocentesis
Secondary prevention post-ACS?
- Aspirin 75mg
- Another antiplatelet-> clopidogrel or ticagrelor for 12 months
- Atorvastatin 80mg
- ACE-inhibitor
- Atenolol or bisoprolol
- Aldosterone antagonist (when clinical HF eg eplerenone)
What are the 4 types of MI?
- 1-> traditional MI (acute coronary event)
- 2-> ischaemia secondary to increased demand or reduced supply of oxyge
- 3-> sudden cardiac death/arrest suggestive of ischaemic event
- 4-> associated with PCI/stenting/CABG
Pathophysiology of acute LVF?
LV unable to move blood through to body-> backlog of blood in LA + pulmonary veins + lungs-> increased pressure in vessels + leak interstitial fluid (pulmonary oedema)-> interferes with gas exchange
Triggers of acute LVF?
Iatrogenic (eg IV fluids), sepsis, MI, arrhythmias
Symptoms of acute LVF?
- Rapid onset breathlessness exacerbated by lying flat
- Type 1 resp failure
- SOB, unwell
- Frothy white/pink sputum + cough
Examination findings in acute LVF?
- Increased RR, reduced sats, tachycardia, 3rd heart sound, bilateral basal crackles, cardiogenic shock (severe)
- If RVF present-> raised JVP + peripheral oedema
Investigations for acute LVF?
- B-type Natriuretic Peptide (BNP) blood test
- Bloods-> infection, kidney, troponin etc
- ECG
- ABG
- CXR
- Echo
What is the BNP blood test?
- Hormone released from ventricles when myocardium stretched beyond normal range
- Acts to relax smooth muscles in vessels + reduce systemic vascular resistance (easier for heart to pump blood)
- Acts as diuretic
- Can be raised in heart failure, tachycardia, sepsis, PE, renal impairment, COPD
What is ejection fraction and what level is considered as normal?
- % of blood in LV squeezed out with contraction
- Normal-> >50%
Signs of heart failure on CXR?
- Alveolar oedema-> Bat wing sign
- Kerley B lines (fluid in septal lines)
- Cardiomegaly-> >50% diameter of lung fields
- DIlated upper lobe vessels-> venous diversion, larger diameter of upper lobe vessels
- Effusions-> pleural
- Fluid in interlobar fissures
Management of acute LVF?
Pour SOD->
- Stop IV fluids + monitor balance
- Sit up-> leave upper lobes clear for gas exchange
- Oxygen
- Diuretics-> IV furosemide 20-50mg stat
In severe->
- IV opiates (vasodilators)
- NIV eg CPAP
- Inotropes-> noradrenaline, to strengthen contractions, in HDU/ICU
What is chronic heart failure?
Impaired LV contraction (systolic) or LV relaxation (diastolic) causing back-pressure of blood through left side of heart
Symptoms of chronic heart failure?
- Breathless on exertion
- Cough + frothy pink/white sputum
- Orthopnoea-> SOB when lying flat
- Paroxysmal nocturnal dyspnoea-> wake up in the night feeling SOB
- Peripheral oedema
Investigations for chronic heart failure?
- Clinical presentation
- BNP
- Echo
- ECG
Causes of chronic HF?
IHD, valvular disease (eg aortic stenosis), HTN, arrythmias (AF)
Management of chronic HF?
- Referral when BNP >2000ng/L
- ACE-i (or ARB)
- Beta-blocker
- Aldosterone antagonist when not controlled (eg spironolactone)
- Loop diuretics for symptoms
- Surgical if underlying cause
What is cor pulmonale?
- Right sided heart failure caused by respiratory disease
- Increased pressure in pulmonary arteries (pulmonary HTN) -> RV unable to pump effectively-> back pressure to RA + VC + systemic venous system
Causes of cor pulmonale?
COPD, PE, interstitial lung disease, CF, primary pulmonary HTN
Symptoms and signs of cor pulmonale?
- SOB, peripheral oedema, syncope, chest pain
- Cyanosis, raised JVP, oedema, 3rd heart sound, murmurs (eg pan-systolic in tricuspid regurg), hepatomegaly
Treatment of cor pulmonale?
Treat underlying cause + long term oxygen therapy
Diagnosis of hypertension?
BP above 140/90 (clinic) or 135/85 (home)
Most common cause of HTN?
Essential or primary HTN (ie no secondary cause) in 95%
Causes of secondary hypertension?
ROPE-> renal disease, obesity, pregancy induced/pre-eclampsia, endocrine (eg Conn’s syndrome)
Complications of HTN?
IHD, CVA, retinopathy, nephropathy, HF
When should blood pressure be measured to screen for HTN?
- Every 5 years
- More often when on borderline for diagnosis
- Yearly in type 2 DM
What are the different stages of HTN?
- Stage 1-> 140/90 or 135/85
- Stage 2-> 160/100 or 150/95
- Stage 3-> 180/120
Investigations for end organ damage in HTN?
- Urine albumin:creatinine ratio + dipstick-> kidney damage
- Bloods-> HbA1C, renal, lipids
- Fundus exam
- ECG
Management of HTN in aged <55 or non-black?
- 1-> ACE i or ARB
- 2-> ACE i or ARB + CCB or TLD
- Step 3-> ACEi/ARB + CCB + TLD
- Step 4-> add spironolactone (when K+ <4.5mmol/L) or alpha/beta blocker (when K+ >4.5mmol/L)
Management of HTN in aged >55 or black + any age?
- 1-> CCB
- 2-> CCB + ACE i or ARB or TLD
- Step 3-> CCB + ACEi/ARB + TLD
- Step 4-> add spironolactone (when K+ <4.5mmol/L) or alpha/beta blocker (when K+ >4.5mmol/L)
ARBs are preferred over ACEis in black patients
Treatment targets in HTN?
- <80 years-> <140/90
- >80 years-> <150/90
What causes the first heart sound (S1)?
Tricuspid + mitral valve closure at the start of systolic contraction of ventricles
What causes the second heart sound (S2)?
Semilunar valve closure (pulmonary + aortic valves) when systolic contraction complete
What causes a third heart sound (S3)?
- Rapid ventricular filling causes chordae tendineae to pull + ‘twang’
- Normal in 15-40 year olds
- Can indicate heart failure as ventricles become stiff + weak
What causes a fourth heart sound (S4)?
- Directly before S1
- Stiff/hypertrophic ventricle + turbulent flow from atria to ventricle
What are the four valve areas when listening for murmurs?
- Pulmonary-> 2nd ICS left sternal border
- Aortic-> 2nd ICS right sternal border
- Tricuspid-> 5th ICS left sternal border
- Mitral-> 5th ICS mid-clavicular line
- Erb’s point-> 3rd ICS left sternal border (for S1 + S2)
How to assess a murmur?
SCRIPT
- Site-> where it’s loudest
- Character-> soft, blowing, crescendo-descresendo etc
- Radiation-> carotids (AS) or left axilla (MR)?
- Intensity-> grade (1-6)
- Pitch (indicates velocity)
- Timing-> systolic or diastolic
What effect does mitral stenosis have on the heart muscle?
LA hypertrophy-> as has to try harder to push blood out of stenosed valve
What effect does aortic stenosis have on the heart muscle?
LV hypertrophy-> as has to try harder to push blood out of stenosed valve
What effect does mitral regurgitation have on the heart muscle?
LA dilatation-> leaky valve allows backflow into chamber + stretches muscle
What effect does aortic regurgitation have on the heart muscle?
LV dilatation-> leaky valve allows backflow into chamber + stretches muscle
What type of murmur does mitral stenosis cause?
- Mid-diastolic, low pitched, rumbling (low velocity)
- Loud S1-> thick valves need large force to shut
What other features is mitral stenosis associated with?
- Malar flush-> back pressure of blood to pulmonary system
- AF-> LA struggles to push blood
Causes of mitral stenosis?
Rheumatic heart disease, infective endocarditis
What type of murmur does mitral regurgitation cause?
- Pansystolic + high pitched + whilstling-> high velocity
- Radiates to left axilla
- May have 3rd heart sound
Causes of mitral regurgitation?
Idiopathic (age), IHD, infective endocarditis, rheumatic heart disease, Ehlers-Danlos, Marfan syndrome
What does mitral regurgitation result in?
Congestive cardiac failure
What murmur does aortic stenosis cause?
- Ejection-systolic, high pitched, crescendo-decrescendo-> due to speed of blood flow during systole
- Radiates to carotids
Signs of aortic stenosis?
- Slow rising pulse + narrow pulse pressure
- Exertional syncope
Causes of aortic stenosis?
Idiopathic age-related calcification or rheumatic heart disease
What murmur does aortic regurgitation cause?
- Early diastolic, soft
- Austin-Flint-> diastolic rumbling murmur, heard at apex, as blood back through aortic + over mitral causing vibration
What clinical sign is aortic regurgitation associated with?
Collapsing/Corrigan’s pulse-> rapid appear + disappearing pulse at carotids (blood out then back in)
Causes of aortic regurgitation?
Idiopathic.age, connective tissue disorders
What scars will someone with a valve replacement typically have?
- Midline sternotomy (mitral/aortic/CABG)
- Right sided mini-thoracotomy (mitral)
How long do bioprosthetic heart valves last?
10 years
How long do mechanical valves last and what is needed to be prescribed alongside them?
- 20+ years
- Warfarin therapy (lifelong) with INR target of 2.5-3.5
Complications of mechanical heart valves?
- Thrombus formation
- Infective endocarditis
- Haemolysis + anaemia (blood churned up in valve)
Treatment for severe aortic stenosis?
TAVI (transcatheter aortic valve implantation)-> catheter in femoral, X ray guidance, implant bioprosthetic valve
What organisms typically cause infective endocarditis?
- Staphylococcus
- Streptococcus
- Enterococcus
Pathophysiology of atrial fibrillation?
- Disorganised electrical activity overrides that of SAN-> unco-ordinated + rapid atrial contraction
- Blood tends to collect in atria + clot-> emboli + strokes
Signs of atrial fibrillation?
- Irregularly irregular ventricle contractions
- Tachycardia
- HF
- No P waves on ECG
Symptoms of AF?
None, palpitations, SOB, syncope, symptoms of other conditions (eg stroke)
What is valvular AF?
When patient has AF alongside mitral stenosis or mechanical heart valve-> valve pathology leads to AF
Causes of AF?
Mrs SMITH-> sepsis, mitral valve pathology, IHD, thyrotoxicosis, HTN
When is rate control used 1st line in AF and what is the treatment aim?
- All with AF-> onset >48 hours
- Aim to get HR <100
When is rhythm control used 1st line in AF and what is the treatment aim?
- Onset <48 hours, there is a reversible cause, the AF is causing heart failure, or symptoms despite rate control
- Return to normal sinus rhythm
What are the options for rate control in AF?
- Beta blocker 1st line
- CCB eg diltiazem (not in HF)
- Digoxin (when sedentary)
When is immediate cardioversion used for AF?
When AF present for <48 hours or haemodynamically unstable
When is delayed cardioversion used in AF?
- When stable + present for >48 hours
- Need anticoagulation for 3+ weeks before (prevent clots forming + mobilising + causing stroke)
What is used for short-term pharmacological cardioversion in AF?
- Flecainide
- Amiodarone-> when structural heart disease
What does electrical cardioversion involve?
- Rapid shock into sinus rhythm
- Sedation or GA
- Cardiac defibrillator
What options are there for long-term medical rhythm control in AF?
- Beta blockers
- Dronedarone (when had successful cardioversion)
- Amiodarone (HF or LV dysfunction)
What is paroxysmal AF?
- Episodes of AF lasting <48 hours
- Anticoagulate based on CHADSVASc score
- May have ‘pill in pocket’ approach when having episodes (flecanide)
Why should flecanide be avoided in atrial flutter?
Can cause 1:1 AV conduction and significant tachycardia
How much does anticoagulation affect risk of stroke in AF?
It reduces the risk by about 2/3rd
How does warfarin work?
- Vitamin K antagonist
- Prolongs the prothrombin time (ie takes longer to clot)
What is the usual INR target for patients with AF taking warfarin?
2-3
What may influence a patient’s INR level when on warfarin?
- CYP450 inducers and inhibitors-> includes alcohol
- Foods containing vitamin K-> leafy green veg
What can be used to reverse the effects of apixaban and rivaroxaban?
Andexanet alfa
What can be used to reverse the effects of dabigatran?
Idarucizumab
Why are DOACs preferred over warfarin?
- No monitoring requirements
- No major interactions
- Equal or better risk of preventing stroke
- Equal or less risk of bleeding
What is the CHA2DS2-VASc scoring tool used for?
- Assess whether a patient with AF should be put on anticoagulants
- Risk of stroke/TIA
What should be done when a patient has a CHA2DS2-VASc score of 1?
Consider anticoagulation
What should be done when a patient has a CHA2DS2-VASc score of more than 1?
Offer anticoagulation
What are the components of the CHA2DS2-VASc scoring tool?
- Congestive heart failure
- HTN
- Age 75 + (scores 2)
- Diabetes
- Stroke or TIA previously (scores 2)
- Vascular disease
- Age 65-74
- Sex (female)
What is the HAS-BLED scoring tool used for?
- Establish patient’s risk of major bleeding when on anticoagulation
- Risk of stroke usually more than of bleed + is harder to treat
What are the components of the HASBLED scoring tool?
Hypertension Abnormal renal or liver function Stroke Bleeding Labile INRs (when on warfarin) Elderly Drugs or alcohol
Which cardiac arrest rhythms are shockable?
- ventricular tachycardia
- ventricular fibrillation
Which cardiac arrest rhythms are non-shockable?
- Pulseless electrical activity (ie any except VF + VT)
- Asystole
Treatment for tachycardia (unstable patient)?
- Consider 3 synchronised shocks
- Consider amiodarone infusion
What rhythms may fall under the narrow complex tachycardia (QRS <0.12s) category?
AF, atrial flutter, supraventricular tachycardias
Treatment for atrial flutter?
- Rate control with beta-blocker or cardioversion
- Radiofrequency ablation of re-entrant rhythm
- Anticoagulation
Acute treatment for SVT?
- Vagal manouvres-> valsalva manouvre, carotid sinus massage
- Adenosine rapid bolus-> slows cardiac condution through AVN + interrupt AVN/accessory pathway
- Direct current cardioversion
What rhythms may fall under the broad complex tachycardia (QRS >0.12s) category?
- Ventricular tachycardia
- SVT with bundle branch block
- AF
What is atrial flutter?
- Re-entrant rhythm-> electrical signal re-circulates in atria due to extra electrical activity-> 300bpm atrial contraction
- Signal to ventricles every 2nd lap-> 150bpm venticular rate
What does atrial flutter look like on an ECG?
- Ventricular rate of 150bpm
- Sawtooth appearance-> P waves repeating
Causes of atrial flutter?
HTN, IHD, cardiomyopathy, thyrotoxicosis
What causes supraventricular tachycardia?
Electrical signal re-entering the atria from ventricles-> self-perpetuating loop + cause narrow complex tachycardia
What does SVT look like on an ECG?
- QRS <0.12 seconds
- QRS the immediate T wave then repeats
What are the different types of SVT?
- AV nodal re-entrant tachycardia-> re-entry point back through AVN
- AV re-entrant tachycardia-> WPW syndrome (accessory)
- Atrial tachycardia-> signal starts somewhere other than SAN
- Paroxysmal-> SVT recurs + remits over time
What do you need to warn the patient about when giving them adenosine?
Will get a scary feeling of impending doom-> brief asystole or bradycardia
Contraindications of adenosine?
Asthma, COPD, HF, heart block, severe hypotension
Long term treatment of paroxysmal SVT?
- Meds-> beta-blockers, CCBs, amiodarone
- Radiofrequency ablation
What is Wolff-Parkinson White syndrome?
Extra pathway (Bundle of Kent) between atria + ventricles
What ECG changes might be present in WPW syndrome?
- Short PR interval (<0.12s)
- Wide QRS (>0.12s)
- Delta wave-> slurred upstroke of QRS complex
Treatment of WPW syndrome?
- Radiofrequency ablation of accessort pathway
- NOT antiarrhythmic meds-> may promote conduction through accessory
When can radiofrequency ablation be used?
AF, atrial flutter, SVTs, WPW syndrome
What is torsades de pointes?
- Polymorphic ventricular tachycardia
- QRS seems to twist around baseline
- Can spontaneously resolve or cause VT + cardiac arrest
Pathophysiology of torsades de pointes?
Prolonged QT interval-> repolarisation delayed so random depolarisation of some myocytes-> spread + cause recurrent contractions without normal repolarisation-> torsades de pointes
Causes of prolonged QT interval?
- Inherited-> long QT syndrome
- Medications-> antipsychotics, citalopram, flecainide, sotalol, amiodarone, macrolide antibiotics
- Electrolyte disturbances-> hypokalaemia, hypomagnesia, hypocalcaemia
Acute management of torsades de points?
- Correct underlying cause
- Magnesium infusion
- Defibrillation (when VT)
Long term management of torsades de pointes?
- Avoid medications that cause prolonged QT
- Beta blockers (not sotalol)
- Pacemaker or implantable defibrillator
What are ventricular ectopics?
Premature ventricular beats caused by random electrical discharges from outside the atria
Presentation of ventricular ectopics?
- Random palpitations
- All ages + can be in healthy patients
- Common in IHD or HF
- Random broad QRS complexes on normal ECG
What is bigeminy?
Ventricular ectopics after every sinus beat (ie 1:1)
Management of ventricular ectopics?
- Bloods-> anaemia, electrolytes, thyroid
- Reassurance
- May need referral if other conditions
What is 1st degree heart block?
- Prolonged PR interval (>0.2s)
- Delayed conduction through AVN
What is second degree heart block?
-Some instances of p waves not leading to QRS complexes
What is second degree heart block (Mobitz Type I ie Wenckebach’s phenomenon)?
- Atrial impulses gradually weaken till doesn’t pass through AVN
- Increasing PR interval then absent QRS after a P wave
What is second degree heart block (Mobitz type II)?
- Intermittent failure or interruption of AV conduction
- Usually set ratio
- Risk of asystole
What is 2:1 heart block?
- 2 p waves for each QRS complex
- Can be Mobitz type I or II
What is third degree heart block?
- Complete heart block-> no relationship between P and QRS
- Risk of asystole
Treatment for bradycardia or AVN blocks (when stable)?
Observe
Treatment for bradycardia or AVN blocks (when unstable or risk of asystole)?
- 1st-> atropine 500mcg IV
- No improvement-> repeat atropine, inotropes, transcutaneous cardiac pacing
- High risk of asystole-> temporary transvenous cardiac pacing or permanent pacemaker
How does atropine work?
Antimuscarinic-> inhibits parasympathetic nervous system
Side effects of atropine?
Antimuscarinic + pupil dilation
What is a pacemaker?
- Deliver controlled electrical impulses to the heart to restore normal activity
- Pulse generator + pacing leads
- Monitors activity + tailors function to that
What interventions are contraindicated when a patient has a pacemaker?
- MRI scan
- TENS machine
- Diathermy in surgery
- Cremation
What are the indications for a pacemaker?
Symptomatic bradycardias, Mobitz type 2 AV block, 3rd degree heart block, severe HF, hypertrophic obstructive cardiomyopathy
What are the different types of pacemaker?
- Single chamber-> in RA or RV
- Dual chamber-> RA + RV
- Biventricular (triple chamber aka cardiac resynch therapy)-> RA + RV + LV
- Implantable cardioverter defibrillators-> cardiovert if identify shockable arrhythmia
What ECG changes might be present in a patient with a pacemaker?
- Line before P or QRS but not both-> single chamber
- Line before P and QRS-> dual chamber