Week 5 - Cardiology Flashcards
What is a clinical trial?
The evaluation of a new therapeutic intervention (i.e. drug, device, procedure) in human volunteers.
Describe the pathway of an action potential as it passes throughout the heart.
SA node>atrial muscle>AV node>common bundle>bundle branches>purkinje fibers>ventricular muscle.
A normal QRS axis is -30 to +90 degrees. How can you tell if there is a normal QRS axis on an ECG?
There should be a positive deflection in leads I and II.
A right axis deviation is +80 to +180 degrees. How can you tell if there is a right deviation on an ECG?
Predominantly negative deflection in leads I and aVL.
A left axis deviation is -30 to -90 degrees. How can you tell if there is a left axis deviation on an ECG?
Predominantly negative deflection in leads II and aVF.
Which leads on an ECG show the electrical activity from the anterior aspect of the heart?
Chest leads V1-V4
Which leads on an ECG show information about the electrical activity from the lateral aspect of the heart?
Chest leads V5 and V6 and limb leads I and aVL.
Which leads on an ECG show information about the electrical activity from the inferior aspect of the heart?
Limb leads II, III and aVF.
What is the difference between a STEMI and an NSTEMI?
A STEMI is caused by complete block of coronary flow.
An NSTEMI is caused by partial block of coronary flow.
Sometimes you can have ST elevation but it is not a myocardial infarction. How would you be sure that it is an MI?
If there is ST elevation in the anterior leads and reciprocal ST depression in the inferior leads.
What does a chest X-ray allow you to visualise on the heart?
Cardiac silhouette - size and position of the heart Great vessels Pulmonary vessels Pulmonary Oedema Pleural effusions
What can an echo doppler show you that a normal echo wouldn’t?
Flow of blood through the heart.
What is a transoesophageal and transthoracic echo?
Transoesophageal is when an ultrasound probe is placed down the throat and the heart is view through the oesophagus.
Transthoracic is when the probe is placed on the chest.
What can be assessed on an echocardiogram?
Heart structure and function, valves, pericardial assessment and inducable ischaemia.
What are the pros and cons of an echocardiogram?
Pros - cheap, available, no radiation, portable.
Cons - requires good acoustic window (good place to place probe for best image), user dependent.
What is the aim of functional stress testing?
Induce ischaemia by increasing the workload of the heart.
How is nuclear perfusion imaging performed? What does is allow you to assess?
Patient takes radioactive tracer and scanned using PET or SPECT, shows perfusion of the heart.
Assess ischaemia and ejection fraction.
What is ejection fraction?
The percentage of blood that is pumped into circulation with each ventricular contraction.
What are the pros and cons of nuclear perfusion imaging?
Pros - availability
Cons - radiation, no structural assessment
What is cardiac CT useful for?
Detecting coronary artery calcium which is a risk for CHD and also studying coronary anomalies i.e. single coronary artery.
What does cardiac CT allow you to visualise? What are its pros and cons?
Coronary artery anatomy and great vessel anatomy.
Pros - good ‘rule out’ for CAD, low risk
Cons - radiation dose, requires low heart rate, no functional assessment of ischaemia.
What is coronary angiography? What does it show?
Catheter inserted into femoral or radial artery and contrast medium injected in and X-ray imaged taken. Shows narrowing of coronary artery.
What are the indications for invasive angiography?
Ischaemia, primary PCI, valve assessment, assessment of ventricular pressure.
What are the pros and cons of invasive angiography?
Pros - gold standard, option for intervention during same procedure, availability.
Cons - radiation, risks - CVA, MI, contrast reaction, bleeding.
What are the indication for cardiac MRI (CMR)?
Assessment of structure and function, perfusion/stress, assessment of great vessels, tissue characterisation.
What are the pros and cons of CMR?
Pros - No radiation, reproducable, gold standard for LV assessment.
Cons - cost, availability, claustrophobia, pacemakers/valve replacement contraindicate
Define heart failure.
Failure of the heart to pump blood at a sufficient rate to meet the metabolic requirements of the tissues - caused by an abnormality of cardiac function and with adequate cardiac filling pressure.
What are the clinical features of heart failure?
Breathlessness, effort intolerance, fluid retention.
What causes of heart failure are common in the UK?
CAD (MI) Hypertension Idiopathic Toxins (i.e. alcohol/chemotherapy) Genetic
What are causes of heart failure that are less common in the UK?
Valve disease, infections (i.e. virus/chaga’s), congenital heart disease, metabolic (i.e. haemochromatosis), pericardial disease (i.e. TB), endocardial disease.
What are the 4 main types of heart failure?
HF-REF (systolic HF)
HF-PEF (diastolic HF)
Chronic (congestive)
Acute (decompensated)
What is the differences between HF-REF and HF-PEF?
HF-REF - patients usually younger, male, coronary aetiology.
HF-PEF - patients usually older, female, hypertensive aetiology
Describe chronic and acute heart failure.
Chronic - present for a period of time, may become acute or have been acute.
Acute - admission to hospital, worsening of chronic or new onset.
Describe briefly in 5 steps the pathophysiology of heart failure.
- Myocardial injury
- Left ventricular systolic dysfunction
- Perceived reduction in ciruculating volume and pressure.
- Neurohumeral activation i.e. RAAS, SNS, natriuretic peptides.
- Systemic vasoconstriction, renal sodium and water retention.
What are the symptoms of heart failure?
Dyspnoea (sometimes when lying flat + at night) and cough
Ankle swelling (+abdomen/legs)
Fatigue
What are the clinical signs of heart failure?
Peripheral oedema (ankles, legs, sacrum, abdomen) Elevated JVP Third heart sound Displaced apex beat (cardiomegaly) Pulmonary oedema (lung crackles) Pleural effusion
The New York Heart Association (NYHA) have a functional classification of heart failure. Briefly describe patient function in the 4 different classes.
I - no symptoms and no limitation in ordinary physical activity.
II - mild symptoms (i.e. breath shortness/angina) and slight limitation during normal activity.
III - Marked limitation due to symptoms, even during very light activity. Only comfortable at rest.
IV - Severe limitations, symptoms even at rest, mostly bedbound.
What investigations for heart failure would be done for every patient with heart failure?
Blood chemistry (U&Es, Cr, urea, LFTs, urate) Haematology - (Hb, RCW) Natriuretic peptides (BNP, NT-proBNP) CXR Echocardiogram ECG
What investigations would be done only in selected patients?
Coronary angiography Exercise test Ambulatory ECG monitoring Myocardial biopsy Genetic testing
What is used to treat acute heart failure treated?
How do these methods work?
Bilevel or continuous airway pressure - peload reduction
Dobutamine, dopamine, milronone - increased inotropy (strength of heart contractions)
Furosemide - natriuesis
Nitrates, morphine - venodilation
Nirates, nitroprusside, dobutamine - arterial vasodilation
Ultrafiltration - aqual natriuesis
What treatment would be required for acute heart failure in a patient with the warm and dry profile?
Adjustment of oral medication
What treatment would you consider for acute heart failure in a patient with the cold and dry profile?
Fluid challenge + inotropic agent
What treatment would be required for acute heart failure in a patient with the warm and wet profile?
Diuretics, vasodilators, ultrafiltration.
What treatment would be required for acute heart failure in a patient with the cold and wet profile?
Diuretics, vasodilators, inotropic agents, vasopressor, consider mechanical circulatory response.
What are the symptoms of MI?
Chest pain, back pain, jaw pain, indigestion, sweatiness/clamminess, SOB, potentially none
What are the clinical signs of MI?
Tachycardia, distressed patient, heart failure (crackles, raised JVP), shock, arrhythmia, none.
What is troponin and what does it mark?
Part of the cardiac myocyte, presence in blood stream is a marker of cardiac necrosis.
What are the 5 different types of MI?
1 - due to primary coronary event 2 - oxygen supply/demand imbalance 3 - sudden cardiac death with possible symptoms of ischaemia 4 - MI associated with stenting 5 - MI associated with CABG
What are some of the non-coronary causes of elevated troponin? (think type 2 MI and chronic causes)
Congestive heart failure, tachyarrhythmias, hypertension, hypotension, sepsis, PE
Renal failure, infiltrative cardiomyopathies i.e. amyloidosis
What could ST depression in the anterior leads indicate? Why is this?
Posterior wall infarct.
Because anterior leads are directly opposite any current generated in posterior wall so posterior ST elevation = anterior ST depression.
What would be the immediate management for a STEMI?
Morphine 10mg iv
Oxygen (if sats<94%)
Nitrates
Aspirin 300mg PO + anti-emetics - metoclopramide 10mg
Clopidogrel - 300mg PO (in ambulance) or ticagrelor 180mg 9in hospital)
Heparin unfractionated 5000U iv
Activate PPCI team at GJNH
What are the options for reperfusion therapy following a STEMI?
PPCI - if possible within 90 minutes
Thrombolytic therapy - tenectaplase (TNK), heparin IV
What are the contraindications for thrombolytic therapy?
head trauma in last 4 weeks, bleeding disorders, suspected aortic dissection, haemorrhagic stroke, ischaemic stroke in last 6 months.
What drugs would be used for secondary prevention of MI?
ACE inhibitors
Beta blockers
Statins
Eplerenone (only for diabetes, LVSD, clinical HF).
What are the potential complications of MI?
Arrhythmias - i.e. AF, VF, VT Heart failure Cardiogenic shock Myocardial rupture - i.e. free wall (tamponade), papillary muscle (mitral regurgitation) Pyschological -anxiety/depression
What would be the subsequent management of an NSTEMI?
Aspirin, clopidogrel or ticagrelor, LMWH or fondaparinux
The GRACE Score is a scoring system to risk stratifiy patients with diagnosed ACS to estimate their mortality. What score would indicate low, intermediate and high risk?
Low ≤108
Intermediate - 109-140
High >140
What are 3 causes of aortic stenosis?
Rheumatic valve disease, congenital, calcification and thickening
What does aortic stenosis lead to?What are some of the symptoms of aortic stenosis?
Increased LV pressure so left ventricular hypertrophy.
Shortness of breath, presyncope, syncope, chest pain, reduced exercise capacity.
What are 5 causes of aortic regurgitation?
Degeneration Rheumatic valve disease Aortic root dilatation Systemic disease - i.e. marfan's syndrome, Ehler's Danlos syndrome Endocarditis
What can aortic regurgitation lead to? What are the symptoms of aortic regurgitation?
Volume overload and LV dilatation.
SOB, reduced exercise capacity
How is the mitral valve different to the other 3?
It only has two leaflets
What are some of the causes of mitral stenosis?
LA dilatation
Atrial fibrillation
Pulmonary hypertension
Secondary right heart dilatation
What are some of the symptoms of mitral stenosis?
Shortness of breath Palpitation Chest pain Haemoptysis Right heart failure symptoms
What are some of the causes of mitral regurgitation?
Volume overload – LA / LV LV and LA dilatation Pulmonary hypertension Secondary right heart dilatation Atrial fibrillation
What are some of the symptoms of mitral regurgitation?
Shortness of breath
Palpitation
Right heart failure symptoms
Define systemic hypertension.
Persistent elevation in arterial blood pressure >140/90mmHg
What are some of the non-modifiable risk factors for developing primary hypertension?
Age
Gender
Ethnicity - afro-caribbean
Genetic factors
What are some of the modifiable risk factors for developing primary hypertension?
Diet Physical activity Obesity Alcohol in excess Stress
What are some of the causes secondary hypertension?
Endocrine - Cushing’s syndrome, thyroid disorders.
Vascular - co-arctation of the aorta.
Renal - renal artery stenosis
Drug - cocaine, NSAIDs
Name 4 conditions that hypertension increases your risk of.
Stroke, MI, heart failure, renal failure
How is hypertension diagnosed?
At least two elevated BP readings, five minutes between readings over at least two visits.
What is atrial fibrillation? What does atrial fibrillation increase your risk of 5 fold?
It is an atrial cardiac arrhythmia.
Stroke
What are the symptoms of AF?
May be asymptomatic
Palpitation
Dyspnoea
Rarely chest pain, syncope
Describe the pulse of an atrial fibrillation patient.
Irregularly irregular
What are the signs of atrial fibrillation on an ECG?
Rate variable
Irregular, narrow QRS
No P waves
What are the signs of atrial flutter on an ECG?
Rate variable
Regular, narrow QRS
Sawtooth atrial activity 300bpm
Variable AV block
What are the objectives of treatment of AF?
Stroke prevention Symptom relief Management of associated cardiovascular disease Control of rate \+/- correction of rhythm
What are 4 essential tests of AF?
ECG
Echocardiogram
Thyroid Function Tests
Liver Function Tests
What is the target heart rate for someone with AF?
<110/min
If still symptomatic target <80/min
What drugs are used to control the rate in AF?
First line: Beta blocker i.e. bisoprolol or rate-limiting Ca++ antagonist i.e. verapamil (if without heart failure)
Second line: digoxin
The CHA2DS2-VASc scoring system is used to determine stroke risk in atrial fibrillation. What risk factors to the letters stand for? What is the maximum number of points?
CHF - 1 Hypertension - 1 Age ≥75 - 2 Diabetes Mellitus - 1 Stroke/TIA/thrombo-embolism - 2 Vascular disease - 1 Age 65-74 - 1 Sex Category (female) - 1 9 points
What drugs are used for anti-coagulation in AF?
Warfarin
NOACs i.e. dabigatran, Apixaban
What methods can be used to control the rhythm in AF?
Direct current cardioversion
Antiarrhythmic drugs
Catheter ablation
Name 3 types of anti-arrythmic drugs that can be used to control rhythm in AF.
Class 1 - Na+ blockers
Class 2 - K+ blockers
Multichannel blockers
What is endocarditis?
Infection of the endocardium (lining of the heart) by formation of a vegetation.
Endocarditis can lead to damage to the heart valves? In what order are the heart valves most commonly affected?
1 - mitral
2 - aortic
3 - tricuspid
4 - pulmonary (rarely)
Which organisms most commonly cause native valve endocarditis (NVE)?
Normally streptococcal type, especially strep. viridans.
Which organisms most commonly cause endocarditis in IVDUs?
Normally Staphylococcus aureas + some gram -ve and fungal causes
Which organisms most commonly cause prosthetic valve endocarditis (PVE)?
Staphylococci more common, CoNS more than S. aureas + gram -ve and fungal causes
What are the two main risk factors for endocarditis?
IVDU
Underlying valve abnormalities
Which heart valve is most commonly affected in endocarditis with IVDU?
Tricuspid
Which bacteria normally causes an acute presentation of endocarditis?
S. aureas
Which bacteria normally causes an subacute presentation of endocarditis?
strep. viridans or enterococcus
Which parts of the ECG wave corresponds to what part of the cardiac cycle?
P wave - atrial depolarisation PR interval - delay at the AV node QRS complex - ventricular depolarisation ST segment - ventricular plateau T wave - ventricular repolarisation
What ECG changes would you expect to see with a posterior wall infarct?
Slight inferior or lateral ST elevation, anterior ST depression.
Which coronary arteries supply the posterior wall of the heart?
Left circumflex or RCA
Which coronary artery supplies the anterior wall of the heart?
Left anterior descending
Which coronary artery supplies the inferior wall of the heart?
Right coronary artery
Which coronary artery supplies the lateral wall of the heart?
Circumflex
What is primary hypertension?
Hypertension when there is no identifiable cause.
What investigations should you include to evaluate a patient with hypertension?
U&E Glucose Lipid profile TFTs LFTs Urine dipstick 12 lead ECG
What lifestyle changes should be made in a patient with hypertension?
Exercise, weight loss, reduction in sodium intake, reduction in alcohol intake, change in diet, smoking cessation.
List some of the pharmacological treatments of hypertension?
Calcium channel blockers Beta blockers Alpha blockers ACE-i, ARB Diuretics - loop, thiazide, potassium sparing.
What co-morbidities should you consider when choosing an anti-hypertensive therapy?
Beta-blockers in heart failure/asymptomatic coronary heart disease.
ACE-i in heart failure
ACE-i in DM
Describe the treatment of chronic heart failure.
First line - Beta blocker + ACEi/ARB
Second line - mineralocorticoid receptor antagonist added to ACEi/ARB
Third line - sacubitril/valsartan
Fourth line - devices i.e. ICD or CRT-P/CRT-D or ivabradine
Fifth line - Digoxin
6th line - consider referral to the national transplant unit.
What is the treatment for valve disease?
Medication - can’t treat valve disease but can treat sequelae i.e. AF
Surgical/procedural - valve replacement, TAVI, mitraclip.
What conditions predispose to or encourage the preogression of AF?
Hypertension Symptomatic heart failure Valvular heart disease Atrial septal defect and other congenital heart defects CAD DM Obesity Thyroid dysfunction COPD + sleep apnoea Chronic renal disease
Define congenital heart disease. Describe its prevalence.
An abnormality foetal heart development.
Prevalence is increasing: currently 3000/million population.
What is an atrial septal defect and which type is the most common?
What are the examination features?
When a hole connects the right and left atria. Leads to shunting left to right.
Secundum ASD.
Pulmonary flow murmur, split second heart sound.
What are the potential complications and treatment of an atrial septal defect?
RV failure
Tricuspid regurgitation
Atrial fibrillation
May close spontaneously or transcatheter or surgical closure.
What is coarctation of the aorta? What are the complications?
Congenital narrowing of the descending aorta.
Lower limb cyanosis, upper body hypertension, berry aneurysms, claudication, renal insufficiency.
What is the treatment for coarctation of the aorta?
Surgical repair via thoracotomy: subclavian flap, end to end, jump graft.
Balloon angioplasty.
What is transposition of the great arteries? What does this lead to?
The aorta and the pulmonary arteries switch to give two separate circulatory systems.
Profound cyanosis.
What is the treatment of transposition of the great arteries?
Arterial switch:
corrective surgery.
What are the 4 features of Tetralogy of Fallot?
- Ventricular septal defect.
- Overriding aorta
- Pulmonary stenosis
- Right ventricular hypertrophy
What is the treatment or Tetralogy of Fallot?
Surgery
BT shunt
Complete repair
What is a univentricular heart? How is it treated?
Only one effective pumping ventricle.
Surgery - aim to create two functioning ventricles. If not feasible then fontan circulation.
Describe fontan circulation.
Single functional ventricle used to support the systemic circulation.
IVC and SVC are directly plumbed into the pulmonary artery, bypassing the heart.
What different scoring systems can be used to assess someone’s surgical risk?
ASA scoring
Metabolic equivalent of task (METs) <4 METs associated with increased perioperative risk.
LEE’s revised cardiac risk index.
What peri-operative measures can be made to reduce risk?
Maintain optimal hydration: not wet or dry.
Adequate analgesia intra and post op (avoid excess opioids)
Avoid PONV
Early mobilisation
What are the risk factors for developing native valve endocarditis?
Underlying valve abnormalities i.e. aortic stenosis, mitral valve prolapse.
What are the clinical features of infective endocarditis?
Fever + murmur = IE until proven otherwise. Fatigue and malaise.
What are some of the embolic events seen in infective endocarditis?
Small emboli - petechiae, splinter haemorrhages, haematuria.
Large emboli - CVA, renal infarction
Right sided endocarditis - septic pulmonary emboli.
What are some of the long term effects of IE?
Splenomegaly Nephritis Vasculitic lesions of skin and eye Clubbing Valve destruction Valve abscess.
When should IE be investigated for in the absence of classical risk presentation?
All patients with S.aureus bacteraemia (SAB)
IVDU with any positive blood cultures
All patients with prosthetic valves and positive blood cultures
How is IE diagnosed?
3 sets of 10ml/bottle blood culture prior to antibiotics + aseptic technique.
Echocardiogram
