Cardiology Flashcards
What is atherosclerosis?
A degenerative condition of arteries characterised by a fibrous and lipid rich plaque with variable inflammation, calcification and a tendency to thrombosis
What are the risk factors for atherosclerosis?
Age, tobacco smoking, high serum cholesterol, obesity, diabetes, hypertension, family history
What does an atherosclerotic plaque consisted of?
Lipid, necrotic core, connective tissue, fibrous cap
Briefly describe the mechanism of atherosclerosis
- Fatty streaks
- Intermediate lesions - layers of smooth muscle, T lymph, platelets to vessel wall
- Fibrous plaques of advanced lesions - impedes blood flow, prone to rupture
- Plaque rupture - thrombosis formation and vessel occlusion
How does atherosclerosis present?
Usually asymptomatic until artery is so narrowed the tissues no longer receive adequate blood supply
Coronary arteries - angina
Brain arteries - TIA
Peripheral arteries - peripheral artery disease
Renal arteries - high BP/ Kidney failure
Give 2 examples of ‘good’ inflammation
Wound healing
Pathogens
Give 2 examples of ‘bad’ inflammation
Atherosclerosis
Rheumatoid arthritis
How is atherosclerosis managed?
Percutaneous coronary intervention
Aspirin
Statins
Clopidogrel/ ticagrelor
What is ischaemic heart disease?
Ischaemic heart disease (coronary heart disease) is the umbrella term for angina, acute coronary syndromes and heart failure
How is IHD managed?
Lifestyle - quit smoking, exercise Anti-platelets - reduce risk of MI Statins - lower cholesterol Beta blockers - prevent angina Coronary angioplasty
How is hypertension managed (lifestyle)?
Treat all patients with BP >160/100mmHg
Life style changes - stop smoking, low fat diet, reduce alcohol and salt intake
How is hypertension managed pharmacologically?
1st line - ACEi (e.g. ramipril)
2nd line - ACEi + CCB (e.g. amlodipine)
3rd line - ACEi + CCB + diuretics (e.g. bendroflumethiazide)
4th line - ACEi + CCB + diuretics + beta blocker (e.g. bisoprolol)
What is angina pectoris?
Recurrent transient episodes of chest pain due to myocardial ischaemia
What are the 4 types of angina?
Stable: induced by effort, relieved by rest
Unstable: occurs on minimal exertion or rest
Decubitus: Precipitated by lying flat
Prinzmetal: Caused by coronary artery spasm
Describe the pathology of angina
Stenosis caused by atheroma increases the resistance within the vessel. During exercise, the resistance falls and increases flow - with atherosclerosis, this is impaired and resistance can’t decrease enough to meet the metabolic demand.
What are the non-modifiable risk factors of angina?
Gender, family history, personal history, age
What are the modifiable risk factors of angina?
Smoking, diabetes, hypertension, hypercholesterolaemia, sedentary lifestyle, stress
What are the 3 main clinical features of angina?
- Constricting discomfort on the chest, jaw, neck, shoulders or arms
- Symptoms brought on by exertion
- Symptoms relieved within 5 min by rest or GTN spray
Name a differential diagnosis of angina
Pericarditis
How is angina diagnosed?
ECG - signs of IHD e.g. BBB
Echo - signs of previous infarcts
CXR
Physiological - stress echo
How is angina managed?
Symptom relief - GTN spray
Betablockers - reduce work of heart and O2 demand
Nitrates - dilate systemic veins to reduce preload on the heart
How is angina managed pharmacologically?
Symptom relief - GTN spray 1st line
Nitrates - dilate systemic veins to reduce preload on the heart
Betablockers - reduce work of heart and O2 demand
Calcium channel antagonists - dilate systemic arteries to reduce afterload
Statins e.g. simvastatin reduces choelsterol
75mg aspirin daily
How is angina managed surgically?
Revascularisation - PCI/ CABG
PCI - a balloon is inflated inside stenosed vessel, opening the lumen.
CABG - open heart surgery but less likely to need repeat revascularisation
What is a myocardial infarction?
Myocardial cell death, releasing troponin. Full-thickness necrosis of an area of myocardium
What is ischaemia?
A lack of blood supply (sometimes cell death)
What is the most common cause of acute coronary syndromes?
Rupture of an atherosclerotic plaque and consequent arterial thrombosis.
Less common: arteritis, coronary artery thrombosis, LV hypertrophy, hypoxia
What are the modifiable risk factors for acute coronary syndromes?
Smoking, diabetes, hypertension, hyperlipidaemia, sedentary lifestyle, cocaine use
How are acute coronary syndromes managed?
Symptom control - manage chest pain with PRN GTN and opiates
Modify risk factors
Cardioprotective medication e.g. antiplatelets (clopidogrel)
Revascularisation
How does unstable angina present?
Sudden onset of prolonged ischaemic cardiac chest pain at rest or on minimal exertion
What is the difference between unstable angina and NSTEMI?
NSTEMI involves enough occlusion to cause myocardial damage and elevation in serum troponin and creatinine kinase. Unstable angina does not cause myocardial damage
Describe the pathology of a myocardial infarction
Results from rupture of an unstable coronary artery atherosclerotic plaque, stimulating the formation of a fibrin-rich thrombus over the plaque. Complete occlusion of the coronary artery leads to full-thickness necrosis
How do MIs present?
Unremitting, severe cardiac chest pain that occurs at rest.
Associated with sweating, breathlessness, nausea, vomiting
How are MIs diagnosed?
MIs have troponin rises, unstable angina does not
ECG to differentiate between NSTEMI and STEMI - ST elevation MI with LBBB are associated with larger infarct
How are MIs managed?
Initial: MOAN - morphine, oxygen (sats <94%), aspirin 300mg, nitrates
Beta blocker IV, thrombolysis (IV alteplase), PCI, CABG
Secondary prevention: 75mg aspirin daily, clopidogrel, statins, beta blockers, risk factor modification
What are the complications of MIs?
Cardiac arrest, cardiogenic shock, LVF, RVF, pericarditis, mitral regurgitation, Dressler’s syndrome
What is the definition of cardiac failure?
The inability of the heart to keep up with the demands on it, and the failure of the heart to pump blood with normal efficiency - cardiac output is inadequate for the body’s requirements
What is systolic failure and what causes it?
Inability of the ventricle to contract normally, resulting in low cardiac output
Causes: IHD, MI, cardiomyopathy
What is diastolic failure and what causes it?
Inability of the ventricles to relax and fill normally, causing increased filling pressures.
Causes: ventricular hypertrophy, constrictive pericarditis, restrictive cardiomyopathy, obesity
What is left ventricular failure and what causes it?
Pulmonary congestion and then overload of right side - heart can’t pump efficiently so blood backs up in the veins that take blood through the lungs
IHD, hypertension, cardiomyopathy
What are the symptoms of LVF?
Dyspnoea, poor exercise tolerance, fatigue, orthopnoea, paroxysmal nocturnal dyspnoea, nocturnal cough, wheeze, Signs: cold peripheries, weight loss, pulmonary oedema, pleural effusion
What is right ventricular failure?
Venous hypertension and congestion - high pressure in the veins of the legs, caused by venous insufficiency where blood leads downwards due to the effect of gravity through leaky valves
What causes RVF?
LVF, pulmonary stenosis, lung disease, hypertension
What are the symptoms of RVF?
Peripheral oedema, ascites, nausea, anorexia, SOB
Signs: weight gain (fluid), pitting oedema, hepatomegaly
What are the risk factors for heart failure?
Past MI, male, 65+, obesity
What is the pathology behind heart failure?
Once the heart begins to fail, compensatory changes occur. As the heart failure progresses, these compensatory changes become overwhelmed and become pathological
How is heart failure diagnosed?
CXR - cardiomegaly, effusion, dilated upper lobe vessels of lung
ECG may indicate cause
Cardiac enzymes: creatinine kinase, troponin
What are the signs of heart failure?
Cardinal symptoms: SOB, fatigue, ankle swelling
Cyanosis, decreased BP, narrow pulse pressure, displaced apex, pulmonary hypertension
How is acute cardiac failure managed?
Medical emergency - high flow O2 (100%), treat arrhythmias, IV opiates - diamorphine and GTN spray
IV furosemide - reduce fluid overload
How is chronic cardiac failure managed?
Stop smoking/ drinking/ eat less salt
Treat cause/ exacerbating factors
ABCD - ACEi, beta blockers, CCBs, diuretics
(Loop diuretics (furosemide) and ACEi to relieve symptoms)
Heart transplant
What is mitral regurgitation?
Backflow through the mitral valve during systole
Acute - back up into the lungs
Chronic - dilation as it has had time to adjust
What are the causes of mitral regurgitation?
Rheumatic fever, infective endocarditis, mitral valve prolapse, cardiomyopathy
How does mitral regurgitation present?
Exertional dyspnoea, pulmonary oedema, fatigue, AF, pansystolic murmur at apex radiating to the axilla
How is mitral regurgitation diagnosed?
ECG: AF, P-mitrale
CXR: Large LA and LV
Echo: assess LV size, function
How is mitral regurgitation managed?
Control heart rate - beta blockers
Anticoagulate
Vasodilators, diuretics
Surgery - repair/ replace valve
What is mitral valve prolapse?
The two valve flaps of the mitral valve do not close smoothly or evenly, but instead bulge upwards into the left atrium
How do mitral valve prolapses present?
Usually asymptomatic, may develop atypical chest pain or palpitations.
Mid-systolic click and/or late systolic murmur
What are the complications of a mitral valve prolapse?
Mitral regurgitation, cerebral emboli, arrhythmias, sudden death
How is a Mitral valve prolapse diagnosed?
Echocardiogram - diagnostic
How is a mitral valve prolapse managed?
Beta blockers may help palpitations and chest pain
Surgery if severe
What is mitral stenosis?
Obstruction of LF inflow that prevents proper filling during diastole
What causes mitral stenosis?
Rheumatic fever, congenital, infective endocarditis, malignant carcinoid
How does a mitral stenosis present?
Pulmonary hypertension - dyspnoea, haemoptysis
Hoarseness - pressure from large LA on local structures
Dysphagia, bronchial obstructions, fatigue, palpitations, chest pain
What are the signs of a Mitral stenosis?
Signs of right-sided heart failure, mitral facies - pink patches on cheeks, low-volume pulse
How is a mitral stenosis diagnosed?
ECG: AF and LA enlargement
CXR: LA enlargement
Echo: assess mitral valve mobility and area
How is a mitral stenosis managed?
Rate control of AF - beta blockers
Anticoagulate with warfarin
Mitral balloon valvotomy, mitral valve replacement
What is aortic stenosis?
Narrowing of the aortic valve opening that restricts blood flow from the left ventricle to the aorta
Describe the pathophysiology of aortic stenosis
A pressure gradient develops between the left ventricle and the aorta (increased afterload).
LV function initially maintained by compensatory pressure hypertrophy.
When compensatory mechanisms exhausted, LF function declines
What causes aortic stenosis?
Senile calcification, congenital, rheumatic heart disease
How does an aortic stenosis present?
Classic triad; angina, syncope, breathlessness
Ejection systolic murmur
How is an aortic stenosis diagnosed?
Echo: LV size and function
Cardiac catheter can access valve gradient, LV function, CAD
How is an aortic stenosis managed?
Valve replacement - definitive treatment
Percutaneous valvuloplasty/ transcatheter aortic valve implantation
What is aortic regurgitation?
Leakage of blood into LV during diastole due to ineffective coaptation of the aortic cusps
What are the causes of aortic regurgitation?
Acute: infective endocarditis, chest trauma
Chronic: congenital, connective tissue disorders, rheumatic fever
How does aortic regurgitation present?
Breathlessness, orthopnoea, palpitations, diastolic blowing murmur
How is aortic regurgitation diagnosed?
CXR: enlarged cardiac silhouette
Echo
Cardiac catheterisation to assess severity of lesion
How is aortic regurgitation managed?
Medical - vasodilators
Serial echocardiograms to monitor progression
Surgical treatment: definitive
What is tricuspid regurgitation?
A disorder in which the tricuspid valve does not close tight enough. This problem causes blood to flow backward into the right atrium when the right ventricle contracts
What causes tricuspid regurgitation?
Rheumatic fever, infective endocarditis, carcinoid syndrome
How does tricuspid regurgitation present?
Fatigue, hepatic pain on exertion, ascites, oedema, pan systolic murmur, jaundice