Cardiovascular Diseases Flashcards
What is stroke volume?
End diastolic volume – end systolic volume
What is cardiac output?
Heart rate x Stroke volume
What is the equation for blood pressure?
CO x Total peripheral Resistance
What is pulse pressure?
Systolic pressure - diastolic pressure
What is mean arterial pressure?
diastolic pressure + 1/3PP
What is preload?
Initial stretching of the cardiac myocytes prior to contraction
What is afteload?
Force against which the ventricles must contract to expel the blood out of the ventricles
What is Ischaemic heart disease?
Common but serious condition where the blood vessels supplying the heart are narrowed and blocked. There is an imbalance between the supply of oxygen to cardiac muscle and cardiac demand.
what are the risk factors of IHD?
Age, obesity, exercise, diet, htn, smoking, FHX, diabetes
What is the pathophysiology of IHD?
Caused by atherosclerosis - formation of this
What is the presentation of IHD?
Angina, chest pain (discomfort, heaviness, squeezing), radiation to left arm, shoulder, neck ,jaw.
What investigations are needed for IHD?
gold standard - CT coronary angiography
HBA1c - exclude diabetes
FBC - anaemia
May have high LDL
What is the QRISK2 score?
predicts risk of CVD in next 10 years
What is the treatment for IHD?
Nitrate GTN spray
Beta blocker - Bisoprolol (negatively chronologically/inotropic)
ACEI - Ramipril - vasodilator - BP control
CCB - arteriodilators - Amlodipine
Dual anti platelet - stop platelet aggregation - aspirin/clopidrogel
Statin - simvastin- reduce cholesterol
PCI/CABG
What is PCI and CABG?
Percutaneous coronary intervention
Coronary artery bypass surgery
Give 2 advantages and 1 disadvantage of PCI
- less invasive
2.convenient and acceptable - high risk of restenosis
Give 1 advantage and 2 disadvantages of CABG
- good prognosis after surgery
- very invasive
- long recovery time
What are acute coronary syndromes?
Acute Coronary Symptoms (ACSs) encompass a spectrum of unstable coronary artery disease.
Unstable angina, STEMI and NSTEMI
What is an example of a chronic coronary syndrome?
Stable angina
What is the definition of angina?
Central crushing chest pain/discomfort arising from the heart, brought on with exertion as a result of myocardial ischaemia . Relieved with 5mins rest or GTN spray.
What is the definition of stable angina?
Chest pain/ discomfort arising from the heart as a result of myocardial ischaemia, induced by effort and relieved by rest.
What are the signs of stable angina?
- Chest pain comes on with exertion and rapidly resolved by rest or GTN spray
- Exacerbated by cold weather, anger and excitement
What are the symptoms of stable angina?
● Central crushing retrosternal chest pain that radiates to arms, jaw and neck
● Dyspnoea
● Palpitations
● Syncope
What is dyspnoea?
Difficulty breathing
What is the pathophysiology of stable angina?
Imbalance between the heart’s oxygen demand and supply, usually from an increase in demand(exercise). Limited supply can be due to limited blood flow due to blockages, atherosclerotic plaques or reduced oxygen carrying of blood (anaemia).
Define atherogenesis
The development of an atherosclerotic plaque
What is athersclerosis?
A hardened plaque built up of fats, cholesterol and other substances in the intimal of an artery, causing the arteries to harden and narrow.
What are the risk factors of atherosclerosis?
Age, smoking, obesity, diabetes, htn, FHx
Describe in 5 steps the progression of atherosclerosis?
- fatty streaks
- intermediate lesions
- fibrous plaques
- plaque rupture
- plaque erosion
What are the constituents of the fatty streaks?
Foam cells
T-lymphocytes
What are the constituents of intermediate lesions?
Foam cells
smooth muscle cells
T - lymphocytes
platelet adhesion
extracellular lipid pools
What are the constituents of a fibrous plaque?
fibrous cap overlies lipid core and necrotic debris
smooth muscle cells
macrophages
foam cells
T-lymphocytes
What is the structure of a atherosclerotic plaque?
Lipid
Necrotic core
connective tissue
Fibrous cap
Why might a plaque rupture?
plaques constantly grow and recede. fibrous cap has to be reabsorbed and redeposited in order to be maintained. if balance shifts, cap becomes weak, plaque ruptures, thrombus formation.
What can cause chemoattractant release?
A stimulus such as endothelial injury
What are the functions of chemoattractants?
chemoattractants signal to leukocytes. Leukocytes accumulate and migrate into vessel walls -> cytokine release IL-1,6 -> inflammation
Describe the progression of athersclerosis
Endothelial injury due to smoking, T2DM
Fatty streak forms - earliest stage-LDL move into endothelium and are phagocytksed by macrophages–> Foam cells
Inflammatory reaction- chemoattractants attract leukocytes, foam cells recruit other inflammatory cells -neutrophils, macrophages, lymphocytes, fibroblasts, platelets
Fibroblasts produce smooth muscle fibrous cap which covers plaque - prone to rupture.
What are the risk factors of stable angina?
Obesity
T2DM
HTN
Smoking
Age
MAlE
FHx
What are the investigations of stable angina?
12 lead ECG - usually normal
CT angiography - Shows narrowing of coronary artery
Stress ECG- exercise stress test
Bloods - FBC for anaemia, Lipid profile
CXR - check heart size and pulmonary vessels
What is the first line investigation for stable angina?
ECG resting = normal
Exercise induced= ischaemia
What is the gold standard for stable angina?
CT coronary angiography - looks at the arteries to see if narrowed or athersclerosis has taken place
What is the treatment for stable angina?
symptomatic: GTN spray
Lifestyle: weightless, more exercise, quit smoking
Treat underlying conditions: HTN and T2DM
What is the pharmaceutical treatment for stable angina?
CCb (amlodipine) or BB
BB+CCB
BB+CCB+ nitrates
What are the revascularistaion treatments?
Percutaneous Coronary Intervention - stunting the narrow artery - risk of thrombosis, less invasive, shorter recovery
Coronary Artery Bypass Graft -good prognosis/ longer recovery
What is the definition of unstable angina?
An acute coronary syndrome classified by. a crushing cardiac chest pain with crescendo pattern. Symptoms frequently occurring at rest, pain not relieved. Deterioration in previously stable angina.
What is the pathology of unstable angina?
Rupture or erosion of the fibrous cap of a coronary artery atheromatous plaque with thrombosis formation, inflammation and vasoconstriction produced by platelet release.
What is the diagnosis and investigations for unstable angina?
● History
● FBC – anaemia aggravates it
● Cardiac enzymes (troponin normal) – excludes infarction
● ECG – Normal / ST depression when patient is in pain
● CT Coronary angiography
● Risk assessment (QRISK2) – if low risk do an elective stress test
- Grace score
What is the management/ treatment for unstable angina?
- Risk factor modification
- PCI/ CABG if risk assessment score high
- Anti platelet therapy- Aspirin or dual therapy with clopidogrel
- Anti coagulants -heparin
- Nitrates
- BB
- Statins
- ACE inhibitors
-CCB
Describe the action of nitrates?
Venodilaters-> reduced venous return -> reduced pre-load -> reduced myocardial work and myocardial demand
What are the symptoms of unstable angina?
Same as stable angina, but occurs at rest.
What is a myocardial infarction?
Necrosis of cardiac tissue due to prolonged myocardial ischaemia due to complete occlusion of an artery by thrombus
What is the epidemiology of an MI?
Most common cause of death in developed countries
1/3 cases occur at night
What is the pathology of a MI?
● Almost always due to a rupture of an atherosclerotic plaque which leads to clot formation which then occludes one of the coronary arteries causing myocardial cell death and inflammation
● So basically, plaque rupture, development of thrombosis, total occlusion of coronary artery , myocardial cell death
What is a STEMI?
- ST elevation
- Tall T waves
- Might present as a new LBBB (WilliaM) (v1- W shape, v6 M shape)
- Pathological Q waves
What is a NSTEMI?
ST depression and/or T wave inversion
What are the risk factors of an MI?
● Age
● Male
● History of premature coronary heart disease
● Diabetes mellitus
● Hypertension
● Hyperlipidaemia
● Family history
What are the symptoms of MI?
●Crushing central chest pain similar to that occurring in angina – described as “elephant sitting on chest:
● Sweating
● SOB/Dyspnoea
● Fatigue
● Nausea
● Vomiting
What are the signs of a MI?
● Occurs at rest
● Last longer than 20 minutes
● Not relived by GTN spray
● Pain may radiate to left arm, neck and/or jaw
● Pulse and BP may vary between being up or down
What is shown on an ECG for a NSTEMI?
ST depression and or T wave inversion
What is shown on an ECG for a STEMI?
ST elevation
Tall T waves
LBBB
Pathological Q waves
What are the Investigation for an MI?
● Clinical history
● ECG
● CT angiography
● CXR
● FBC
● U&E
● Blood glucose and lipids
What is the management for MI?
● Acute (initial management)
o MONAC
▪ Morphine
▪ Oxygen (if sats are <94%)
▪ Nitrates –
▪ Aspirin 300mg – chewed in order to increase absorption
- Clopidogrel -75mg
o Refer for PCI if within 12hr or –>,thrombolysis (IV alteplase) if over 12 hr then conider PCI
-CABG
What is the Grace score for unstable angina and NSTEMI?
Predictor of mortality from MI in next 6months - 3 years in patients with ACS
Describe the action of beta blockers
Beta blockers are beta 1 specific. They antagonise sympathetic activation and so are negatively chronotropic and inotropic. myocardial work is reduced and so is myocardial demand = symptom relief
Name 3 beta blockers
bisoprolol/ B1-specific
Atenolol
Propanolol - non selective
What are the side effects of BB?
bradycardia, tiredness, erectile dysfunction, cold peripheries
When would BB be contraindicated?
Asthma
What are the secondary prevention for an MI?
o Modification of risk factors
o Aspirin – 75mg daily
o Clopidogrel/ticagrelor -75mg for a year
o Statins -atrovastatin - life
o Beta blocker life–
o ACE inhibitors - life
Name 3 ACEI
Ramipril, enalapril, perindopril
Why do ACEI lead to increased Kinin?
ACE also converts bradykinin to inactive peptides. So ACEI lead to a build up of bradykinin
What are the side effects due to an increase in kinin?
dry chronic cough
rash
anaphylactoid reaction
What are the side effects of ACEI?
hypotension, hyperkalaemia, acute renal failure, teratogenic
Name 3 ARBs
candesartan, valsartan, losartan
What are MI complications?
Heart failure due to ventricular fibrillation
Mitral incompetence
LV wall rupture
Cariogenic shock
LV aneurysm
Dressler’s syndrome – pericarditis following cardiac intervention/surgery
What are the differential diagnosis of chest pain?
● Cardiac – ACS, Aortic dissection, pericarditis, myocarditis
● Respiratory – PE, pneumonia, pleurisy, lung cancer
● MSK – rib fracture,
● GORD
what is the definition of heart failure?
A clinical syndrome where the heart is unable to pump enough blood/O2 to satisfy the needs of metabolising tissues.
What is the epidemiology of heart failure?
Annual incidence of 10% in patients over 65.
50% of patients die within 5 years
What are the causes of Heart failure?
● Ischaemic Heart Disease – most common cause in the world
● Hypertension – most common cause in Africa
● Cardiomyopathy
● Valvular heart disease – aortic stenosis
● Congenital heart disease
What are the risk factors of heart failure?
● Age – 65+
● Obesity
● Gender – male
● People who have had a previous MI
-smoking
What is systolic heart failure?
o Failure to contract
o Ejection fraction <40% (SV/EDV)
What are the causes of systolic heart failure?
▪ IHD
▪ MI
▪ Hypertension
▪ Cardiomyopathy
What is diastolic heart failure?
o Inability to relax and fill
o There is reduced preload because there is abnormal filling of the LV
o Ejection fraction >50%
What causes diastolic heart failure?
aortic stenosis
hypertrophic cardiomyopathy
what is low output HF?
Decreased cardiac output, fails to increase with exertion.
What could low output heart failure be due to?
- pump failure - systolic HF, increased heart rate
- Excessive preload - mitral regurgitation
- Chronic increased afterload - aortic stenosis, hypertension
What is high output heart failure?
When the cardiac output is higher than usual due to an increased peripheral demand - anaemia, pregnancy, hyperthyroidism.
What is the pathology of heart failure?
normally raised preload = raised after load = high CO by frank starling law
Failing hearts = low CO due to dysfunctional starling law
- compensatory mechanism activates
-soon compensatory fails and heart undergoes cardiac remodelling
-heart less well adapted to function therefore increased RAAS +SNS will exacerberate fluid overload
- HF affecting both L+R circuits =congetsive HF
What are the compensatory changes during heart failure?
- sympathetic stimulation
-RAAS - Cardiac changes
What happens during sympathetic stimulation?
- Increased Air and noradrenaline
Improves ventricular function by increasing HR and myocardial contractility
What is the RAAS system?
- Increases ADH, Aldosterone
activation increases Na+ and water retention
increases blood pressure and
What cardiac changes occur?
Ventricular dilation - as increased volume of blood remaining after systole, myocardial fibres are stretched and myocardial contraction is restored. leads to myocyte damage.
What are the mechanisms of HF?
- increased preload
- increased after load
- salt and water retention - RAAS/SNS
- Myocardial remodelling.
what are the 3 cardinal symptoms of HF?
- SOB
- Fatigue
-Ankle swelling - fluid retention
What is the presentation of heart failure?
3 cardinal signs +
-orthopnoea - dyspnoea worse lying flat
-oedema
3rd, 4th heart sounds
Raised JVP
Bibasal crackles
Hypotensive
tachycardic
What does LHS failure result in?
Pulmonary vessel backlog therefore pulmonary oedema
What is the result of RHS failure?
results in systemic venous back log - peripheral oedema
What are the investigations for heart failure?
CXR - ABCDE
ECG- may show evidence of underlying causes - abnormal
Bloods- BNP high
FBC
Echocardiogram - check chambers
What is CXR - ABCDE?
o Alveolar oedema (“Bat’s wings”)
o Kerley B lines (interstitial oedema)
o Cardiomegaly
o Dilated upper lobe vessels of lung
o Effusion (pleural)
What is BNP?
o Brain Natriuretic Peptide – not specific as may be raised in acute PE
▪ Secreted by ventricles in response to increased myocardial wall stress
▪ Increased in patients with HF
▪ Levels correlate with ventricular wall stress and severity of HF
What is the management for HF?
conservative - lifestyle changes
Pharmacological
-ACEi +BB
-Spironolactone +furosemide
Surgery = revascularisation
Name 2 loop diuretics?
furosemide, bumetanide
Name a thiazide diuretic and where does it work?
bendroflumethiazide - distal tubules
Name a potassium sparing diuretic
spironolactone
Give 5 potential side effects of diuretics
hypovolemia
hypotension
reduced serum Na+/K+
Erectile dysfunction
increased uric acid -gout
Name 4 calcium channel blockers
amlodipine
felodipine
diltiazem
veramipril
Name 2 dihydropyridines
They are a class of calcium channel blockers
Amlodipine/felodipine = arterial vasodilators
How does amlodipine work?
It is a dihydropyridine calcium agonist that inhibits the influx of calcium ions into smooth and cardiac muscle. This reduces myocardial contractility, and the formation of electrical impulses reduces.
What are the side effects of amlodipine?
Abdominal pain, dizziness, drowsiness, headaches
What is cor pulmonale?
Right sided heart failure caused by chronic pulmonary arterial hypertension
What are the causes of cor pulmonale?
Chronic lung disease
Pulmonary vascular disorders
Neuromuscular and skeletal diseases
what are the symptoms of cor pulmonale?
Dyspnoea
fatigue
syncope
What are the signs of cor pulmonale?
Cyanosis
tachycardia
raised JVP
Oedema
What are the investigations for cor pulmonale?
Arterial blood gas - hypoxia +/-
Hypercapnia - build up of CO2 in the blood stream
What is the management for cor pulmonale?
- treat underlying cause
- give oxygen to treat respiratory failure
- treat cardiac failure - diuretics
What is the definition of an aneurysm?
An aneurysm is a permanent localised dilation of an artery to twice normal diameter. They may be asymtpmatic or cause symptoms.
What is a true aneurysm? What arteries are most affected?
Affects all 3 layers (intimal, media and adventitia)
Have different shapes – saccular or fusiform
▪ Abdominal aorta – most common
▪ Iliac, popliteal and femoral
▪ Thoracic
What is a false aneurysm?
● False aneurysm
o Collection of blood under adventitia only (outer layer)
o Can happen after trauma
What are the causes of an aortic aneurysm?
● Atheroma – persistent inflammation weakens the arterial wall
● Trauma
● Connective disorders
o Marfan’s – gene coding for fibrillin-1 affected (fibrillin-1 used in ECM structure)
o Ehlers-Danlos syndrome – affects gene that usually alter the structure, production or processing of collagen or proteins that interact with collagen
What are the risk factors of AAA?
● Smoking
● Family History
● Age
● Male
● HTN
● Trauma
● COPD
● Hypercholesterolaemia
What are the symptoms of AAA?
●Asymptomatic - unruptured
Epigastric pain radiating to flank
Pulsatile mass in abdo
Hypotensive
Tachycardic
What are the signs of AAA?
- pulsatile abdominal swelling - normal but if diameter is >5.5cm it suggests it is unruptured
- expansile aorta - suggests aortic rupture - epigastric pain and hypovolaemic shock
- hypotension
- collapse
what investigations are used for AAA?
- abdominal ultrasound
- CT and or MRI angiography
What is the management for AAA?
Non ruptured:
aSx +<5.5 cm = monitor
Sx +>5.5 or growing rapidly = surgery (Endovascular repair, or open surgery)
Ruptured:
- stabilise ABCDE
-Fluids + transfusion
AAA graft surgery -emergency
What is the pathology of an AAA?
Smooth muscle, elastic and structural degeneration of all 3 layers. With leukocyte infiltrate
What is an aortic dissection?
A tear in the intimal layer of the aorta which leads to blood dissecting / collecting through the media
What is the epidemiology of an aortic dissection?
- affects males more than females
Most common emergency affecting the aorta - common presentation 50-70
What is the pathology of an aortic dissection?
Blood dissects media and intima and pools in false lumen which can propagate forwards or backwards decreasing perfusion to end organs ; organ failure + shock
What is the classification of aortic dissection?
Type A- proximal to left subclavian artery (ascending arch)
Type B- distal to left subclavian (descending thoracic)
What are the most common location of AD?
- sinotubular junction -where aortic root becomes tubular aorta
- just distal to left subclavian artery
What are the causes of aortic dissection?
- chronic hypertension
- pregnancy
- connective tissue disorders
-aneurysms
-infection
-atherosclerosis
-trauma
What are the symptoms of aortic dissection?
Abrupt onset of severe tearing central chest pain
Shock/ hypotension
-new aortic murmur/ regurgitation
-low left arm peripheral pulse
-neurological signs - affected carotid perfusion - syncope
-cardiac tamponade
What are the investigations for aortic dissection?
- CT/MRI angiography confrims diagnosis
-CXR - shows widened mediastinum/ aorta - Transoesophageal echocardiogram - shows intimal flap and false lumen and classifies into A and B
What is the treatment for AD?
Surgical. -open repair / EVAR
Medical - BB - esmolol or labetolol
Beta and alpha blockers - prevents reflex tachycardia and low BP
-vasodilator - sodium nitroprusside
What are the complications of AD?
- cardiac tamponade
aortic regurgitation
pre renal AKI
What is cardiac Arrhythmia?
An abnormality of cardiac rhythm. They can lead to sudden death, syncope, HF, dizziness, palpitations or no symptoms at all.
What is bradycardia?
- slow heart rate
-<60bpm - More likely to cause symptomatic arrhthymias
- normal during sleep and in well trained athletes
What is tachycardia?
- fast heart rate
- > 100bpm
- subdivided into:
supra ventricular tachycardias - arise from the atrium or AV junction
Ventricular tachycardias- arise from ventricles
What are supra ventricular tachycardias and what are the 4 types?
Any tachycardia which arises from the atrium or the AV junction.
- Atrial fibrillation
-Atrial flutter
- AV nodal re-entry tachycardia
-AV reciprocating tachycardia
What is atrial flutter?
An irregular organised atrial rhythm at a rate of 250-350bpm.
What does atrial flutter look like on an ECG?
p wave produces a saw tooth pattern - definitive diagnosis
what are the causes of atrial flutter?
- idiopathic
- coronary heart disease
- hypertension
- pericarditis
-AF
what is the clinical presentation of an atrial flutter?
Palpitations, syncope, fatigue
Dyspnoea
what is the treatment for an atrial flutter?
Beta blocker/ bisoprolol ( suppress further arrhythmias) - rate control
+anticoagulation medication
What is AV nodal re-entry tachycardia (AVNRT)?
The most common type of SVT, sudden episodes of an abnormally fast heartbeat
What are the risk factors for AVNRT?
- exertion
- alcohol
- caffeine
what is the presentation of AVNRT?
Regular rapid palpitations, abrubt onset and sudden termination
SOB
What does AVNRT look like on an ECG?
P waves not visible ( or seen before or after QRS immediately)
Normal QRS
What is AV reciprocating tachycardia (AVRT)?
A tachycardia with an accessory pathway for impulse conduction - often hereditary
What is the best known type of AVRT?
Wolf Parkinson white syndrome
- where there is an accessory pathway for conduction - bundle of Kent. A pre excitation syndrome excites ventricles earlier than typical pathway - causing delta waves