Cardiovascular Flashcards
Define angina, and the difference between stable and unstable angina
Angina is the mismatch of oxygen demand an supply to the heart muscle, causing chest pain
- Stable angina is described as a chronic coronary syndrome, when the associated chest pain occurs predictably, for a short time, and is relieved with rest/GTN spray
- Unstable angina is described as new onset angina, or abrupt deterioration of stable angina, often occurring at rest, and is an acute coronary syndrome requiring emergency admission
Define acute coronary syndrome
- unstable angina
- STEMI = ST-elevation myocardial infarction
- NSTEMI = non-ST-elevation myocardial infarction
Describe the epidemiology of acute and chronic coronary syndromes
More common in men, and in older ages
What are the causes of stable angina?
Atherosclerosis (IHD)
Also triggered by exercise, cold weather, heavy meals, emotional stress
What are the causes of acute coronary syndromes?
Atherosclerosis (IHD)
What are the risk factors for IHD (causing chronic/acute coronary syndromes)?
Age
Cigarette smoking
Family history
Diabetes mellitus
Hyperlipidaemia
Hypertension
Kidney disease
Obesity
Physical inactivity
Stress
Male
What are the associations of acute and chronic coronary syndromes?
Atherosclerosis
Hypertension
Hyperthyroidism
Valvular heart disease
Hypertrophic cardiomyopathy
Polycythaemia
Diabetes
CKD
Describe the pathophysiology of IHD
- impairment of blood flow by proximal arterial stenosis
- increased distal resistance e.g. left ventricular hypertrophy
- reduced oxygen carrying capacity of blood e.g. anaemia
What are the signs/symptoms of stable angina?
Chest pain/tightness/discomfort (induced by exertion, relieved by rest/GTN spray)
Breathlessness
Sweating and pale
Gastrointestinal discomfort and nausea
*no fluid retention (unlike heart failure)
*palpitations and syncope are rare
What are the signs/symptoms of acute coronary syndromes?
Chest pain/tightness/discomfort (prolonged, new-onset, occurring at rest, not relieved by GTN spray, can be atypical in women or diabetics)
Sweating and pale
Nausea and vomiting
Fatigue and syncope
Palpitations
Shortness of breath
What are the investigations needed for stable angina?
ECG = abnormalities can’t confirm confirm diagnosis
Exercise testing (continuous ECG while walking on treadmill, relies on patient’s ability)
Stress echo (pharmacological stressor, needs highly skilled operator)
GOLDSTANDARD but invasive: coronary angiography
What investigations are needed for acute coronary syndromes?
ECG = STEMI will show ST elevation and pathological Q waves after a few days, unstable angina may show T wave inversion or ST depression, but normal ECG can’t exclude unstable angina or NSTEMI
Troponin = raised levels become detectable 3-6 hours after MI and stays elevated for several days, may be slightly elevated in unstable angina showing risk of cardiac events/death (not raised in stable angina)
GOLDSTANDARD = coronary angiography (shows presence and severity of coronary artery disease)
What are the treatments for stable angina?
Lifestyle changes (stop smoking, weight loss, exercise, diet)
Medication:
- nitrates (GTN spray for rapid-relief and long acting tablet - vasodilation to reduce BP which can be side effect)
- beta-blocker (first line treatment, reduce oxygen demand of the heart)
- calcium channel blockers
- aspirin (secondary prevention, cyclo-oxygenase inhibitor to reduce platelet aggregation), or clopidogrel if intolerant
- statin (HMG CoA reductase inhibitor to reduce LDL cholesterol production)
- ACE inhibitor (consider for patient who also have diabetes, less vasoconstriction to lower BP)
Revascularisation if becomes unstable angina:
- PCI (coronary angioplasty/stenting)
- CBAG (internal mammary artery/saphenous vein used for coronary bypass)
What is the treatment for acute coronary syndromes?
- Arrange hospital admission for any suspected ACS
- Resuscitation if required
- Pain relief = GTN spray, opiate
- Immediate 300mg of aspirin (or clopidogrel is intolerant) if ST elevation on ECG
- Oxygen if hypoxic
- Revascularisation = immediate PCI in STEMI, consider angiography with follow-on PCI in NSTEMI (if troponin elevated)/unstable angina
- Fibrinolysis (if PCI is not possible within 2 hours, high risk of bleeding)
- Consider: nitrates, beta-blockers, calcium channel blockers, ACEi
What are the complications of IHD?
Cardiovascular complications caused by coronary artery disease…
- stroke
- MI
- unstable angina
- sudden cardiac death
Other complications…
- anxiety and depression
- reduced quality of life
Define pericarditis
Acute pericarditis is inflammation of the pericardium (with or without effusion)
Describe the epidemiology of pericarditis
Difficult to quantify
80-90% of all pericarditis are idiopathic
What are the causes of pericarditis?
Viral = enteroviruses, herpesviruses, adenoviruses
Bacterial = TB (common cause worldwide)
Autoimmune = e.g. rheumatoid arthritis
Neoplastic = secondary tumours (e.g. breast)
Traumatic and iatrogenic = oesophageal perforation, radiation injury, post-myocardial infarction syndrome, PCI, pacemaker lead insertions
What are the signs/symptoms of pericarditis?
Chest pain - severe, pleuritic (worse on inspiration), rapid onset, left anterior chest/epigastrium, relieved by sitting forwards, exacerbated by lying down
Breathlessness
Cough
Fever
Pericardial rub may be heard
Signs of effusion or cardiac tamponade
What are the investigations needed for pericarditis?
ECG - saddle-shaped ST elevation, PR depression (but may be normal)
Bloods - FBC, ESR to determine cause, troponin (to rule out STEMI)
Chest X-ray - shows associated pneumonia and pericardial effusion
Echocardiogram - shows pericardial effusion
What is the treatment for pericarditis?
Sedentary activity until resolution of symptoms and ECG/CRP
NSAIDs or aspirin (high doses)
Colchicine (reduces recurrence)
Treat underlying cause
What are the complications of pericarditis?
Pericardial effusion
Cardiac tamponade
Define pericardial effusion
Accumulation of fluid in the pericardial sac
What are the causes of pericardial effusion?
Pericarditis
Malignancy
Post-MI
Idiopathic
What are the signs/symptoms of pericardial effusion?
Chest pain/pressure/discomfort (relieving by sitting forwards, exacerbated by lying down)
Dyspnoea
Muffled heart sounds
Palpitations and tachycardia
Pulsus paradox (exaggeration of normal respiratory variation in systemic blood pressure - >10mmHg decrease with inspiration)
Signs of cardiac tamponade
What investigations are needed for pleural effusion?
ECG (low voltage QRS)
Bloods = FBC, U+Es, cardiac enzymes
Chest X-ray = shows enlarged, globular heart if effusion present
MRI/CT/echocardiogram = detect effusion and inflammation
What is the treatment for pericardial effusion?
Oxygen therapy to relieve symptoms
Treat underlying conditions
Surgical removal of fluid
What are the complications of pericardial effusion?
Cardiac tamponade (haemodynamic comprise and death)
Chronic pericardial effusion
Define cardiac tamponade
A pericardial effusion that raises intrapericardial pressure, compressing the heart chambers, decreasing venous return and filling of the heart, so reducing cardiac output
What are the signs/symptoms of a cardiac tamponade?
Beck’s triad…
- falling BP
- rising JVP (jugular venous pulse)
- muffled heart sounds
Pulsus paradox due to reduced stroke volume (exaggeration of normal respiratory variation in systemic blood pressure - >10mmHg decrease with inspiration)
What investigations are needed for cardiac tamponade?
ECG
Echocardiogram (diagnostic)
What is the treatment for cardiac tamponade?
Remove fluid (pericardiocentesis)
What are the complications of cardiac tamponade?
Sudden cardiac arrest -> death
Define tetralogy of Fallot
A congenital heart disease characterised by…
- Ventricular septal defect
- Pulmonary stenosis
- Hypertrophy of the right ventricle
- Overriding aorta
Describe the pathophysiology of tetralogy of Fallot
- stenosis of RV outflow leads to RV being at higher pressure than the left
- deoxygenated blood passes from the RV to the LV through the ventral septal defect, leading to cyanosis
What are the sings/symptoms of tetralogy of Fallot?
Symptoms and severity of illness vary depending on the degree of pulmonary stenosis
- Infants may gradually become cyanotic after the ductus arteriosus closes causing increasing right to left flow through the VSD, hypoxic spell symptoms include restlessness and agitation
- In unoperated adults, cyanosis is very common
- In repaired adults, late symptoms include exertional dyspnoea, palpitations, clubbing, RV failure, syncope
What are the investigations needed for tetralogy of Fallot?
Echocardiogram to show anatomy and degree of stenosis
Cardiac CT/MRI useful in surgery planning
What are the treatments of tetralogy of Fallot?
Surgery (usually before the age of 1) to close ventricular septal defect and correct pulmonary stenosis
Define ventricular septal defect
A congenital heart defect characterised by an abnormal connection between the two ventricles, meaning that blood flows from the high pressure LV to the low pressure RV causing increased blood flow to the lungs
What are the sings/symptoms of ventricular septal defect?
Small defect: only small increase to pulmonary blood flow, asymptomatic, loud systolic murmur, some endocarditis risk, need no intervention
Large defect: very high increase in pulmonary flow, causing breathlessness, tachycardia, poor feeding, failure to thrive, large heart on CXR requires intervention in infancy, may lead to Eisenmenger’s syndrome
Define Eisenmenger’s syndrome
Pulmonary artery hypertension, causing damage to the pulmonary vasculature and increase in resistance of the blood flowing to the lungs, increasing the RV/A pressure and shunting deoxygenated blood to the LV/A through the A/VSD, causing cyanosis and clubbing
Define atrial septal defect
A congenital heart defect characterised by an abnormal connection between the two atrium, with the slightly higher pressure in the LA causing blood to shunt into the RA, increasing flow into the right heart and lungs
What are the clinical features of atrial septal defect?
Small defect: only small increase in flow, no right heart dilatation, often asymptomatic, but shunt can increase with age
Large defect: significant increase in flow, right heart dilatation, requires surgical closure, may present with chest pain, arrhythmias, dyspnoea, fixed split 2nd heart sound, big heart and pulmonary arteries on CXR, may lead to Eisenmenger’s syndrome
Define patent ductus arteriosus
A congenital heart disease characterised by the ductus arteriosus not closing after birth, causing blood to flow from the aorta into the pulmonary arteries
What are the signs/symptoms of patent ductus arteriosus?
Small defect: Little flow from aorta to pulmonary arteries, usually asymptomatic, some endocarditis risk
Large defect: Torrential flow from aorta to pulmonary arteries, continuous ‘machinery’ murmur, breathless, poor feeding, and failure to thrive, big heart on CXR, requires surgical closure, can lead to Eisenmenger’s syndrome
Define coarctation of the aorta
A congenital heart disease characterised by narrowing of the aorta at the sites of insertion of the ductus arteriosus
What are the signs/symptoms of coarctation of the aorta?
Mild: presents with hypertension (often right arm), incidental murmur, should be repaired to prevent problems in the long term
Severe: complete/almost complete obstruction of the aortic flow, presents with collapse and heart failure, bruits (buzzes) over the scapulae, systolic murmur, needs urgent repair (surgical or stenting)
What are the complications of coarctation of the aorta?
Hypertension (causing early IHD, strokes, etc.)
Re-coarctation requiring repeat intervention
Aneurysm formation at the site of repair
Define bicuspid aortic valve disease and the problems it can cause
A congenital heart disease characterised by an abnormally bicuspid valve (should be tricuspid), which will degenerate and become regurgitant faster than normal valves
Associated with coarctation and dilation of the aorta
Define pulmonary stenosis
A congenital heart disease characterised by narrowing of the right outflow tract of the heart, which can be valvular, sub-valvar, supra-valvar, or branch
What are the clinical features of pulmonary stenosis?
Mild: well tolerated for many years, seen as right ventricular hypertrophy
Severe: Right ventricular failure as neonate, poor pulmonary blood flow, tricuspid regurgitation
Define cardiomyopathy, and list the types
Cardiomyopathies are inherited cardiac conditions relating to disease of the heart muscle, including…
- hypertrophic cardiomyopathy
- dilated cardiomyopathy
- restricted cardiomyopathy
- arrhythmogenic cardiomyopathy
Describe the pathophysiology of each type of cardiomyopathy
Hypertrophic cardiomyopathy = caused by increased size/thickness of the heart muscle, leading reduced ventricular volume and less effective pumping of the blood
Dilated cardiomyopathy = caused the heart muscle walls to become thin and stretched, leading to decreased force of contraction
Restrictive cardiomyopathy = caused by stiffening of the muscle walls, affecting the relaxation and pumping
Arrhythmogenic cardiomyopathy = caused by fibro-fatty replacement of the myocytes
What are the signs/symptoms of the cardiomyopathies?
Present with symptoms of heart failure
Describe the P wave on an ECG
Represents atrial depolarisation
Upright in leads I, II, V2 to V6
Monophasic in lead II, biphasic in V1
Normal duration < 0.12s (3 small squares)
Normal amplitude < 2.5mm (2.5 small squares) in limb leads, < 1.5mm (1.5 small squares) in chest leads
Absent = AF
Tall = right atrial enlargement
Wide = left atrial enlargement
Describe the PR interval on an ECG
Represents the times between atrial and ventricular contraction (conduction through AV node)
From the onset of the P wave to the start of the QRS complex
Normal duration is between 0.12 and 0.2s (3-5 small squares)
Too long = AV block (delayed contraction)
Too short = pre-excitation syndromes
Describe the PR segment on an ECG
Between the end of the P wave and the start of the QRS complex
Usually isoelectric (flat)
PR segment depression = pericarditis, atrial ischemia/infarction (MI)
Describe the QRS complex on an ECG
Represents ventricular depolarisation
Dominantly upright in leads I and II
Normal duration = 0.06-0.1s (1.5-2.5 small boxes), can be up to 0.12 in healthy patients
Narrow complexes = supraventricular origin
Broad complexes = ventricular origin/aberrant conduction (e.g. bundle branch block)
Normal amplitude > 0.5mV (1 large box) in at least one limb lead, and > 1.0mV (2 large boxes)
High voltage (tall) QRS = left ventricular hypertrophy
Describe the QT interval on an ECG
Represents the time taken for ventricular depolarisation and repolarisation (ventricular systole)
From the start of the Q wave to the end of the T wave
Normal duration = 0.35-0.45s
Shortens in faster heart rates, lengthens in slower heart rates
Prolonged QT interval is associated with increased risk of ventricular arrythmias (caused by congenital long QT syndrome, drugs, low K, Mg, Ca)
Describe the ST segment on an ECG
Represents the time between ventricular depolarisation and repolarisation
From the end of the S wave (J point) to the beginning of the T wave
Should be isoelectric (flat)
Most common abnormality is STEMI
Saddle-shaped ST elevation = pericarditis
Describe the T wave on an ECG
Represents ventricular repolarisation
Upright in I, II, V2 to V6 (same orientation as QRS complex)
Duration relates to QT interval
Normal amplitude < 5mm in limb leads, < 10mm in chest leads
Peaked/flattened T waves = hyper/hypokalaemia
Inverted T waves = normal in children, sign of myocardial ischemia/infarction
What should happen to the R and S waves in the limb leads
The R wave should grow from V1 to at least V4
The S wave should grow from V1 to at least V3 and disappear in V6
What orientation are all the waves in aVR?
Negative
What is the RR interval used for
Rate = duration between each heart beat
- 300/number of large boxes between each R
- or number of R waves in 10s x 6
Rhythm =
- a regular rhythm has a constant RR interval
- regularly irregular rhythm has variable RR interval but with a pattern
- irregularly irregular rhythm has variable RR interval with no pattern
Which ECG leads examine the lateral surface of the heart?
I, aVL, V5, V6
Which ECG leads examine the inferior surface of the heart?
II, III, aVF
Which ECG leads examine the septal surface of the heart?
V1, V2
Which ECG leads examine the anterior surface of the heart?
V3, V4
Which leads show ST elevation if the left anterior descending artery is occluded?
Anterior: V1-V4
Lateral: V5-V6, I, aVL
Which leads show ST elevation if the right coronary artery is occluded?
Inferior: II, III, aVF