Cardiology Flashcards
What is S4 heart sound and which part of the ECG does this sound coincide with?
S4 heart sound is caused by atrial contraction against a stiff ventricle occurring just before the S1 sound. It may be heard in aortic stenosis, hypertrophic cardiomyopathy or HTN.
It coincides with the P wave on the ECG
What causes S3 - 3rd heart sound?
caused by diastolic filling of the ventricle
considered normal if < 30 years old (may persist in women up to 50 years old)
heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock) and mitral regurgitation
What is the first line investigation for stable angina?
Contrast-enhanced CT coronary angiogram
how is anginal chest pain defined?
- constricting discomfort in the front of the chest, or in the neck, shoulders, jaw or arms
- precipitated by physical exertion
- relieved by rest or GTN in about 5 minutes
patients with all 3 features have typical angina
patients with 2 of the above features have atypical angina
patients with 1 or none of the above features have non-anginal chest pain
how is stable angina managed?
aspirin + statin
GTN
Beta blocker or CCB as first line
If CCB used as monotherapy a rate-limiting one such as verapamil or diltiazem should be used
If CCB in combo with BB then use a longer-acting dihydropyridine calcium channel blocker (e.g. amlodipine, modified-release nifedipine)
If monotherapy does not work then add in the other
Then consider adding in a long actin nitrate, ivabradine nicorandil, ranolazine
what is Arrhythmogenic right ventricular cardiomyopathy?
a form of inherited cardiovascular disease which may present with syncope or sudden cardiac death. It is generally regarded as the second most common cause of sudden cardiac death in the young after hypertrophic cardiomyopathy.
Pathophysiology
inherited in an autosomal dominant pattern with variable expression
the right ventricular myocardium is replaced by fatty and fibrofatty tissue
around 50% of patients have a mutation of one of the several genes which encode components of desmosome
What is the JVP wave form
a’ wave = atrial contraction
large if atrial pressure e.g. tricuspid stenosis, pulmonary stenosis, pulmonary hypertension
absent if in atrial fibrillation
Cannon ‘a’ waves
caused by atrial contractions against a closed tricuspid valve
are seen in complete heart block, ventricular tachycardia/ectopics, nodal rhythm, single chamber ventricular pacing
‘c’ wave
closure of tricuspid valve
not normally visible
‘v’ wave
due to passive filling of blood into the atrium against a closed tricuspid valve
giant v waves in tricuspid regurgitation
‘x’ descent = fall in atrial pressure during ventricular systole
‘y’ descent = opening of tricuspid valve
How does arrhythmogenic right ventricular cardiomyopathy present?
palpitations
syncope
sudden cardiac death
What investigations for Arrhythmogenic right ventricular cardiomyopathy and what do they show?
ECG abnormalities in V1-3, typically T wave inversion. An epsilon wave is found in about 50% of those with ARV - this is best described as a terminal notch in the QRS complex
echo changes are often subtle in the early stages but may show an enlarged, hypokinetic right ventricle with a thin free wall
magnetic resonance imaging is useful to show fibrofatty tissue
WHat is the management of arrhythmogenic right ventricular cardiomyopathy ?
drugs: sotalol is the most widely used antiarrhythmic
catheter ablation to prevent ventricular tachycardia
implantable cardioverter-defibrillator
WHat is Naxos disease?
an autosomal recessive variant of ARVC
a triad of ARVC, palmoplantar keratosis, and woolly hair
what murmur is heard in ASD?
Ejection systolic murmur heard louder on inspiration
what causes ejection systolic murmurs
louder on expiration
aortic stenosis
hypertrophic obstructive cardiomyopathy
louder on inspiration
pulmonary stenosis
atrial septal defect
also: tetralogy of Fallot
What causes pansystolic murmur
mitral/tricuspid regurgitation (high-pitched and ‘blowing’ in character)
tricuspid regurgitation becomes louder during inspiration, unlike mitral reguritation
during inspiration, the venous blood flow into the right atrium and ventricle are increased → increases the stroke volume of the right ventricle during systole
ventricular septal defect (‘harsh’ in character)
what causes a late systolic murmur
mitral valve prolapse
coarctation of aorta
what causes early diastolic murmur
aortic regurgitation (high-pitched and ‘blowing’ in character)
Graham-Steel murmur (pulmonary regurgitation, again high-pitched and ‘blowing’ in character)
What causes mid-late diastolic murmur?
mitral stenosis (‘rumbling’ in character)
Austin-Flint murmur (severe aortic regurgitation, again is ‘rumbling’ in character)
what causes a continuous machine-like murmur?
patent ductus arteriosus
how is DVT/PE investigated in pregnancy?
Suspected DVT - USS Doppler
PE - if DVT also suspected the USS doppler, if just PE - then the decision to perform a V/Q or CTPA should be taken at a local level after discussion with the patient and radiologist
what is the treatment of prinzmetal angina?
dihydropyridine calcium channel blocker
Felodipine
How is SVT managed and prevented?
Acute management
vagal manoeuvres:
Valsalva manoeuvre: e.g. trying to blow into an empty plastic syringe
carotid sinus massage
intravenous adenosine
rapid IV bolus of 6mg → if unsuccessful give 12 mg → if unsuccessful give further 18 mg
contraindicated in asthmatics - verapamil is a preferable option
electrical cardioversion
Prevention of episodes
beta-blockers
radio-frequency ablation
What is given for SVT prevention in pregnancy?
Metoprolol
what is pulmonary capillary wedge pressure?
Pulmonary capillary wedge pressure (PCWP) is measured using a balloon tipped Swan-Ganz catheter which is inserted into the pulmonary artery. The pressure measured is similar to that of the left atrium (normally 6-12 mmHg).
One of the main uses of measuring the PCWP is determining whether pulmonary oedema is caused by either heart failure or acute respiratory distress syndrome.
In many modern ITU departments PCWP measurement has been replaced by non-invasive techniques.
why is an asymmetric dosing regimen of isosorbide mononitrate recommended?
An asymmetric dosing regimen would involve taking the morning dose as normal, then taking the second dose in the early afternoon. This allows a sufficiently long nitrate-free period and helps reduce tolerance.
what is the mechanism of action of amiodarone?
he main mechanism of action is by blocking potassium channels which inhibits repolarisation and hence prolongs the action potential. Amiodarone also has other actions such as blocking sodium channels (a class I effect)
what are the monitoring requirements of amiodarone?
TFT, LFT, U&E, CXR prior to treatment
TFT, LFT every 6 months
where do thiazide/thiazide like diuretics act?
inhibits sodium reabsorption by blocking the Na+-Clˆ’ symporter at the beginning of the distal convoluted tubule
Potassium is lost as a result of more sodium reaching the collecting ducts.
What are the adverse effects of amiodarone use?
thyroid dysfunction: both hypothyroidism and hyper-thyroidism
corneal deposits
pulmonary fibrosis/pneumonitis
liver fibrosis/hepatitis
peripheral neuropathy, myopathy
photosensitivity
‘slate-grey’ appearance
thrombophlebitis and injection site reactions
bradycardia
lengths QT interval
what are the common adverse effects of thiazide/thiazide like diuretics?
dehydration
postural hypotension
hypokalaemia - due to increased delivery of sodium to the distal part of the distal convoluted tubule → increased sodium reabsorption in exchange for potassium and hydrogen ions
hyponatraemia
hypercalcaemia
the flip side of this is hypocalciuria, which may be useful in reducing the incidence of renal stones
gout
impaired glucose tolerance
impotence
Rare adverse effects
thrombocytopaenia
agranulocytosis
photosensitivity rash
pancreatitis
where do loop diuretics act?
Loop diuretics (furosemide, bumetanide) act by inhibiting the Na+/K+/2Cl- cotransporter in the thick ascending limb of the loop of Henle. This causes loss of water along with sodium chloride, potassium, calcium, and hydrogen ions.
what are the are the adverse effects of loop diuretics?
hypotension
hyponatraemia
hypokalaemia, hypomagnesaemia
hypochloraemic alkalosis
ototoxicity
hypocalcaemia
renal impairment (from dehydration + direct toxic effect)
hyperglycaemia (less common than with thiazides)
gout
what is pulmonary artery hypertension defined as?
defined as a resting mean pulmonary artery pressure of >= 20 mmHg
what are the features of pulmonary artery hypertension?
progressive exertional dyspnoea is the classical presentation
other possible features include exertional syncope, exertional chest pain and peripheral oedema
cyanosis
right ventricular heave, loud P2, raised JVP with prominent ‘a’ waves, tricuspid regurgitation
How is pulmonary artery hypertension managed?
Treat underlying conditions
Following this - acute vasodilator testing is central to deciding on the appropriate management strategy.
If there is a positive response - oral calcium channel blockers
If there is a negative response:
prostacyclin analogues: treprostinil, iloprost
endothelin receptor antagonists
non-selective: bosentan
selective antagonist of endothelin receptor A: ambrisentan
phosphodiesterase inhibitors: sildenafil
what is acute vasodilator testing?
Acute vasodilator testing aims to decide which patients show a significant fall in pulmonary arterial pressure following the administration of vasodilators such as intravenous epoprostenol or inhaled nitric oxide
What are the causes of pericarditis?
viral infections (Coxsackie)
tuberculosis
uraemia
post-myocardial infarction
early (1-3 days): fibrinous pericarditis
late (weeks to months): autoimmune pericarditis (Dressler’s syndrome)
radiotherapy
connective tissue disease
systemic lupus erythematosus
rheumatoid arthritis
hypothyroidism
malignancy
lung cancer
breast cancer
trauma
what are the features of pericarditis?
chest pain: may be pleuritic. Is often relieved by sitting forwards
other symptoms include a non-productive cough, dyspnoea and flu-like symptoms
pericardial rub
what would ECG show in pericarditis?
the changes in pericarditis are often global/widespread, as opposed to the ‘territories’ seen in ischaemic events
‘saddle-shaped’ ST elevation
PR depression: most specific ECG marker for pericarditis
WHat are the investigations in pericarditis?
ECG
all patients with suspected acute pericarditis should have transthoracic echocardiography
bloods
inflammatory markers
troponin: around 30% of patients may have an elevated troponin - this indicates possible myopericarditis
What is the management of pericarditis?
treat underlying cause
avoid strenuous physical activity until resolution of symptoms
NSAIDs and colchicine
when should pericarditis be managed in the hospital?
patients who have high-risk features such as fever > 38°C or elevated troponin should be managed as an inpatient
What happens to BP in pregnancy?
Falls in first half of pregnancy before rising to pre-pregnancy levels before term. During a healthy pregnancy, blood pressure will typically fall during the first half of pregnancy due to systemic vasodilation and increased blood volume. The systolic pressure tends to drop by 5-10 mmHg and the diastolic by as much as 10-15 mmHg. This decrease reaches its nadir between the mid-second and early third trimester, after which it gradually rises back towards baseline prepregnancy levels just before term.
