Cardiology Flashcards
What is are the risks of verapamil and beta-blocker concurrent use?
Heart block + fatal arrest.
Can use nicorandil for angina instead if patient on verapamil.
Which organism is is commonly associated with infective endocarditis amongst IVDU?
Staphylococcus aureus is commonly associated with infective endocarditis amongst IVDU.
What are the organisms which would cause BC negative endocarditis?
Culture negative causes include:
prior antibiotic therapy
Coxiella burnetii
Bartonella
Brucella
HACEK: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)
What is a rare organism causing endocarditis in a native valve?
Staphylococcus lugdunensis is incorrect. This organism is a rare cause of native valve endocarditis.
In which demographic of patients is staph epidermis a cause of endocarditis?
This organism is associated with prosthetic valve endocarditis.
How does the Valsalva manoueuvre work?
Stages of the Valsalva manoeuvre
1. Increased intrathoracic pressure
2. Resultant increase in venous and right atrial pressure reduces venous return
3. The reduced preload leads to a fall in the cardiac output (Frank-Starling mechanism)
4. When the pressure is released there is a further slight fall in cardiac output due to increased aortic volume
5. Return of normal cardiac output
What does a third (S3) heart sound indicate?
S3 (third 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 ECG changes do you see for Brugada syndrome?
1) convex ST segment elevation > 2mm in > 1 of V1-V3 followed by a negative T wave
2) partial right bundle branch block
3) the ECG changes may be more apparent following the administration of flecainide or ajmaline - this is the investigation of choice in suspected cases of Brugada syndrome
What is the most common gene mutation seen in Brugada syndrome?
Mutations in the SCN5A gene (which encode the myocardial sodium ion channel protein are the most common gene abnormality seen in Brugada syndrome
How do thiazide diuretics work?
Thiazides/thiazide-like drugs (e.g. indapamide) - inhibits sodium reabsorption by blocking the Na+-Clˆ’ symporter at the beginning of the distal convoluted tubule
What is the classification criteria for aortic dissection?
DeBakey classification
type I - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally
type II - originates in and is confined to the ascending aorta
type III - originates in descending aorta, rarely extends proximally but will extend distally
What drugs may potentiate the action of warfarin?
Factors that may potentiate warfarin
liver disease:
P450 enzyme inhibitors, e.g.: amiodarone, ciprofloxacin
cranberry juice
drugs which displace warfarin from plasma albumin, e.g. NSAIDs
inhibit platelet function: NSAIDs
What is the medical management of HOCM?
Management
Amiodarone
Beta-blockers or verapamil for symptoms
Cardioverter defibrillator
Dual chamber pacemaker
Endocarditis prophylaxis*
What drugs should you avoid in someone with HOCM?
nitrates
ACE-inhibitors
inotropes
What does Bisferiens pulse indicate?
Bisferiens pulse - mixed aortic valve disease
How does hydralazine work?
Mechanism of action
increases cGMP leading to smooth muscle relaxation
How do you manage aortic stenosis?
Management
if asymptomatic then observe the patient is a general rule
if symptomatic then valve replacement
if asymptomatic but valvular gradient > 40 mmHg and with features such as left ventricular systolic dysfunction then consider surgery
options for aortic valve replacement (AVR) include:
surgical AVR is the treatment of choice for young, low/medium operative risk patients. Cardiovascular disease may coexist. For this reason, an angiogram is often done prior to surgery so that the procedures can be combined
transcatheter AVR (TAVR) is used for patients with a high operative risk
balloon valvuloplasty
may be used in children with no aortic valve calcification
in adults limited to patients with critical aortic stenosis who are not fit for valve replacement
What pulse abnormality is most associated with patent ductus arteriosus?
Patent ductus arteriosus - large volume, bounding, collapsing pulse
What is the target INR for mechanical aortic and mitral valves?
Aortic - 3
Mitral - 3.5
Which protein is effected in HOCM?
HOCM is usually due to a mutation in the gene encoding β-myosin heavy chain protein or myosin binding protein C
Which part of the QRS complex is used for synchronisation?
Electrical cardioversion is synchronised to the R wave
What medications are patients with prosthetic heart valves and mechanical heart valves started on?
1) Prosthetic heart valves: bioprosthetic: aspirin
2) Mechanical: warfarin + aspirin
Which ECG changes do you see in hypothermia?
J-waves are associated with hypothermia
What is the difference in the mechanism of action of fondaparinux and other anticoagulants?
Fondaparinus activates antithrombin III which potentiates the inhibittion of coagulation factors Xa and is given SC.
Direct thrombin inhibitors are normally given IV however dabigatran (DOAC) is an example of a direct thrombin inhibitor which is taken orally.
How long after birth should you continue magnesium sulfate in a female with eclampsia?
24 hours
What is the first-line treatment for a patient with pericarditis?
NSAIDs and colchicine
Which factor is most strongly associated with risk of sudden death in the first six months after myocardial infarction?
Low left ventricular ejection fraction
What is the pathophysiology of catecholaminergic polymorphic ventricular tachycardia (CPVT)?
CPVT is an autosomal dominant condition which causes sudden cardiac death. The most common cause is a defect in the ryanodine receptor (RYR2) which is found in the myocardial sarcoplasmic reticulum.
What are the features of catecholaminergic polymorphic ventricular tachycardia (CPVT)?
- exercise or emotion-induced polymorphic ventricular tachycardia resulting in syncope
- sudden cardiac death
- symptoms generally develop before the age of 20 years
How is catecholaminergic polymorphic ventricular tachycardia (CPVT) managed?
- beta-blockers
- implantable cardioverter-defibrillator
Which of the following is the most appropriate management of warfarin therapy in a patient who is going for emergency surgery?
Patients on warfarin undergoing emergency surgery - give four-factor prothrombin complex concentrate
Which murmur do you hear in atrial septal defect?
Ejection systolic murmur louder on inspiration
What is a Still’s murmur?
A Still’s murmur, also known as an ‘innocent murmur’ or ‘vibratory murmur’ is a common quiet systolic murmur heard in young children.
Which one of the following interventions should be offered to reduce the risk of developing pre-eclampsia again?
Low-dose aspirin (75-150 mg daily) has been shown to reduce the risk of developing pre-eclampsia in women at high risk, such as those with a history of pre-eclampsia in a previous pregnancy. According to the UK National Institute for Health and Care Excellence (NICE) guidelines, low-dose aspirin should be offered from 12 weeks gestation until the birth of the baby for women at high risk of developing pre-eclampsia.
What would you see on a tissue biopsy for someone with HOCM?
Myofibrillar hypertrophy with chaotic and disorganized fashion myocytes (‘disarray’) and fibrosis
What would the ECG findings and exercise test results show for someone with cardiac syndrome X?
Normal coronary angiograms despite ECG changes on exercise stress testing
In diabetes, what is the first line anti-hypertensive?
ACE inhibitors/A2RBs are first-line regardless of age
Which enzymes do statins inhibit?
HMG-CoA reductase
Which valvular abnormality may you get secondary to pulmonary hypertension?
Tricuspid regurgitation
Which organism is more likely to be the cause of endocarditis in someone with very poor dental hygeine?
Viridans streptococci e.g. Streptococcus sanguinis
What should patients with heart failure and LVEF be treated with?
Patients with heart failure with reduced LVEF should be given a beta blocker and an ACE inhibitor as first-line treatment
What ECG changes would you see in digoxin toxicity?
1) down-sloping ST depression (‘reverse tick’, ‘scooped out’)
2) flattened/inverted T waves
3) short QT interval
4) arrhythmias e.g. AV block, bradycardia
How would S1 sound in complete heart block?
Complete heart block causes a variable intensity of S1
Is warfarin safe in breast feeding?
Yes
Which protein is the first to rise after a myocardial infarction?
Myoglobin
What is a useful marker of reinfarction?
CK-MB is useful to look for reinfarction as it returns to normal after 2-3 days (troponin T remains elevated for up to 10 days)
How may ticagrelor cause dyspnoea?
Due to the impaired clearance of adenosine
What is Eisenmenger syndrome and what would be the definitive treatment?
Left to right shunt
Definitive treatment: heart-lung transplant
How do ACE inhibitors work?
The renoprotective effects of ACE inhibitors are mediated through dilation of the glomerular efferent arteriole
What can you use in the medical management of peripheral vascular disease?
Naftidrofuryl is a 5-HT2 receptor antagonist which can be used for peripheral vascular disease
Where is BNP synthesised in the heart?
BNP is primarily synthesised and secreted by ventricular cardiomyocytes in response to increased wall tension or stretch, although some is also produced by atrial tissue.
What are some side effects of Ivabradine?
Ivabradine use may be associated with visual disturbances including phosphenes and green luminescence
What are the cardiology DVLA recommendations for the most common heart conditions?
1- No restrictions: HTN untill poorly controlled (approaching 180)
2- 2Days : Catheter Ablation
3- 1 week : all percutaneous procedures e.g PCI , Pacemakers
4- 1 month : Prophylactic ICD, CABG , ACS without PCI
5- 6weeks : Heart Transplantation
6- 6Months : Therapeutic ICD
7- AAA 6cm , notify DVLA yearly review , 6.5 banned for driving
What are some factors/medications that may potentiate warfarin?
Factors that may potentiate warfarin
1) liver disease
2) P450 enzyme inhibitors, e.g.: amiodarone
3) ciprofloxacin
4) cranberry juice
5) drugs which displace warfarin from plasma albumin, e.g. NSAIDs
6) inhibit platelet function: NSAIDs
Why should nitrates be avoided in right ventricular myocardial infarctions?
Nitrates should be avoided in the likely diagnosis of right ventricular myocardial infarct due to causing reduced preload
How long should anticoagulation be continued after successful cardioversion for atrial fibrillation?
At least 4 weeks after successful cardioversion.
If there is structural abnormalities or the atrial fibrillation is likely to re-occur then long-term anti-coagulation is recommended.
In someone with endocarditis, what should you monitor on their ECG?
PR interval: a prolonged PR interval would indicate an aortic root abscess
In which condition do you see a short PR interval?
Wolff-Parkinson-White syndrome
Which ECG changes do you see in hypocalcaemia?
Long QT interval —> greater than 0.44s
What are the causes of long-QT?
1) Electrolyte abnormalities: hypokalemia and hypocalcemia
2) Drugs: tricyclic antidepressants, antihistamines, erythromycin, clarithromycin, amiodarone, haloperidol
3) Congenital long QT syndromes: more than 10 different types recognised
myocardial
4) Infarction/significant active myocardial ischemia
cerebrovascular accident (subarachnoid haemorrhage)
5) Hypothermia
What may you hear on auscultation of the heart in pulmonary hypertension?
Pulmonary hypertension is a cause of a loud S2 (due to a loud P2)
What is the most common cause of death post myocardial infarction?
Ventricular fibrillation
If there is a high risk of failure of cardioversion for AF, what can you use to help reduce the risk of failure?
If high-risk of failure of cardioversion (previous failure), offer electrical cardioversion after at least 4 weeks treatment with amiodarone
AV block can occur following which type of MI?
AV block can occur following an inferior MI (right coronary artery lesion)
What is the mechanism of action of nicorandil?
Nicorandil is a vasodilatory drug used to treat angina. It is a potassium-channel activator with vasodilation is through activation of guanylyl cyclase which results in increase cGMP.
What are the adverse effects of Nicorandil?
headache
flushing
skin, mucosal and eye ulceration
gastrointestinal ulcers including anal ulceration
What are the contraindications of Nicorandil?
left ventricular failure
Name 3 examples of centrally acting anti-hypertensive medications
1) methyldopa: used in the management of hypertension during pregnancy
2) moxonidine: used in the management of essential hypertension when conventional antihypertensives have failed to control blood pressure
3) clonidine: the antihypertensive effect is mediated through stimulating alpha-2 adrenoceptors in the vasomotor centre
How do you manage Prinzmetal angina?
Prinzmetal angina - treatment = dihydropyridine calcium channel blocker
How does Dipyridamole work?
Dipyridamole is an antiplatelet mainly used in combination with aspirin after an ischaemic stroke or transient ischaemic attack.
Mechanism of action
inhibits phosphodiesterase, elevating platelet cAMP levels which in turn reduce intracellular calcium levels
other actions include reducing cellular uptake of adenosine and inhibition of thromboxane synthase
Which channel is affected in long QT syndrome?
Long QT syndrome - usually due to loss-of-function/blockage of K+ channels. Sotalol is an antihypertensive which can cause this as it is a K+ channel blocker
Define pulmonary artery hypertension
Pulmonary arterial hypertension (PAH) may be defined as a resting mean pulmonary artery pressure of >= 20 mmHg. Endothelin is thought to play a key role in the pathogenesis of PAH. It is more common in females and typically presents between the ages of 30-50 years.
Around 10% of cases are autosomal dominant.
What are the features of pulmonary artery hypertension?
Features
1) progressive exertional dyspnoea
2) exertional syncope, exertional chest pain and peripheral oedema
3) cyanosis
Clinical signs:
right ventricular heave: indicating right ventricular hypertrophy or dilatation
loud P2: early in the disease reflects increased pulmonary artery pressure and may be accompanied by a palpable P2 in severe cases. With advanced PAH there may be right ventricular failure leading to a soft S2
raised JVP with prominent ‘a’ waves: reflects increased resistance to right atrial emptying due to elevated right ventricular end-diastolic pressure
tricuspid regurgitation
How do you manage pulmonary artery hypertension?
If there is a positive response to acute vasodilator testing (a minority of patients)
oral calcium channel blockers
If there is a negative response to acute vasodilator testing (the vast majority of patients)
prostacyclin analogues: treprostinil, iloprost
endothelin receptor antagonists
non-selective: bosentan
selective antagonist of endothelin receptor A: ambrisentan
phosphodiesterase inhibitors: sildenafil
What is the pathophysiology of a cholesterol embolism?
cholesterol emboli may break off causing renal disease
the majority of cases are secondary to vascular surgery or angiography. Other causes include severe atherosclerosis, particularly in large arteries such as the aorta
What are the features of a cholesterol embolism?
Features
eosinophilia
purpura
renal failure
livedo reticularis
What is the mechanism of action of ticagrelor?
Ticagrelor has a similar mechanism of action to clopidogrel - inhibits ADP binding to platelet receptors
What is Epstein’s anomaly?
Ebstein’s anomaly is a congenital heart defect characterised by low insertion of the tricuspid valve resulting in a large atrium and small ventricle. It is sometimes referred to as ‘atrialisation’ of the right ventricle. Ebstein’s anomaly may be caused by exposure to lithium in-utero.
What are the associated conditions with Epstein’s anomaly?
1) Patent foramen ovale (PFO) or atrial septal defect (ASD) is seen in at least 80% of patients, resulting in a shunt between the right and left atria
2) Wolff-Parkinson White syndrome
What are the clinical features of Epstein’s anomaly?
1) cyanosis
2) prominent ‘a’ wave in the distended jugular venous pulse
3) hepatomegaly
4) tricuspid regurgitation
5) pansystolic murmur, worse on inspiration
6) right bundle branch block → widely split S1 and S2
What are the ECHO findings of someone with HOCM?
Echo findings - mnemonic - MR SAM ASH
mitral regurgitation (MR)
systolic anterior motion (SAM) of the anterior mitral valve leaflet
asymmetric hypertrophy (ASH)
What are the most common cyanotic and acyanotic congential heart diseases?
Cyanotic: TGA most common at birth, Fallot’s most common overall
Acyanotic: VSD most common cause
What is the pathophysiology of Takayasu’s arteritis?
Takayasu’s arteritis is a large vessel vasculitis. It typically causes occlusion of the aorta and questions commonly refer to an absent limb pulse. It is more common in younger females (e.g. 10-40 years) and Asian people.
What condition is Takayasu’s arteritis associated with?
Renal artery stenosis
What are the clinical features of transposition of the great arteries?
cyanosis
tachypnoea
loud single S2
prominent right ventricular impulse
‘egg-on-side’ appearance on chest x-ray
How do you manage transposition of the great arteries?
maintenance of the ductus arteriosus with prostaglandins
surgical correction is the definite treatment.
Which medication can you use to reverse bleeding on dabigatran?
Idarucizumab
Why is there a loading period for amiodarone?
Amiodarone has a long half-life - it is highly lipophilic and widely absorbed by tissue, which reduces its bioavailability in serum. Therefore, a prolonged loading regime is required to achieve stable therapeutic levels
What is the most specific ECG finding in pericarditis?
PR depression
Can you drive a HGV with a pacemaker?
ICD means loss of HGV licence, regardless of the circumstances
What is the mechanism of action of furosemide?
Furosemide - inhibits the Na-K-Cl cotransporter in the thick ascending limb of the loop of Henle
Which murmur would you hear in an atrial septal defect?
Atrial septal defect - ejection systolic murmur louder on inspiration
What are Aschoff bodies?
Aschoff bodies are granulomatous nodules found in rheumatic heart fever
What are the five clinical features of tetralogy of fallot?
ventricular septal defect (VSD)
right ventricular hypertrophy
right ventricular outflow tract obstruction
pulmonary stenosis
overriding aorta
How do thiazide diuretics cause hypokalaemia?
Mechanism of hypokalaemia due to thiazides: increased delivery of sodium to the distal part of the distal convoluted tubule
Where is the commonest site of an atrial myxoma?
Left atrium
When do you see pulsus alternans?
Pulsus alternans - seen in left ventricular failure
In which condition is a ‘jerky’ pulse a characteristic feature of?
HOCM
Which murmur may you hear in an atrial myxoma?
Mid-diastolic murmur, ‘tumour plop’
When can you use flecainide in AF?
Someone with accesory pathway like WPW (instead of AV blocking nodes –> higher risk of heart block
Flecainide is a sodium channel blocker (Class Ic anti-arrhythmic) which will reduce the excitability of the atrial and ventricular myocardium without AV nodal blockade.
Which medications enhance/reduce the effects of adenosine?
dipyridamole enhances effect
aminophylline reduces effect
In which condition is adenosine contraindicated?
Asthma
What are the criteria for urgent valvular replacement?
Severe congestive cardiac failure
Overwhelming sepsis despite antibiotic therapy (+/- perivalvular abscess, fistulae, perforation)
Recurrent embolic episodes despite antibiotic therapy
Pregnancy
Post-MI, a patient has persistent ST elevation but not chest pain. What is your diagnosis?
Persistent ST elevation following recent MI, no chest pain - left ventricular aneurysm
What do you monitor in a patient recently started on statins?
LFTs at baseline, 3 months and 12 months and fasting lipid profile to monitor response
Which organism in infective endocarditis carries a good prognosis?
Streptococcal infection
What are the poor prognostic factors in infective endocarditis?
Staphylococcus aureus infection (see below)
prosthetic valve (especially ‘early’, acquired during surgery)
culture negative endocarditis
low complement levels
What are the indications for surgery in infective endocarditis?
severe valvular incompetence
aortic abscess (often indicated by a lengthening PR interval)
infections resistant to antibiotics/fungal infections
cardiac failure refractory to standard medical treatment
recurrent emboli after antibiotic therapy
