March Flashcards
Rheumatic fever develops due to infection of…
Streptococcus pyogenes (recent 2-6 weeks)
Immune response in rheumatic fever
B and T cells produce IgG and IgM antibodies and CD4+ T cells are activated
there is then a cross-reactive immune response (a form of type II hypersensitivity) thought to be mediated by molecular mimicry
What is M protein?
Virulence factor in cell wall of streptococcus pyogenes
Antibodies against M protein cross react with ryosin and smooth muscles of arteries
What gives rise to the clinical features in rheumatic fever?
Antibodies against M protein cross react with myosin and smooth musce of arteries
Name of the granulomatous bodies found in Rheumatic fever
Aschoff bodies
Diagnosis of Rheumatic fever
Recent streptococcus infection
2 major criteria or 1 major with 2 minor criteria
Major criteria for diagnossi of rheumatic fever
erythema marginatum
Sydenham’s chorea: this is often a late feature
polyarthritis
carditis and valvulitis (eg, pancarditis)
The latest iteration of the Jones criteria (published in 2015) state that rheumatic carditis cannot be based on pericarditis or myocarditis alone and that there must be evidence of endocarditis (the clinical correlate of which is valvulitis which manifests as a regurgitant murmur)
subcutaneous nodules
Minore criteria for diagnosis of Rheumatic fever
raised ESR or CRP
pyrexia
arthralgia (not if arthritis a major criteria)
prolonged PR interval
Evidence of recent streptococcus infection
Antibodies raised
Positive throat swab
Positive rapid group A streptococcal antigen test
Management of rheumatic fever
antibiotics: oral penicillin V
anti-inflammatories: NSAIDs are first-line
treatment of any complications that develop e.g. heart failure
Patau syndrome is caused by which genetic abnormality
Trisomy 13
Which cardiac abnormality is most associated with Trisomy 13?
Ventricular septal defect
Which murmur may be heard with a ventricular septal defect?
Pansystolic murmur
AVSD is mostly associated with which syndrome?
Down’s Trisomy 21
Which condition is associated with coarctation of the aorta?
Marfans
What is Ebstein’s anomaly?
occurs when the tricuspid valve is displaced towards the apex of the right ventricle. It is a rare congenital heart disease and associated with added heart sounds on auscultation
Risk factor for Ebstein’s anomaly?
Maternal lithium used during pregnancy
Post natal presentations of VSD?
failure to thrive features of heart failure hepatomegaly tachypnoea tachycardia pallor
Management of moderate to severe VSD
nutritional support
medication for heart failure e.g. diuretics
surgical closure of the defect
Sign of aortic dissection on chest x-ray
Widened mediastinum
Type A aortic dissection occurs where?
Ascending aorta
Type B aortic dissection occurs where?
Descending aorta
Possible investigations of aortic dissection
Chest X -ray
CT Angiography of chest, abdomen, pelvis
Transoeosophageal echocardiography
Management of type A aortic dissection
Surgery - target systolic BP to 100-120
Management of Type B aortic dissection
Conservative
Bed rest
Reduce pressure with IV labetalol
Complications of aortic dissection
Complications of backward tear
aortic incompetence/regurgitation
MI: inferior pattern is often seen due to right coronary involvement
Complications of a forward tear
unequal arm pulses and BP
stroke
renal failure
What is electrical cardioversion synchronised to?
R wave
Name the subunits of troponin and what they bind to
troponin C: binds to calcium ions
troponin T: binds to tropomyosin, forming a troponin-tropomyosin complex
troponin I: binds to actin to hold the troponin-tropomyosin complex in place
Key suggestive finding of aortic dissection on CT
False lumen
Blurring of the posterior wall of the descending aorta on CT is a sign of ???
retroperitoneal, contained rupture of an aortic aneurysm. This may present with hypovolaemic shock (hypotension, tachycardia, tachypnoea) and collapse.
Classic presentation of rupture aortic aneurysm
Shock
Abdominal pain radiating to the back
Pulsatile mass
How is recurrent DVT in cancer patients who are adequately anticoagulated managed?
‘Consider inferior vena caval filters for patients with recurrent proximal DVT or PE despite adequate anticoagulation treatment only after considering alternative treatments such as:
increasing target INR to 3–4 for long term high-intensity oral anticoagulant therapy or
switching treatment to LMWH.’
Most common cause of sudden cardiac death in the young?
HOCM - Hypertrophic Obstructive Cardiomyopathy
What is Hypertrophic Obstructive Cardiomyopathy?
autosomal dominant disorder of muscle tissue caused by defects in the genes encoding contractile proteins
Pattern of inheritance of HOCM
Autosomal dominant
Genetic defect in HOCM
mutation in the gene encoding β-myosin heavy chain protein or myosin-binding protein C
Describe the cardiac dysfunction seen in HOCM and effect on cardiac output
results in predominantly diastolic dysfunction
left ventricle hypertrophy → decreased compliance → decreased cardiac output
Features of HOCM
often asymptomatic
exertional dyspnoea
angina
syncope
typically following exercise
due to subaortic hypertrophy of the ventricular septum, resulting in functional aortic stenosis
sudden death (most commonly due to ventricular arrhythmias), arrhythmias, heart failure
jerky pulse, large ‘a’ waves, double apex beat
ejection systolic murmur
increases with Valsalva manoeuvre and decreases on squatting
hypertrophic cardiomyopathy may impair mitral valve closure, thus causing regurgitation
When is syncope likely to occur in someone with HOCM?
Following exercise
What type of murumur is present in HOCM?
Ejection systolic murmur
Decreases on squatting
Increases with valsalva manouevre
Name two associations with HOCM
Friedreich’s ataxia
Wolff-Parkinson White
ECHO findings in HOCM
MR SAM ASH
Mitral reurg
Systolic anterior motion of anterior mitral valve leaflet
Assymetric hypertrophy
ECG findings in HOCM
left ventricular hypertrophy
non-specific ST segment and T-wave abnormalities, progressive T wave inversion may be seen
deep Q waves
atrial fibrillation may occasionally be seen
What is murphy’s sign?
Murphy’s sign is elicited in patients with acute cholecystitis by asking the patient to take in and hold a deep breath while palpating the right subcostal area. If pain occurs on inspiration, when the inflamed gallbladder comes into contact with the examiner’s hand, Murphy’s sign is positive
LFT results in cholecystitis
raised ALP and liver transaminases. The ALP level result in cholestatic diseases however, is usually raised to a much greater extent than liver transaminases.
Causes of gynaecomastia
Obesity Testicular cancer Cannabis Alcohol Klinefelter syndrome
Why does gynaecomastia occur in testicular cancer?
Increased oestrogen:androgen ratio
AFP is a tumour marker for which cancers?
Testiuclar
Hepatocellular carcinoma
Mechanism of dipyridamole
non-specific phosphodiesterase inhibitor and decreases cellular uptake of adenosine
elevating platelet cAMP levels which in turn inhibits platelet aggregation and thrombus formation
Inhibits thromboxane synthase
Indication of dipyridamole
an antiplatelet mainly used after an ischaemic stroke, transient ischaemic attack or prosthetic valve replacement
action of a direct oral anticoagulant (DOAC), an example being dabigatran.
Factor Xa antagonist
mechanism of antiplatelet agents such as clopidogrel and ticagrelor.
P2Y12 receptor antagonists
Hyperacute transplant rejection is caused by
pre-existing antibodies against ABO or HLA antigens
Branches of the external carotid
eight branches
3 from its anterior surface ; thyroid, lingual and facial. The pharyngeal artery is a medial branch.
The posterior auricular and occipital are posterior branches.
Why does nephrotic syndrome have increased risk of arterial and venous thrombosis?
loss of antithrombin III via the kidneys
Complications of nephrotic syndrome
increased risk of thromboembolism related to loss of antithrombin III and plasminogen in the urine
deep vein thrombosis, pulmonary embolism
renal vein thrombosis, resulting in a sudden deterioration in renal function
hyperlipidaemia
increasing risk of acute coronary syndrome, stroke etc
chronic kidney disease
increased risk of infection due to urinary immunoglobulin loss
hypocalcaemia (vitamin D and binding protein lost in urine)
Presenting features of Wernicke encephalopathy
ataxia, ophthalmoplegia and/or encephalopathy
Features of Korsakoff’s syndrome
chronic neurological deterioration that is characterised by deficits in anterograde and retrograde memory which leads to confabulation
Wernicke-korsakoff syndrome occurs due to which deficiency seen in which groups of patients
Thiamine deficiency
Alcoholic
Symptoms of alcohol withdrawal
disorientation, confusion, sweating, tremor, agitation, and anxiety.
Wernicke’s encephalopathy untreated leads to which condition?
Korsakoff’s syndrome
What is reaction formation?
transforming an unacceptable feeling or impulse into its extreme opposite. Instigating a physical fight with his boyfriend’s other partner would be an example of reaction formation.
What is sublimation?
Replacing an unacceptable wish with a course of action that is similar to the wish but does not conflict with one’s value system
a mature ego defence mechanism whereby one channels unacceptable thoughts, feelings or impulses into socially acceptable alternatives.
how does gentamicin cause AKI?
Renal cell apoptosis
Which drug used in triple therapy for infective endocarditis can cause AKI?
Gentamicin
Triple therapy - gentamicin, vancomycin, amoxicillin
How does penicillin cause AKI?
Acute interstitial nephritis
Genetic mutations in nephrogenic diabetes
the more common form affects the vasopression (ADH) receptor
the less common form results from a mutation in the gene that encodes the aquaporin 2 channel
The vasopressin receptor mutation in nephrogenic diabetes is which type of mutation
X linked
Mutation in the genes endoign the aquaporin 2 channel seen in nephrogenic diabetes is inherited how?
Autosomal recessive
2 aims of treatment in management of hyperkalaemia
Stabilise cardiac membrane - calcium gluconate
Short-term shift in potassium from extracellular to intracellular fluid compartment - insulin/dextrose infusion, nebulised salbutamol, loop diuretics, calcium resonium, dialysis
What type of drug is nicorandil and mechanism of action?
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.
Adverse effects of nicorandil
Headache
Flushing
skin, mucosal and eye ulceration
gastrointestinal ulcers including anal ulceration
Contraindications of nicorandil
Left ventricular failure
Drugs that must be stopped in AKI
non-steroidal anti-inflammatory drugs
aminoglycoside antibiotics (e.g. gentamicin)
angiotensin-converting enzyme inhibitors (e.g. ramipril), angiotensin II receptor antagonists (e.g. losartan
diuretics.
Terlipressin is used to treat
vasopressin-analogue used in the treatment of haemorrhage from oesophageal varices
Desmopressin is used in treatment of which condition
Central diabetes insipidus
Goserelin is used to treat which condition
Prostate cancer
Indapamide is used to treat which conditions
Thiazide like diuretic - heart failure and hypertension
Carbimazole is used to treat which condition
Hyperthyroidsim
2 forms of diabetes insipidus
decreased secretion of antidiuretic hormone (ADH) from the pituitary (cranial DI)
or an insensitivity to antidiuretic hormone (nephrogenic DI).
Causes of cranial diabetes insipidus
idiopathic post head injury pituitary surgery craniopharyngiomas histiocytosis X DIDMOAD is the association of cranial Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy and Deafness (also known as Wolfram's syndrome) haemochromatosis
Causes of nephrogenic Diabetes Insipidus
genetic: the more common form affects the vasopression (ADH) receptor, the less common form results from a mutation in the gene that encodes the aquaporin 2 channel
electrolytes: hypercalcaemia, hypokalaemia
lithium
lithium desensitizes the kidney’s ability to respond to ADH in the collecting ducts
demeclocycline
tubulo-interstitial disease: obstruction, sickle-cell, pyelonephritis
Features of diabetes insipidus
Polyuria
Polydipsia
Investigation of diabetes insipidus
high plasma osmolality, low urine osmolality
a urine osmolality of >700 mOsm/kg excludes diabetes insipidus
water deprivation test
What type of condition is familial hypercholesterolaemia?
Autosomal dominant
Effect of alcohol on ACE-i
Alcohol compounds the antihypertensive effects of ACE inhibitors
Trend in bloods in refeeding syndrome
A large release of insulin in refeeding syndrome causes a rapid shift of K+, Mg2+ and PO4- into cells, causing hypokalaemia, hypophosphataemia and hypomagnesemia
Mode of inheritance of Alport’s Syndrome
X-linked dominant