9. Cardiovascular Flashcards
What is intermittent bacteraemia?
Infection spilling into the blood from another source (e.g. pneumonia, pyelonephritis, meningitis, abscess) which results in bacteria levels rising and falling periodically when the immune system kicks in.
What is bacteraemia?
Presence of bacteria in the blood
bacteraemia + signs/symptoms of infection = bloodstream infection
Positive bacteria blood culture whenever bloods are taken. Associated with endocarditis, mycotic aneurysm, pacing lead infection.
Continuous bacteraemia.
What does a DTP of >2 diagnose?
differential time to positivity
CRBSI (catheter related blood stream infection)
DTP = time taken for blood culture from through-line catheter to become positive Vs. from peripheral vein.
if the time is much quicker at the catheter, then the catheter is the source of infection.
Most common bacterial cause of catheter infections?
Coagulase negative Staphylococcus
+ staphylococcus Aureus
Most common bacterial cause of infective endocarditis?
Staphylococcus Aureus
+ Streptococci viridans
+ Coagulase negative staphylococcus
What is a mycotic aneurysm?
Dilation of the vessel wall due to infection
staph. aureus, strep. spp, salmonella, E.coli
A medical emergency involving inflammation of the leptomeninges and CSF.
Meningitis
leptomeninges = inner layers i.e. arachnoid + pia matter
What is meningoencephalitis?
Inflammation of meninges AND brain parenchyma
Type of meningitis that is usually caused by bacteria and develops rapidly.
- Acute pyogenic
- Aseptic
- Bacterial
- Chronic
- Acute pyogenic
What are chronic causes of meningitis?
- Mycobacterium Tuberculosis
- Neurosyphilis
- Cryptococcus
Type of meningitis that is usually caused by virus.
- Acute pyogenic
- Aseptic
- Bacterial
- Chronic
Aseptic
Headache, photophobia, fever, neck stiffness are clinical features of what?
Meningitis
Most common cause of meningitis in neonates?
Streptococcus Agalactiae
Most common cause of meningitis in adults?
Streptococcus Pneumoniae
+ Neisseria meningitidis
Main cause of viral meningitis?
Enteroviruses: Coxsackie + Echovirus
+ HSV
Acute inflammation of the brain parenchyma usually caused by virus?
Encephalitis
Most common causes of viral encephalitis?
Herpes viruses (HSV1/2/VZV) Rabies
Acute progressive viral encephalitis that is almost always fatal unless vaccine is given quickly.
Rabies
from dog bites
What are the 4 stages of rabies?
- Prodromal phase - fever, nausea, fatigue
- Furious phase - seizures, twitching, hydrophobia
- Dumb phase - paralysed, disorientated, stuporous
- Coma/death
Please Fight Dogs
Tabes dorsalis is a symptom of what?
slow degeneration of nerve cells
Neurosyphilis
Brain abscess = pus in the brain parenchyma
What is the most common bacterial cause?
Streptococci
Staph Aureus most common after surgery/trauma.
Surgical drainage is the main treatment method for brain abscess’.
Which antibiotic is given in addition?
1. Penicillin
2. Gentamicin
Penicillin
gentamicin cant cross blood/brain barrier
What causes ischaemic heart disease?
Myocardial ischaemia due to coronary atherosclerosis and ventricular hypertrophy.
Does angina pectoris cause myocardial death?
No
MI causes myocardial death
What makes up acute coronary syndrome?
- MI
- Unstable angina (constant angina due to poor blood flow to heart muscle)
- Sudden cardiac death
Myocardial infarction affecting the inner 1/3rd of heart muscle.
Subendocardial
most susceptible to MI due to having less perfusion
Myocardial infarction affecting full thickness of heart muscle.
Transmural
Build up of fluid in the pericardial space.
Cardiac tamponade
Blood markers of ischaemic heart disease (IHD).
Troponins T + I
+ Creatine kinase MB
How does the artery of a patient with hypertension differ to a normal artery?
- Narrow lumen
- More smooth muscle
- very elongated nuclei
Outline the renin-angiotensin-aldosterone system.
The reactions?
Where the hormones come from?
Their effect?
- Renin (from kidneys) converts angiotensinogen (from liver) = angiotensin I
- ACE (from lungs) converts angiotensin I = angiotensin II
angiotensin II stimulates vasoconstriction, aldosterone release, vasopressin (ADH) release, cardiac/vascular hypertrophy - Angiotensin II stimulates aldosterone release (from adrenal glands) which stimulates salt + water reabsorption in kidneys.
Give 3 causes of secondary hypertension.
- Cushing’s syndrome
- Conn’s disease
- Pheochromocytoma (tumour of adrenal glands)
- Correction (narrowing of aorta)
- Renal artery stenosis
What BP is classed as malignant hypertension?
BP > 190/120 mmHg
sudden increase in BP, medical emergency, irreversible organ damage
Left ventricular hypertrophy is seen in what?
Systemic left sided hypertensive heart disease (HHD)
What is Cor pulmonale?
Pulmonary right sided hypertensive heart disease (HHD)
with Right ventricular hypertrophy
Abnormal dilation of vessel/heart wall due to weakened wall.
Aneurysm
What is a false aneurysm (pseudo aneurysm)?
Damage to vessel wall, blood leaks out and form a ‘pulsating’ haematoma
What is an arterial dissection?
Blood enters the wall of artery, haematoma between its layers.
Heart is unable to pump enough blood to meet the metabolic demands of the body.
Heart failure
Dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea, and fluid in the airways is associated with which sided heart failure?
Left sided failure
Left ventricle cannot pump enough blood to tissues.
(increased hydrostatic pressure in pulmonary circulation due to pulmonary congestion results in fluid entering airways)
Nutmeg liver, congestive splenomegaly, oedema of arms + legs, cor pulmonale are associated with which sided heart failure?
Right sided failure
Right ventricle cannot pump enough blood to lungs.
Congestion of blood in the venous systems due to left sided failure.
Type of valvular heart disease where the valves do not close completely, resulting in volume overload of heart.
Regurgitation
Type of valvular heart disease where the valves do not open completely, resulting in pressure overload of the heart.
Stenosis
Most common valvular abnormality?
Calcific Aortic stenosis
(due to wear and tear over lifespan, occurs earlier if you have congenital abnormality i.e. bicuspid valve instead of tricuspid)
What are the risk factors for heart failure?
- Smoking
- Obesity/Diabetes
- Hypertension
- Hypercholesterolaemia
- age
- sex (men)
Myxomatous degeneration of the mitral valve results in what?
Mitral Valve Prolapse (MVP)
‘floppy valve’ - some blood regurgitates back into left atrium.
What valvular heart defects can Rheumatic heart disease cause?
Aortic stenosis
Mitral stenosis
(these are also the most common vhd)
What causes rheumatic heart disease?
Follows on from a group A streptococcus infection.
sore throat
Which of these congenital malformations are Left > Right shunts?
- Transposition of great arteries
- Ventricular septal defect
- Tetralogy of Fallot
- Atrial septal defect
- Patent ductus arteriosus
- Truncus arteriosus
- Atrioventricular septal defect
- Tricuspid atresia
- Total anomalous pulmonary venous connection
2, 4, 5, 7
Anything with a ‘D’ = left > right shunt
Everything else with a ‘T’ at the start = right > left shunt
‘righT’
Which gene abnormalities are associated with congenital heart defects?
- Trisomy 21 Down’s syndrome
- XO Turner’s syndrome
- Chr 22q11.2 deletion - DiGeorge syndrome
Cyanosis is associated with which congenital shunt direction?
Right > Left
deoxygenated blood bypasses lungs
What is the biggest concern with a Right > Left shunt?
Irreversible pulmonary hypertension
What is the most common congenital heart defect?
Ventricular septal defect
What makes up the Tetralogy of Fallot?
- Ventricular septal defect (large)
- Pulmonary stenosis
- Aorta overrides the VSD - takes oxygen poor blood to the body
- Right ventricular hypertrophy - RV needs to work harder so hypertrophies, pumping even more blood to LV
What is coarctation of the aorta?
Congenital narrowing of the aorta causing obstruction to blood flow.
frequently seen in females with Turners syndrome
What is peripheral vascular disease?
Atherosclerosis of arteries supplying arms and legs, leading to narrow vessels and restricted blood flow.
What are the risk factors for Peripheral vascular disease?
- Smoking
- Obesity/Diabetes
- Hypertension
- Hypercholesterolaemia
- Age
- Sex (men)
Hormone which has a protective effect against peripheral vascular disease.
Oestrogen
How do chronic and acute peripheral vascular disease present differently?
Acute = 6 P’s
Pale, Pulseless, Painful, Paralysed, Paraesthetic (pins + needles), Perishing cold
Chronic = NO P's as collateral vessels form Intermittent claudication (pain when walking), tissue loss eventually
A type of vasculitis affecting the large arteries in the head. Considered a medical emergency as it can lead to blindness.
Giant cell arteritis / Temporal arteritis
Inflammation of the endocardium mainly involving the valves.
Endocarditis
What are the main causes of endocarditis?
Staphylococcus Aureus
Streptococcus viridans
Vegetations of these bacteria form on the damaged valves.
What are the key clinical features of infective endocarditis?
FROM JANE
Fever
Roth spots
Osler’s nodes
Murmurs
Janeway lesions
Anaemia
Nail splinter hemorrhages
Emboli
What is pericarditis?
What is a common cause?
Inflammation of pericardial sac.
Coxsackie B
(acute = less than 6 months) (chronic = more than 6 months)
Dressler’s syndrome is a common cause of what?
Pericarditis
fluid build up in the pericardium post MI
Inflammation of myocardium.
Myocarditis
What is myocarditis caused by?
Adenovirus ‘common cold’
What is the main cause of mitral stenosis?
Rheumatic fever
valve looks like ‘fishes mouth’
Aschoff bodies are associated with what?
Rheumatic fever
What are the 4 cardiomyopathies?
- Hypertrophic
- Arrythmogenic right ventricular cardiomyopathy
- Restrictive
- Dilated
‘HARD’
Which cardiomyopathes are completely genetic?
Hypertrophic cardiomyopathy
Arrythmogenic right ventricular cardiomyopathy (autosomal dominant)
What happens to stroke volume in hypertrophic cardiomyopathy?
Decreased stroke volume
Cardiomyopathy with impaired ventricular pumping and is caused by alcohol + autosomal dominant inheritance.
Dilated cardiomyopathy
A type of cardiomyopathy that is due to mutations in the sarcomere gene?
Hypertrophic
The biomarker commonly used to identify myocardial damage?
Troponin
A common organism in infective endocarditis?
Streptococcus Viridans
A type of meningitis in which there are increased polymorphs in the CSF?
Bacterial
A common cause of aneurysms?
Atherosclerosis
Gram positive cocci that grown in pairs and is a common cause of meningitis?
Streptococcus Pneumoniae
Clinical syndrome resulting from pressure on the heart due to a build-up of fluid in the pericardial space?
Cardiac Tamponade
Tabes dorsalis is a neurological manifestation due to infection with this organism?
Treponema Pallidum
neurosyphilis
The inflammation of large-to-medium sized arteries that can lead to permanent blindness if untreated?
Giant cell arteritis
An adrenal tumour that may be associated with secondary hypertension?
Pheochromocytoma
Right-sided heart failure due to lung disease is called….?
Cor pulmonale
A hormone that acts on the kidneys to stimulate reabsorption of salt and water?
Aldosterone
