Cardio fifth yr Flashcards
What is pericarditis + its causes?
Condition referring to inflammation of pericardial sac - lasting for less than 4-6 weeks
Aetiology = viral infections (Coxsackie), TB, uraemia, post MI (early - fibrinous pericarditis, late - autoimmune pericarditis (Dresslers)), radiotherapy, CTD (SLE, RA), hypothyroidism, malignancy (lung/breast), trauma
Features of pericarditis?
Chest pain - can be pleuritic, relieved by sitting forwards
Non-productive cough
Dyspnoea
Flu-like Sx
Pericardial rub
Ix and Tx for pericarditis?
ECG - global/widespread, saddle-shaped ST elevation, PR depression
Transthoracic ECHO
Bloods - inflammatory markers, troponin (30% of pt’s may have elevated troponin - indicates possible myopericarditis)
Outpatient, unless fever >39 or elevated troponin then inpatient
Treat underlying cause
Strenuous physical activity avoided until Sx resolution
Combination of NSAIDs and colchicine are first line with acute idiopathic or viral pericarditis - until Sx resolution and normalitistion of inflammatory markers, followed by tapering of dose
RFs for infective endocarditis?
previous episode of endocarditis
previously normal valves - MV most commonly affected
rheumatic valve disease
prostethic valves
congenital heart defects
IVDUs - typically causing tricuspid lesion
recent piercings
Causes of infective endocarditis?
Staph aureus - most common cause - particularly common in acute presentation and IVDUs
Strep viridian’s - most common in developing countries, linked with poor dental hygiene
Staph epidermidis - colonise indwelling lines, most common following prosthetic valve surgery, 2 months post-op spectrum of organisms returns to normal
Strep bovis - associated with colorectal cancer
Non-infective - SLE, malignancy (marantic endocarditis)
Culture negative causes - prior ABx therapy, Coxiella burnetti, Bartonella, Brucella, HACEK (haemophilis, actinobacillus, cardiobacterium, eikenella, kingella)
Poor prognostic factors for infective endocarditis?
Staphylococcus aureus infection
prosthetic valve (especially ‘early’, acquired during surgery)
culture negative endocarditis
low complement levels
What is infective endocarditis?
condition where the inner lining of the heart (the endocardium) becomes inflamed secondary to an infection.
M>F (2:1)
higher in multimorbid pt’s, elderly, internal cardiac devices, IVDU
mostly left-sided
divided into native or prosthetic valve
Pathophysiology of infective endocarditis?
Transient bacteraemia
Damage to valvular tissue - aggregation of platelets and fibrin
Formation of vegetations - pathogens bind to platelet-fibrin matrix and proliferate causing vegetation
Vegetations can embolism causing further complications. Emboli from left side > cerebral infarcts or cerebral abscess. Right side - mycotic aneurysms, pulmonary infarcts, pulmonary abscesses
Deposition of immune complexes (type 3 hypersensitivity reaction) in skin, kidneys, eyes
Sx of infective endocarditis?
Hx - systemic infection (fever, malaise, night sweats, anorexia), anaemia (fatigue, breathlessness)
O/E
fever, tachycardia
new or changing heart murmur
splinter haemorrhages
oslers nodes (tender in fingers)
Janeway lesions (painless on palms)
Roth spots - retinal haemorrhages, pale in centre
clubbing - late sign
mild splenomegaly
bi-basal lung crepitation
clinical features from emboli (e.g., weakness from stroke)
Ix for infective endocarditis?
Vitals
ECG - exclude AV block as may be seen in aortic root abscesses which is a rare complication of IE
urine dipstick - microscopic haematuria
blood cultures - 3 sets taken 30 mins apart
FBC - exclude anaemia, check WCC to check infection
CRP/ESR - inflammatory markers
U&E - baseline if starting on nephrotoxic ABx such as gentamicin
TTE - identify vegettions
TOE - more detail than TTE
CXR - part of infection screen if Dx unclear, or if HF suspected
CT - if root abscess present
Modified Duke criteria for infective endocarditis?
Infective endocarditis diagnosed if
pathological criteria positive, or
2 major criteria, or
1 major and 3 minor criteria, or
5 minor criteria
Pathological criteria - Positive histology or microbiology of pathological material obtained at autopsy or cardiac surgery (valve tissue, vegetations, embolic fragments or intracardiac abscess content)
Major criteria - positive blood cultures (2 positive BC’s showing typical organisms consistent with IE), evidence of endocardial involvement (positive ECHO, new valvular regurgitation)
Minor criteria - predisposing heart condition or IVDU, microbiological evidence doesn’t meet major criteria, fever >38, vascular phenomena (major emboli, splenomegaly, clubbing, splinter haemorrhages, Janeway lesions, petechiae or purpura), immunological phenomena (glomerulonephritis, Osler’s nodes, Roth spots)
Management of infective endocarditis?
IV ABx for 2 weeks before switching to oral. Tx for at least 6 weeks in prosthetic valve, 2-6 weeks for native valve.
start of the antibiotic course is taken from the first day a negative set of blood cultures is obtained
choice of antibiotic regimen depends on multiple factors including previous antibiotic use, the type of valve affected (native vs prosthetic), the microorganism involved and the antibiotic sensitivity of the particular organism
initial blind - native (amoxicillin and consider low-dose gentamicin), pen allergic, MRSA or severe sepsis (vancomycin + low dose gentamicin), prosthetic valve (vancomycin, rifampicin, + low dose gentamicin)
Native caused by staph - flucloxacillin
Caused by streptococci - benzylpenicillin
Indications for surgery:
severe valvular incompetence
aortic abscess (^ PR interval)
infections resistant to ABx/fungal infectons
cardiac failure refractory to standard medical Tx
recurrent emboli after ABx Tx
Complications of infective endocarditis?
Localised = valve destruction, HF, arrhythmias and conduction disorders, MI, pericarditis, aortic root abscess
Systemic = emboli, immune complex deposition, septicaemia, death
Management of stable angina?
Lifestyle changes - smoking cessation, cut down alcohol intake, dietary modification, exercise, target BMI <25
Medication - all pt’s receive aspirin and a statin if no CI. Sublingual GTN to abort angina attacks. Beta-blocker or calcium-channel blocker first-line depending on comorbidities, CI’s and pt preference.
if Ca-channel blocker as mono therapy should be rate-limiting - so verapamil or diltiazem. If in combination with beta-blocker then longer-acting dihydropyridine (amlodipine, nifedipine).
If poor response to initial Tx, then increase to maximum tolerated dose.
If not tolerated, add BB or CCB depending on which mono therapy
If can’t tolerate addition of CCB or BB, consider: long-acting nitrate, ivabradine, nicorandil, ranolazine
if pt taking both BB and CCB, then only add third drug whilst awaiting PCI or CABG
if using nitrate - asymmetric dosing interval to minimise nitrate tolerance
Procedure/surgical intervention - PCI with coronary angioplasty (catheter, ballon dilatation, stent)
CABG - if severe stenosis, midline sternotomy scar, graft vein (usually great saphenous vein) and bypass stenosis,
What is angina?
Constricting chest pain, due to increased demand of the heart (during exertion) but there is insufficient supply of blood to meet demand
due to narrowing of coronary arteries reducing blood flow to myocardium
stable as on exertion and relieved by rest or GTN
NICE define anginal pain as the following:
1. constricting discomfort in the front of the chest, or in the neck, shoulders, jaw or arms
2. precipitated by physical exertion
3. 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
Ix for stable angina?
For patients in whom stable angina cannot be excluded by clinical assessment alone NICE recommend the following (e.g. symptoms consistent with typical/atypical angina OR ECG changes):
1st line: CT coronary angiography - gold standard
2nd line: non-invasive functional imaging (looking for reversible myocardial ischaemia) - MPS with sPECT, stress ECHO
3rd line: invasive coronary angiography
Baseline Ix:
examination - heart sounds, signs of HF, BMI
BP
ECG
FBC - check for anaemia
U&Es - prior to starting ACEi and other meds
LFTS - prior to statins
Lipid profile
TFTs - thyrotoxicosis can exacerbate angina
HbA1c and fasting glucose
MOA of nitrates?
release of nitric oxide in smooth muscle, activating guanylate cyclase which then converts GTP to cGMP, which in turn leads to a fall in intracellular calcium levels
in angina they both dilate the coronary arteries and also reduce venous return which in turn reduces left ventricular work, reducing myocardial oxygen demand
Side effects of nitrates?
hypotension
tachycardia
headaches
flushing
nitrate tolerance - asymmetric dosing
Why are beta-blockers not used concurrently with non-dihydropyridine calcium channel blockers such as verapamil?
risk of complete heart block
What is heart failure?
defined as a clinical syndrome where the heart is unable to pump enough blood to meet the metabolic needs of the body
usually result of structural or functional heart disease, but the term is also sometimes used more broadly e.g. high-output heart failure
How is heart failure classified?
By ejection fraction - can have normal or abnormal LVEF. Reduced LVEF is typically defined as < 35 to 40%. So HF-rEF or HF-pEF. HF-rEF patients typically have systolic dysfunction (impaired myocardial contraction during systole - ineffective pumping), whereas HF-pEF patients have diastolic dysfunction (impaired ventricular filling during diastole - ineffective filling)
By time - acute or chronic. Most urgent Sx are usually due to LVF causing pulmonary oedema.
By left/right - HF-rEF and HF-pEF typically develop left-sided heart failure - due to increase LV afterload (HTN or aortic stenosis) or increase LV preload (AR resulting in back flow to LV)
Right-sided heart failure is caused by either increased right ventricular afterload (e.g. pulmonary hypertension) or increased right ventricular preload (e.g. tricuspid regurgitation).
High-output HF - ituation where a ‘normal’ heart is unable to pump enough blood to meet the metabolic needs of the body. Causes = anaemia, AVM, Paget’s, pregnancy, thyrotoxicosis, thiamine deficiency
Systolic vs diastolic dysfunction in heart failure?
Systolic:
Ischaemic heart disease
Dilated cardiomyopathy
Myocarditis
Arrhythmias
Diastolic:
Hypertrophic obstructive cardiomyopathy
Restrictive cardiomyopathy
Cardiac tamponade
Constrictive pericarditis
Sx of heart failure?
Left ventricular failure typically results in:
pulmonary oedema
dyspnoea
orthopnoea
paroxysmal nocturnal dyspnoea
bibasal fine crackles
cardiac wheeze
cardiac cachexia - WL
Right ventricular failure typically results in:
peripheral oedema
ankle/sacral oedema
raised jugular venous pressure
hepatomegaly - right hypochondriac pain
weight gain due to fluid retention
anorexia (‘cardiac cachexia’)
What is cardiac output?
stroke volume X HR
stroke volume - volume of blood pumped in 1 beat
What is ejection fraction?
stroke volume / end diastolic volume
normal 55-70%
Causes of HFrEF?
decreased contractility - coronary artery disease, volume overload (valvular disease - MR/AR, and RAAS neurohormonal system) and dilated cardiomyopathy
increased afterload - HTN, aortic stenosis - LV becomes hypertrophied, (increasing O2 demand, decreasing O2 supply)
Causes of HFpEF?
stiff left ventricle
left ventricular hypertrophy - doesn’t stretch, doesn’t fill during diastole
restrictive cardiomyopathy
myocardial fibrosis
pericardial constriction
RFs for HFrEF and HFpEF?
obesity
HTN
DM
renal disease
RFs for HFpEF?
elderly
2:1 F:M
higher co-morbidity burden - HTN, AF, anaemia, COPD
Dx of heart failure?
clinical diagnosis
Hx
O/E - bibasal crackles, peripheral oedema, raised JVP, additional heart sounds (S3 in dilated ventricle, S4 poor LV compliance)
Ix for heart failure?
NTproBNP - released from atria and ventricle during volume expansion and pressure overload - prognostic marker
if high (>2000) - assessment within 2 wks
if raised (400-2000) - assessment within 6 wks
Imaging -
CXR - pulmonary oedema, pleural effusion, upper flow distribution, cardiomegaly
ECHO - valves, volume of chambers, EF
Scoring systems for HF?
Framingham
Boston