Cardiovascular Flashcards
Pathophysiology of Infective Endocarditis
Turbulent flow through abnormal valve
Congenital abnormality, Nodules from RHD, Heart valve trauma, etc
Platelets and fibrin attach to damaged valvular epithelium forming sterile vegetations
Transient bacteraemia arising from mouth, skin, gut, urinary tract etc seeds bacteria onto sterile vegetations.
Common causative agents
• Viridans Streptococci (Mouth)
• S.aureus (Skin/Nose)
• Enterococcus (Gut)
• HACEK
Valves have little blood supply therefore WBC can’t effectively get to site of infection
Infected vegetations enlarge and shed infected emboli and lead to valvular destruction
• Embolic phenomena > Infarct
Impaired valve function > Heart failure
Risk factors for developing Infective Endocarditis
Recent dental, endoscopic or operative procedure Valve disease Prosthetic valves Past ARF Heart disease/operations IVDU Immunosuppresion
Clinical Presentation: Symptoms of Infective Endocarditis
Fever + New murmur = IE until proven otherwise
Fever + Fatigue
Acute Heart Failure
Embolic Phenomena
Clinical Presentation: Signs of Infective Endocarditis
General manifestations of sepsis
Malaise, anorexia, weight loss, fever, rigor, night sweats, anaemia, clubbing, splenomegaly
Cardiac Manifestations
• New/Changing murmur
Secondary to valve destruction. May progress to heart failure and pulmonary oedema
• New harsh pansystolic murmur + acute deterioration
Due to IV septum perforation/rupture of a sinus of valsalva aneurysm into the RV
• Tachycardia/Hypotension
Secondary to sepsis
• Heart-block
• Intracardiac abscess
• Pericarditis
Manifestations of immune complex deposition
• Clubbing
• Skin: petechiae, splinter haemorrhages, Osler’s nodes, Janeway lesions
• Eyes: Roth’s spots, conjunctival splinter haemorrhages, retinal flame haemorrhages
• Renal: Microscopic haematuria, glomerulonephritis, renal impairment
• Cerebral: Toxic encephalopathy
Musculoskeletal: Arthralgia, arthritis
Outline Dukes Classification for diagnosis of Infective Endocarditis
Dukes Classification
Specificity 99%, Sensitivity 92%
• Major Criteria
○ 2 x positive blood culture with typical microbe
Persistently positive blood culture; single positive culture for Coxiella Burnettii
○ Evidence of endocardial involvement (Positive ECHO)
Oscillating intracardiac mass (vegetation); abscess; new partial dehiscence of prosthetic valve; new valve regurgitation
• Minor Criteria
○ Predisposing condition/IVDU
○ Fever >38 degrees
○ Vascular phenomena/stigmata
○ Positive blood culture not meeting above criteria
○ ECHO abnormality not meeting above criteria
Definite IE: 2 major criteria, or 1 major criteria and 3 minor criteria, or 5 minor criteria
Possible IE: Findings that fall short of definite endocarditis but are not rejected
Rejected diagnosis: Firm alternative diagnosis, sustained resolution of clinical features with <4 days of antibiotic therapy
DDx for Infective Endocarditis
Rheumatic Fever
Atrial Myxoma
Other cardiac neoplasms
SLE
What investigations should you order if you suspect Infective Endocarditis and why do you want each of them?
Blood cultures Need three sets at least 20 minutes apart before treatment is started FBC ?Leucocytosis ?Thrombocytopenia ?anaemia ESR/CRP (high) CXR ?Heart failure Echo ?vegetations ?regurg ?abscess Other • ECG • Urinalysis ?haematuria ?proteinuria • U&Es (baseline) Serum Ig ?Polyclonal elevation
Management of Infective Endocarditis
Key points
• NVE vs PVE ?duration
• Strep vs Staph vs Entero vs HACEK ?Abx
• Cardiac surgery?
Streptococcus viridans group
• NVE: Benzyl-penicillin 1.2 g/4 h IV for 4 weeks
• PVE: Benzyl-penicillin 1.2 g/4 h IV for 6 weeks with Gentamicin for first 2 week
• Penicillin allergy: Vancomycin
Staphylococcus species
• MSSA
○ NVE: Flucloxacillin 2 g/ 6 h IV 4-6 weeks with gentamicin for at least 1st week
○ PVE: Flucloxacillin 2 g/ 6 h IV 6 weeks, Gentamicin for first 2 weeks + Rifampicin 600 mg bd PO for 6 weeks
• MRSA
○ NVE: IV Vancomycin for 4-6 weeks + Gentamicin for first week
○ PVE: Vancomycin + rifampicin for 6 weeks + gentamicin for 2 weeks
HACEK organisms
• NVE: IV cephalosporin (Ceftriaxone) for 4 weeks
• PVE: IV cephalosporin (Ceftriaxone) for 6 weeks
Coxiella burnettii
• NVE/PVE: Doxycycline for 3-4 years + second agent (co-trimoxazole, rifampicin, quinolone)
• Need to carefully monitor IgG titre
Usually require surgery
Clinical monitoring of Infective Endocarditis
• Signs of infection, persistent pyrexia and persistence of systemic symptoms • Persistent fever may be due to drug resistance, concomitant infection or allergy • Changing cardiac murmur • Signs of heart failure • Development of new embolic phenomena • Inspect IV access sites daily • Echo • ECG Blood cultures
Define Heart Failure
The term heart failure refers to a clinical syndrome of signs and symptoms arising from the heart being unable to sufficiently pump blood to meet the bodies requirements. It is not a diagnosis, but rather the clinical manifestation of multiple, progressive forms of heart disease.
What are 4 ways in which Heart Failure can be classified ?
Left vs Right
Preserved EF vs Intermediate EF vs Reduced EF
Low output vs High output
Acute vs Chronic
What are the symptoms of left-sided Heart failure?
Left sided - Breathlessness (Dyspnoea) ○ Exertional ○ At rest ○ Orthopnoea > PND - Fatigue - Nocturnal cough/wheeze - Nocturia - Cold peripheries - Weight loss Muscle wasting
What are the symptoms of right-sided Heart Failure?
- Peripheral oedema
- Ascites
- Nausea and anorexia
- Facial engorgement
- Neck pulsation
Epistaxis
What are the causes/precipitants of heart failure?
Cardiac - Arrhythmia - Ischaemia/Infarction - Valve pathology - Hypertension - Cardiomyopathy Respiratory - Chronic lung disease > Cor Pulmonale - PE Medication - Non-compliance - Discontinuation of diuretic - Commencement of drugs that cause salt and water retention > fluid overload Other - Anaemia - Thyrotoxicosis - Infection + Fever Anaesthesia + Surgery
Outline the NYHA classification of Heart Failure
I: Cardiac disease, but no symptoms and no limitation in ordinary physical activity
II: Mild symptoms (mild SOB and/or angina) and slight limitation of ordinary activity
III: Marked limitation in activity due to symptoms even during less than ordinary activity e.g. Walking short distances (20-100m). Comfortable only at rest
IV: Severe limitation. Experiences symptoms even at rest. Mostly bed bound patients
If Heart failure is suspected, what investigations would you order and why?
FBC ?Hb (anemia)
U&Es ?Hyperkalaemia (arrhythmia) ?hyponatremia (longstanding CHF/renal failure)
Pro-BNP ?cardiac vs non-cardiac dyspnoea
ECG - ECG ?arrhythmia ?ischaemia (old/new) ?LVH ?LBBB
CXR ?alveolar oedema ?kurly-B lines ?cardiomegaly ?distended pulmonary vessels ?effusion
Echo ?regional (infarct) vs global (Dilated cardiomyopathy) wall motion abnormalities ?valvulopathy ?Estimate EF
Coronary angiography r/o CAD
Outline the non-pharmacological and pharmacological management of chronic heart failure
Correct underlying cause
- Rate control arrhythmias
- Thrombolysis for acute infarcts
- CABG/Angioplasty for ischaemia
- Medication review
- Control thyroid disease
- Pharmacological
1. Frusemide
Loop diuretic = symptom relief
Inhibit Na/K/Cl transporter at ascending LOH
IV vs Oral (2:1 effect)
SE: Low K+, ototoxic
Risk of hypotension after first dose: Falls risk, give at night
2. ACEi(>ARB)
Improves symptoms and prolongs life
Inhibits Ang I conversion to Ang II > Decreases water retention and decreases BP
SE: Dry cough, angioedema, hypotension
Warn of hypotension after first dose: Falls risk, give at night!
3. B-blocker
Not given initially > give only once NYHA stage 1 or 2
Lower BP
Negative chronotrope: SA node effects/AV node transmission
Negative Inotrope (short term): Stabilise with diuretics first!
Positive Inotrope (long term): Start low, go slow
4. Spironolactone
K+ sparing (aldosterone antagonist)
Can give if NYHA stage 4 or 4
Add if 1) K+ <3.2mmol/L, 2) predisposition to arrhythmia, 3) concurrent digoxin therapy, 4) pre-existing K+ loosing condition
SE: Hypotension, hyponatraemia, hyperkalaemia
5. Digoxin
Vasodilators
What medications should you avoid in managing chronic heart failure?
NSAIDs: Worsens renal function
Calcium Channel Blockers: Negative inotrope
What is the definition of Grade 1, Grade 2 and Grade 3 Hypertension?
Mild (Grade 1): 140-159/90-99
Moderate (Grade 2): 160-179/100-109
Severe (Grade 3): >180 systolic +/- >110 diastolic
What are the primary and secondary causes of hypertension?
Primary - Idiopathic (95%) Secondary • Phaechromocytoma Paroxysmal sweating, palpitations and headache • OSA Daytime sleepiness etc • Renal artery stenosis/CKD • Coarctation of aorta • Adrenal tumour, Conn's or Cushing's • Medication: COCP, NSAIDs Pregnancy
What are the important points to ask in a history when a patient has hypertension
OPTICPR! When the diagnosis was made What reading were they getting prior to diagnosis How was the BP being monitored What treatments have they tried in the past? Side effects? What treatments are they on now? Side effects? What readings are they getting after treatment? Complications • Stroke • Heart Failure • Peripheral vascular disease • Renal failure Risk factors for Cardiovascular disease • DM • Hyperlipidaemia • FHx of CAD Lifestyle factors (ask about attempts/success with any of these) • Obesity • Lack of physical activity • Excessive alcohol intake High salt diet
In examining a patient with Hypertension, what are key signs/things not to miss?
Cardiovascular System
Blood pressure
Both arms, Lying/Standing
Signs of Cushing’s
Moon face, Weight gain, Purple striae, Buffalo hump, Proximal muscle weakness
Radio-femoral delay
Hypertensive Retinopathy (See opthalm notes)
