Cardiology JC005: Fever And A Heart Murmur Flashcards
Common valvular disease
- Valvular stenosis
- valve cannot open properly
- hypertrophy of ***proximal chamber —> dilatation when chamber fails - Valvular regurgitation
- dilatation of chamber on ***either side of valve
Diseases:
1. Mitral stenosis
2. Mitral regurgitation
3. Mitral valve prolapse
4. Aortic stenosis
5. Aortic regurgitation
6. Tricuspid regurgitation
Symptoms of valvular heart disease
- LH failure
- progressive exertional dyspnea - RH failure
- ankle edema
- hepatic pain (∵ hepatic congestion) - Chest pain
- myocardial ischaemia - Palpitations
- AF (common) - Fatiguability
- low CO - Complications
- thromboembolism
- infective endocarditis
- problems during pregnancy
***Investigations of valvular heart disease
- ***ECG
- chamber enlargement
- AF - CXR
- dilated heart - ***Echocardiogram
- Valvular architecture
- Chamber size
- Chamber function
- Doppler: Valvular gradient / regurgitant volume
- Low dose dobutamine (β1 selective: ↑ CO): assess ischaemia, contractile reserve - Exercise testing
- functional capacity - Cardiac catheterisation
- Associated coronary artery disease
- **Pressure gradient
- **Inject contrast to assess regurgitant lesions
Chronic Rheumatic Heart Disease
Rheumatic: diseases affecting CT
MS > MR + MS > MR
Common valvular involvement:
1. Mitral
2. Aortic + Mitral
3. Aortic
4. Tricuspid
- Mitral stenosis
- 95% Rheumatic
- 5% Congenital (rare)
- Normal: 2 cm^2
- Stenosis: <1 cm^2
***Haemodynamics:
LV inflow obstruction
—> ↑ LA pressure
—> ↑ Pulmonary venous pressure
—> ↑ Thickness of pulmonary vascular bed
—> Pulmonary arterial hypertension (2nd stenosis)
—> RH failure
Symptoms of MS
- Respiratory symptoms
- ***SOB on exertion
- Paroxysmal Nocturnal Dyspnea (PND) - Chronic RV failure
- Congestive cardiac failure - AF
- **∵ ↑ LA size
- 50-75% of MS
- important cause of **Cardiac decompensation
—> Normal LA contributes 20% of LV filling, become more important in MS
—> ↑ Ventricular rate —> ***↓ Diastolic LV filling —> ↓ SV + CO - Systemic embolisation
- LA enlarged —> Stasis of blood
Signs of MS
- Malar flush
- MS —> pulmonary hypertension —> CO2 retention —> Vasodilatory effects - Pulse volume
- small, irregular if AF - JVP
- loss of A wave (in AF)
- ↑ JVP (in RH failure) - Precordium
- Tapping apex
- Parasternal heath
- Loud S1
- Opening snap (OS)
- Mid diastolic rumble (at apex)
—> enhanced by exercise / lying on left side - Signs of complications
- Pulmonary edema
- Embolisation: peripheral vessels, stroke
Investigations of MS
- CXR
- **↑ LA (straight L heart border)
- **Pulmonary edema —> Kerley’s A + B lines
(A: thickened interlobular septa that contain lymphatic connections between perivenous and bronchoarterial lymphatics deep within the lung parenchyma
B: thickened subpleural interlobular septa and usually seen at lung bases) - ECG
- **Bifid P wave (P mitrale) if sinus rhythm —> Left atrial enlargement
- **AF
- ***RVH - Echocardiogram
- Thickened + Doming
- Parallel diastolic movement of MV
- Size of MV opening (significant MS < 1.5 cm^2) - Cardiac catheterisation
- assess associated coronary artery disease
- assess RH pressure
- unnecessary if pure MS - Clinical severity
- symptoms
- signs:
—> Pulmonary HT
—> Duration of murmur
—> Interval between S2 and OS
Treatment of MS
Medical:
1. ***Diuretics
- Digoxin (if AF) / Ca blockers / β-blockers
- ***Rate control drugs - ***Anticoagulation (Valvular AF)
- Warfarin
- history of embolisation
- paroxysmal / sustained AF
Surgical:
1. ***Valvuloplasty
- Percutaneous balloon dilatation
- if valve not calcified and no significant MR
- Valvotomy (closed / open)
- MV replacement (MVR)
- mechanical / bioprosthetic valve
- if valve calcified / badly destroyed
Causes of Acute decompensation of MS
- ***AF
- Chest infection
- ***Pregnancy (↑ intravascular volume by 30%)
- Mitral regurgitation
Incomplete closure of Mitral valve during systolic phase
Etiology:
1. ***Rheumatic (50% associated with MS)
- ***Mitral valvular prolapse (MVP)
- ***Rupture chordae tendinae
- degenerative / collagen disease e.g. Marfan, Ehler Danlos
- infective e.g. IE
- active rheumatic heart disease - Papillary muscle dysfunction
- ∵ ischaemia / MI - ***LV dilatation (functional MR)
- ∵ enlarged MV ring
Haemodynamics:
1. ***Volume overload of LV —> LV enlargement + failure
2. ↑ LA pressure only in systole —> ∴ pulmonary hypertension usually a late feature
Symptoms of MR
- Exercise limitation
- ***Heart failure
- Acute rupture of chordae
- Acute LV failure (∵ LV no time adapt to ↑ volume)
Signs of MR
Precordium
- LV dilatation (displaced apex)
- S1 not increase
- S2 obscured by murmur
- S3 usual
- Pansystolic
- Heard at apex —> Radiate to axilla
Investigations
- CXR
- ~ MS + ***LV enlargement - Echocardiogram
- define cause of MR
- Doppler: blood flow - Cardiac catheterisation
- assess MR severity
- assess associated CAD
Treatment of MR
MV repair / replacement
Indication:
- Symptomatic
- Asymptomatic: ↑ Heart size, ↓ LV ejection fraction (LVF)
- Functional MR
- Poor LV
- Refractory HF
- Mitral valvular prolapse
Systolic prolapse of MV into LA
- Isolated
- Associated with **Secundum ASD, **PDA, **Turner’s syndrome, **Wolff-Parkinson-White syndrome
Clinical features:
1. Asymptomatic
2. Atypical chest pain
3. Palpitation
4. Mid systolic click + Late systolic murmur (accentuated by Standing: ↓ Venous return —> ↓ LV volume —> ↑ Laxity of chordae —> ↑ MVP —> ↑ Duration of murmur)
Complications:
1. Progressive severe MR may require MV replacement
2. Emboli
3. AF
- Aortic stenosis
Etiology:
- Rheumatic (often associated with MS)
- Non-rheumatic
—> ***Calcific AS
—> Congenital: Valvular (Bicuspid —> easier to get stenosis), Subvalvular, Supravalvular
Severe AS:
- ***AV area <1 cm^2
- Mean pressure gradient >50 mmHg (lower in HF)
According to age:
- <60: Rheumatic, Congenital (Bicuspid, Unicuspid)
- 60-75: Calcified bicuspid valve (male usually)
- >75: Degenerative calcification (female usually)
Haemodynamics:
1. Gradient developed across AV obstructing aortic outflow during systole
—> Compensatory LV hypertrophy (no dilatation until HF)
- Inadequate ↑ in CO during exercise
—> symptoms of HF
Clinical features of AS
- Exertional dyspnea
- Angina pectoris
- inadequate blood supply to an already enlarged myocardium - Congestive cardiac failure
- Syncope / Sudden death
- when AS become symptomatic —> mortality 50% in 3 years
Signs of AS
- Slow rising pulse
- Heaving apex (LV hypertrophy)
- ↓ A2 (if calcified + severely stenotic)
- Thrill + Ejection systolic murmur at Aortic area —> Radiate to Carotid artery
Treatment of AS
Aortic valvular replacement
- for symptomatic
- may reverse LV impairment
- Aortic regurgitation
Incomplete closure of AV during Diastolic phase
Etiology:
1. Rheumatic
- Non-rheumatic (Degenerative)
- Infective endocarditis (diseased valve / normal valve in drug addict)
- Syphilis (Dilatation of aortic valvular ring)
- Congenital
- Marfan
- Congenital bicuspid valve - Seronegative rheumatoid syndrome
- Ankylosing spondylitis
- Reiter’s syndrome
- Psoriatic arthropathy - Traumatic
- Aortic dissection
- Rupture sinus of valsalva (into LV / RV)
- External trauma
Haemodynamic:
Regurgitation volume
—> ↑ LV end-diastolic volume (with normal LVEDP)
—> ↑ SV in compensated case by LV dilatation
—> Deterioration of LV function
—> ↑ LVEDP + ↓ SV
—> SOB + HF + Early MV closure (∵ ↑ LVEDP) (causing impedance to LV filling)
Symptoms:
- ~ AS
Signs of AR
- Collapsing pulse (***Pulse pressure >50 mmHg)
- ↑ Systolic pressure ∵ ↑ SV
- ↓ Diastolic pressure ∵ Blood leave aorta and regurgitate back to heart quickly - Displaced apex (LV dilatation)
- Early blowing diastolic murmur following S2 (left lower sternal border)
Eponyms (Classical signs):
1. Austin-Flint murmur (Diastolic murmur across MV)
2. Duroziez sign (to and fro murmur over femoral arteries)
3. Quincke’s pulse (capillary pulsation in finger tips / mucous membranes)
4. Tranle’s sign (pistol shot murmur)
5. De Musset’s head bobbing sign
6. Corrigan’s pulse (rapid upstroke + collapse of carotid artery)
- Tricuspid regurgitation
Etiology:
- **Functional RH failure secondary to LH disease e.g. DCMP, valvular heart disease
- **Rheumatic
- ***Infective endocarditis
- Infiltrative
S/S:
1. RH failure
2. Systolic S wave (Giant V wave in JVP)
3. RV heave
4. Pansystolic murmur (over LSB, ↑ with inspiration)
5. Pulsatile liver, Ascites
6. Cardiac cirrhosis
Treatment:
1. Bed rest
2. **Diuretics +/- Spironolactone
3. **Valvuloplasty
Infective endocarditis
- Only type of valvular infection / Cardiac infective disease
- caused by Microbial infection of Endocardial lining of heart (or blood vessels)
- **Abnormal valve + **Turbulence —> ***Bacterial adherence / infection
- insidious
Predisposing CVS etiologies
1. **Valvular (MR > MS, AR > AS, prosthetic, normal in IVDA)
2. **Shunts (Congenital, Post-surgical e.g. VSD, PDA, AV fistula)
***Clinical features of IE
History + Examination + Investigations
- Systemic infections
- Fever, Chills, Rigors (highly variable)
- Pallor, Weight loss, Splenomegaly
- Anaemia, Leukocytosis, ↑ ESR, ↑ CRP, ***+ve blood culture - Manifestations of IV lesions
- Heart: **Chest pain, Heart failure
- Embolism: **Stroke, Cold limbs
- Changing murmurs (progressively severe), Signs of HF, Petechiae, **Roth spots, **Osler’s nodes, **Janeway lesions, **Splinter haemorrhage
- RBC urine, CXR, ***Echocardiogram (detect vegetations), Arteriography, Liver-spleen scan - Manifestations of Immunological reactions
- Arthralgia, Myalgia, Tenosynovitis, **Glomerulonephritis
- **Arthritis, Uraemia, Vascular phenomena, Finger clubbing
- Proteinuria, Polyclonal Ig casts, **↑ RF, **↓ Complements, ***Immune complex
Janeway lesions vs Osler’s nodes
Janeway lesions (Immunological reaction)
- Macular non-painful
- Erythematous
- Palms + Soles
Osler’s nodes (Peripheral emboli)
- Tender papulopustules
- Pulp of finger
***Diagnosis of IE
- Clinical features
- Blood cultures
- **3 venous cultures (different sites + separate **>=30 mins) - Other investigations
- ***Transthoracic Echocardiogram (for vegetation)
- Transesophageal echocardiogram (better delineation of vegetation) - ***Modified Duke criteria
***Modified Duke criteria
Pathologic criteria:
1. Microorganisms demonstrated in a vegetation
2. Pathologic lesions = confirmed by histology
Clinical criteria:
Definite:
- 2 major
or
- 1 major + 3 minor
or
- 5 minor
Major:
1. **Blood culture showing persistent bacteraemia of typical organisms (>2/3)
2. **Evidence of endocardial involvement: **moving masses, abscess, **new MR, prosthetic valve dehiscence
Minor:
1. Predisposing lesions / main-lining addicts
2. Fever >38oC
3. Embolic phenomenon
4. IC disease (GN, Osler’s nodes, Roth’s spots, RF)
5. Atypical organisms in blood culture
6. Other Echo features of endocarditis
Organisms: Native valves
- Streptococcus (2nd Commonest)—> Penicillin
- **Viridans (e.g. Sanguis, Mutans): **oropharynx, >50% IE
- Bovis: **GI, elderly, underlying CA colon / polyp
- **Group A (Pyogenes): beta-haemolytic, attacks normal valves
- ***Group B (Agalactiae): friable vegetation - Enterococci (Faecalis, Faecium)
- GI, urethra
- resistant to penicillin (cephalosporin resistant) —> need Aminoglycoside
- post GI / GU manipulation - ***Staphylococcus (Aureus, Epidermidis) (Commonest)
- skin
- variable sensitivity
- fulminant valve destruction, prosthetic valve, mainlining addicts - HACEK (Haemophilus, Aggregatibacter, Cardiobacterium hominis, Eikenella corrodens, Kingella)
- oropharynx
- variable sensitivity
- large vegetation (difficult to isolate)
Streptococci
Classifications:
- Bio-assay (Beta-haemolysis)
- Serology (Lancefield grouping)
Lancefield Group A: Pyogenes
- **Rheumatic fever
- SBE (subacute bacterial endocarditis)
- **Scarlet fever
- **Toxic shock syndrome
- **Pharyngitis
- Cellulitis
- ***GN (strains: M type 1, 2, 4 etc.)
Lancefield Group B: Agalactiae
- **Neonatal sepsis
- **UTI
- SBE (subacute bacterial endocarditis)
Culture-negative endocarditis
- Inadequate technique
- Prior antibiotics
- ***Fastidious organisms
- Mycoplasma
- HACEK
- Abiotrophia
- Bartonella - ***Fungal (mainlining addicts, immunocompromised)
- lethal
***Treatment of IE
Initiate (according to likely organisms) while pending for cultures
Principles:
1. Eradicate source of infection (e.g. dental extraction)
2. **Bactericidal agents (∵ host defence is reduced)
3. **IV treatment + **High dose antibiotics
4. **Adequate treatment duration
5. Surgery + complications management
Clinical assessment of progress:
1. Physical signs
2. Body weight
3. Urine testing
4. Renal function
5. Blood counts
- ESR may take weeks to ↓
6. Drug level
7. ***Echocardiogram (for vegetation size)
8. Fever may take 1-2 weeks to ↓
Medical:
- High dose, IV, Prolonged
- Streptococcus: **Penicillin G 12-18 megaunits + **Gentamicin 1mg/kg q8h for 2 weeks
- Penicillin resistant / allergic: **Vancomycin 15mg/kg q12h for 4-6 weeks
- MRSA: **Vancomycin
Surgical:
- Native valve endocarditis:
—> Haemodynamic instability e.g. HF
—> Large emboli / embolic events
- Prosthetic valve endocarditis: Surgery required
—> Early (< 3 months): intraoperative contamination (usually Staphylococcus)
—> Late (> 3 months): foreign bodies, early surgery required - Fungal endocarditis
—> ∵ anti-fungal not effective
Summary of IE
- Variable clinical presentation
- acute to low grade fever - Broad spectrum of complications
- cardiac + neurologic complications - Diagnosis should be suspected in patients with fever in setting of relevant cardiac / non-cardiac risk
- 3 sets of blood culture
- Echocardiogram important
Antibiotic prophylaxis for IE
- IE more likely result from frequent exposure to random bacteraemia with daily activities than bacteraemia caused by dental, GI tract, GU tract procedure
- Prophylaxis only prevent an exceedingly small number of IE cases
- Risk of antibiotic-associated adverse events > benefits
- Maintenance of optimal oral health and hygiene can reduce incidence of bacteraemia from daily activities —> more important than prophylactic antibiotics
Reasonable situations:
***High risk patients
- Dental procedures involving Gingival tissues / Periapical region of teeth / Perforation of oral mucosa
- Procedures on respiratory tract / infected skin, skin structures, MSS tissue
***GU / GI tract procedures: NOT recommended
High risk patients
- Prosthetic cardiac valve / Prosthetic material used for cardiac valve repair
- Previous IE
- Congenital heart disease (CHD)
- **Unrepaired cyanotic CHD
- Completely repaired CHD with **prosthetic material / device by surgery / catheter
—> first 6 months after procedure
- Repaired CHD with ***residual defects at site / adjacent to site of prosthetic patch / device (which inhibit endothelialisation) - Cardiac transplantation recipients who develop cardiac valvulopathy (∵ on ***immunosuppressant)
Regimens for prophylaxis
- Penicillin
- Amoxicillin
- Ampicillin
- Ceftriaxone - Clindamycin
- Macrolide
- Azithromycin
- Clarithromycin
