Heart Valves and Murmurs Flashcards
Define pericarditis
Inflammation of the visceral and/or parietal serous pericardium
What are the possible causes of pericarditis?
- Idiopathic
- Viral (e.g. Coxsackie)
- Secondary to autoimmune
- Malignancy
- Post MI
Describe the clinical presentation of pericarditis
- Retrosternal chest pain
- Pleuritic and positional
- Pericardial friction rub
- Widespread concave ST elevation on ECG
Define pericardial effusion
Describe the pathology
What are the possible causes?
Accummulation of fluid within the pericardial space (blood, exudate, transudate)- inelastic pericardium limits how much fluid can accumulate.
Causes:
- Secondary to pericarditis or systemic disease, e.g:
- SLE
- RA
- Malignancy
- Uraemia
- Infection
- Trauma
- Idiopathic
- Post cardiac surgery
Describe the clinical features of pericardial effusion
- Features of underlying disease
- Quiet, muffled heart sounds
- Look for features of cardiac tamponade
- Chronic effusions may give enlarged globular heart on CXR
Define cardiac tamponade and its pathology
Medical emergency where accumulation of fluid in the pericardial sac restricts cardiac filling and compromises cardiac output. Inelastic pericardium restricts how much fluid can accumulate- pericardial pressure rises and compromises cardiac filling.
What are some possible causes of cardiac tamponade?
- Pericardial effusion causes:
- SLE
- RA
- Malignancy
- Uraemia
- Infection
- Trauma
- Post MI (ventricular rupture)
- Aortic dissection
Describe the clinical presentation of cardiac tamponade
- Tachypnoea
- Dyspnoea
- Beck’s triad:
- Hypotension (falling)
- Muffled heart sounds
- Jugular venous distension (rising)
- Needs urgent decompression
Define myocarditis
Describe the pathology
What are the possible causes?
Group of conditions characterised by inflammation of the myocardium in the abscence of predominant ischaemia.
Causes:
- Wide range of infectious causes (e.g Coxsackie virus)
- Non infectious, immune and toxin/drug related causes
Inflammatory cell infiltrate with or without evidence of myocyte injury
Describe the clinical presentation of myocarditis
- Acute or chronic presentations
- Mainly clinical features of heart failure
- Prognosis related to underlying cause
Define cardiomyopathies
Wide group of myocardial diseases (many have a strong genetic component) associated with mechanical and/or electrical dysfunction of the heart.
What should be excluded before diagnosing cardiomyopathies?
Ischaemic, hypertensive, valvular and congenital causes should be excluded.
What are the clinical features of cardiomyopathies?
Features of HF (systolic and/or diastolic dysfunction, arrhythmias, sudden death)
What are the main types of cardiomyopathies?
- Dilated
- Hypertrophic
- Restrictive
Define hypertrophic cardiomyopathy
What are the causes?
Describe the clinical features
The most common cardiomyopathy. Hypertrophy of left ventricle and interventricular septum
Caused by genetic mutations in sarcomeric proteins.
Pathology:
- Disorganised enlarged myofibres
- Asymmetrical septal hypertrophy may obstruct LV outflow tract
Clinical presentation:
- Manifests in adolescents/young adults
- Complications include arrhythmias and sudden death
Define dilated cardiomyopathies
Describe the pathology
What are the clinical features?
Characterised by left ventricle dilation and often hypertrophy (after ischaemia/abnormal loading excluded)
Pathology:
- Dilated left ventricle +/- hypertrophy and systolic dysfunction
Clinical notes:
- Features of progressive cardiac failure
What are some of the causes of dilated cardiomyopathies?
- 30% due to genetic mutations
- Post myocarditis
- Alcohol
- Some chemotherapy agents
- Storage disorders
- Autoimmune
- Idiopathic
What is restricted cardiomyopathy?
What are the causes?
Describe the pathology and clinical features
Characterised by poorly compliant left ventricle with normal ventricular wall thickness.
Causes:
- Idiopathic
- Associated with infiltrative disease e.g. amyloidosis, haemochromatosis, sarcoidosis
Pathology:
- Poor compliance leads to restrictive filling and diastolic dysfunction
What is arrhythmogenic right ventricular cardiomyopathy?
Progressive replacement of ventricular myocardium with fibrous tissue leading to RV failure, arrhythmias and sudden death.
What are the main causes of valve disease?
What causes the clinical manifestations?
Conditions that cause:
- Degeneration, fibrosis or calcification of valve leaflets
- Direct damage to endothelium/valve structure
- Distortion/damage to supporting structures
Clinical manifestations are related to:
- Valve stenosis (narrowing)
- Valve regurgitatation (incompetence)
- Valvular vegetations
What is calcific valvular degeneration?
Describe the pathology
Which valve is most commonly affected?
Cumulative chronic injury from repetitive mechanical stress causes calcification (deposition of hydroxyapatite)
Results in valve dysfunction as the mounds of calcification impair the valves’ ability to open- usually results in a stenotic valve.
Obstructed outflow leads to increased pressure overload on the left ventricular myocardium.
Aortic valve most commonly and significantly affected.
What is myxmatous degeneration?
Describe the pathology
Who is most at risk?
Deposition of mucoid (myxomatous) material within valve leaflets (usually mitral), often with associated thinning of other supporting tissues.
Results in floppy mitral valve leaflets that prolapse back into the left atrium during ventricular systole.
Affects mainly females, many asymptomatic.
Who is most at risk from calcific valvular degeneration?
Older patients
Presents 1-2 decades earlier in patients with congenitally bicuspid valves
What is rheumatic heart disease?
Describe causes and pathology
Who is most at risk?
What are the complications?
Acute, immune mediated multisystem inflammatory disease
Classically occurs after group A streptococcal pharyngitis. Thought to be due to a cross reaction of streptococcal antigens with host proteins.
Can lead to acute rheumatic carditis and may progress to chronic rheumatic heart disease due to repeat injury to the valves.
Characterised by fibrotic valvular disease that deforms valves (particularly mitral) due to thickened leaflets, fusing of commissures and short thick chordae tendinae.
Main cause of mitral stenosis.
Define endocarditis
What are the types?
What usually results?
Inflammation of the endocardial surface of the heart, including valves, chordae tendinae, septal defects, as well as mural surfaces.
Types:
- Infective (usually bacterial)
- Non-infective (e.g. SLE associated)
Usually results in vegetations forming on endocardial surfaces which may be locally destructive or a source of emboli.
Can also affect prosthetic valves
Describe the pathology of infective endocarditis
What are the clinical presentations?
Mainly bacterial:
- Streptococcus viridans
- Staphylococcus aureus
Pathology:
- Bacteraemia due to infection, dental/surgical procedures, IVDU
- Abnormal valve and/or virulent organism
- Vegetations form from thrombus (fibrin/platelets/cells) and bacteria
- May be locally destructive or a source of septic emboli
- Mitral and aortic valve most commonly affected (N.B tricuspid valve in IVDU)
Clinical notes:
- Often non-specific fever/malaise
- New onset murmur +/- clinical effects of valve dysfunction
- Embolic effects: many ‘classical’ clinical signs- most rare
- Blood cultures and echocardiography
What forms the normal heart sounds?
What can be palpated to allow for differentiated when heart rate is increased?
S1: closure of atrioventricular valves
S2: closure of the semilunar valves
Carotid artery can be palpated to allow for differentiated when heart rate is increased
Describe the physiological splitting of the second heart sound
During inspiration, pulmonary valve may close later than aortic valve leading to ‘splitting’ of S2.
Describe pathological ‘fixed’ splitting of the second heart sound
May be ‘fixed’ when the right side of the heart is chronically overloaded e.g. atrial-septal defect.
True fixed splitting is characteristic of this defect.
Describe the pathological reverse splitting of the second heart sound
Reversed splitting e.g. during expiration, may occur, associated with delay of blood flow through aortic valve.
What is a third heart sound
= dull, low frequency extra heart sound heard during early diastole.
- Caused by rapid filling of left ventricle in early diastole
- Can be pathological: large, poorly contracting LV or mitral regurgitation
- Or physiological: healthy young adults, athletes, pregnancy, fever
What are fourth heart sounds?
Low frequency extra heart sound that may be heard in late diastole (atrial contraction).
Caused as atrial contraction pushes blood into ‘stiff’ LV
Regarded generally as pathological and associated with conditions that reduce compliance of the left ventricle e.g. hypertrophy secondary to HTN, aortic stenosis.
What are cardiac murmurs?
Produced by turbulent flow across abnormal valve, septal defect or obstructed outflow tract.
May also be generated by increased flow through normal valves (innocent/flow murmurs)
When listening to a cardiac murmur, what should be recorded?
- Location (where it is heard loudest)
- Radiation
- Timing- systolic or diastolic / early, mid or late (palpate carotid to establish this)
- Intensity (grade)
- Character and pitch e.g blowing, harsh, rumble, low or high
- Accentuating manouevres e.g. posture, breathing, squatting, hand grip, valsalva
Describe the grading of intensity of cardiac murmurs
Grade 1: Heard by an expert in optimum conditions
Grade 2: Heard by a non-expert in optimum conditions
Grade 3: Easily heard, no thrill
Grade 4: Loud murmur with a thrill
Grade 5: Loud murmur, heard over a wide area, with a thrill
Grade 6: Extremely loud, heard without a stethoscope
What is aortic stenosis?
What are the causes?
Describe the clinical presentation
Narrowing of aortic valve
Prevalence increases with age.
Causes:
- Calcific aortic valve disease most common (rheumatic heart disease)
Clinical notes:
- LV hypertrophy (concentric) may develop (pressure overload)
- Reduced exercise tolerance
- Dyspnoea
- Angina
- Syncope
What may be found on examination in a patient with aortic stenosis?
- Mid (ejection) systolic murmur (may be ejection click at onset)
- Crescendo-descrendo pattern
- Radiates to carotids
- May be associated thrill and S4
- Narrow pulse pressure
Describe the causes and clinical presentation of patients with aortic regurgitation
What may be found on examination?
Causes:
- Dilation of aortic root (e.g. due to connective tissue disease, aortic root dissection, idiopathic)
- Valve disease e.g. bicuspid valve, endocarditis
Clinical notes:
- LV hypertrophy (eccentric) /dilation may develop (volume overload)
- Features of acute or chronic HF
Examination:
- Early diastolic high pitched decrescendo murmur
- May be ejection systolic flow murmur & S3
- Wide pulse presure
- E.g. collapsing pulse; Corrigan’s; Quincke’s’ de Musset’s
- Displaced apex beat
Describe mitral regurgitation, its causes and clinical presentation
Incompetence of the mitral valve resulting from damage to any part of the mitral valve apparatus.
Causes:
- Wide range of causes:
- Post MI (papillary muscle damage)
- Functional (due to dilation of LV)
- Endocarditis (leaflets)
- Myxomatous degeneration (leaflets/chordae)
Clinical notes:
- LV hypertrophy (eccentric)/ dilation may develop (volume overload)
- Features of acute or chronic heart failure
What might be found on examination in a patient with mitral regurgitation?
- Holo (pan) systolic blowing murmur
- Radiates to axilla
- S3 may be heard
- Displaced apex beat
- Thrill may be present
What is a mitral valve prolapse?
List the causes, clinical manifestations and examination findings
Common valve disorder where one or both mitral valve leaflets billow back into the left atrium
Causes:
- Mainly myxomatous degeneration of leaflets/chordae
Clinical notes:
- Many asymptomatic
- May be associated mitral regurgitation
Examination:
- Mid-systolic click caused by tensing of the chordae tendinae as leaflet(s) prolapse
- Timing shifts with manouevres, e.g valsalva, squatting
- Classically associated with late systolic murmur
What is mitral stenosis?
Describe the causes, clinical manifestations and examination findings
Narrowing of mitral valve opening due to thickening and fusion of leaflets
Causes:
- Rheumatic heart disease (most common)
Clinical notes:
- Features of pulmonary congestion and poor cardiac output +/- pulmonary HTN
- Left atrial enlargement
Examination:
- Low pitched rumbling mid-diastolic murmur
- Often associated opening snap from stiffened valve leaflets
- AF may be present
- Malar flush/mitral fascies
