Valvular Heart Disease Flashcards
what are heart sounds 1 and 2 caused by
- S1: closing of AV valves at the start of the systolic contraction of the ventricles
- S2: closing of semilunar valves once the systolic contraction is complete
what is S3 caused by and what does it indicate in young vs old people
roughly 0.1 seconds after S2
- rapid ventricular filling causing the chordae tendinae to pull to their full length and twang like guitar string
- ‘gallop rhythm’
- can be normal in young (15-40 years) healthy people because the heart functions so well that the ventricles allow rapid filling
- in older patients, it can indicate heart failure, as the ventricles and chordae are stiff and weak and reach their limit much faster than usual
what is S4 caused by
heard directly before S1
- always abnormal and relatively rare
- indicates a stiff or hypertrophic ventricle and is caused by turbulent flow from that atria contracting against a non-compliant ventricle
where should you auscultate for heart sounds
how can you describe the features of a murmur
- Site: where is the murmur loudest?
- Character: soft / blowing / crescendo (getting louder) / decrescendo (getting quieter) / crescendo-decrescendo (louder then quieter)
- Radiation: can you hear the murmur over the carotids (aortic stenosis) or left axilla (mitral regurgitation)?
- Intensity: what grade is the murmur?
- Pitch: is it high-pitched or low and rumbling? Pitch indicates velocity.
- Timing: is it systolic or diastolic?
“This patient has a harsh / soft / blowing, Grade …, systolic / diastolic murmur, heard loudest in the aortic / mitral / tricuspid / pulmonary area, that does not / radiates to the carotids / left axilla. It is high / low pitched and has a crescendo / decrescendo / crescendo-decrescendo shape. This is suggestive of a diagnosis of mitral stenosis / aortic stenosis.”
what are the 2 ways in which valvular heart disease functions
- hypertrophy: thickens both outwards and into the chamber
- dilatation: thinning and expanding of the myocardium affecting the chamber immediately before the pathological valve
- mitral stenosis: left atrial hypertrophy
- aortic stenosis: left ventricular hypertrophy
- mitral regurg: left atrial dilatation
- aortic regurg: left ventricular dilatation
what are the 3 classical symptoms of aortic stenosis
angina, heart failure, syncope
most common inital symptoms: decrease in exercise tolerance/dyspnoea on exertion
what are the common causes of AS
- idiopathic age-related calcification
- congenital bicuspid valve
- CKD
- rheumatic heart disease
what type of murmur does AS cause
ejection systolic, high pitched crescendo-decrescendo murmur which radiates to the carotid/neck, best heard at the aortic area (2nd intercostal space on the rright)
what are other signs of AS
- Thrill in the aortic area on palpation
- Slow rising pulse
- Narrow pulse pressure (the difference between systolic and diastolic blood pressure)
- Exertional syncope (lightheadedness and fainting when exercising) due to difficulty maintaining a good flow of blood to the brain
how is the severity of AS assessed
what are 4 indications for sugery in AS
- symptomatic regardless of severity
- asymptomatic severe AS + LV systolic dysfunction
- asymptomatic severe AS + abnormal exercise test
- asymptomatic severe AS at time of other cardiac surgery e.g. CABG
in older AS patient with significant co-morbidities, what intervention should be considered
transcatheter aortic valve implantation (TAVI)
- femoral artery
what type of murmur does AR cause
early diastolic blowing murmur best heard at the left sternal edge
- can also cause Austin Flint murmur heard at the apex - diastolic rumbling murmur caused by back flow of blood through the aortic valve and over the mitral valve causing it to vibrate
what are signs of AR
- Thrill in the aortic area on palpation
- Collapsing pulse
- Wide pulse pressure
- Heart failure and pulmonary oedema
- De Musset’s sign (head bobbing)
why does AR cause a collapsing pulse
A collapsing pulse or water hammer pulse is a forcefully appearing and rapidly disappearing pulse
- occurs as blood is forcefully pumped out of the left ventricle, then immediately flows backwards through the incompetent aortic valve
what are common causes of AR
- Idiopathic age-related weakness
- Bicuspid aortic valve
- Connective tissue disorders, such as Ehlers-Danlos syndrome and Marfan syndrome
what is the standard medical therapy in patients with severe AR and LV dilatation
ACEi - afterload reduction
how is AR assessed
ECHO - quantifies severity and assesses rest of heart
what are indications for surgery in patient with chronic AR
● Symptomatic severe AR
● Asymptomatic severe AR with evidence of early LV systolic dysfunction (EF < 50% or LV end-systolic diameter > 5 cm or LV end-diastolic diameter > 7·0 cm)
● Asymptomatic AR of any severity with aortic root dilatation > 5·5 cm (or > 4·5 cm in Marfan syndrome or bicuspid aortic valve)
what type of murmur does mitral stensois cause
mid-diastolic, low pitched rumbling murmur
- due to low blood flow velocity
- loud S1 due to thick valves requiring a large systolic force to shut then shutting suddenly
- opening snap after S2 which triggers the onset of the murmur
what are signs of mitral stenosis (3)
- tapping apex beat (palpable, prominent S1)
- malar flush: due to back pressure of blood into pulmonary system, causing rise in CO2 and vasodilation)
- AF: caused by LA struggling to push blood through stenotic valve causing strain and electrical disruption
what are causes of mitral stenosis (2)
- rheumatic heart disease
- infective endocarditis
when examining pt, look for signs that suggest an underlying cause e.g. splinter haemorrhages, Janeway lesions, Osler’s nodes, offer fundoscopy for Roth spots in infective endocarditis
how does MR cause congestive cardiac failure
- mitral regurg is an incompetent mitral valve causing backflow of blood from the left ventricle into the left atrium during systolic contraction of the LV
- the leaking causes a reduced ejection fraction and a backlog of blood waiting to be pumped through the left side of the heart - CCF
what type of murmur does MR cause
pan-systolic, high-pitched ‘whistling’ murmur due to high velocity blood flow through the leaky valve, which radiates to the left axilla
- might also heart S3
what are common causes of MR
- mitral valve prolapse: more common in pt w Marfan’s and pectus excavatum
- idiopathic weakening w age
- ischaemic heart disease
- rheumatic heart disease
what are the surgical options for MR and when is it generally indicated
mitral valve replacement of mitral valve repair indicated in severe MR for:
- symptomatic pt
- asymptomatic pt w mild-moderate LV dysfunction
what medical therapy might be used in MR
largely restricted to diuretics
- ACEi may be beneficial in pt w functional or ischaemic MR
- ACEi/B-blockers if LV systolic dysfunction present to reduce the severity of MR
what is tricuspid regurgitation
incompetent tricuspid valve, allowing blood to flow back from the right ventricle to the right atrium during systolic contraction of the right ventricle
what kind of murmur does tricuspid regurgitation cause
pan-systolic murmur
- split second heart sound due to the pulmonary valve closing earlier than the aortic valve, as the right ventricle empties faster than the left ventricle
what are signs of TR
- Thrill in the tricuspid area on palpation
- Raised JVP with giant C-V waves (Lancisi’s sign)
- Pulsatile liver (due to regurgitation into the venous system)
- Peripheral oedema
- Ascites
what are causes of tricuspid regurg
- Pressure due to left-sided heart failure or pulmonary hypertension (“functional”)
- Infective endocarditis
- Rheumatic heart disease
- Carcinoid syndrome
- Ebstein’s anomaly
- Connective tissue disorders, such as Marfan syndrome
what is pulmonary stenosis
narrowed pulmonary valve, restricting blood flow from the right ventricle into the pulmonary arteries
what kind of murmur does pulmonary stenosis cause
ejection systolic murmur loudest in the pulmonary area with deep inspiration
- widely split second heart sound, as the left ventricle empties much faster than the right ventricle
what is pulmonary stenosis caused by
usually congenital and associated with:
* Noonan syndrome
* Tetralogy of Fallot
what is infective endocarditis
infection of the endothelium (the inner surface) of the heart
- most commonly, it affects the heart valves
- can be acute, subacute or chronic, depending on how rapidly and acutely the symptoms present and the causative organism
what are risk factors to infective endocarditis
- Intravenous drug use
- Structural heart pathology (see below)
- Chronic kidney disease (particularly on dialysis)
- Immunocompromised (e.g., cancer, HIV or immunosuppressive medications)
- History of infective endocarditis
what are predisposing cardiac conditions to infective endocarditis
- mitral valve prolapse
- prosthetic heart valves
- rheumatic heart disease
- valvular heart disease
- ICDs e.g. pacemakers
what are the most common causative organisms of infective endocarditis
S.aureus
- strep viridans
- enterococcus
- 2-10%
what are the presenting symptoms of IE
- fever
- fatigue
- night sweats
- muscle aches
- anorexia
often non-specific but should always be suspected in patients with unexplained fever, bacteraemia or systemic illnes and/or apparently new murmur or other features of illness
what are examination findings of IE
- New or “changing” heart murmur
- Splinter haemorrhages (thin red-brown lines along the fingernails)
- Petechiae (small non-blanching red/brown spots) on the trunk, limbs, oral mucosa or conjunctiva
- Janeway lesions (painless red flat macules on the palms of the hands and soles of the feet)
- Osler’s nodes (tender red/purple nodules on the pads of the fingers and toes)
- Roth spots (haemorrhages on the retina seen during fundoscopy)
- Splenomegaly (in longstanding disease)
- Finger clubbing (in longstanding disease)
what are routine initial investigations for IE
● Full blood count
● ESR and CRP
● U&Es
● Liver function tests
● Urine dipstick analysis and MSU for microscopy/culture
● Chest
what are the key diagnostic investigations for IE
- blood culutres
- echo
- Special imaging investigations may be used in patients with prosthetic heart valves, where it can be more challenging to determine whether an infection is present in the prosthesis:
18F-FDG PET/CT
SPECT-CT
when and how should blood culutres be taken for IE
essential BEFORE starting abx
- at least 3, preferably 6 sets taken from different sites over several hours at least 6 hours
- gap between repeated sets may be shorter if abx are required more urgently i.e. if septic but equally if pt stable, it is reasonable to delay abx to allow comprehensive sampling
if cultures are negative despite high level of suspicion of IE, sample can be taken in special media that allows for growth of fastidious organisms
why is TOE preferred over transthoracic
- usueful in detectioin of mitral valve and prosthetic valve vegetations
- more sensitive at detecting aortic root and setpal abscesses and leaflet perforations
what criteria is used to diagnose infective endocarditis
modified Duke criteria
- 1 major + 3 minor
- 5 minor
what are major criteria of diagnosing IE
Positive blood cultures
- typical organism from 2 blood cultures
- persistent positive blood cultures taken > 12 hours apart
- > 3 positive blood cultures taken over more than 1 hour
Endocardial involvement
positive echo findings (vegetation, abscess)
new valvular regurgitation
dehiscence of prosthesis
what are minor criteria of diagnosing IE
- Predisposing valvular or cardiac abnormality
- IV drug abuser
- Pyrexia > 38°C
- Embolic phenomenon
- Vasculitic phenomenon
- Blood cultures suggestive (organism grown but not achieving major criteria)
- Suggestive echo findings (but not meeting major criteria)
how are abx best delivered in IE
tunnelled central venous line when prolonged courses of IV abx are required
IV broad spec-abx e.g. amoxicillin + optional gent is the mainstay of treatment
how long is the duration of abx therapy in IE
- 4 weeks with native heart valves
- 6 weeks with prosthetic heart valves
what abx are used to treat endocarditis caused by streptococci
benzylpenicillin IV or vanc + low-dose gent
e.g. 8mg BD
what abx are used to treat endocarditis caused by enterococci
amoxicillin IV or vanc + low-dose gent IV
e.g. 80mg BD
what abx are used to treat endocarditis caused by staphylococci
flucloxacillin/benzylpenicllin/vanc + gent/fusidic acid
give examples of how response to therapy in IE is closely monitored
- Echo once weekly: assess vegetation size and complications e.g. valve destruction or intracardiac abscess
- ECG x2 weekly: detection conduction disturbances
- blood tests x2 weekly: ESR, CRO, FBC, U&Es
referral for consideration of surgery is indicated in IE patient with…?
- moderate to severe cardiac failure due to valve compromise
- valve dehiscnece
- uncontrolled infection despite abx therapy
- large vegetations/abscess
- coxiella/fungal infection
- sinus of valsalva aneurysm
what are key complications of IE
- Heart valve damage, causing regurgitation
- Heart failure
- Infective and non-infective emboli (causing abscesses, strokes and splenic infarction)
- Glomerulonephritis, causing renal impairment
what are causes of acute pericarditis
- viral Coxsackie infection
- TB
- uraemia
- cT disorders e.g. SLE, RA
- malignancy e.g. lung/breast cancer
what are key features of pericarditis
- chest pain: may be pleuritic often relieved on sitting forward
- non-productive cough
- dyspnoea
- flu-like symptoms
- pericardial rub
what are ECG changes seen in pericarditis
- often global/widespread as opposed to present in territories as in ischaemic events
- ‘saddle-shaped’ ST elevation
- PR depression: most specific marker
what investigation should all patients with suspected acute pericarditis have
transthoracic echo
how is acute pericarditis managed
majority of patients can be managed as outpatient but those with high-risk features e.g. temp >38 or elevated trop should be treated as inpatient
- treat underlying cause
- avoid strenous physical activity until symptom resolution
- combination of NSAIDs/colchicine 1st line for acute idiopathic/viral pericarditis
what is atrial myxoma
most common primary cardiac tumour
where does atrial myxoma commonly affect
75% in LA, commonly attached to the fossa ovalis
what are the features of atrial myxoma
- systemic: dyspnoea, fatgiue, weight loss, pyrexia of unknown origin, clubbing
- emboli
- AF
- mid-diastolic murmur
what does an echo of atrial myxoma show
pedunculated heterogeous mass typically attached to the fossa ovalis region of the intersitial septum
what do mechanical heart valves carry a high risk of and how is this managed
clot formation
- dual anticoagulation and antiplatelet
- warfarin with a target INR of 3.5 for mitral valves and 3.0 for aortic valves
how can acute mitral regurgigation arise
post MI - may be due to ischaemia or rupture of the papillary muscle
- acute hypotension
- flash pulmonary oedema
