Valvular emergencies

Introduction

• 2.5-fold risk of death and 3-fold risk of stroke compared to general population
• The New Murmur
  • Benign or physiological
    • Do not cause symptoms or findings of cardiovascular disease
    • Soft, systolic ejection murmurs that begin after S1, end before S2 and no abnormal heart sounds
  • Systolic murmurs
    • May be associated with anaemia, sepsis, volume overload or any other cause of increased CO
    • Look for underlying cause vs. management of murmur itself
  • Patients without chest pain, dyspnoea, fever or other signs attributable to valvular disease do not need emergent echo but need referral
  • Any diastolic murmur or new systolic murmur with symptoms at rest is pathological and needs inpatient echo
  • Always consider endocarditis, especially if valvular insufficiency

Algorithm for new murmur

• Diastolic – Urgent echo
• Systolic
  • Mid-systolic grade 2 (audible but soft)
    • Asymptomatic
    • No signs of CVD
    • Normal ECG and CXR
    • Murmur does not increase with valsalva or standing
    • = No further workup
    • Symptomatic, signs of CVD, abnormal ECG/CXR, murmur increases with Valsalva or standing
    • = Needs urgent echo
  • Mid-systolic grade 3 (loud but no thrill)/Early or late systolic/Holosystolic
    • Needs urgent echo

Grading system for murmurs

Dynamic manoeuvres

Mitral stenosis

• Rheumatic heart disease is most common
• Usually presents with gradual onset pulmonary congestion and AF
• Mitral annular calcification is a non-rheumatic cause
  • Most common in women, elderly and those with HTN/Chronic renal failure
  • Rarely causes severe symptoms
• Clinical features
  • Exertional dyspnoea, often precipitated by anaemia/sepsis (increased CO)
  • Systemic emboli are a risk (particularly if in AF)
  • Haemoptysis is rare but can be massive
  • Recurrent bronchitis, fatigue, paroxysmal AF
  • Signs:
    • Mitral facies (peripheral cyanosis of cheeks)
    • Mid-diastolic rumbling murmur with crescendo towards S2 (presystolic accentuation disappears if in AF)
    • S1 usually loud with loud opening snap heard to right of apex
    • Apical pulse is small and tapping due to underfilled LV
    • Severe disease (<1cm2)
      • Small pulse pressure
      • Soft first heart sound (immobile leaflets)
      • Early opening snap
      • Long murmur
      • Diastolic thrill at apex
• Diagnosis and treatment
  • ECG: Notched or biphasic P waves (P mitrale) and right axis deviation
  • CXR: Straightening of left heart border (LA enlargement) and later pulmonary congestion
  • Echo: Severe <1cm2
• Medical management
  • Symptom control
    • Beta-blockers to reduce HR, increase diastolic filling time
    • AF with RVR or dyspnoea on exertion may benefit from rate control
  • Anticoagulation if LA diameter >55mm OR in AF, a left atrial thrombus or history of systemic emboli
• Surgical for symptomatic disease
  • Balloon valvotomy, valve repair or valve replacement before onset of severe pulmonary hypertension

Mitral regurgitation

• Usually chronic and slowly progressive
• Most common cause is fibroelastic deficiency syndrome, seen in the elderly
• Mitral valve prolapse is another cause seen in younger patients
• Can be secondary to dilated LV with papillary muscle displacement and subsequent valve dysfunction
• Chronic MR
  • Left atrium dilates to accommodate increased flow to keep pressures normal
  • Stroke volume is augmeted, maintaining effective forward flow despite backflow
• Acute MR
  • Results in rapid-onset pulmonary congestion and peripheral oedema
  • Typically due to papillary muscle or chordae tendinae rupture fro MI or valve leaflet perforation due to IE
• Clinical features
  • Acute MR: Severe dyspnoea, peripheral oedema, tachycardia, cardiogenic shock. S4 gallop and harsh apical systolic murmur loudest in early-mid systole diminishing before S2
  • Chronic MR: Eventual exertional dyspnoea, sometimes with AF
    • Late systolic left parasternal lift and lateral displacement of apex beat
    • High-pitched holosystolic murmur heard at apex
    • S1 soft and obscured by murmur
    • S3 often heard followed by short diastolic rumble, indicating increased flow into the ventricle
    • Signs of systemic thromboembolism may be first suggestion of MR with AF
    • Dynamic manoeuvres
      • Inspiration – Softer due to decreased venous return to left side of heart
      • Expiration – Louder due to increased venous return to left side of heart
      • Valsalva – Softer as straining against closed glottis reduces venous return to the right and then the left side of the heart
      • Standing to squatting – Louder owing to increase in venous return
      • Squatting to standing – Softer owing to reduced venous return
      • Isometric exercise (hand-grip) – Louder owing to increased systemic vascular resistance and afterload
    • Severe disease
      • High grade murmur
      • Small volume pulse
      • Enlarged LV
      • Loud S3
      • Soft S1
      • Signs of pulmonary hypertension
      • Signs of LV failure
• Diagnosis
  • Think of acute MR in any patient new-onset and marked pulmonary oedema
    • Especially if normal heart size on CXR or do not respond to therapy
    • Look at ECG for anteroinferior ischaemia
  • Chronic MR
    • ECG signs of LV hypertrophy and LA enlargement
    • CXR shows LA and ventricular enlargement proportional to regurgitant volume
• Treatment
  • Acute MR
    • Oxygen, PPV, nitrates (reduce afteroad, to increase forward flow and restore mitral valve competence as LV size diminishes
    • Inotropic support as bridge to surgery (if structural disruption)
    • Aortic balloon pump may be effective bridge
    • Medical therapy is aimed at improving forward flow with emergent cardiology and surgical consultation during optimisation
  • Chronic MR
    • Treat acute symptoms
    • Control AF with RVR using beta-blockers or CCB’s
    • Start anticoagulation to prevent systemic embolisation
    • Cardiology consultation

Mitral valve prolapse

• Systolic billowing of one or both leaflets into the LA with/without mitral regurgitation
• Characterised by myxomatous degeneration of the valve due to inherited connective tissue defects
• Most common valvular disease in developed countries (2.4% of population)
• Presence of concomitant mitral regurgitation determines prognosis
• Clnical features
  • Mostly asymptomatic
  • May present with atypical chest pain, palpitations, fatigue, anxiety or dyspnoea unrelated to exertion
  • Signs such as scoliosis, pectus excavatum and low body weight may be seen
  • If exercise induces symptoms, morbidity increases
• Auscultation
  • Mid-systolic click
  • Maneuvers that decrease preload (Valsalva/standing) will cause the click to occur earlier in diastole
  • Increased preload by squatting or hand gripping causes systolic click to move later into systole
  • A late systolic murmur that crescendos into S2 is heard in some
  • Dynamic manoeuvres
    • Inspiration – Softer due to decreased venous return to left side of heart
    • Expiration – Louder due to increased venous return to left side of heart
    • Valsalva – Systolic click and murmur occurs earlier as straining against closed glottis reduces venous return to the right and then the left side of the heart causing LV volume to reduce
    • Standing to squatting – Louder and later click/murmur owing to increase in venous return and increase in LV volume
    • Squatting to standing – Softer and earlier click/murmur owing to reduced venous return and reduced LV volume
    • Isometric exercise (hand-grip) – Later click owing to increased systemic vascular resistance and afterload with subsequent increase in LV volume
• Diagnosis and therapy
  • Emergency evaluation focuses on identification of long-term complications such as AF or heart failure
  • Refer to cardiologist if suspected
  • Palpitations attributable to mitral valve prolapse may respond to beta-blockers but should be left to cardiologist
  • Antithrombotic therapy only indicated if TIA/stroke or AF
  • If prolapse and MR, require endocarditis prophylaxis

Aortic stenosis

• Most common cause in developed countries is degenerative calcification, associated with increased age, smoking, dyslipidaemia and diabetes
• Rheumatic heart disease is the most common cause worldwide
• Bicuspid aortic valves and congenital heart disease are also seen
• 3% prevalence if >74 years old
• Typically long asymptomatic period with LV hypertrophy to preserve EF
  • Ultimately LV hypertrophy impairs filling and increases myocardial oxygen demand with slow reduction in cardiac output, coronary and systemic blood flow
• Clinical features
  • Classic triad: Dyspnoea, chest pain and syncope
  • Many patients with severe stenosis (<1cm2) are asymptomatic
  • Often stepwise: Dyspnoea -> chest pain -> syncope -> signs of heart failure
  • Once symptoms start, mortality increases
• Physical exam
  • Late peaking systolic murmur at right 2^nd ICS, radiating to carotids, with single or paradoxically split S2, S4 gallop and reduced carotid pulse with delayed upstroke and long plateau (pulsus parvus et tardus)
  • Brachioradial delay is also seen
  • Severe disease (<1cm2 or gradient >50mmHg)
    • Delayed carotid upstroke
    • Weak carotid pulse
    • Narrowed pulse pressure
    • Sustained apex beat
    • Absent or decreased A2
    • S4 gallop
    • Late peaking murmur
    • Long murmur
    • Signs of LV failure
    • *All less reliable in the elderly
  • Dynamic manoeuvres
    • Inspiration – Softer due to decreased venous return to left side of heart
    • Expiration – Louder due to increased venous return to left side of heart
    • Valsalva – Softer as straining against closed glottis reduces venous return to the right and then the left side of the heart
    • Standing to squatting – Louder owing to increase in venous return and increase in LV volume
    • Squatting to standing – Softer owing to reduced venous return and reduced LV volume
    • Isometric exercise (hand-grip) – Softer owing to increased systemic vascular resistance and afterload with subsequent reduction in pressure gradient across aortic valve
• AS with AF = Dire consequences
  • AS typically have diastolic dysfunction due to LV hypertrophy and are reliant on atrial kick for filling
  • If then given GTN for chest pain or dyspnoea, can collapse
• Natural history
  • AS becomes haemodynamically significant as valve area approaches <1cm2
  • As the valve becomes tighter, the pressure gradient across the valve increases
  • >50mmHg indicates severe disease
  • Ultimately the gradient may decrease owing to decreased stroke volume associated with advanced disease
  • The comparably low pressure at the aortic root results in low coronary perfusion pressure with high LV wall tension with subsequent LV ischaemia, with further reduction in CO and coronary pressure
  • This self-perpetuating vicious cycle of reduced systemic pressure and LV ischaemia leads to haemodynamic collapse
  • Tachycardia in response to this further increases O2 demand and reduces the time spent in diastole for thickened/hypertrophied LV filling
• Diagnosis
  • ECG: LV hypertrophy + LBBB or RBBB in 10%
  • Late CXR findings are LV hypertrophy (not dilation) and pulmonary congestion
• Treatment
  • APO: Oxygen, PPV. Use nitrates, beta-blockers, CCB’s and diuretics with caution
  • Phenylephrine (pure alpha agonist) is the vasopressor of choice
    • The massive afterload of aortic stenosis is at the level of the valve with little contribution from systemic vasculature
    • Phenylephrine acts to increase diastolic pressure, coronary perfusion and reduce the pressure gradient across the stenotic valve
    • Phenylephrine may also produce a reflex bradycardia to reduce myocardial demand and diastolic filling time
    • Noradrenaline is a reasonable alternative but risks tachycardia
  • Reducing preload or afterload can cause significant hypotension
    • Preload dependent for cardiac output
    • Reduced afterload in presence of fixed valvular stenosis may reduce systemic blood pressure and subsequent coronary artery perfusion pressure
  • Positive inotropic agents such as dobutamine and adrenaline must be used with extreme caution as tachycardia (with reduced cardiac output) and myocardial ischaemia (due to increased oxygen demand) may occur
  • Induction agents risk preload loss and myocardial depression
    • Ensure euvolaemic and err on mild hypervolaemia in this situation
    • High-dose fentanyl and low-dose midazolam is a reasonable option
    • Ketamine risks tachycardia and propofol is likely too vasodilatory
  • New-onset AF may require cardioversion urgently
  • If newly symptomatic, admit
    • Without surgery 40-50% mortality within 1 year
    • If discharged, need to avoid vigorous activity and need prompt review by Cardiologist. 
  • Prophylactic antibiotics for endocarditis are not required
• Need surgical valve replacement, TAVI or balloon valvuloplasty as soon as symptomatic, asymptomatic with LV dysfunction or if jet peak velocity >4m/s
• If there is concomitant aortic regurgitation, a slightly higher heart rate may prove beneficial to achieve balance between LV filling and preventing excessive regurgitation times
• Using vasodilatory afterload reduction agents e.g. dobutamine will likely NOT improve cardiac output as the afterload is actually at the level of the valve, not the systemic vasculature
• Avoiding hypertension is important though as the dual hit of valve stenosis with systemic hypertension may prove too much for the already beleaguered LV
• A balloon pump may prove useful in improving diastolic coronary flow to the hypertrophied LV

Aortic regurgitation

• Slowly progressive over years
• Ultimately leads to LV dilatation and hypertrophy
• Get wide pulse pressures
• Tachycardia shortens diastole, which decreases regurgitant volume and mutes symptoms early on
• In contrast, increased afterload e.g. exercise, exacerbates regurgitant flow and may precipitate symptoms
• Over time, increased LV dilatation and hypertrophy leads to impaired systolic function and reduced CO with failure symptoms
• 50% of cases due to leaflet disorders secondary to bicuspid aortic valves, infective endocarditis or rheumatic heart disease
• Non-valvular causes include aortic dissection, aort root dilatation (Marfan’s) or aortitis
• Also frequently associated with aortic stenosis and can be severe in this case
• Clinical features
  • Acute:
    • Rapid dyspnoea, pulmonary oedema, tachycardia and cardiogenic shock
    • Sudden onset ripping or tearing pain suggests acute aortic dissection
    • Fever or IVDU suggests endocarditis
  • Exam
    • High-pitched blowing diastolic murmur immediately after S2 at left sternal border 2/3^rd ICS
    • May get systolic ejection murmur due to increased SV and S3 due to ventricular dilatation also
    • Austin Flint murmur (mid-diastolic rumble) may be heard in left lateral position at apex using Bell of stethoscope
    • Widened pulse pressure
    • Corrigan (water-hammer) pulse
    • Louder on expiration
    • Severe disease
      • Collapsing pulse
      • Wide pulse pressure (>80mmHg)
      • Long decrescendo diastolic murmur
      • S3
      • Soft A2
      • Austin Flint murmur (Low-pitched rumbling mid-diastolic and presystolic murmur audible at the apex caused by shudder of the anterior mitral leaflet in response to a regurgitant jet)
      • Signs of LV failure
• Exam
  • Accentuated praecordial apex beat
  • Pulsus bisferiens (small then strong and broad pulse – biphasic)
  • Duroziez sign (to-and-fro femoral murmur)
  • De Musset sign (head bobbing)
  • Quincke sign (capillary pulsations visible at proximal nail bed when pressure applied to tip)
• Chronic AR:
  • Exertional dyspnoea or fatigue
  • Chest pain due to myocardial ischaemia due to low diastolic pressures and coronary flow
  • Palpitations due to large stroke volume or PVC’s
  • Symptoms of LV failure occur late
• Diagnosis
  • Acute AR
    • CXR may show acute pulmonary oedema without cardiac enlargement (if acute)
      • May shows signs of dissection
    • ECG
      • Sinus tachycardia
      • Ischaemic changes or ST elevation due to dissection involving coronary arteries
  • Chronic AR:
    • CXR: Cardiomegaly, aortic dilatation, evidence of heart falure
    • ECG: LV hypertrophy
• Treatment
  • Acute: Immediate surgical intervention
    • Medical: Oxygen, intubation for respiratory failure, nitroprusside + inotropes can augment forward flow and reduce LV end-diastolic pressure
    • Diuretics and nitrates are usually ineffective
    • Beta-blockers are CI in acute aortic regurgitation (commonly used in aortic dissection but if acute aortic regurgitation co-exists, do better with tachycardia to reduce time/volume of regurgitation flow
    • Aortic balloon pumps are also contraindicated as worsen regurgitant flow
    • If mild AR due to endocarditis, antibiotics may be sufficient without operative intervention
  • Chronic AR:
    • Vasodilators e.g. ACEi, dihydropyridines
    • Those who are symptomatic, have low EF or who have significant LV dilatation – consider aortic valve replacement

Right-sided valve disease

• Trivial TR and PR are common
• Pathological TR usually in setting of:
  • Elevated right sided pressure or volume overload
    • E.g. Pulmonary hypertension, chronic lung disease, PE or atrial septal defects
• Tricuspid stenosis is rare and usually accompanied by regurgitation
• Pulmonic valve is least likely to be affected by acquired disease
• Acute onset tricuspid disease is usually due to endocarditis, and typically aggressive organisms (e.g. S. aureus)
• Clinical
  • Right heart failure signs and symptoms
  • Exertional dyspnoea is often the first symptoms if associated with pulmonary hypertension
  • Tricuspid regurgitation
    • Murmur is soft, blowing and holosystolic along left lower sternal edge and increases with respiration
    • Systolic waveform may be seen in JVP in severe TR
  • Tricuspid stenosis
    • Rumbling crescendo-decrescendo diastolic murmur before S1
    • Along left lower sternal edge, increases with inspiration and often preceded by opening snap
• Exam
  • Pulmonic stenosis
    • Exertional dyspnoea, syncope, chest pain and signs of right heart failure
    • Harsh systolic murmur, best head in left 2^nd ICS, increased with inspiration
  • Pulmonic regurgitation
    • High-pitched and blowing diastolic murmur (Graham Steell murmur) increased with inspiration
    • Best heard over left 2^nd/3^rd ICS
  • Typically have right ventricular thrill and heave
• Treatment
  • Treat underlying cause
  • Diuretics treated effects of elevated venous pressures but need to use with caution to avoid volume depletion (as reliant on preload) and electrolyte abnormalities
  • If symptomatic pulmonic or tricuspid stenosis, may be candidates for balloon valvotomy
  • Severe TR due to structural valve abnormality may require valve replacement

Prosthetic valve disease

• Mechanical
  • Valve thrombosis or thromboembolism rate 8% per year (1-2% with anticoagulation)
  • Embolic risk highest in first 3 post-operative years
  • Emboli more common from mitral than aortic valves
  • Major bleeding complications on warfarin 1.4% per year
• Antiplatelet therapy is recommended for all patients with any prosthetic valve
• Complications
  • Thrombosis
  • Dehiscence of sutures
  • Gradual degeneration
  • Sudden fracture
  • Symptoms are usually slowly progressive but acute failure and death can occur
• Prosthetic valve endocarditis
  • Occurs in 6% of patients within 5 years of surgery
  • Early causes (first year) include S. epidermidis and S. aureus
  • Late cases usually the same as native valves (Strep viridans, Serratia, Pseudomonas
• Clinical features
  • Cardiac remodelling persists despite valve replacement
  • Patients are likely to have concomitant CAD, systemic hypertension, LV failure or AF
  • Acute onset of respiratory distress, APO or cardiogenic shock
    • Think mechanical valve failure, tearing of a bioprosthesis or large clot obstructing the valve and preventing closure
  • Paravalvular leak can also present with AHF
  • Slowly progressive HF can occur with gradual thrombus formation
  • Mechanical valves often have loud metallic sounds
    • Aortic valves often have systolic murmurs but diastolic murmurs should always be considered pathological
    • A ‘quiet’ mechanical valve is concerning
  • Aortic bioprostheses usually cause a short mid-systolic murmur
  • Mitral bioprostheses usually cause a short diastolic rumble
    • Loud holosystolic murmur indicates dysfunction
• Diagnosis of dysfunction and complications
  • Consider this in any patient with a valve replacement and new or progressive dyspnoea, CCF, decreased exercise tolerance or pain
  • Suspect thromboembolism, septic embolism or ICH in any patient with prosthetic valve and new neurological deficit (like AF)
  • Consider endocarditis in patient with prosthetic valve and persistent fever/fever without source
• Treatment and disposition
  • Cardiology and cardiothoracic consult
  • Emergent surgery and thrombolytic therapy are options for thrombotic complications
  • Lesser degrees of obstruction may simple require optimisation of anticoagulation
  • Obtain consultation on all if suspicious for complication
• Reversal of anticoagulation in the ED
  • Mechanical mitral valves INR 2.5-3.5 target
  • Bileaflet mechanical valves in aortic position INR 2-3
  • Aspirin for all patients with prosthetic valves
  • If INR 5-10 without bleeding: Withold warfarin and consider IV Vit K 1-2.5mg
  • If Severe bleeding, give FFP + prothrombinex 50IU and avoid high-dose Vitamin K due to risk of overcorrection

Pregnant women with valvular disease

• Increased CO and blood volume
  • Accentuate murmurs in mitral and aortic stenosis
• Reduced SVR
  • May attenuate aortic or mitral regurgitant murmurs
• Asymptomatic mild lesions are well tolerated
• Symptomatic disease, pulmonary HTN or LV dysfunction requires high-risk obstetric follow-up
• Neonatal complications associated:
  • Prematurity
  • IUGR
  • RDS
  • Intraventricular haemorrhage
  • Death
• Mild disease: medical Rx
• Moderate or severe stenotic valvular disease: Balloon valvotomy or surgery
• Aortic or mitral regurgitation who have severe symptoms may also require surgery
• Endocarditis prophylaxis is not required for delivery
• Presentations during pregnancy
  • Extremis, dyspnoea, pulmonary oedema, angina, syncope
  • Hypercoagulable state makes native dysfunctional or prosthetic valve thrombosis more likely and anticoagulation is recommended (LMWH or UFH)
  • Low-dose aspirin is recommended in 2^nd and 3^rd trimesters for pregnant patients with mechanical or bioprosthetic valves

Last Updated on December 21, 2023 by Andrew Crofton