Heart Murmur, Emergency Medicine

Basics

Description

Sounds created by physiologic processes or functional and structural anomalies of the heart.
Stenotic lesions:
- Pressure overload in the chamber preceding the valve, leading to hypertrophy of the chamber in an attempt to overcome the increased resistance
Regurgitant lesions:
- Volume overload of the chamber preceding the valve, leading to chamber dilatation in an attempt to accommodate the regurgitant blood volume
Genetic abnormalities:
- Congenital defects associated with abnormal cardiac blood flow

Etiology

Aortic stenosis:
- Rheumatic heart disease
- Congenital bicuspid valve
- Calcification
- Prosthetic valve
Aortic regurgitation:
- Rheumatic heart disease
- Endocarditis
- Aortic dissection
- Prosthetic valve
Mitral stenosis:
- Rheumatic heart disease
- Rheumatologic disorders (systemic lupus erythematosus)
- Calcification
- Cardiac tumors (atrial myxoma)
- Congenital
- Prosthetic valve
Mitral regurgitation, acute:
- Endocarditis
- Papillary muscle rupture or dysfunction
- Rupture of chordae tendineae
- Prosthetic valve
Mitral regurgitation, chronic:
- Rheumatic heart disease
- Mitral valve prolapse
- Connective tissue disease (Marfan syndrome)
Mitral valve prolapse:
- Congenital
- Connective tissue disease
Tricuspid stenosis:
- Rheumatic heart disease
Tricuspid regurgitation:
- Rheumatic heart disease
- Endocarditis
- Pulmonary HTN
Pericardial friction rub:
- Pericarditis
- Pericardial effusion
Ventricular septal defect:
- Congenital
- Traumatic
- Postinfarction
Ventricular assist device
- Implantable pump supplements or replaces ventricular function

Pulmonic stenosis:
- Congenital
- Maternal-fetal rubella exposure
- Rheumatic heart disease
Pulmonic regurgitation:
- Congenital
- Rheumatic heart disease
- Pulmonary HTN
Atrial septal defect:
- Congenital
Patent ductus arteriosus:
- Congenital
- Prematurity
- Maternal-fetal rubella exposure
Coarctation of the aorta:
- Congenital
- Turner syndrome
Hypertrophic cardiomyopathy/idiopathic hypertrophic subaortic stenosis:
- Congenital
- Genetic predisposition

Diagnosis

Signs and Symptoms

Aortic stenosis:
- Systolic crescendo-decrescendo murmur radiating to carotids
- Carotid pulse described as parvus et tardus: Diminished intensity and late upstroke
- Angina
- Dyspnea on exertion
- Exertional syncope
Aortic regurgitation:
- Diastolic blowing murmur at left sternal border
- Pulmonary edema
- Dyspnea
- Tachycardia
- Chest pain
- Widened pulse pressure
- Austin Flint murmur: Diastolic rumble from exposure of mitral valve to regurgitant flow
- Corrigan pulse or water hammer pulse: Rapid upstroke and downstroke of the carotid pulse
- Quincke pulse: Pulsations seen at nail beds
- de Musset sign: Head bobbing with carotid pulse
Mitral stenosis:
- Diastolic, rumbling murmur at apex
- Loud S1 with opening snap
- Dyspnea
- Orthopnea
- Hemoptysis
- Pulmonary edema
- Emboli to systemic circulation
- Atrial fibrillation
Mitral regurgitation, acute:
- Systolic, harsh, crescendo-decrescendo murmur at apex
- Pulmonary edema
Mitral regurgitation, chronic:
- Holosystolic murmur at apex radiating to axilla
- Dyspnea on exertion
- Fatigue
- Atrial fibrillation
Mitral valve prolapse:
- Early to mid-systolic click often followed by systolic murmur
- Palpitations
- Chest pain
Tricuspid stenosis:
- Diastolic, high-pitched murmur
- Peripheral edema
- Hepatosplenomegaly
- Ascites
- Fatigue
- Atrial fibrillation
- Large A wave in the jugular venous pulse
Tricuspid regurgitation:
- Holosystolic, blowing murmur along left sternal border
- Peripheral edema
- Hepatosplenomegaly
- Ascites
- Atrial fibrillation
- Large V wave in the jugular venous pulse
Patent ductus arteriosus:
- Continuous machinery murmur
- CHF
Pericardial friction rub:
- Intermittent murmur
- Systolic and/or diastolic component
Ventricular septal defect:
- Harsh, holosystolic murmur loudest along lower left sternal border
Ventricular assist device:
- Mechanical hum at apex
- Continuous or pulsatile
- May have adequate perfusion without palpable pulse or measurable BP

Pulmonic stenosis:
- Systolic crescendo-decrescendo ejection murmur at left upper sternal border
- Severe lesions may have a thrill
- Widely split S2
- Dyspnea with exertion in serious cases
- May have signs of right heart failure
Pulmonic regurgitation:
- High-pitched, early, decrescendo diastolic murmur
- Widely split S2
- Associated with Graham Steell murmur of pulmonary HTN (high-pitched early diastolic murmur)
- May have signs of right heart failure
Atrial septal defect:
- Systolic ejection murmur in secundum defect
- Secundum associated with pulmonary HTN
- Wide fixed S2
- No murmur in PFO
Patent ductus arteriosus:
- Continuous machinery murmur at upper left sternal border with systolic thrill
- Cyanosis
- Bounding peripheral pulses
- Tachypnea
Coarctation of the aorta:
- Continuous or late systolic murmur
- Possible aortic click related to bicuspid valve
- Difference between upper and lower extremity pulses
Hypertrophic cardiomyopathy/idiopathic hypertrophic subaortic stenosis:
- Systolic, harsh, crescendo-decrescendo murmur at left sternal border
- Increased intensity with Valsalva
- Dyspnea
- Chest pain
- Exertional syncope
- Sudden death

Physical Exam

Auscultation of heart and lung sounds
Evaluation of pulses, peripheral perfusion, and edema

Essential Workup

For more details, see Valvular Heart Disease, Mitral Valve Prolapse, Congenital Heart Disease, Patent Ductus Arteriosus, Pericarditis, and Pericardial Effusion/Tamponade.

Diagnosis Tests & Interpretation

Imaging

EKG
CXR
Echo:
- Evaluate valves, chambers, flow
CT:
- Rule out aortic dissection

Diagnostic Procedures/Surgery
Acute regurgitant lesions: Cardiac catheterization

Differential Diagnosis

See Etiology.

Treatment

Pre-Hospital

IV fluids:
- Patients with critical aortic stenosis are very sensitive to fluid shifts.
Oxygen as appropriate

Initial Stabilization/Therapy

Oxygen
IV access
Cardiac monitor
Treat symptoms (CHF, dysrhythmias)
Exercise care with fluids and medications in aortic stenosis

Ed Treatment/Procedures

For more details, see Endocarditis, Valvular Heart Disease, Mitral Valve Prolapse, Congenital Heart Disease, Patent Ductus Arteriosus, Pericarditis, and Pericardial Effusion/Tamponade.

Medication

Digoxin: 0.5 mg IV, then 0.25 mg IV 6 and 12 hr later
Diltiazem (Cardizem):
- 0.25 mg/kg (17.5 mg for 70 kg person) IV over 2 min
- May rebolus after 15 min with 0.35 mg/kg IV
- Start drip at 5-15 mg/hr
Furosemide (Lasix):
- 20-80 mg IV; may increase dose if necessary
- Max. of 600 mg per 24 hr
Heparin:
- 80 U/kg bolus IV, then drip at 18 U/kg/hr
- Monitor partial thromboplastin time
Metoprolol (Lopressor): 5 mg IV q5-15 min for 3 doses, as tolerated
Nitroglycerin:
- 10-20 Î¼g/min IV
- Titrate to effect
- Max. 300 Î¼g/min
Nitroprusside:
- 0.3 Î¼g/kg/min IV
- Titrate to effect
- Max. 10 Î¼g/kg/min
- Protect bag from light
- Thiocyanate toxicity from prolonged use
Propranolol (Inderal):
- 1-3 mg IV q2-5min up to max 5 mg
- No additional doses for 4 hrs after reaching max dose or desired response

Follow-Up

Disposition

Admission Criteria

Signs of cardiac ischemia
Syncope or near syncope
Pulmonary edema
Hemodynamic instability
Endocarditis
Arrhythmia

Discharge Criteria

Asymptomatic
Hemodynamically stable

Issues for Referral
Patients with new murmurs should be referred to their caregiver or a cardiologist.

Follow-Up Recommendations

Patients should always inform their medical and dental caregivers that they have a heart murmur.
To avoid an infection of the lining of the heart, antibiotics may be needed before procedures such as teeth cleaning.

Pearls and Pitfalls

Patients with new heart murmurs and fever need to be assessed for endocarditis.

Additional Reading

Bonow RO, Carabello BA, Chatterjee K, et al. ACC/AHA 2006 guidelines for the management of patients with valvular heart disease. Circulation. 2006;114:e84-e231.
Frank JE, Jacobe KM. Evaluation and management of heart murmurs in children. Am Fam Physician. 2011;84:793-800.
Nishimura RA, Carabello BA, Faxon DP, et al. ACC/AHA 2008 Guideline update on valvular heart disease: Focused update on infective endocarditis. Circulation. 2008;118:887-896.
www.blaufuss.org/tutorial/
www.easyauscultation.com/heart-sounds.aspx

Codes

ICD9

394.0 Mitral stenosis
424.1 Aortic valve disorders
785.2 Undiagnosed cardiac murmurs
996.02 Mechanical complication due to heart valve prosthesis
395.9 Other and unspecified rheumatic aortic diseases
424.0 Mitral valve disorders
746.4 Congenital insufficiency of aortic valve

ICD10

I05.0 Rheumatic mitral stenosis
I35.0 Nonrheumatic aortic (valve) stenosis
R01.1 Cardiac murmur, unspecified
T82.09XA Mech compl of heart valve prosthesis, initial encounter
I06.8 Other rheumatic aortic valve diseases
I34.0 Nonrheumatic mitral (valve) insufficiency
I34.1 Nonrheumatic mitral (valve) prolapse
I35.1 Nonrheumatic aortic (valve) insufficiency
Q23.1 Congenital insufficiency of aortic valve

SNOMED

88610006 Heart murmur (finding)
60573004 Aortic valve stenosis (disorder)
86466006 Rheumatic mitral stenosis (disorder)
250974001 Prosthetic aortic valve regurgitation (disorder)
12023003 Rheumatic disease of aortic valve
409712001 mitral valve prolapse (disorder)
48724000 Mitral valve regurgitation (disorder)
60234000 Aortic valve regurgitation (disorder)
72352009 bicuspid aortic valve (disorder)

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