Case:An active 75 yo farmer comes to your office after experiencing a fainting spell while baling hay. The episode occurred without warning and he had no symptoms following the episode. However, on close questioning he admits to some breathlessness and vague chest heaviness with his usual heavy exertion over the past few months and a very unwelcome tendency to want to slow down which he reluctantly attributed to his age. He has been healthy all his life, doesn’t smoke and has not seen a doctor in 30 years. He served in the army in 1942; no abnormalities were reported during his induction physical.
Physical ExamRobust looking older man with a laceration on his forehead from falling on the handle of his pitchfork.
BP 135/90 P 68 bpm, regular RR-12 T-98.6 F
JVP 6 cm with normal “a” and “v” waves
Carotids: Difficult to palpate, delayed upstroke
Lungs: Clear
Heart: Palpation: Palpable “thrill” over the mid LSB. PMI 5 ICS, 2 cm lateral to the MCL. Palpable presystolic impulse followed by a sustained ventricular lift.
Auscultation: Loud S4. S1 is normal. A single S2 (P2) is heard at the upper left sternal border but no S2 is heard at the lower left sternal border. There is a 4/6 systolic ejection murmur (crescendo-decrescendo) heard best at the R 2nd interspace but radiating widely to the LSB, and to the neck. No diastolic murmurs.
Abdomen and extremities are unremarkable.
Aortic Stenosis
Aortic Stenosis: Etiology
Congenital bicuspid aortic valve
Rheumatic aortic valve disease
Calcific (senile) aortic stenosis
Norma Burns:Norma Burns:
Pathophysiology of Aortic Stenosis Left ventricular outflow obstruction
LV systolic pressure > aortic pressure
Concentric left ventricular hypertrophySustains high LV pressuresNormalizes wall stress (radius x pressure/wall thickness)Eventually results in impaired LV diastolic compliance
LA hypertrophy and enlargement Severe stenosis: Limits ability to increase stroke
volume on demand
Critical aortic stenosis = fixed cardiac output
Aortic Stenosis
Key Physical Findings in SevereAortic Stenosis
Carotid impulse: “parvus et tardus”
JVP: Prominent “a” wave
Heart: Systolic thrill Palpable presystolic impulse (S4)Sustained apical systolic impulseS4
Coarse late peaking systolic ejection murmur (may radiate to neck and/or LSB)
Attenuated/absent aortic component of S2
Natural History of Aortic Stenosis Long asymptomatic “latent” period “Cardinal” symptoms of severe aortic stenosis
DyspneaAnginaSyncope
Sudden death Left ventricular dilatation and contractile failure Endocarditis Arrhythmias
Ventricular tachycardiaConduction system diseaseAtrial fibrillation
Natural History of AS
Mechanisms of Dyspnea inAortic Stenosis
LVH diastolic dysfunction
Progressive LV dilation and contractile failure systolic dysfunction
Mechanisms of Anginal Chest Pain in
Aortic Stenosis Increased wall stress increased
myocardial O2 demand, exceeds ability to coronary flow to meet demand
Associated coronary artery disease
Mechanisms of Syncope in Aortic Stenosis
Fixed cardiac output: Vasodilation (exercise, vagal stimulation, drug induced), inability to augment CO, drop in cerebral perfusion pressure.
Heart block: Ca++ deposits in aortic ring encroach upon conduction tissue
Ventricular arrhythmias (LVH, ischemia)
Diagnostic Studies in Aortic Stenosis ECG: LVH with repolarization changes “strain
pattern” Chest X-Ray: Aortic root dilation
(aortic valve Ca++) Echo: Aortic valve thickening and restricted
motion Doppler: Gradient across aortic valve and aortic
valve area can be estimated from increased flow velocity across aortic valve
Cath: Measure gradient across aortic valve and calculate valve area
Treatment of Aortic Stenosis Mild to moderate asymptomatic aortic stenosis:
Close follow up: History and physical exam, serial echocardiograms
Endocarditis prophylaxis
Severe, symptomatic aortic stenosis (1 year survival 57%)Aortic valve replacement with either mechanical or bioprosthetic valve
- Ten year survival ~75%- Complications of prosthetic heart valves: infection, thromboembolism, mechanical
failure
Severe, symptomatic aortic stenosis NOT surgically treatable: Palliative option: aortic balloon valvuloplasty
CASE:
A 52 yo salesman is referred to you for evaluation of a heart murmur. He had applied for a pilot’s license and was denied because of the murmur. He is asymptomatic and physically active. He denies chest pain, dyspnea or dizzy spells and gives no history of a murmur being mentioned during his last physical exam five years ago. He has no family history of heart disease. He has never had high blood pressure or diabetes, doesn’t smoke, and takes no medications. A lipid profile done five years ago was reported to be “OK”.
Physical ExamBP - 145/45 P - 78 reg RR - 12 Temp:98.6F
Carotids: Very brisk with sharp collapse
JVP: 5 with normal ‘a’ and ‘v’ waves
Lungs: Clear
Heart: Palpation: PMI is enlarged (4fb), in the anterior axillary line
Auscultation: S1 normal, S2 soft. A 2/6 early peaking systolic ejection murmur at the upper RSB and a 3/6 holodiastolic blowing murmur, heard best at the lower LSB when you ask the patient to hold his breath in expiration and lean forward. There is a different 2/6 low-pitched diastolic murmur at the apex.
Pulses are all very prominent and brisk; audible pulse overthe femoral arteries
Additional Testing
ECG: LVH with massive voltage in the lateral precordial leads (V4-V6)
Chest X-Ray: Large heart, predominant left ventricular enlargement. No congestive heart failure.
Echo: Marked left ventricular dilation, estimated EF 65%. The end diastolic dimension is 65 mm and the end diastolic dimension is 55 mm. Aortic valve: bicuspid and thickened.
Doppler: Severe aortic regurgitation. The aorta is slightly enlarged (4.2 mm). *
Aortic regurgitation
Major Causes of Aortic Regurgitation
Leaflet Dysfunction Aortic Root Dilation
Rheumatic fever Systemic hypertensionEndocarditis Dissecting aneurysmTrauma Aortitis (syphilis)Bicuspid aortic valve Reiter’s syndromeRheumatoid arthritis Ankylosing spondylitisMyxomatous degeneration Ehlers-DanlosAnkylosing spondylitis Osteogenesis imperfectaMarfan’s syndrome Pseudoxanthoma elasticumFenfluramine-phentermine Marfan’s syndromeAnnulo-aortic ectasia
Physical Findings in Aortic Regurgitation Wide pulse pressure: Bounding pulses Soft aortic second sound (A2) Early diastolic murmur (blowing) immediately
after A2
Upper RSB with root dilationMid to lower LSB with leaflet dysfunction
Systolic murmur at base (similar to aortic stenosis) Austin Flint murmur: mid to late diastolic
“rumble” at apex
*
Some Really Neat Physical Findings in Severe Chronic Aortic Regurgitation deMusset’s sign: Head bob with each systolic pulsation
Corrigans’s pulses: “Pistol shot” pulses over femoral artery
Mueller’s sign: Pulsation of the uvula
Duroziez’s sign: Systolic/diastolic bruit over femoral artery
Quincke’s pulses: Capillary pulsations seen in the nailbeds
Becker’s sign: Pulsation of retinal arteries and pupils
Hill’s sign: Popliteal BP exceeds brachial BP by > 60 mmHg
Pathophysiology of Chronic Aortic Regurgitation
Slowly progressive diastolic volume overload
Augmented stroke volume with rapid runoffIncreased systolic pressure with low diastolic pressure: wide pulse pressure
Progressive left ventricular dilation, some hypertrophy
Increased diastolic compliance with maintenance of normal diastolic pressures initially
Late systolic failure with reduced ejection fraction and CHF
Acute vs. chronic aortic regurgitation
Acute Aortic Regurgitation
Sudden diastolic volume overload without LV dilation:
- Acute elevation in left ventricular diastolic pressure pulmonary edema- Acute LV systolic failure hypotension
Provide inotropic support, vasodilator therapy if tolerated, urgent valve replacement.
Natural History of Chronic Aortic Regurgitation
Long asymptomatic phase; may be decades long. Left ventricular systolic dysfunction ( decline in
EF) NOTE!! LV dysfunction may occur in the absence of symptoms
Symptoms associated with LV dysfunction:- Exercise intolerance
- Dyspnea on exertion Angina (rare) Sudden death (rare)
Natural history of aortic regurgitation
Factors Influencing Severity ofAortic Regurgitation
Size of regurgitant orifice
Gradient across aortic valve in diastole (i.e. worse AR with high diastolic BP)
Duration of diastole
Management of Chronic Aortic Regurgitation
Close follow up of left ventricular size and function with serial echocardiograms (Every few years with mild AR, every 6-12 months with severe AR)
Endocarditis prophylaxis Medical therapy:
Vasodilator therapy: reduces blood pressurereduces regurgitant volume
Delays need for aortic valve replacement Digoxin (enhance systolic function) Diuretics (reduce LA pressure) Do NOT slow heart rate! Aortic valve replacement with mechanical or bioprosthetic
valve
Criteria for Aortic Valve Replacement in Chronic Aortic Regurgitation
SymptomsCongestive heart failureDeclining exercise tolerance on exercise testingAngina
Anatomy, regardless of symptoms:Left ventricular dysfunction: EF <50%Progressive left ventricular dilation or decline in EF on serial studiesSevere dilation (echo): - Left ventricular diastolic dimension >75 mm
- Left ventricular systolic dimension >55 mmAortic root dimension >50 mm
Right Sided Valve Disease:Read Harrison, 14th Edition: Pages 1322-1323
Tricuspid stenosis
Tricuspid regurgitation
Pulmonic stenosis
Pulmonic regurgitation
Reference Sources for Valvular Heart Disease
Reading: Harrison, 14th Edition p 1311-1323
Computer:
Umedic: Aortic stenosis, aortic regurgitation, mitral stenosis, mitral regurgitation
Instructional Programs:
Heart Sounds and Murmurs