Aortic & Mitral Stenosis and Regurgitation

Mitral Stenosis

MITRAL STENOSISGradient across the valveValve area (normally is over 4cm2)
Mild<5mmHg>1.5 cm2
Mod5 – 10mmHg1.0 – 1.5 cm2
Severe> 10mmHg< 1.0 cm2

Taken from American Heart Association Task Force / American College of Cardiology Guidelines 2006.

 

Murmur MS

  • The first heart sound is loud (causing a palpable tapping apex)
  • The second heart sound is normal
  • There is an opening snap in diastole heard shortly after the first heart sound
  • There is rumbling diastolic murmur heard most clearly with the bell of the stethoscope over the apex with the patient in the left lateral position.
  • There are no other added sound
  • Murmur is accentuated by exercise
  • Consider anticoagulation with warfarin due to high risk of AF.

Aortic Stenosis

Aortic STENOSIS  Gradient across the valveValve area (normally is over 2cm2)
Mild<25 mm Hg>1.3-2cm2
Mod25-40mm Hg0.7-1.3cm2
Severe>40 mmHg< 0.7cm2
  Other markersCardiomegaly/ Impaired LV function/ Dysrhythmias 

Taken from American Heart Association Task Force / American College of Cardiology Guidelines 2006.

Murmur AS

  • The first heart sound is normal
  • The second heart sound is soft (stenosed valve closes slowly)
  • There is a harsh ejection systolic murmur heard loudest in the aortic area that radiates to both carotids.
  • There are no other added sounds [there may be an ejection click in patients with a bicuspid aortic valve]
  • The diagnosis is most likely to be aortic stenosis
  • The differential would include MR however the fact the murmur has the characteristics of an ESM loudest etc makes this less likely

Aortic stenosis – causes

  • Degenerative calcification (Calcific AS)*
    • Rheumatic Heart disease
    • Bicuspid aortic valve – Patients can present late with symptoms
    • Congenital

*thought to be unrelated to cholesterol although new evidence emerging

Aortic And Mitral Regurgitation

Aortic Regurgitation

American Heart Association Task Force/ American College of Cardiology Guidelines 2006Regurgitant fraction of cardiac outputRegurgitant Orifice size
Mild<30%<0.1cm2
Moderate30-50%0.1-0.29 cm2
Severe* *increase in LV dilatation>50%  >0.3 cm2

Murmur AR

  • The first heart sound is normal
  • The second heart sound is normal
  • There is no systolic murmur
  • There is an early diastolic murmur heard loudest in expiration at the left sternal edge with the patient sat forwards.
  • There are no other added sounds [there may be an ejection click in patients with a bicuspid aortic valve]
  • The diagnosis is most likely to be aortic regurgitation. The differential diagnosis of a diastolic murmur includes mitral stenosis but this murmur has no features to suggest that.

Other features

  • Collapsing pulse.
  • Wide pulse pressure
  • Corrigan’s sign: prominent arterial pulsations in the neck
  • de Musset’s sign (head nodding in time with the heart beat)
  • Quincke’s Sign(pulsation of the capillary bed in the nail)
  • Traube’s sign (Pistol shot femoral pulses! A load systolic murmur is heard over the femorals as a result of the hyperdynamic circulation)
  • Thrusting apex (volume overloaded LV in the same was as a HOCM could do this)

AR tips

  • Remember rheumatic fever / endocarditis / rheumatoid arthritis / Marfan’s / ankylosing spondylitis / SBE / Hypertensive heart disease/ syphilis / osteogenesis imperfecta as causes.

 Mitral Regurgitation

American Heart Association Task Force/ American College of Cardiology Guidelines 2006Regurgitant fractionRegurgitant Orifice size
Mild<30%<0.2 cm2
Moderate30-50%0.2-0.39 cm2
Severe* *need LA and LV size to be increased>50% and LV dilatation and LA dilatation>0.4 cm2

Common Causes

  • Remember anything which affects either the LV size/ the valve leaflets (SBE, connective tissue disease/ age related degeneration/ chordae tendinae rupture post MI (connections to the papilliary muscle that stop the valve from prolapsing) can cause MR.
  • Degenerative disease
  • LV dilatation of any cause causing a functional MR – IHD, hypertensive heart disease
  • Rheumatic Heart disease
  • Other (SLE/ diseases of connective tissue (e.g. Marfan’s/ Ehlers Danlos/ pseudoxanthoma elasticorum, SLE)

Murmur of MR

  • The first heart sound is soft
  • The second heart sound is normal
  • [There may be a third heart sound/ there are no added sounds]
  • There is a pan systolic murmur heard loudest at the apex radiating to the axilla.
  • The diagnosis is mitral regurgitation

Other Miscellaneous Cardiac Murmurs : Timing / congenital problems etc / Cardiac Cycle

Pulmonary Stenosis American Heart Association Task Force/ American College of Cardiology Guidelines 2006Criteria
Severe PSGradients >60mmHg across the Valve
Commonest Causes of Congenital Heart DiseaseCondition
1) VSDInitially LàR shunt that can then reverse causing an Eisenmenger’s syndrome (i.e. initially not cyanosis as oxygenated blood is being shunted from Là R. But… if this reverses then deoxygenated blood will be shunted from Rà L causing cyanosis
2) ASDFixed wide splitting of S2
3)Patent Ductus ArteriosusCollapsing pulse Continuous machinery murmur (blood shunting from pulmonary artery to subclavian artery- conservative Mxàpercutaneous closure]
4) Fallot’s TetralogyVSD, Aorta that overrides VSD, RVH and Pulmonary stenosis. History: Blalock Shunt: pulmonary artery to the subclavian artery.

Prosthetic/ Metal Heart Valves Anticoagulate Target INR of 3.5 (3-4.5)

Metal Ball& CageMetal Tilting DiskMetal Dual Tilting discTissue
Starr EdwardsBjork ShileySt JudeXenograft (e.g. Porcine) Homograft (e.g. cadaveric)


Cardiac Cycle


Cycle
LV Volume
End of systole 60ml Blood left in LV
Atrial Diastole: 30ml of blood passively fills the ventricle90ml blood in LV at end of diastole
Atrial Systole: 40ml more blood flows into the LV130ml Blood in the LV
Ventricular Systole: approx 70ml of blood is ejected from the 130 ml in the LV. This represents the stroke volume.   The ejection fraction is SV/ (SV+LV end diastolic volume ) i.e. 70/(70+60)130mlà60ml
End of systole60 ml of blood in LV