6. The total stroke volume ejected by the LV is increased in patients with
AR.
In AR the entireLV stroke volume is ejected into a high-pressure zone, the
aorta.
An increase in the LV end-diastolic volume (increased preload)
constitutes the major hemodynamic compensation for AR.
The dilation and eccentric hypertrophy of the LV allow this chamber to
eject a larger stroke volume
Therefore, severe AR may occur with a normal effective forward stroke
volume and a normal LVEF together with an elevated LV end-diastolic
pressure and volume.
However, through the operation of Laplace’s law, LV dilation increases the
LV systolic tension required to develop any given level of systolic
pressure. Ultimately, these adaptive measures fail. As LV function
deteriorates, the end-diastolic volume rises further and the forward
stroke volume and EF decline. Deterioration of LV function often
Pathophysiology
7. The reverse pressure gradient from aorta to LV, which drives the AR flow,
falls progressively during diastole, accounting for the decrescendo
nature of the diastolic murmur.
In patients with acute severe AR, the LV is unprepared for the regurgitant
volume load.
LV compliance is normal or reduced, and LV diastolic pressures rise
rapidly, occasionally to levels >40 mmHg. The LV pressure may exceed
the LA pressure toward the end of diastole, and this reversed pressure
gradient closes the mitral valve prematurely.
Myocardial ischemia may occur in patients with AR because myocardial
oxygen requirements are elevated by LV dilation, hypertrophy,
and elevated LV systolic tension, and coronary blood flow may be
compromised
8.
9. History
Approx. 3/4th of pure/predominant AR – men
Acute AR – cardiogenic shock and pulmonary oedema
Chronic AR – long latent period
Palpitations, esp. on lying down
Exertional dyspnoea, 1st symptom of diminished cardiac
reserve
Orthopnoea, PND, excessive diaphoresis
Angina (nocturnal angina)
Systemic fluid accumulation- congestive hepatomegaly
& pedal oedema
10. Physical findings
Corrigan’s pulse – ‘water-hammer’ pulse
Quincke’s pulse – alternate flushing & paling of skin at
the root of nail, when pressure applied to the tip of
nail
Traube sign – pistol shot sound over femoral artery
Duroziez’s sign – to and fro murmur over femoral
artery
Widened pulse pressure , this widening is less in acute
AR
11. Palpation
Apex beat – shifted down & laterally; heaving
Systolic expansion & diastolic retraction of apex
Diastolic thrill- left sternal border
Systolic thrill- suprasternal notch, transmitted along
carotids
12. Auscultation
A2 absent
Systolic ejection murmur – BAV
Occasionally, S4
Diastolic murmur-
high pitched, blowing, decrescendo
3rd ICS, left sternal border
Louder and longer in severe AR
Louder along left border than right – primary valvular disease
End expiration, sitting up & leaning forward
Cooing – eversion of the valvular cusps
S1 S2 S1
13. Mid systolic ejection murmur – isolated AR
Base of heart
Transmitted along the carotid arteries
Austin Flint murmur – severe AR
Soft, low pitched, rumbling
Mid to late diastolic murmur
Intensified by strenous & sustained hand grip
Due to diastolic displacement of anterior leaflet of mitral valve
14. Investigations
ECG
Signs of left ventricular hypertrophy
ST depression & T wave inversion (L1, aVL ,V5 ,V6) “LV
strain”
15.
16. Echocardiography
Size of LV increased, systolic fuction normal initially
A rapid, high-frequency diastolic fluttering of the
anterior mitral leaflet produced by the impact of the
regurgitant jet is characteristic
Cause of AR
17. Colour flow doppler imaging
Central jet width > 65% of LV outflow
Regurgitant volume >= 60ml/beat
Regurgitant fraction >= 50%
Diastolic flow reversal in proximal descending thoracic aorta
SEVERE AR
18. Chest X ray
Chronic severe AR
Apex shifted to left & down
Left anterior oblique and lateral – shifted posteriorly,
encroaching on to spine
Aortic root disease
Aneurysmal dilatation
Aorta filling retrosternal space in lateral view
21. Treatment
Acute AR
IV diuretics and vasodilators
Intraaortic balloon counterpulsations contraindicated
Β blockers better avoided
Surgery is the treatment of choice and necessary in 24
hours
22. Chronic AR
Diuretics , vasodilators
Vasodilators 1st choice as anti-hypertensives
Cardiac arrhythmias and systemic infections promptly
treated
Penicillin therapy – syphilitic aortitis
Β blockers and ARBs retard the rate of aortic root
enlargement in Marfan syndrome & aortic root
dilatation
23. Surgery
Asymptomatic until development of myocardial or LV
dysfunction
If surgery delayed, normal function cannot be restored
Therefore, regular follow with echocardiography in 6-
12months
AVR is treatment of choice
severe AR and progressive LV dysfunction defined by an
LVEF <50%, an LV endsystolic dimension >50 mm, or an
LV diastolic dimension >65 mm.
24. AVR with mechanical or tissue prosthesis – Rheumatic
disease
Primary surgical repair – Infective endocarditis,
Traumatic
Narrowing the annulus or by excising a portion of the
aortic root without replacing the valve – Aneurysmal
dilatation