• Also called hypoplastic right heart syndrome.

Embryology

• May be due to fetal endocarditis during late gestation.

Pathology

• Pulmonary atresia-
  • 75%- valvular/membranous
  • 25%- infundibular/muscular
• Right ventricle-
  • RV components-
    • Tripartite- 58% (inlet, apex and outlet)
    • Bipartite- 34% (only inlet and outlet)
    • Unipartite- 8% (only inlet)
    • Note that in unipartite and bipartite types, all three components of RV are actually present, but there is muscle overgrowth in some components.
  • RV size-
    • Usually small.
    • Dilated RV in 10%- due to tricuspid regurgitation, in some cases due to Ebstein’s anomaly.
• Tricuspid valve-
  • Corresponds to RV size
  • Usually hypoplastic
  • Sometimes (10%) dilated, leading to severe TR. In some cases, this is due to Ebstein’s anomaly.
• Pulmonary artery-
  • Usually confluent.
  • Usually normal or mildly hypoplastic. Moderate or severe hypoplasia in 6%.
• ASD-
  • Usually large enough for unobstructed blood flow from right atrium to left atrium
• Ductus-
  • Pulmonary circulation is maintained by a patent ductus. If it closes, death will occur.
  • There are no aortopulmonary collaterals (MAPCAs support pulmonary circulation in pulmonary atresia with VSD and hence there is only mild cyanosis)
  • Obtuse angle between ductus and proximal aorta (normal)- late onset pulmonary atresia; acute angle- early onset.
• Coronary anomalies
  • Communications between right ventricle and coronary arteries. RV- thick walled myocardial spaces- distended capillaries- coronary artery.
  • The term sinusoids is pathologically incorrect. Ventriculo-coronary arterial connections or VCC is correct.
  • Mainly located at RV apex.
  • More likely in small right ventricles, especially in monopartite.
  • Cause is non-regression of embryonic channels due to high RV pressure.
  • VCC causes myocardial ischemia due to coronary steal- causes RV and LV ischemia.
  • Even if no VCC is present, high RV luminal pressure decreases coronary flow to RV causing RV ischemia leading to RV fibrosis.
  • Types of coronary circulation (judged by coronary opacification during right ventricular angiography)-
    • No opacification- 58%
    • Mild opacification- 15%
    • Major opacification, but antegrade coronary flow from aorta preserved- 17%
    • Major opacification with coronary atresia or significant stenosis- 8%
  • RV dependent coronary circulation-
    • Atresia or severe stenosis of proximal coronary artery- RV decompression (during repair) would cause myocardial ischemia due to inadequate pressure to drive coronary flow.
    • No coronary stenosis, but coronary is ectatic- RV decompression would cause coronary steal through the dilated vessel into the RV.

Classification-

• Greenwold classification-
  • Type I- small right ventricle
  • Type II- large right ventricle with tricuspid regurgitation
• Bull and de Leval classification-
  • Group I- tripartite RV
  • Group II- bipartite RV
  • Group III- unipartite RV
• Milliken classification (surgically oriented)-
  • Mild, moderate or severe hypoplasia of tricuspid annulus, RV cavity and RVOT.

Hemodynamics

• Fetus-
  • Foramen ovale is large to accommodate increased flow.
  • Ductus carries blood from aorta to pulmonary artery (reverse of normal).
  • Ductus carries only 10% of cardiac output (normal 60%).
• After birth-
  • RV pressure is high (suprasystemic).
  • No TR.
  • Blood that enters RV goes out through coronaries- circular shunt (as this drains back to RA).
  • RA is enlarged.
  • RA pressure is more than LA pressure- flow across non-restrictive ASD.
  • LA and LV are dilated.
  • Blood enters pulmonary circulation via ductus in newborn.
  • Ductus closes at normal time- profound cyanosis- death.
  • With significant TR, RV dilates and RV pressure is subsystemic.

Clinical features

• Cyanosis noted at birth. Cyanosis worsens in first or second day. Tachypnoea and metabolic acidosis culminating in death.
• No precordial activity, no murmurs (sometimes closing ductus murmur).
• Type II- RV activity, PSM of TR.

Natural history

• Severe TR- hydrops fetalis.
• 50% are dead by 2 weeks.
• 85% are dead by 6 months.

ECG

• Adult precordial pattern in neonate (no RV, LV prominence)- also seen in tricuspid atresia.
• QRS axis is +30⁰ to +90⁰ – helps to distinguish from tricuspid atresia where there is left axis deviation.

Chest X-ray

• Pulmonary arteries appear normal or mildly hypoplastic.
• Cardiomegaly only in type II.
• Decreased pulmonary blood flow.
• Aortic arch is always left sided. (Right aortic arch is present in 25 – 50% of PA with VSD)
• DDs of massive cardiomegaly with decreased pulmonary blood flow-
  • Ebstein’s anomaly
  • PA with IVS type II
  • Uhl’s anomaly

Echocardiography

• Thick membrane at pulmonary valve level with no flow across it.
• RV is hypoplastic. RV endocardium shows deep invaginations which may or may not communicate with coronaries.
• RA is dilated
• There is right to left shunt across ASD
• There is a ductus with left to right shunt
• Type II has to be carefully distinguished from Ebstein’s anomaly (functional pulmonary atresia).
• Surgical importance-
  • RV components
  • Tricuspid valve Z-score

Cardiac catheterization

• Always needed to look for
  • RV morphology
  • VCC and coronary stenosis/atresia and
  • PA anatomy.
• RA pressure is higher than LA pressure.
• Same oxygen saturations in venacavae, RA and RV.
• Same oxygen saturations, though lower than normal, in LA, LV and aorta.

Management

• Start PGE1 0.1 μg/kg/min.
• Then do cath study. Then plan further strategy based on RV type and sinusoids
• Tripartite RV and bipartite RV-
  • Neonate- BT shunt + RV-PA connection (transannular RVOT patch/closed valvotomy/percutaneous laser)
  • 6 to 18 months-
    • TV Z-score > -2 and arterial oxygen saturation > 70% with BT shunt occlusion
      • Yes- Two ventricular repair (RVOT reconstruction + closure of BT shunt)
      • No- One and a half ventricular repair (BDG + RVOT reconstruction)
• Monopartite RV and any type RV with RV dependent coronary circulation-
  • BT shunt- BDG or Hemi-Fontan- Fontan
• Coronary atresia- Cardiac transplantation
• Type II- Cardiac transplantation or Starnes’ procedure (convert to tricuspid atresia, then BT – BDG- TCPC)

• Mitral valve apparatus-
  • Papillary muscles
  • Chordae tendineae
  • Leaflets
  • Annulus
• Common causes of MR-
  • Rheumatic
  • MVP
  • CAD
  • Cardiomyopathy (dilated, hypertrophic)
  • IE
  • Annular calcification
• List of causes of MR-
  • Papillary muscles-
    • CAD (ischemia, MI)
    • Severe anemia
    • Shock
    • Amyloidosis
    • Sarcoidosis
    • Abscess
    • Granuloma
    • Neoplasm
    • Dilated cardiomyopathy
    • Trauma
    • Rupture (MI)
    • Parachute mitral valve
  • Chordae tendineae-
    • Idiopathic rupture
    • Myxomatous degeneration (MVP, Marfan syndrome, Ehlers-Danlos syndrome, Pseudoxanthoma elasticum)
    • Osteogenesis imperfect
    • Relapsing polychondritis
    • IE
    • Acute LV dilation due to any cause
    • Acute rheumatic fever
    • Blunt chest trauma
    • Following PTMC
  • Leaflets-
    • Rheumatic
    • Myxomatous degeneration (MVP, Marfan syndrome, Ehlers-Danlos syndrome, Pseudoxanthoma elasticum)
    • IE
    • SLE
    • Scleroderma
    • Mitral valve clefts or fenestrations
    • Trauma
    • Following PTMC
    • Atrial myxoma
  • Annulus-
    • Abscess (IE)
    • Annular calcification
    • Dilation of annulus- dilated cardiomyopathy
    • LV submitral aneurysm
  • Other causes-
    • SAM- HCM
    • Prosthetic valve-
      • Suture interruption due to surgical technique or IE
      • Strut fracture
      • Immobilized disc
      • Immobilized ball
      • Biological valve cusp perforation or degeneration
    • Hypereosinophilic syndrome
    • Endomyocardial fibrosis
• Associations of parachute mitral valve-
  • Endocardial cushion defects
  • Endocardial fibroelastosis
  • TGA
  • Anomalous origin of left coronary
• Causes of MR in IE-
  • Leaflet perforation
  • Vegetations preventing leaflet coaptation
  • Chordal rupture
  • Annular abscess
  • Chordal rupture
  • Valve retraction during healing phase
• Causes of MR in RHD-
  • Leaflet rigid and retracted
  • Chordae shortened
• Causes of MR in blunt chest trauma-
  • Leaflet damage
  • Chordal rupture
• Mitral annulus
  • Normal diameter is 10 cm
  • Normally constricts during systole
• LV submitral aneurysm-
  • Sub-Saharan Africa
  • Posterior
• Mitral annular calcification-
  • More in women
  • Risk factors for development- HT, DM, DLP
  • Increases morbidity and mortality due to associated coronary and carotid atherosclerosis
  • Causes-
    • Atherosclerosis
    • Marfan syndrome
    • Hurler syndrome
    • CRF
    • Hyperparathyrodism
    • Rheumatic heart disease
  • Mechanism of MR-
    • Lack of systolic constriction
    • Immobilization of leaflets
  • May involve conduction system- AV block, IVCD
• Chordal rupture is more common in the posterior chordae
• Posterior papillary muscle gets ischemic more commonly than the anterior one as it gets only one supply (PDA) while the latter gets two (LAD & LCx).
• Causes of MR in CAD-
  • RWMA causing tethering of PML
  • Papillary muscle ischemia
  • LV failure (see below)
• Causes of MR in LV failure-
  • Alteration of spatial relation between papillary muscles
  • Annular dilation
  • Poor annular systolic constriction
• Ischemic MR has poorer prognosis than other causes of MR- due to associated ischemia

Pathophysiology

• Factors determining regurgitant volume-
  • Regurgitant orifice
  • LV-LA pressure gradient
• Regurgitant orifice can be increased by-
  • Increasing preload
  • Increasing afterload and
  • Decreasing LV contractility
• LV-LA pressure gradient can be increased by increasing SVR.
• 50% of MR occurs before aortic valve opening

  The progression of an MR with a regurgitant fraction of 50% are shown below.

  	EDV	ESV	EF	TSV	FSV	LAP
  N	120	50	60	70	70	10
  a/c MR	140	40	70	100	50	25
  c/c MR	200	60	70	140	70	15
  c/c MR decom	220	100	55	120	60	25

• In acute phase, LA is non-compliant. This allows only a slight increase in EDV. ESV is decreased, though only slightly, due to low afterload as LV is able to eject into the LA which is low pressured compared to the aorta. The total stroke volume increases to a lesser degree than it does in chronic MR where the large EDV due to the compliant LA leads to a large increase. Since TSV increases only slightly, forward stroke volume falls.
• In the chronic phase, LA compliance increases and hence EDV rises. ESV rises to normal. The high EDV allows normal forward stroke volume.
• In longstanding cases, LV may decompensate due to prolonged hemodynamic overload. Then, due to incomplete LV emptying ESV increases. Also, due to drop in total stroke volume, forward stroke volume decreases.

  The changes in preload and afterload are as below.

  	Preload	Afterload
  N	N	N
  a/c MR	Increase	Decrease
  c/c MR	Increase	N
  c/c MR decom	Increase	Increase

• In all phases of MR, preload is increased due to increase in EDV. In acute MR, the increase is slight, in chronic MR there is a prominent increase while in chronic decompensated MR, it increases further as EDV increases further.
• Afterload is decreased in acute MR due to ejection into the LA which has lower pressure compared to the aorta. In chronic MR, due to LV dilation, the afterload increases to normal. In decompensated chronic MR, it increases to above normal.
• LV wall tension is very low in acute MR while in chronic compensated MR it is normal or high.
• MR begets MR due to increased EDV causing annular dilation.
• Myocardial oxygen demand is not much increased in MR due to normal wall tension. So myocardial ischemia is less likely in MR than in AR or AS.
• In MR, due to reduced afterload, EF is increased (EF is afterload dependent). So EF less than 60% indicates LV dysfunction.
• Increased ESV/ESD is another indicator of LV dysfunction in MR.
• LA pressure-
  • Tall v wave
  • Rapid y descent (unless coexistent MS)
  • Early diastolic pressure more than LV pressure (reason for mitral MDM)
  • Late diastolic pressure less than LV pressure (higher if coexistent MS)
  • Higher LA pressure in acute MR than in chronic MR
• LA compliance-
  • Normal or reduced-
    • Usually seen in acute MR
    • Hypertropied atrial wall
    • PVR increases in 6 to 12 months
  • Marked increase -
    • Usually seen in chronic severe MR
    • Atrial wall has little muscle, more fibrous tissue
    • PVR normal
    • AF always present
    • COP may be low
    • Moderate increase-
  • Commonest group

Symptoms

• Fatigue- due to low cardiac output
• Dyspnoea- more likely in acute MR and in chronic decompensated MR
• Right heart failure symptoms like ascites and edema- more likely in acute MR and in chronic decompensated MR
• It is important to understand that chronic MR may become symptomatic only after the onset of irreversible LV dysfunction.
  

Physical examination

• Sharp upstroke of pulse
• Hyperdynamic LV apex
• Palpable S3 may be present
• Parasternal late systolic impulse due to LA enlargement
• If leaflet disease is the cause of MR- soft S1
• Wide split S2- due to early A2 due to reduced LVET
• Loud P2 if PAH
• S3 – not a sign of heart failure in MR
• Mitral MDM- not a sign of heart failure in MR
• PSM-
  • Begins with S1 and extends beyond A2
  • Flat topped
  • High pitched & blowing
  • Radiates to left axilla or base (PML prolapse) or spine (AML prolapse)
  • No change with AF or VPCs
  • Little correlation between intensity of murmur and severity of MR
• Severe MR with soft or no murmur- silent MR-
  • LV dilation
  • Acute MR
  • Paraprosthetic MR
• Late systolic murmur-
  • Seen in MVP and papillary muscle dysfunction
  • Usually MR is not severe
  • S1 is not soft
• Early systolic murmur-
  • Acute MR (due to large LA v wave)
• Dynamic auscultation-
  • Non-MVP MR murmur is distinguished from MVP murmur by increase with squatting and decrease with standing (opposite with MVP).
  • MR murmur is distinguished from AS/HCM murmur by increase with isometric handgrip (opposite for AS/HCM).

Echocardiography

• Mitral annular calcification is seen between mitral valve apparatus and posterior wall.
• TEE is useful to see if repair is possible in MVP.
• Features of severe MR-
  • Effective regurgitant orifice 0.4 cm2 or more
  • Regurgitant volume 60 ml or more
  • Regurgitant fraction 50% or more
  • MR jet reaching LA posterior wall (with high aliasing velocity of course!)
  • Pulmonary vein systolic flow reversal
• MVP is defined as more than 2 mm systolic displacement of mitral leaflet into LA

ECG

• LAE, LVE

Radiography

• LAE (more than in MS)
• Interstitial edema is seen with acute MR, chronic decompensated MR or with coexistent MS.
• Annular calcium is seen as a C shaped opacity in posterior third of heart in lateral or RAO.

Cardiac MRI-

• Useful for MR quantification when echo is suboptimal

LV angiography-

• Qualitative estimation of MR- by LA opacification
• Quantitative estimation of MR- by finding total stroke volume from LV angio and forward stroke volume by Fick method; then the difference is found

Disease course

• Asymptomatic severe MS-
  • Yearly risk of cardiac death- 4%
  • 5 year chance of needing surgery- 30%
  • 10 year chance of needing surgery- almost all
  • Main series- Sarano, Rosenhek, Rosen
• MR needing surgery, but not undergoing surgery- 5 year survival is 30% – Horstkotte
• Poorer outcome in MR due to flail leaflet- annual mortality rate of 6.3%- Ling

Medical management

• Acute MR- afterload reduction with nitroprusside.
• Chronic MR- ACE inhibitors and nifedipine are used, but have not been proven to be effective in studies.

Surgery-

• Conditions in which repair of mitral valve is possible-
  • MVP
  • Chordal rupture
  • Papillary muscle dysfunction
  • Annular dilation
  • Leaflet perforation due to IE
  • Rheumatic MR in the young
• Steps of mitral valve repair in PML prolapse-
  • Reduction excision of posterior leaflet
  • Reattachment of posterior leaflet
  • Repair of posterior leaflet
  • Insertion of annuloplasty ring
• Annuloplasty ring-
  • As part of MVP repair
  • For MR due to dilated cardiomyopathy
  • For MR due to regional LV dysfunction with annular dilation
• Disadvantages of mitral replacement-
  • LV dysfunction due to loss of annular-chordal-papillary muscle continuity
  • IE risk
  • Mechanical prosthesis- thrombus, hemorrhage
  • Bioprosthesis- deterioration
• Operative mortality (STS database)-
  • Repair- 2%
  • Replacement- 6%
  • Replacement with CABG- 10 to 13%
  • Replacement in elderly- 14%
• Percutaneous mitral repair-
  • Edge to edge technique
  • Coronary sinus approach to mitral annuloplasty
• MV repair or replacement in MR with LV dysfunction-
  • Improvement in LV function- usual
  • Same LV function- less common
  • Deterioration of LV function- uncommon
• Indications for surgery-
  • Symptoms present-
    • EF > 30% + ESD ≤ 55 mm (class I)
    • EF < 30% or ESD > 55 mm + chordal preservation possible (class IIa)
  • No symptoms-
    • EF ≤ 60% (class I)
    • ESD ≥ 40 mm (class I)
    • New onset AF (class IIa)
    • Pulmonary HT (class IIa)
    • Successful MV repair highly likely (class IIa)

Acute MR

• Clinical features
  • Murmur-
    • Decrescendo- ends before A2
    • Low pitched
    • Soft
  • LV S4
  • PAH is common
  • PA v wave may cause early P2 leading to paradoxical split of S2
• Echo-
  • Severe MR jet
  • No LA or LV dilation
  • Prominent systolic motion of LV
• Medical management-
  • Afterload reduction with IV nitroprusside
  • If hypotension, all dobutamine also
  • IABP
• Surgery-
  • Needed as an emergency
  • If MI is causing papillary muscle dysfunction, if possible, defer surgery for 4 to 6 weeks. For rupture, immediate surgery is needed.

	Trial	Population	Arm 1	Arm 2	Arm 3	Result
PCI vs Med
	ACME	Single or multivessel CAD	PCI	Med		Same
	MASS	Proximal LAD	PCI	CABG	Med	Same
	RITA-2	Stable angina	PCI	Med		Death or MI higher with PCI.
	COURAGE	Single or multivessel CAD	BMS	Med		Same
	OAT	Post MI 3 to 28 days, asymptomatic high risk cases	PCI	Med		Same
PCI vs CABG
	EAST	Multivessel	PCI	CABG		Same
	BARI	Multivessel	PCI	CABG		Same. DM- CABG better survival.
	ARTS	Multivessel	BMS	CABG		Same. More revascularisation with PCI. DM- CABG better survival.
	ARTS-2	Multivessel	DES	CABG		Same. Equal revascularisation with PCI when compared to ARTS CABG group.
	SoS	Multivessel	PCI	CABG		More mortality and revascularisation in PCI.
	ERACI II		PCI	CABG		Less death or MI with PCI. More revascularisation with PCI.
	SYNTAX	LMCA & TVD	PES	CABG		1 year follow-up. LMCA- Major adverse cardiac or cerebrovascular events equal. More revascularisation in PCI. TVD- Both MACCE & revascularisation more in PCI. Both LMCA & TVD- Both MACCE & revascularisation more in PCI.
	PRECOMBAT	LMCA	SES	CABG		Ongoing. Korea.
CABG vs Med
	CASS		CABG	Med		CABG better.
	ECSS		CABG	Med		CABG better.
	VACS		CABG	Med		CABG better.
Medical
	Antiplatelet trialists’ collaboration	Aspirin				Decreases mortality
	CHARISMA	Stable angina	Dual antiplatelet	Aspirin		Same
	CAPRIE	Stable angina	Clopidogrel	Aspirin		Clopidogrel was better than aspirin
	HOPE	Stable angina	Ramipril	Placebo		Ramipril was better than placebo.
	EUROPA	Stable angina	Perindopril			Perindopril was useful.
	WHI	Stable angina	HRT in postmenopausal women			Harmful
	BEAUTIFUL	Stable angina and systolic dysfunciton	Ivabradine	Placebo		With heart rate more than 70/mt, ivabradine reduces coronary endpoints. Considering all patients, there was no benefit.
	INITIATIVE	Stable angina	Ivabradine	Atenolol		Similar

]]> http://www.heartpearls.com/2010/05/stable-angina-clinical-trials.html/feed 0 http://www.heartpearls.com/2010/05/diagnose-this-infant%e2%80%99s-chest-x-ray.html http://www.heartpearls.com/2010/05/diagnose-this-infant%e2%80%99s-chest-x-ray.html#comments Sun, 02 May 2010 03:19:36 +0000 Dr Jayachandran Thejus MD http://www.heartpearls.com/2010/05/diagnose-this-infant%e2%80%99s-chest-x-ray.html

(Courtesy Dr Shan)

Scroll down for the diagnosis.

Diagnosis- Situs solitus with dextrocardia.

Stomach bubble is on left and liver shadow is on right.

Heart is on right with cardiac axis directed to right.

Is this narrow complex narrow complex tachycardia with short RP interval likely to be AVRT or AVNRT?

We can see a retrograde P wave well away from the QRS, in the ST segment. This is more likely to be AVRT. In AVNRT, P is either not seen as it is buried in the QRS or it is seen at the end of the QRS causing a pseudo R’ or S.

Try to think of a diagnosis before scrolling down for the answer.

The ECG shows atrial fibrillation with Ashman phenomenon.

The RR interval is long between the first and second beats. This causes the effective refractory period of the right bundle to be longer than normal causing RBBB aberrancy as the third beat has come at a short RR interval thus falling within this ERP. Note that in spite of coming at a short RR interval, the fourth beat is not having aberrancy as the preceding RR is short (hence ERP is not increased after the third beat).

Before scrolling down, try to think of the possible diagnoses for this ECG.

This ECG shows a regular narrow complex tachycardia at a rate of 140/min.

It is a long RP tachycardia with superior P axis.

The possibilities are-

• Fast-slow AVNRT (slow retrograde conduction in an AVNRT)
• PJRT (slow retrograde conduction in an AVRT)
• Ectopic atrial tachycardia (focus near AV node)

Evidently, this patient has LBBB. The question is whether there is MI or not. Scroll down for the discussion after you have formed your opinion about the issue.

The criteriae derived from the GUSTO I study to diagnose MI in the presence of LBBB are-

• Discordant ST elevation of 5 mm
• Concordant ST elevation of 1 mm and
• Concordant ST depression of 1 mm (applicable only in v1 to v3).

Now take a look at the ECG again and then scroll down.

In the present ECG, v2 shows discordant ST elevation of more than 5 mm and v5 shows concordant ST elevation of 1 mm. Thus there is MI.

• Valvular disease
  • Common causes-
    • Rheumatic
    • Bicuspid aortic valve
    • Calcific aortic valve disease (usually AR is mild)
    • Infective endocarditis (cusp damage, vegetation interfering with coaptation)
    • Trauma (ascending aortic tear causes cusp prolapse)
    • Large VSD
    • Membranous subaortic stenosis
  • Less common causes-
    • After percutaneous balloon valvulotomy
    • Myxomatous degeneration of aortic valve
    • Congenital AR- unicommissural, quadricuspid
    • Rupture of congenitally fenestrated valve (usually due to hypertension)
    • Connective tissue disease- SLE, RA, AS, Takayasu, Whipple, Crohn, Jaccoud arthropathy
    • Anorectic drugs
• Aortic root disease-
  • Root dilation-
    • Marfan syndrome
    • Cystic medial necrosis other than Marfan
    • Bicuspid aortic valve
    • Syphilis
    • Hypertension
    • Age related
    • Connective tissue disease- ankylosing spondylitis, osteogenesis imperfecta, Behcet syndrome, psoriatic arthritis, ulcerative colitis with arthritis, relapsing polychondritis, reactive arthritis, GCA
    • Appetite suppressants
    • AR itself may increase AR due to ascending aortic dilation- AR begets AR
  • Root dissection

Chronic AR

Pathophysiology

• Preload is increased due to-
  • Increased EDV
  • (Note- Preload is the tension in the myocardium just before contraction- correlates with EDV)
  • (Note- Tension from Wikipedia-In physics, tension is the magnitude of the pulling force exerted by a string, cable, chain, or similar object on another object. It is the opposite of compression. As tension is the magnitude of a force, it is measured in newtons and is always measured parallel to the string on which it applies)
• Afterload is increased due to-
  • Increased LV systolic pressure and
  • LV dilation
  • (Note- Afterload is the tension in the myocardium during contraction- it is proportional to PR/h where P is ventricular pressure, R is radius of ventricle and h is wall thickness)
• Myocardial ischemia occurs due to-
  • Increased myocardial oxygen demand due to-
    • Increased afterload
    • Increased LV ejection time
    • Increased LV mass
  • Decreased myocardial oxygen supply due to-
    • Decreased aortic diastolic pressure
    • Decreased diastolic filling time due to increased LV ejection time
    • Decreased effective stroke volume
• LV dysfunction occurs due to-
  • Increased afterload
  • Myocardial ischemia and
  • Increased LV mass
• LV mass increase in AR-
  • Due to replication of sarcomeres in series and due to increased interstitial connective tissue
  • The increase is more than that in AS
• Systolic wall stress in AR-
  • Initially, increased LV wall thickness (stress α tension/wall thickness) does not allow stress to increase in spite of increased afterload
  • Later, thickness cannot increase further to cope up with increased afterload. This is called afterload mismatch.
• In AR, forward stroke volume does not fall due to-
  • Increased stroke volume to compensate for the leak (this occurs due to increased EDV)
• In AR, LV is able to overcome the increased afterload due to-
  • Increased preload (Frank- Starling—increased preload increases contractility) and
  • LV hypertrophy (more muscle mass to contract)
• LVEDP in AR-
  • Compensated phase- normal due to
    • Complete LV emptying (as LV function is compensatorily increased to deal with the increased afterload)
    • Increased LV compliance.
  • Decompensated phase- increased due to
    • Incomplete LV emptying (as LV function is not good enough for the increased afterload)
    • Decreased LV compliance due to interstial fibrosis
• ESV in AR-
  • Compensated phase- normal due to complete LV emptying
  • Decompensated phase- increased due to incomplete LV emptying
• Exercise in AR-
  • Compensated phase- Forward cardiac output usually increases efficiently without increase in LVEDP. The reasons are-
    • Decrease in SVR causes less AR
    • Diastole shortens (compared to systole) causing less AR
  • Decompensated phase- Failure to generate adequate cardiac output (fatigue on exertion). Increase in LVEDP (dyspnoea on exertion).

Symptoms

• Palpitations
  • Occurs before LV dysfunction occurs unlike the other symptoms
  • Due to increased EDV
  • More on lying down
  • More after a VPC
• Fatigue, dyspnoea and angina
  • Occurs after LV dysfunction occurs
  • Angina may be nocturnal due to lower heart rate at night (more AR)

Physical examination

• Eponyms in AR-
  • Common-
    • de Musset sign- head nodding
    • Water-hammer pulse or Corrigan pulse or collapsing pulse- high volume pulse with quick ascent, ill sustained peak and quick collapse. Palpate in radial artery with arm elevated.
    • Bisferiens pulse- best palpated in brachial or femoral arteries.
    • Pistol shot sounds or Traube sign- femoral artery distal compression produces double sounds (systolic and diastolic)
    • Muller sign- systolic pulsation of uvula
    • Duroziez sign- femoral artery- systolic murmur with proximal compression and diastolic murmur with distal compression
    • Quincke sign- pressure on tip of fingernail, fingertip transillumination or glass slide on lip
    • Lighthouse sign- flushing and blanching of forehead
    • Landolfi’s sign- papillary constriction and dilation
    • Becker’s sign- retinal vessel pulsation
    • Rosenbach’s sign- liver pulsation
    • Gerhardt’s sign- splenic pulsation
    • Hill’s sign or popliteal-brachial gradient- Popliteal BP 20 mmHg more than brachial BP.
  • Uncommon-
    • Morton and Mahon sign- same as lighthouse sign
    • Ashrafian sign- pulsatile pseudoproptosis
    • Bozzolo sign- pulsatile nasal mucosa
    • Drummond sign- systolic expulsion of air from nose when mouth is closed
    • Mayen’s sign- when arm is raised, diastolic BP drops by more than 15 mmHg
    • Penny sign- flushing of wheals
    • Palmar click- pulsating palm
    • Dennison sign, Shelley sign- pulsatile cervix
    • Lincoln sign- popliteal pulsation
    • Sherman sign- dorsalis pedis prominent pulsation in age of 75 yrs or more
    • Other names for collapsing pulse-
      • Watson’s pulse
      • Cannon ball pulse
      • Pulsus celer
      • Rhazes pulse or Al Razi pulse
      • Cuming sign
      • Vieussens pulse
• High volume pulse
• High pulse pressure, high systolic pressure, low diastolic pressure. Beginning of phase IV should be taken as diastolic BP. Diastolic BP is higher in mild AR and in severe AR with heart failure (due to peripheral vasoconstriction).
• Hyperdynamic diffuse apex displaced laterally and inferiorly.
• Parasternal systolic retraction.
• Palpable LVS3
• Systolic thrill at aortic area and over carotids (carotid shudder)
  • (Note- Carotid shudder was initially described by Evans and Lewes in 1945 in AS + AR. Later, in 1976, it was shown by Alpert et al to be present in pure AS and pure AR also. In the same year, Chapman documented it in ascending aortic dissection also. Generally, the term is used in pure AS.)
• S1 may be soft.
• A2-
  • Soft or absent in valvular cause of AR
  • Normal or accentuated in AR due to root dilation (tambour sound)
• S2 split-
  • Paradoxical split can occur (prolonged LVET)
  • Aortic ejection sound may occur due to aortic distension due to increased stroke volume
• LVS3 can occur in pure AR and in AR with LV failure.
• EDM-
  • High frequency
  • Begins with A2
  • Better heard with patient sitting and leaning forward, breath held in expiration.
  • Decrescendo.
  • High pitched in mild AR and rough in severe AR.
  • Early diastolic in mild AR and holodiastolic in severe AR.
  • Late diastolic component is abolished in LV failure due to high LVEDP.
  • Cooing dove murmur in cusp eversion or perforation.
  • Valvular cause of AR- radiation to left sternal border. Root dilation causing AR- radiation to right sternal border.
  • Increased with squatting and isometric exercise
  • Decreased with amyl nitrite and Valsalva
  • Cole-Cecil murmur- EDM radiating to apex and left axilla
• MSM-
  • May be associated with a carotid thrill
  • Higher pitched than the murmur of AS
• Austin Flint murmur-
  • Mid diastolic murmur with presystolic accentuation
  • Seen in severe AR only
  • Causes-
    • AR jet impinging on AML forcing it down thus decreasing mitral orifice
    • Turbulence when AR jet meets mitral inflow jet
    • AML fluttering due to AR jet
    • LV endocardial vibrations due to AR jet
  • With LV failure, due to elevated LVEDP, Austin Flint murmur begins and ends earlier
  • Increased with isometric exercise, reduced by amyl nitrite

Echocardiography

• Points to note-
  • Cause of AR
  • Severity of AR
  • LV function
• High frequency diastolic fluttering of AML- seen in M mode- seen even in mild AR (unlike Austin Flint murmur)
  

  	Mild	Moderate	Severe
  Jet width/LVOT diameter		1/4 to 2/3
  Vena contracta (mm)		3 to 6
  Pressure half-time (ms)	> 700		<250
  LV dilation	Absent	Absent	Present
  Flow reversal in descending thoracic or abdominal aorta	Absent	Absent	Present
  Regurgitant orifice area (cm2)		0.1 to 0.3
  Regurgitant volume (ml)		30 to 60
  Regurgitant fraction		30 to 50

   

• Continuity equation-
  • Regurgitant volume= LVOT flow- mitral flow
  • Regurgitant fraction= Regurgitant volume/ LVOT flow
  • Regurgitant area= Regurgitant volume/ AR TVI
• PISA-
  • Regurgitant area= Flow through aliasing hemisphere surface/AR peak velocity
  • Regurgitant volume= Regurgitant area x AR TVI
  • Regurgitant fraction= Regurgitant volume/LVOT flow
• (Note- In continuity equation, regurgitant volume is calculated first. In PISA, the calculations in order are regurgitant area, regurgitant volume and regurgitant fraction.)

ECG

• High LV voltage
• Q in lateral leads
• Tall upright T waves in lateral leads initially; later strain pattern.

Radiography

• LV enlargement
• LA enlargement if heart failure or mitral valve disease
• Ascending aortic dilation- more than in AS
• Look for ascending aortic aneurysm
• Linear calcifications in ascending aorta- syphilitic aortitis

Angiography

• For assessing AR, contrast injection into aortic root must be at 25 to 35 ml/sec!

Radionuclide angiography

• LV/RV stroke volume ratio > 2 indicates severe AR

MRI

• Can accurately measure severity of AR by measuring regurgitant volume, regurgitant fraction and regurgitant area
• Used when echo is suboptimal

Natural history

• Main studies- Bonow et al, Borer et al
• No symptoms, normal EF-
  • Annual chance of symptoms or LV dysfunction- 6%
  • Annual chance of sudden death- 0.5%
• Angina-
  • Death in 4 years
• Heart failure-
  • Death in 2 years
• Survival and NYHA class in severe AR-
  • NYHA I- 10 yr survival of 75% (equal to general population)
  • NYHA III or IV- 4 yr survival 28%

Medical management

• If diastolic BP is high, vasodilators like nifedipine or ACE inhibitors are to be given
• Beta blockers should be avoided

Surgery

• Indications for surgery in chronic severe AR-
  • Class I-
    • Symptoms
    • Symptoms on TMT
    • EF less than 50% (echo, RVG or MRI)
  • Class IIa-
    • LVESD > 55 mm (50 to 55 is IIb)
    • LVEDD> 75 mm (70 to 75 is IIb)
• Patients with severe LV dysfunction (EF < 25%) before AVR may not have an improvement in LV function after AVR.
• Aortic valve repair-
  • Usually not possible, so AVR will be needed (unlike mitral repair which if often successful)
  • Cusp resuspension or cusp resection for cusp detachment from annulus due to trauma
  • Pericardial patch for cusp perforation in IE
  • Root dilation causing AR-
    • Encircling suture
    • Subcommissural annuloplasty
    • Aortic graft with prosthetic valve- coronaries need to be reimplanted
    • Aortic graft alone
• AVR-
  • Large prosthesis can be implanted as annulus is dilated- so less chance of prosthetic gradient.
  • Operative mortality- 3 to 8%

Acute AR

• Causes-
  • Infective endocarditis
  • Aortic dissection
  • Trauma
• Pathophysiology
  • Normal LV size (not increased as compliance is not increased)
  • Increased LVEDP (dyspoesa) + decreased cardiac output (shock)
  • Increased LVEDP as LV cannot dilate rapid enough to accommodate the regurgitant volume
  • Decreased cardiac output due to-
    • Decreased forward stroke volume because-
      • EDV does not increase as LV compliance does not increase (In chronic AR, increased EDV increases total stoke volume so that forward stroke volume, which is total stroke volume – regurgitant volume, is maintained)
    • Decreased total stroke volume due to-
      • Premature mitral closure due to increased LVEDP
      • Tachycardia (less diastolic filling time). Tachycardia is a compensatory response to decreased cardiac output.
• Physical examination-
  • Hypotension with tachycardia as a compensatory response
  • Dyspnoea due to increased LVEDP
  • Normal pulse pressure
  • No peripheral signs of AR
  • S1 is soft or absent due to premature closure
  • P2 may be loud
  • EDM-
    • Shorter than the murmur of chronic AR (due to rapidly rising LV diastolic pressure)
    • Lower pitched than the murmur of chronic AR (due to rapidly rising LV diastolic pressure)
  • Austin Flint murmur-
    • Shorter than in chronic AR, no presystolic accentuation (due to rapidly rising LV diastolic pressure)
• Echocardiography-
  • AR jet- low end diastolic velocity
  • Mitral valve- late opening and premature closure
  • LV size- normal
  • EF- normal
  • Aortic valve- premature opening
• ECG-
  • Non specific ST-T changes
• Radiography-
  • PVH, pulmonary edema
  • Normal heart size
• Management-
  • Early surgery
  • During preparation for surgery-
    • Dopamine/dobutamine + nitroprusside
    • Do not put on IABP (increased peripheral resistance during diastole increases AR)
    • Do not give beta blockers for tachycardia (increased diastolic interval increases AR)