1. HEMODYNAMICS & NATURAL HISTORY OF
PULMONARY STENOSIS
DR.GOPIDI APARANJI
SRI JAYADEVA INSTITUTE OF CARDIOVASCULAR SCIENCES
& RESEARCH, BANGALORE

2. EPIDEMIOLOGY
• PS at some level +/ other associated lesions, 25 - 30% of all
CHD
• Isolated Pulmonary valve stenosis, 8 to 10% of all CHD
(described by Morgagni, 1761)
• Isolated Pulmonary Valve stenosis, in 80 to 90% of all RVOTO
• Familial occurrence :-
- 2.1% incidence of CHD (usually PS or TOF), in siblings of
patients with PS (Campbell et al)
-A/c to 2nd Natural history study of CHD, incidence were 1.1%
for definite CHD and 2.1% for possible CHD.

3. • Association with Genetic Diseases ( Syndromes)
-Noonan
-Rubella
-Williams
-Allagile Syndromes
• Prevalence of PS - Asia > Europe and USA
• ACQUIRED PS
- rare, especially in children.
- Aetiologies
- Carcinoid syndrome
- Infective endocarditis
- Homograft dysfunction

4. ANATOMICAL CLASSIFICATION OF PS

5. SEVERITY CLASSIFICATION OF PS
• Based on the Doppler flow gradient across the area of
stenosis, as found at TTE
• Graded -mild, moderate, severe and critical.
• Whilst the first 3 are regarded as acyanotic congenital cardiac
defects,
• Critical PS can cause cyanosis due to the associated right-to-
left shunting through the patent foramen ovale (PFO) or an
ASD

6. GRADING OF PULMONARY
STENOSIS

7. • Three morphologic types of pulmonary stenosis involve the
pulmonary valve:
(1) Typical mobile dome-shaped
(2) Dysplastic
(3) Bicuspid.
• CLASSIC PS –
valve is conical and dome shaped, commisural fusion
2-4 raphe may be visible, but there is no separation of valve
leaflets.
• Dysplastic valves are trileaflet with markedly thickened
(disorganized Myxomatous tissue )cusps, Hypoplastic

8. CLINICAL HISTORY
• Valvular PS
• Asymptomatic(mostly)
• Symptoms rare in childhood, become more common with
increasing age.
• Initial symptoms usually exertional dyspnea and fatigue
• Can have chest pain, syncope, even sudden death with
strenuous exercise

9. • Central cyanosis present in presence of inter-atrial
communication.
• Peripheral edema, ascites due to RV failure
• Peripheral cyanosis during exercise in presence of RV failure
• Dome shaped PS, normal birth weight and growth
• In Noonan syndrome, growth and development are poor.

10. • Intermittent and mild or recurrent and brisk hemoptysis
(due to dilated thin walled intra-pulmonary artery aneurysm )
• Severe PS  giant A wave  subjective awareness during
exercise or excitement
• IE can occur in mobile dome shaped PS

11. PULMONARY STENOSIS WITH INTERATRIAL
COMMUNICATION
• In 1769, Giovanni Battista Morgagni described PS with a PFO.
• In 1848, Thomas Peacock published “Contraction of the Orifice
of the Pulmonary Artery and Communication Between the
Cavities of the Auricles by a Foramen Ovale”
• Two forms :-
• 1. Severe pulmonary valve stenosis with a R to L shunt through
a PFO ( Group 1 )

12. • This form clinically present as Isolated PS with central cyanosis.
• 2. A nonrestrictive interatrial communication is almost always an
OS-ASD, the shunt is L to R, and PS is necessarily mild to moderate(
Group 2)
• This group present as Large ASD like picture.

13. PULMONARY STENOSIS WITH VSD
• Non-restrictive VSD can occur with PS varying from mild to
severe to complete ( pulm atresia)
• Restrictive VSD can occur with mild to severe PS
• A large non-restrictive VSD with PS is Fallots tetralogy
• Multilevel obstruction RVOT – hallmark of TOF
• M/C in TOF is infundibular stenosis
• Typical PV in TOF is thickened, obstructive, frequently
bicuspid

14. NATURAL HISTORY
• Course and prognosis of patients with PS-IVS depends on the severity
of obstruction
• Sharland indicates that isolated pulmonary stenosis represents 0.8%
of cases of structural heart disease diagnosed during fetal life in their
series.
• Termination of pregnancy was the choice in 20% of families.
• Pulmonary stenosis may remain stable, progress, or rarely with
natural remodeling of the valve, the severity of pulmonary
stenosis may seemingly improve

15. • Mild PS
• Gradient < 30 to 35mmHg, RVP<50% of SVP:-
• Benign course, normal hemodynamic response to exercise, no
intervention required
• 4-8 years F/U of 214 pts with mild PS-no death
• Moderate PS
• Gradient < 64mmHg, RVP>50% of SVP).
• Most data suggests mod PS may develop progressively greater
obstruction-during periods of rapid growth

16. • In view of development of both systolic and diastolic RV dysfunction in
long term Mod PS, most recommendation is to do PBV with gr >40 to 50
mmHg.
• Severe PS (gradient > 64mmHg)
• Intervention is recommended asap
• Chance of irreversible change in cardiac function can develop due to
myocardial fibrosis.
• So, relief of Severe PS recommended without undue delay

17. • The First Report from the Joint Study on the Natural History of CHD-
1977
• 565 patients with pulmonary stenosis were included- mild to severe
PS included
• The pressure gradients remained stable in the majority,
• 14% there was a significant increase and
• In another 14% a significant decrease

18. • Progression of severity depends on the age and baseline severity of
obstruction
• Only 3 patients with initial gradients of < 40 mmHg who at
follow-up study had gradients of >60 mmHg .
• Increases almost never occurred in patients over 12 years of age
• Most were likely to occur in patients under 4 years with initial
gradients > 40 mmHg

19. • Second Joint Study on the Natural History of Congenital Heart
Defects -1993.
• This follow-up study revealed that the probability of 25-year
survival was 95.7%,
• The probability of survival was less (80%) in a subgroup of patients
entering the first study > 12 years of age with cardiomegaly

20. • Patients with gradients < 25 mmHg did not experience an increase
in gradient
• It was recommended that those with gradients > 50 mmHg should
undergo intervention.
• It was less clear about the need for intervention for those with
gradients between 40 and 49 mmHg.

21. • Pulmonary regurgitation was assessed both clinically and by
Doppler
• Among the 113 patients managed medically, the corresponding
percentages were 51.3% and 89.4%,
• Whereas among 197 surgically managed patients, they were 13.2%
and 42.1%
• Sudden unexpected death occurred in 0.5% of the patient

22. • Samanek has studied the probability of natural survival of children
born in central Bohemia.
• Data on 109 children born with pulmonary stenosis
• 1-year, 2-year, and 15-year survival rate to be 97%, 96% and 94%,
respectively

23. • Campbell in 1969 -The mortality rates for congenital pulmonary
stenosis rise from
• 2% per annum in the first decade
• 3.4% in the third
• 6% in the fourth
• 7% per annum in the fifth and later decades.
• 19 ± 7% live to the age of 40 years

24. • Nand and Mehta-Natural history of asymptomatic valvar pulmonary
stenosis in 51 infants using 2D ECHO and Doppler
• 15% developed significant stenosis that needed intervention.
• They recommend frequent follow-up of asymptomatic infants with
mild pulmonary stenosis during the first 2 years of life to detect rapid
progression that may need intervention.

25. MODIFIED NATURAL HISTORY

26. • Russell Claude Brock- 1948
• Reported 3 patients with pulmonary stenosis treated successfully by closed
transventricular pulmonary valvotomy
• Caspi and his colleagues-SX VS PBV
• The early postoperative gradient was 20 ± 2 mmHg; the post-balloon
valvotomy gradient was 18 ± 3 mmHg
• PBV yields good results in patients with critical pulmonary stenosis with
essentially normal-sized right ventricle
• Surgical pulmonary valvotomy is required for patients with right ventricular
hypoplasia

27. • The Pediatric Cardiac Care Consortium-
• 1099 procedures
• 416 were SX procedures and 683 were PBV
• A mortality rate of 4.3%- 30 days following surgery.
• Mortality attributable to PBV- 0.15%

28. • Freedom from a second procedure for pulmonary stenosis treated
in the 1st week of life was 66.1%
• Treated between 1 and 3 months of age-82.6%.
• Treated between 3 and 6 months- 92.7%.
• Overall, freedom from a second pulmonary valve procedure was
93.5%

29. • McCrindle and his colleagues of the VACA Registry Investigators
• Assessed independent predictors of long-term results after balloon
pulmonary valvuloplasty
• Prognostication after PBV depends on the valvar anatomy
• Use of an appropriate ratio of balloon to valve hinge point diameter
in the setting of typical valve morphology should optimize the
chance of long-term success

30. • Kopecky and his colleagues-1988
• Long-term outcome at 20–30 years F/U of 191 patients -underwent
surgical pulmonary valvotomy for Valvar PS at the Mayo Clinic b/w 1956
and 1967
• The mean age (± SD) at operation was 13.6 ± 13.1 years
• Eight patients died within 30 days of operation
• Mean duration of follow-up was 23.9 ± 3.9 years.

31. • Kaplan–Meier estimates of survival, excluding hospital mortality, were
99%, 96%, 95%, 92% and 90% at 5, 10, 15, 20, and 25 years,
respectively.
• Late death occurred in 9.25% of survivors.
• The mean age at death was 38 years, ranging from 5 to 65 years.
• Predictors of late death were older age, higher preoperative RVP,
history of preoperative syncope, edema, or cyanosis, and the
requirement for preoperative medical treatment

32. • Kirklin and Barratt-Boyes -1993
• States that survival of neonates born with critical valvular
pulmonary stenosis is about 80% at 4 years.
• 75% of neonates undergoing an accomplished pulmonary
valvotomy require no further procedure.
• A few patients require a repeat valvotomy and about 10% require a
transannular patch.
• About 2% cannot sustain a two-ventricle repair and a Fontan-type
of operation or one-and a-half ventricle repair will be required

33. • Gildein and his colleagues
• 18 neonates in whom pulmonary valvuloplasty was attempted.
• Freedom from reintervention was 90%, 84% and 84% at 1, 2 and 8
years, respectively
• Balloon dilatation of critical pulmonary valve stenosis encourages
catch-up growth of the pulmonary valve, and surgery can be avoided
even in those with a hypoplastic pulmonary valve annulus.

34. POST PROCEDURE PR
• The reported incidence of pulmonary regurgitation after surgical
valvotomy or balloon valvuloplasty varies considerably from as low
as 10–50% or more according to studies cited by Kirklin and Barratt-
Boyes.
• Shimazaki and his colleagues -The actuarial freedom from
symptoms was 77% at 37 years, 50% at 49 years, and 24% at 64
years

35. SUMMARY-NATURAL HISTORY
• Beyond infancy, mild congenital pulmonary stenosis tends not to progress
in severity
• 1-year, 2-year, and 15-year survival rate to be 97%, 96% and 94%,
respectively
• Intervention for congenital pulmonary valvular stenosis has evolved from
surgery to catheter-based intervention.
• Balloon valvuloplasty for patients ≥ 2.0 years provides excellent
outcomes.
• freedom from a second pulmonary valve procedure was 93.5%

36. • Most consider systolic pressure gradients between 40 and 50 mmHg
indication for intervention.
• Balloon valvuloplasty with oversized balloons especially in neonates tends
to induce important pulmonary insufficiency.
• Congenital pulmonary valvular stenosis secondary to a dysplastic
pulmonary valve may require surgery with valvectomy ± a transannular
patch in those with a small annulus.
• Balloon valvuloplasty is the procedure of choice for critical pulmonary
stenosis in the neonate, require an additional procedure, perhaps as many
as 20–30%.

37. PHYSIOLOGY
• Main is rise in RV pressure proportional to degree of Pulmonary
stenosis.
• Increase in RV mass by 2 mechanisms
 Fetal myocardium by Hyperplasia + inc no.of capillaries
 Adult myocardium by Hypertrophy( no change in capillary)
• In presence of fixed and severe obstruction RV eventually fails
• Failing ventricle, inability to increase Cardiac Output during
exercise, peripheral cyanosis develops
• In presence of PFO/ASD, central cyanosis can happen.

38. NEONATAL CRITICAL PS PHYSIOLOGY
• Severe PS  fetal RV CO  larger than normal RL shunt
• RV often hypoplastic
• Severe RV hypertrophy
• Reduced RV flow during development
• At birth cyanotic neonate, rapidly progressive HF
• Suprasystemic RV pressure
• Even if stenosis relieved, RL shunt ad cyanosis persists for months

39. HEMODYNAMICS
• Resting RVP >30-35 mm Of Hg & pressure gradient of >10 mm og
Hg across the PV-abnormal
• Severity of PS based on the RVP & gradient
• MILD-RVP<50% of LVP, gradient <35-40 mm of Hg
• MODERATE-RVP>75% of LVP, gradient 40-60 mm of Hg
• SEVERE-RVP>75% of LVP, gradient > 60-70 mm of Hg

40. VALVAR PS

41. VALVAR PS

42. SUPRAVALVAR PS

43. PS WITH PR

44. PR

45. PERIPHERAL BRANCH PA STENOSIS

46. INCIDENCE
• 2% to 3% of all CHDs.
• Isolated peripheral pulmonary artery stenosis was described first by
Maugars & Schwalbe.
• Valvar pulmonary stenosis and VSD, are present in about 2/3rd of
the cases.
• Hypoplasia of Pulmonary arteries is seen frequently with TOF

47. GENETIC MUTATIONS
• Williams syndrome – chr 7 deletion – abnormal elastin production
• Alagille syndrome – chr 20 deletion  JAG1 or NOTCH2 mutation
• Noonans syndrome- chr 12 mis sense mutation –> 50% have
PTPN11 mutation  part of RAAS/ RAF/ MEK/ ERK signal
transduction pathway
• These genetic abnormalities can be sporadic or familial with AD
inheritance

48. SYNDROMIC ASSOCIATIONS
• Congenital rubella, PPAS is a/w PDA & ASD.
• Cutis laxa
• Ehlers–Danlos syndrome
• Silver–Russell syndrome

50. PPAS in WILLIAM SYNDROME
• 2ND most common CVS abnormality
• More common in patients in 1st year of life
• Incidence of PS in WS  37-75% (majority studies -40%)
• Most commonly inv Branch & peripheral Pas. (diffuse> discrete
stenoses)

51. • The natural history of PAS in WS is improvement with age, due to the
change in arterial medial tension that occurs in the postnatal period.
• Pulmonary arterial concentrations of elastin normally decrease in the
first few months of life, at a time when PVR is normalizing.
• Theoretically, the decrease in pulmonary arterial pressure lessens
the arterial medial tension in the pulmonary arteries, decreasing the
role of elastin.
• As a result, there is improvement in the arterial stenoses as the
patient grows

52. CLASSIFICATION  GAY et al
• 4 types
1. Stenosis inv MPA or RPA & LPA
2. Stenosis in Bifurcation of MPA extending into both branches
3. Multiple peripheral stenoses
4. Combination of main & peripheral stenoses

54. CLINICAL FEATURES
• Pts with U/L PAS or mild to moderate B/L PA stenosis are usually
asymptomatic.
• Dyspnea & fatigue are mild as long as the right ventricle maintains a
normal SV at rest and augments its SV with exercise.
• Cardiac output is inadequate even at rest when the hemodynamic
burden imposed on the RV leads to RV failure
• RV failure is the MCC of death

55. • Hemoptysis  Dilated thin-walled intrapulmonary artery aneurysms
distal to the stenoses of PA branches
• Cyanosis  2’ to intracardiac R L shunts
• SCD  RVMI & an abnormal RCA.
• RV failure is a/w hepatomegaly, ascites, PE
• Atrial tachy arrhythmias 2’ to RV Diastolic Dysfunction.

56. PATHOPHYSIOLOGY
• Elevation of systolic pressures of RV & PA depends on severity &
distribution of stenosis.
• When obstruction is severe , RVET is prolonged & the PA trunk
proximal to the obstruction behaves as an extension of RVOT.
• So, the pressure tracing proximal to the stenosis resembles RV with
high systolic & low diastolic pressure.

57. • When stenosis is U/L with no LR shunt, RV pressure is normal.
• Systolic pressure gradient across the stenosis underestimates the
severity as the flow to stenotic side is low.
• But the diastolic pressure gradient across MPA & stenotic side is
proportional to severity of obstruction.

58. CARDIAC CATHETERISATION
• Done to confirm the diagnosis & to determine the severity & anatomy.
• Withdrawal pressure tracings from distal branches will give stenotic
pressure gradients.
• Systolic pressure gradient > 10 mm Hg is abnormal in the absence of
LR shunt causing increased PBF
• In U/L PAS, measured gradient underestimates the severity d/t
preferential flow to the unobstructed side.

60. • Artifactual gradients d/t
a) Overly large catheter in a small vessel
b) In premature infants, due to the size discrepancy b/w the
pulmonary branches and the main trunk
• In B/L PAS, pulmonary trunk becomes an extension of the RVOT
systolic tracing similar to RV, but dicrotic notch is low with slow
descent f/b low diastolic pressure

61. PULMONARY STENOSIS IN YOUNG ADULT
• Hemodynamically significant PS may be more symptomatic compared to
childhood
• Concomitant infundibular stenosis not infrequent
• TR with RV failure can present and PS gradient may be underestimated
• PBV treatment of choice
• After PBV, infundibular stenosis/spasm can be there and if severe beta-
blockers can be used
• Post PBV PR, not reported as a significant issue

62. PULMONARY ARTERY STENOSIS IN
YOUNG ADULTS
• Isolated PPAS is rarely seen in adult patients, and often is
misdiagnosed as CTEPH.
• These patients typically present with exertional dyspnea & fatigue,
and symptomatic improvement has been seen following balloon
angioplasty.
• Systemic vasculitis with pulmonary arterial involvement should be
excluded.

63. • The presence of murmurs consistent with PAS in many of these
patients in childhood or adolescence suggests a congenital etiology
with slow progression.
• Inadequately repaired Branch PAS may be seen in patients who
underwent childhood repairs of lesions such as TOF, truncus
arteriosus, or TGA (if arterial switch procedure was utilized).
• Abnormal distribution of pulmonary blood flow has been associated
with reduced exercise capacity

64. THANK YOU