Systolic anterior motion of mitral valve - SAM

1. Critical Case ConferenceCritical Case Conference
Gagan Kumar MDGagan Kumar MD

2. HPIHPI
•Admitted on 1/26/2011
•80 Y female
–weakness and nausea x 1 day.
–Had troponin leak
•Ruled out for ACS
•Started CPAP and Nocturnal oxygen
•Cardiology consulted for Troponin leak
•Planned for RHC & LHC
–Not done due to high INR
–Then again for candidiasis in groin area.

3. Past Medical HistoryPast Medical History
•RA (rheumatoid arthritis)
•Atrial fibrillation
•Right Diaphragm paralysis with right middle lobe
collapse. 2008 ? probably had since birth. admission
6/08 for hypoxia, multifactorial sectondary to right
phrenic nerve palsy. On home oxygen therapy 2L NC
•OSA with hypoventilation, does not use CPAPCPAP
•DVT (deep venous thrombosis) 5/08
•Aortic stenosis
•Unspecified essential hypertension
•BCC (basal cell carcinoma of skin)
•Depression
•RA (refractory anemia)
•Hyperlipidemia

4. Family historyFamily history
•Mother: HTN, CAD (died at 94)
•Father: melanoma
•Social history:
–5 pack years, quit 1972
–No EtOH
–Retired homemaker

5. MedicationsMedications
•ClonazePAM (KLONOPIN) 0.5 mg tablet Take 0.5 mg by mouth nightly.
•Escitalopram (LEXAPRO) 20 MG tablet Take 1 Tab by mouth
daily.
•Lisinopril (PRINIVIL OR ZESTRIL) 40 MG tablet Take 1 Tab by
mouth daily.
•Metoprolol (LOPRESSOR) 25 MG tablet Take 1 Tab by mouth 2
times daily. pt needs f/u visit for further refills.
•Potassium chloride SA 20 MEQ tablet Take 20 mEq by
mouth daily.
•Warfarin (COUMADIN) 3 MG tablet Take 6 mg by mouth every
Monday. Take 3 mg by mouth every Sunday, Tuesday, Wednesday,
Thursday, Friday & Saturday.

6. Hospital courseHospital course
•ECHO done 1/27/2011
LV size is upper normal. There is severe asymmetric basal septal hypertrophy, with
an approximate 2:1 septal to inferolateral wall ratio.
There also appears to be systolic anterior motion of the mitral chords.systolic anterior motion of the mitral chords.
There is at least a 40 mm Hg peak LVOT dynamic gradient40 mm Hg peak LVOT dynamic gradient,, which is probably
underestimated due to technical limitation of study.
Visually estimated LVEF is 65-70%.
The right ventricle appears moderately enlarged with normal systolic function.
The left atrium visually appears severely enlargedleft atrium visually appears severely enlarged.
The right atrium is severely enlarged.
There are moderate fibrocalcific changes of the aortic valve which does not
appear to be significantly stenotic.Mild to moderate aortic regurgitation.
The mitral leaflets appear mildly thickened. There is moderate mitral annular
calcification present.There is mild to moderate mitral regurgitationmild to moderate mitral regurgitation.
There is mild to moderate tricuspid regurgitation.
Estimated PA systolic pressure by tricuspid regurgitant Doppler velocity is 60
mmHg.
No obvious significant pericardial effusion.

7. Hospital courseHospital course
•On 1/30/2011 – increasing oxygen requirements
& found unresponsive.
•She was found to be in Atrial fibrillation
•ABG shows – respiratory acidosis & hypoxia.
•Transferred to MICU

8. Vitals 1/30/2011Vitals 1/30/2011

9. EKG on admission 1/26/2011EKG on admission 1/26/2011

10. EKG on the day of transfer to EKG on the day of transfer to
MICU 1/30/2011MICU 1/30/2011

11. I&OI&O

12. LabsLabs

15. Problem listProblem list
•Acute hypercapnic respiratory failure,
superimposed on chronic respiratory
acidosis
•Acute neurologic failure (no drugs)
•Atrial fibrillation with RVR
•Urinary retention
•Hypertrophic cardiomyopathy with SAM
•SIRS possible sepsis (fever of 101
O
f)

16. Hospital courseHospital course
•She was intubated A/C 18/600/5/70
•Started on amiodarone drip
•Started on Norepinephrine which was
weaned off in 5 hours.
•CVP 8-13
•Started on Vancomycin + Zosyn
•Given IVF ~ 2L

17. Hospital courseHospital course
•Antibiotics changed as per culture reports
–Urine grew enterococcus
–Sputum miniBAL grew MRSA
•Extubated on 2/1/2011
•BiPAP at night after extubation
•Beta blockers added: metoprolol
increased to 150mg BID to control HR

18. Questions?Questions?
•Was the hypotensive crisis due to atrial
fibrillation with some role of sepsis?
•What was ‘SAM’? Did it have any role in
the events?
•Is the management any different in
tachyarrhythmia with SAM?

19. Systolic Anterior Motion of the Systolic Anterior Motion of the
Mitral ValveMitral Valve

20. AnatomyAnatomy
http://www.mitralvalverepair.org/content/view/51/

21. AnatomyAnatomy
http://www.echoincontext.com/learn_anat.htm

22. What is SAM?What is SAM?
•Anterior movement of mitral valve (either
of the leaflets) during systole.
–Mostly involves anterior leaflet
•Maximal anterior motion in HCM patients
occurs before maximal posterior wall
contraction—approximately two-thirds of
the way through systole

23. Why does it happen?Why does it happen?
•Venturi effectVenturi effect: increased flow velocity in
LVOT
•Anterior and inward displacement of
papillary muscle with elongation of valve
leaflet ® creates slack in leafletslack in leaflet.
•Flow dragFlow drag: Pushing force of the flow
•TimingTiming of papillary muscle contraction

24. Three following features are necessary for SAMThree following features are necessary for SAM
• Mitral-septal contact and obstruction: anterior position of
mitral coaptation
•Angle of flow onto the mitral valve, such that flow gets
behind the mitral valve (angle of attack)
•Chordal slack
FLOW DRAG

25. Once the mitral valve touches the septum  a narrowed
orifice occurs
Pressure difference across the orifice becomes the new
hydrodynamic force across the mitral leaflet
This pressure difference pushes the leaflet further into the
septum, narrowing the orifice further
amplifying feedback loop is established that cycles for
much of ejection (longer in systole that it cycles, the
higher the gradient)
Time course through systole after Time course through systole after
‘flow drag’‘flow drag’

26. What accentuates SAM?What accentuates SAM?
•Decreased preloadDecreased preload
–Dehydration
–Orthostasis
–Valsalva
•Decreased afterloadDecreased afterload
–Vasodilators
•Increased LV ionotropyIncreased LV ionotropy
–Fever / Exercise / Dobutamine

27. Clinical findingsClinical findings
•On examination:
–LV heave
–S
1
normal; S
2
paradoxical splitting; S
4
–Systolic ejection murmur – left sternal border
–Increases with valsalva, vasodilators
–Decreases with squatting, vasopressors

28. ECHOECHO
http://www.mpoullis.net/dvdecho/not%20included2/yale/Yale%20Atlas%20of%20Echo-%20Left%20parasternal%20long%20axis%20view_files/lpla_art.gif
Parasternal long axis view

29. ECHOECHO
•Parasternal long axis
view
•HCM shows significant
hypertrophy of
–the interventricular
septum (IVS)
–posterior left ventricular
wall (PWLV); the echo-
free space behind the
posterior wall is a
pericardial effusion (PE).
RV: right ventricle
Ao: aorta
LV: left ventricle
LA: left atrium.

30. M – mode ECHOM – mode ECHO
time
ECG

32. Hemodynamics in HCM with fixed Hemodynamics in HCM with fixed
left ventricular outflow obstructionleft ventricular outflow obstruction
LV
LVOT Aorta

33. HCM with variable left ventricular HCM with variable left ventricular
outflow tract obstructionoutflow tract obstruction
LVOT LVOT
gradientgradient

34. Brockenbrough–Braunwald–Morrow Brockenbrough–Braunwald–Morrow
signsign
AO = Descending aorta;
LV = Left ventricle; LV = Left ventricle;
After the third QRS complex, the ventricle
has more time to fill. Since there is more
time to fill, the left ventricle will have more
volume at the end of diastole (increased
preload).
Due to the Frank–Starling law of the
heart, the contraction of the left ventricle
(and pressure generated by the left
ventricle) will be greater on the
subsequent beat (beat #4 in this picture).
Because of the dynamic nature of the
outflow obstruction in HCM, the the
obstruction increases obstruction increases moremore than the than the
left ventricular pressure increaseleft ventricular pressure increase. This
causes a fall in the aortic pressurefall in the aortic pressure as
the left ventricular pressure risesleft ventricular pressure rises (seen
as the yellow shaded area in the picture).

35. HistoryHistory
•SAM was reported in late 1960’s with
Hypertrophic Cardiomyopathy (HCM)
–Thought to be specific for this entity
–Associated with LVOT obstruction
•Later both the findings were proven wrong
–SAM is present in 30-60% of HCM
–HCM with SAM: only 25-50% have LVOT obstruction
–SAM can be present in absence of HCM

36. Hemodynamic consequencesHemodynamic consequences
•Diastolic dysfunction
•Prolongation of systolic ejection
•Reduction in stroke volume
•Disrupts MV functioning ® MR
•Microvascular dysfunction
•Intolerant to tachyarrythmias

37. Medical TreatmentMedical Treatment
•Negative ionotropes –Negative ionotropes –
Decrease LV ejection acceleration
↓
Decrease hydrodynamic force on mitral valve
↓
Decreased feedback loop
ββ-blockers-blockers
DisopyramideDisopyramide
VerapamilVerapamil

38. Medical TreatmentMedical Treatment
•Start with ββ-blockers-blockers :
–prolonging diastole ® prolongs filling time.
But doesn’t decrease LVOT gradient.
•VerapamilVerapamil: causes vasodilation.

39. Medical TreatmentMedical Treatment
•DisopyramideDisopyramide:
–use in combination with β-blockers.
–Reduces gradient and prolongs exercise time
•Side effectsSide effects
–Anticholinergic side effects (BPH)
–Can accelerate AV conduction ( hence always used
with beta blockers)
–Prolongs QT interval (stop if QTc increases by > 25%)
•Avoid with amiodarone/ sotalol etc.

40. Things to avoidThings to avoid
•Use diuretics with extreme caution !!!
–Reduce preload ® increase obstruction
•Hemodynamics can be compromised by
vasodilators
–ACEI
–ARBs
–Nitrates
–Nifedipine
•Positive inotropes
–Digoxin

41. Non-Surgical TreatmentNon-Surgical Treatment
•DDD pacing with short AV delayDDD pacing with short AV delay
–Reduced LVOT gradient by 50%
–Not much difference in exercise capacity
–Can use in elderly or who have contraindication to
surgery.
–Can use more negatively ionotropic medications since
they are now protected against bradycardia.

42. Non-Surgical TreatmentNon-Surgical Treatment
•Alcohol ablation of septum
–Small balloon catheter is placed into a proximal septal artery
–Contrast is injected into the target septal perforator
–After occlusion of a septal perforator by a small balloon to prevent back
leakage, 1 to 4 mL of absolute alcohol in injected into the distal
perforator
–Balloon is left inflated for 5 to 10 minutes
•36% reduction in acceleration
•Complications
–Death in 0% to 4%
–LAD dissection
–Leakage of alcohol back into the LAD with LAD occlusion and large
infarction
–Complete heart block in 9% to 38%

43. Schematic Diagram of Alcohol
Septal Ablation

44. Classical myotomy-myectomyClassical myotomy-myectomy is the ‘gold standard’
therapy for patients with severely symptomatic hypertrophic
obstructive cardiomyopathy more than three quarters of all
long-term survivors are in functional class I or II (New York
Heart Association) and overall survival after 18 years (mean
follow up 8.1 years) was 68%, with a linearized mortality rate
of 1.9% per patient-year.

45. Patients with obstructive HCM and mild or no symptoms have only
slight excess mortality.
However, patients with markedly elevated resting LVOT gradients markedly elevated resting LVOT gradients
are at a high risk of heart failure and death. are at a high risk of heart failure and death.
These findings may have important implications for therapy, including
the timing of septal reduction therapy

46. ‘‘SAM’ in common situationsSAM’ in common situations

47. SAM & HTNSAM & HTN
•FrequencyFrequency: 1% to 30% of patients with
LVH from HTN
•Maximal SAM occurred at the end of
systole with the mitral valve still anteriorly
displaced
•“Venturi effect” may be more pronounced
in this subgroup

48. SAM & HTNSAM & HTN
•Implications??
–Vasodilators may increase SAM & LVOT
obstruction
–Negatively ionotropes have beneficial effects

49. SAM & DiabetesSAM & Diabetes
•In poorly controlled diabetics (HbA
1c
> 13)
–SAM occurred in 65% of diabetics with
β-stimulation (10% in controls)
–Possibly related to greater LV mass in those
who exhibit SAM
–May have implications in septic patients on
pressors – especially Norepinephrine

50. SAM & ACSSAM & ACS
Compensatory hyperkinesis in non-infarcted
ventricular segments

Reduced systolic diameter of the outflow
tract

Provides substrate for obstruction
SAM

51. SAM & ACSSAM & ACS
•Causes new murmur & can be confused
with VSDVSD or papillary muscle rupturepapillary muscle rupture
•Clinical Implications !!!Clinical Implications !!!
–Inotropes & Vasodilators will WORSEN the
shock & increase LVOT obstruction
–Control heart rate & decrease
hyperadrenergic & hypercontractile state –
use BB or Vasoconstrictors ( to increase
afterload) – like phenylephrine

52. Stress EchocardiographyStress Echocardiography
• SAM present in 8-35%SAM present in 8-35%
•Especially Dobutamine stress test*Especially Dobutamine stress test*
•Mostly caused by mid cavity obstruction Mostly caused by mid cavity obstruction
but may have SAM & LVOT obstructionbut may have SAM & LVOT obstruction
•Consensus is that the changes are due to
catecholamine effect rather than a
physiological response (like exercise)
* The Effect of Dobutamine Stress on Left Ventricular Outflow Tract Gradients in Hypertensive Patients.
ANGIOLOGY 2004 55: 295

53. Approximately two-thirds of
patients with symptomatic non-
obstructive HCM have latent LVOTO.
This study suggests that all patients all patients
with symptomatic non-obstructive with symptomatic non-obstructive
HCM should have exercise stress HCM should have exercise stress
echocardiographyechocardiography.

54. Ventricular under-filling
Altered ventricular and papillary muscle geometry
+ increased ventricular contraction and outflow
tract velocity
increase drag forces on the mitral valve leaflets
SAM
General anesthesia !!General anesthesia !!
Hypovolemia
Vasodilator
Effect
of drugs
Peri-operative hypotension

55. SAM after mitral valve surgerySAM after mitral valve surgery
•Up to 5% of mitral valve repair
•MechanismMechanism: anterior displacement of the mitral
coaptation point, shifting the mitral leaflets
towards the LVOT
•Increased risk if
–excess of redundant tissue in the posterior leaflet
–ratio of anterior leaflet length to posterior leaflet length
of less than 1.3
–Insertion of an annuloplasty ring

56. SAM after mitral valve surgerySAM after mitral valve surgery
•What to do in these cases?
–Discontinuation of inotropes.
–Give appropriate fluid therapy.
•Reassess

57. SAM: Take home pointsSAM: Take home points
•SAM of Mitral Valve can be present in conditions other
than HOCM with important clinical applications.
•Hypovolemia/ Increased adrenergic flow/ Vasodilators
can accentuate latent SAM.
•ECHO is useful in diagnosis.
•Management consists of
–Negative inotropes
–Avoid vasodilators
–Give fluids
–Increase Afterload.

58. Comments & QuestionsComments & Questions

59. 00548171