Critical Case ConferenceCritical Case Conference

Gagan Kumar MDGagan Kumar MD

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.

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

Family historyFamily history

• Mother: HTN, CAD (died at 94)

• Father: melanoma

• Social history:– 5 pack years, quit 1972– No EtOH– Retired homemaker

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.

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 probablyunderestimated 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 notappear 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.

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

Vitals 1/30/2011Vitals 1/30/2011

EKG on admission 1/26/2011EKG on admission 1/26/2011

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

I&OI&O

LabsLabs

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 101Of)

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

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

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?

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

AnatomyAnatomy

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

AnatomyAnatomy

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

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

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

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

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’

What accentuates SAM?What accentuates SAM?

• Decreased preloadDecreased preload– Dehydration– Orthostasis – Valsalva

• Decreased afterloadDecreased afterload– Vasodilators

• Increased LV ionotropyIncreased LV ionotropy– Fever / Exercise / Dobutamine

Clinical findingsClinical findings

• On examination: – LV heave

– S1 normal; S2 paradoxical splitting; S4

– Systolic ejection murmur – left sternal border– Increases with valsalva, vasodilators– Decreases with squatting, vasopressors

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

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.

M – mode ECHOM – mode ECHO

time

ECG

Hemodynamics in HCM with fixed Hemodynamics in HCM with fixed left ventricular outflow obstructionleft ventricular outflow obstruction

LVLVOT Aorta

HCM with variable left ventricular HCM with variable left ventricular outflow tract obstructionoutflow tract obstruction

LVOT LVOT gradientgradient

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).

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

Hemodynamic consequencesHemodynamic consequences

• Diastolic dysfunction

• Prolongation of systolic ejection

• Reduction in stroke volume

• Disrupts MV functioning MR

• Microvascular dysfunction

• Intolerant to tachyarrythmias

Medical TreatmentMedical Treatment

• Negative ionotropes –Negative ionotropes –Decrease LV ejection acceleration

↓Decrease hydrodynamic force on mitral valve

↓Decreased feedback loop

ββ-blockers-blockersDisopyramideDisopyramide VerapamilVerapamil

Medical TreatmentMedical Treatment

• Start with ββ-blockers-blockers : – prolonging diastole prolongs filling time. But

doesn’t decrease LVOT gradient.

• VerapamilVerapamil: causes vasodilation.

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.

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

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.

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%

Schematic Diagram of Alcohol Septal Ablation

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.

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

‘‘SAM’ in common situationsSAM’ in common situations

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

SAM & HTNSAM & HTN

• Implications??– Vasodilators may increase SAM & LVOT

obstruction

– Negatively ionotropes have beneficial effects

SAM & DiabetesSAM & Diabetes

• In poorly controlled diabetics (HbA1c > 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

SAM & ACSSAM & ACS

Compensatory hyperkinesis in non-infarcted ventricular segments

Reduced systolic diameter of the outflow

tract

Provides substrate for obstruction

SAM

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

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

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.

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 drugsPeri-operative hypotension

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

SAM after mitral valve surgerySAM after mitral valve surgery

• What to do in these cases?– Discontinuation of inotropes.– Give appropriate fluid therapy.

• Reassess

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.

Comments & QuestionsComments & Questions

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