Hypertrophic Obstructive Cardiomyopathy (Case Presentation)

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Hypertrophic Obstructive Cardiomyopathy(Case
Presentation)

• Ashraf Andrawis, MD
• Norman Bolden, MD
• Metrohealth medical center- CWRU
• Department of anesthesiology

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History (1)

• 35 YO Hispanic female, 37 weeks pregnant
  Presented to OB ward on 02/ 2002 for OB f/u
• H/O syncope Pt. Collapsed at home during last
  pregnancy, required emergency C/S, had
  complicated postoperative course, required ICU
  admission and CVP monitoring for 1 week
• HOCM (IHSS) diagnosed
• Cardiology recommendation to avoid future
  pregnancy and permanent sterilization

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History (2)

• CP and chest heaviness (like baby sitting on my
  chest)
• SOB when doing household activities and when
  laying flat (use 3 big pillows or sleeping in a
  chair)
• Atypical CP
• Required hospital admission X 2 during pregnancy
• CCU admission (11/01) to R/O (PE / MI), heparin
  24 h, negative serial ECG and cardiac enz. And
  V/Q scan.
• O/B H/R admission (01/02) to R/O (MI / CHF)
• Heaviness of Lt. Shoulder and Lt. Arm with
  exertion
• Nausea and palpitations when walking

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History(3)

• PMHx
• Anxiety
• HOCM (IHSS) diagnosed 2000
• OBHx
• 37 Weeks Pregnancy, G6P3023, EDD 02/27/02
• PSHx
• Ectopic pregnancy 1987
• Therapeutic abortion 2000
• C- section ?
• 1985 ? child with spina bifida
• 1997 ? child with heart murmur
• 2000 ? child with heart murmur

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Physical

• V.S BP 112/67, HR 83, RR 20
• Wt 119 Kg, Ht 6 Ft
• HEENT PEERL, EOMI
• MP class 2, TMD 5 cm, mouth opening 3FB, good
  neck mobility, and own dentition
• Lungs CTA B/L
• Heart ejection systolic murmur grade 3/6 at Lt.
  sternal border radiates to the base and the
  apex, no JVD, no Gallop
• Neurological AAO x 3, non focal
• ASA class 3

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Labs and studies (1)

• CK-MB 1.0
• Fetal lung maturity 77.3
• CXR slight cardiac enlargement, no infiltrate

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(No Transcript)
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Labs and studies (2)

• Transthoracic echocardiogram on 01/24/2002
• Left ventricular systolic function EF 65,
  hyperdynamic
• Right ventricular systolic function normal
• Valves
• AR mild
• MR , PR trivial
• PAP 34/12
• Subaortic stenosis with fibrocalcific changes,
  peak gradient 70 mmHg, mean gradient 41 mmHg
• Compared to prior study dated 11/08/01
• (peak gradient 90, mean gradient 60)

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Chronology

• Feb. 06, 2002 Preoperative assessments, chart,
  cardiology consult and echocardiography results
  reviewed, Anesthesia plan D/W Pt.
• Feb. 07, 2002
• At 0930 AM, pt to OR, standard 5 ASA monitors
  applied
• 18 G IV Line, Right Radial A-line and Right IJ 9
  Fr introducer placed, SG catheter placed,
  wedge at 49 cm, no complication
• Defibrillator pads applied to treat possible
  arrhythmia
• Left uterine displacement applied
• Initial VS BP 130/70 HR 80 CVP 11
  PA 22/11 CO 4.6 SVO2 72

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Intraoperative Management

• 1215 PM Smooth IV rapid sequence induction with
  Sux 120 mg, STP 350 mg, ETT 7 placed, ETCO2
  BS B/L
• IVF bolus maintenance fluid given to keep CVP
  11-15 cmH2O
• Surgery started at 1222
• Maintenance of anesthesia Enflurane 0.6-0.8, N2O
  
• Labetalol ,Esmolol, Fentanyl titrated to keep BP
  130-140/60-70 and HR 70-90
• Total IVF 3000 cc, EBL 1200 cc, UOP 300ml
• Delivery Of fetus at 1229
• Surgery end at 1322
• Pt. successfully extubated ? high risk unit then
  to CCU
• Postop VS HR 97 BP 140/75 CVP 15
  
  PA
  49/25 CO 4.5 SVO2 70
• Postoperative course stable, Pt. D/C home POD
  4

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Hypertrophic obstructive cardiomyopathy Overview

• Background
• Pathophysiology
• Histology
• Clinical picture
• Diagnosis and Differential
• Treatment
• Anesthetic consideration
• Therapeutic approach of pregnant Pt. With HOCM

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Hypertophic cardiomyopathy (HOCM)Background

• Genetic disorder
• Autosomal dominant with variable penetrance
• Molecular basis
• Defect in sarcomeric protein genes as myosin
  heavy chain, actin, tropomyosin
• Abnormal myocardial Ca kinetics
• Increase Ca intracellular ? hypertrophy and
  cellular disarray
• Other terms
• Idiopathic hypertrophic subaortic stenosis (IHSS)
• Asymmetric septal hypertrophy (ASH)
• Leading cause of sudden death in preadolescent
  and adolescent

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Hypertophic cardiomyopathy (HOCM)Pathophysiology
(1)

• Hypertrophy in any region of left ventricle
• SAM systolic anterior motion of anterior MV
  leaflet against hypertrophic septum (Bernoulli
  effect)
• dynamic pressure gradient across LV outflow
  tract
• midsystolic intraventricular obstruction of the
  flow
• SAM - Septal Contact ? dynamic obstruction
  increased by
• ? afterload
• ? preload
• ? contractility

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Hypertophic cardiomyopathy (HOCM)Pathophysiology
(2)

• Diastolic Dysfunction
• Due to prolongation of isovolumic relaxation time
  (AV closure to MV opening)
• ? LV filling pressure
• ? Ventricular volume
• Atrial contribution to ventricular filling 75
• Poor Compliance
• ? LVEDP for any LVEDV
• ? CPP gradient
• Subendocardial ischemia

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Normal Anatomy
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Hypertophic cardiomyopathy (HOCM)
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Hypertophic cardiomyopathy FACTS

• Sex Male gt female (younger, more symptomatic)
• Age
• Most common in 30s - 40s
• Most common autopsy finding in previously healthy
  athletes
• Recent study, elderly with severe mitral annular
  calcification ? sub-aortic obstruction
• Frequency
• 0.5 of outpatient population
• Prevalence 0.05-0.2
• 25 of first degree relative

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Hypertrophic cardiomyopathy (HOCM) FACTS

• Morbidity / Mortality
• Sudden death younger Pt., aggressive genotype
• Arrhythmia A- fib, A- flutter, v-tach. or v-fib
• CHF MR and diastolic dysfunction
• Angina adults gt children
• Syncope and pre-syncope

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Hypertrophic cardiomyopathy (HOCM)
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Hypertophic cardiomyopathy (HOCM)Histologic
Findings (1)
Gross disorganization of the muscle bundles and
myofibrillar disarray
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Hypertophic cardiomyopathy (HOCM)Histologic
Findings (2)

• Abnormal intramural coronary arteries (see arrow)
  
• Reduction in the size of the lumen
• Thickening of the vessel wall
• 80 of cases

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Hypertophic cardiomyopathy (HOCM)

• Dizziness
• ? by
• Exertion
• Hypovolemia
• Maneuver (rapid standing or valsalva)
• Medication (diuretics, NTG and Vasodilator Meds)
• Arrhythmia ? hypotension ? decrease cerebral
  perfusion
• Dyspnea
• Most common symptom, 90
• ? Lt Ventricular Diastolic filling pressure ? ?
  PAP
• Orthopnea and Paroxysmal Nocturnal Dyspnea
• Pulmonary venous congestion
• Early signs of CHF

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Hypertophic cardiomyopathy (HOCM)

• Angina
• Common with no CAD
• Impaired diastolic relaxation ? MVO2 ?
  Sub-endocardial ischemia
• ? Capillary density leads to ? flow to
  hypertrophic muscle
• Extramural compression of coronaries
• ? Systolic ejection time leads to ? diastolic
  interval for coronaries perfusion
• Syncope and pre-syncope
• Very common
• ? CO with exertion or arrhythmia
• High risk of sudden death
• Urgent work-up and aggressive treatment

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Hypertophic cardiomyopathy (HOCM)

• Palpitation
• Ventricular Arrhythmia 75
• SVT 25
• A- fib 5-10
• Sudden cardiac death (SCD)
• 6 in children
• Related to extreme exertion
• MCC of SCD is arrhythmia
• 80 V-fib

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Causes of Ischemia in HOCM

• ? Myocardial muscle mass
• ? Myocardial oxygen demand (? wall stress)
• ? Diastolic filling pressures
• ? Coronary capillary density
• ? Vasodilatory reserve
• Abnormal intramural coronary arteries
• ? Systolic compression of coronary arteries

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Hypertophic cardiomyopathy (HOCM)Physical (1)

• Double apical impulse
• Forceful left atrial contraction against
  non-compliant ventricle
• Triple apical impulse
• Late systolic bulge near isometric contraction
• S1 normal
• S2 normal or paradoxical split
• S3 gallop decompensated Lt. ventricle
• S4 atrial systole against hypertrophic ventricle
• Jugular venous pulse prominent a- wave
• Double carotid arterial pulse declines in mid
  systole as gradient develop

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Hypertophic cardiomyopathy (HOCM)Physical (2)

• Systolic Ejection Murmur Crescendo - Decrescendo
• Between apex and left sternal border
• Radiate to suprasternal notch
• ? by
• ? Preload (volume loading)
• ? Afterload (vasopressor)
• ? by
• ? Preload (nitrates, diuretic, standing)
• ? Afterload (vasodilator)

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Hypertrophic cardiomyopathy (HOCM)Physical (3)

• Holosystolic Murmur of MR
• Retrograde ejection of blood flow into low
  pressure left atrium
• Best heard at apex and axilla
• Pt. with SAM and significant LV outflow
  gradients
• Diastolic Decrescendo Murmur of AR 10 of Pt.
• Systolic anterior motion

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Hypertophic cardiomyopathy (HOCM)

• Lab studies
• Blood test non specific
• Genetic testing for high risk group
• ECG
• ST-T wave abnormalities
• LV hypertrophy, LA enlargement
• Axis deviation (left gt right)
• Conduction abnormalities (P-R prolongation, BBB)
• A-fib (poor prognostic sign)

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Hypertophic cardiomyopathy (HOCM)

• Two - Dimensional Echocardiography and Doppler
• MR and Mitral prolapse
• Flow velocity gt 4.0 m/s
• LV outflow gradient gt 50 mm Hg
• EF high to normal
• Small LV cavity
• Left atrial enlargement
• Septal thickness 4-6 mm thicker than normal
• The hallmarks
• SAM of Mitral valve
• Asymmetric septal hypertrophy

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Two- Dimensional Echocardiography
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Two- Dimensional Echocardiography
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Hypertophic cardiomyopathy (HOCM)

• Radionuclide study
• Absence of CAD
• Defects of myocardial perfusion
• Cardiac catheterization
• Degree of outflow obstruction
• Diastolic characteristics of the left ventricle
• LV anatomy
• Coronary arteries anatomy
• Holter monitoring
• Nonsustained atrial or ventricular arrhythmia /
  24 h

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HOCM
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Left-Side Cardiac Pressures

• Aortic upstroke rates
• Delayed
• supravalvular AS
• valvular AS
• subvalvular AS
• Rapid and parallel to the LV pressure
• HOCM
• (From Criley JM, Siegel RJ Subaortic stenosis
  revisited The importance of the dynamic pressure
  gradient. Medicine 72412, 1993.)

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CXR HOCM
Cardiac enlargement gt 1/2 thoracic width
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Hypertophic cardiomyopathy (HOCM)Differential
Diagnosis

• Aortic Stenosis
• Restrictive Cardiomyopathy
• Glycogen Storage Disease, Type 2

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Hypertophic cardiomyopathy (HOCM)

• Goals
• ? Ventricular contractility
• Myocardial depression
• ? Ventricular volume
• Volume loading
• ? Ventricular compliance and outflow tract
  dimensions
• ? Pressure gradient across the LVOT
• Vasoconstriction

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Hypertophic cardiomyopathy (HOCM) Medical Care

• Activity
• Avoid Competitive level sports when
• Significant outflow gradient
• Significant arrhythmia
• Marked LV hypertrophy
• History of sudden death in relatives
• Identified malignant genotype

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Hypertophic cardiomyopathy (HOCM) Medical Care

• The purpose of pharmacologic therapy
• ? Inotropic state of left ventricle
• ? ? pressure gradient
• ? Compliance of the Lt.Ventricle
• ? Diastolic dysfunction

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Hypertophic cardiomyopathy (HOCM) Medications

• Beta-Blockers (Metoprolol, Propranolol,
  Atenolol, Sotalol )
• Calcium Channel blockers (Verapamil)
• Antiarrhythmic amiodarone and disopyramide
• Antitussives avoid coughing
• Antibiotic prophylaxis against endocarditis
• Anticoagulation Atrial fibrillation

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Hypertophic cardiomyopathy (HOCM) Beta -
blockers

• ? Pressure gradient across LVOT
• ? Inotropic state of left ventricle.
• ? Diastolic dysfunction
• ? Lt. Ventricle compliance
• ? HR
• ? Myocardial oxygen consumption
• ? Myocardial ischemia potential

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Hypertophic cardiomyopathy (HOCM)
Antiarrhythmics

• Amiodarone (Cordarone)
• To date,
• Only one pharmacological agent, has been shown
  to reduce the incidence of arrhythmogenic sudden
  cardiac death

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Hypertophic cardiomyopathy (HOCM)
Contraindication

• Inotropic
• Sympathomimetic
• Nitrates
• Except in patients with CAD
• Digitalis
• Except with uncontrolled A-fib.
• Diuretics
• ? Preload and ventricular volume
• ? Outflow gradient

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Hypertrophic cardiomyopathy (HOCM) Surgical Care
(1)

• Mitral Valve Replacement
• Catheter septal ablation
• 96 ethanol infusion of LAD to destroy
  myocardial tissue
• Left ventricular myomectomy or septal myotomy
• Indications
• severe symptoms refractory to medical therapy
• outflow gradient gt50 mm Hg
• Verapamil (improve diastolic) and myomectomy
  (improve systolic)
• 2 mortality overall
• Retrospective study survival rate higher with
  surgical treatment

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Hypertrophic cardiomyopathy (HOCM)
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Hypertophic cardiomyopathy (HOCM) Surgical Care
(2)

• Implantable Cardioverter Defibrillator (ICD)
• Prevents sudden death
• Automatically detects, recognizes, and treats
  arrhythmia
• Many prospective studies
• In adults with CAD and ? EF, the ICD has been
  demonstrated
• to be superior to antiarrhythmic drug therapy

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Hypertophic cardiomyopathy (HOCM) Anesthetic
considerations (1)Pre-operative period

• Pre-medication
• Avoid anxiety producing tachycardia
• ?-blocker and/or Ca channel blocker
• Continue untill the day of surgery and
  postoperative
• Avoid arrhythmia
• Aggressive treatment of arrhythmia
• Antiarrhythmic Meds
• Cardioversion
• Maintain adequate intravascular volume and
  preload

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Hypertophic cardiomyopathy (HOCM) Anesthetic
considerations (2) Intra-operative Monitoring

• Contractility and HR avoid direct or reflex
  increase
• Arterial BP
• Avoid hypotension
• Bifid shape waveform "spike-and-dome"
• CVP high normal - elevated / vasoactive meds.
• PAC
• PCWP high normal - elevated
• Overestimates pt. true volume status
• PAC with pacing capability
• CPP use vasoconstrictor / avoid inotropes

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Hypertophic cardiomyopathy (HOCM) Anesthetic
considerations (3) Inhalation Anesthetics

• Negative inotropy
• Decrease SAM-Septal contact
• Ideal for dose dependant myocardial depression
• (Halothane gt Enflurane gt Isoflurane gt Desflurane,
  Sevoflurane)
• Avoid hypotension due to underlying hypovolemia

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Hypertophic cardiomyopathy (HOCM) Anesthetic
considerations (4) Regional anesthesia

• Relatively contraindicated
• Continuos spinal/epidural
• Avoid bolus administration
• Avoid hypotension
• Replace intravascular volume
• Vasopressor

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Hypertophic cardiomyopathy (HOCM) Anesthetic
considerations (5) IV Vasopressors

• Phenylepherine
• Low risk / high yield choice for hypotension
• Augment perfusion and CPP
• Decrease pressure gradient
• Increase vagal reflex

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Hypertrophic cardiomyopathy (HOCM) Anesthetic
considerations (6)

• MR with HOCM
• Inotropes and Vasodilators worsen ventricular
  ejection
• Vasoconstrictors improve ventricular ejection

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Hypertophic cardiomyopathy (HOCM) Pregnancy

• Reported 100 pregnancies in patients with HOCM
• Favorable outcome in most cases
• New onset or worsening CHF reported in 20 of
  cases
• SVT and A - fib. with fetal distress reported,
  leading to hemodynamic deterioration and
  direct-current cardioversion
• Sudden death in one Pt. at 28 weeks
• Fetal outcome in most cases is not affected by
  maternal HOCM

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Hypertophic cardiomyopathy (HOCM) Therapeutic
Approach of Pregnancy

• Indications for drug therapy during gestation
  include
• Arrhythmias
• Elevated left ventricular filling pressure
• beta - blocker and calcium antagonists
• Dual-chamber pacing
• before pregnancy in symptomatic patients.
• ICD
• syncope or life-threatening arrhythmias

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Hypertophic cardiomyopathy (HOCM) Therapeutic
Approach of Pregnancy

• Induction of labor
• Prostaglandin ? risky because of vasodilator
  effect
• Oxytocin ? well tolerated
• Tocolytic agents
• ?-agonist ? LVOT obstruction
• MgSO4 is preferred
• Avoid
• Blood loss
• Vasodilators
• Sympathetic stimulation

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Hypertophic cardiomyopathy (HOCM) Therapeutic
Approach of Pregnancy

• Continous spinal and epidural anesthetics
• Avoid vasodilator effect by bolus administration
• Antibiotic prophylaxis
• higher risk for infective endocarditis

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Thank You ,

• The End