Hocm mpuh

Dr. Nilesh ParikhMD,PDCC

(Card.Anaes)

Consultant Anaesthesiologist

NADIAD

Anaesthesia for HOCM patient

Hypertrophic Obstructive Cardiomyopathy

Dr. Nilesh Parikh

Here is a patient named Kamlaben B Patel 85 yrs. Old,having # N/F, requring DHS Surgery.pt. is a known case of HTN Since 15 yrs. and she is taking Tab Amlodepine-Atenolol combination. Patient has been investigated and diagnosed to have HOCM by 2D ECHO., how would you proceed for this case?

Hypertrophic obstructive cardiomyopathy

Overview

• Background

• Pathophysiology

• Clinical picture

• Diagnosis

• Treatment

• Anesthetic consideration

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Hypertrophic Obstructive CardioMyopathy (HOCM) is a rare genetic disorder characterized by left ventricular outflow tract (LVOT) obstruction. Clinical presentation ranges from absence of symptoms to sudden death. These patients presents considerable challenges and requires maintenance of desired hemodynamic parameters and management of specific complications. Factors like Tachycardia, Hypovolemia, Vasodilation andincreased cardiac contractility leads to exacerbation of the obstruction. Decrease in venous return and SVR or increase in myocardial contractility worsens the LVOT obstruction. These patients are highly prone to arrhythmias like AF & VT Management of anesthesia in these patients poses considerable challenges for the anesthesiologist.

Background

Prevalence of HCM: 1:500 to 1:1000 individuals ○ This occurrence is higher than previously thought, suggesting

a large number of affected but undiagnosed people

Men affected by almost 2:1 ratio over women

Global disease with most cases reported from USA, Canada, Western Europe, Israel, & Asia

Most common cause of SCD, age < 40 yr

Most common cause of SCD, in competitive

athletes

Normal Anatomy

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Hypertophic cardiomyopathy (HOCM)

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Hypertrophic cardiomyopathy (HOCM)

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Pathophysiology of HOCM

Involves 4 interrelated processes:

– Left ventricular outflow obstruction

–Diastolic dysfunction

–Myocardial ischemia

–Mitral regurgitation

Pathophysiology

• 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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• 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 ischemia12

Pathophysiology

Symptoms:

Dyspnea on exertion (90%)

- Reduced diastolic relaxation & LV filling

Angina (70-80%) - Inadequate myocardial perfusion

Syncope (20%) - Vasovagal attack/ transient arrhythmias

Palpitation (10%) - AF

- Loss of atrial contribution in LV filling

- Rapid rate

- 50 % pts of AF manifests as systemic embolisation


• Lab studies:

– Blood test: non specific

– Genetic testing: for high risk group

• ECG:

– ST-T wave abnormalities

– LV hypertrophy, LA enlargement

– Axis deviation (left > right)

– Conduction abnormalities (P-R prolongation, BBB)

– A-fib (poor prognostic sign) 14

Electrocardiogram

LV strain pattern

LBBB/ RBBB / Lt ant hemiblock

ECG


• Two - Dimensional Echocardiography and Doppler

• MR and Mitral prolapse

• Flow velocity: > 4.0 m/s

• LV outflow gradient: > 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 hypertrophy17

X ray

Cardiomegaly

LA enlargement

Small aorta

Pulmonary edema

CXRHOCM

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Cardiac enlargement > 1/2 thoracic width


• 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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Medications

• Beta-Blockers: (Metoprolol, Propranolol, Atenolol, Sotalol )

• Calcium Channel blockers: (Verapamil)

• Antiarrhythmic: amiodarone and disopyramide

• Antitussives: avoid coughing

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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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Calcium Channel Blockers:

Verapamil

Improves symptoms and exercise capacity (patients without marked obstruction to LV outflow)

Beneficial effect on ventricular relaxation and filling

Better angina control than BB

Hemodynamic deterioration with CCB agents - lowering of the afterload in the presence of severe outflow tract gradients and high diastolic filling pressures


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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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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Anesthetic considerations 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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Anesthetic considerations

Inhalation Anesthetics

• Negative inotropy

• Decrease SAM-Septal contact

• Ideal for dose dependant myocardial depression

(Halothane > Enflurane > Isoflurane > Desflurane, Sevoflurane)

• Avoid hypotension due to underlying hypovolemia

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Regional anesthesia

• Relatively contraindicated

• Spinal should be avoided

• Epidural can be given

• Avoid bolus administration

• Avoid hypotension

• Replace intravascular volume

• Use Vasopressors like noradrenalineand phenylephrine

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IV Vasopressors

• Phenylepherine /Noradrenaline

– Low risk / high yield choice for hypotension

–Augment perfusion and CPP

–Decrease pressure gradient

– Increase vagal reflex

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Hypertrophic cardiomyopathy (HOCM)


• MR with HOCM

Inotropes and Vasodilators worsen ventricular ejection

Vasoconstrictors improve ventricular ejection

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Here is a patient named Kamlaben B Patel 85 yrs. Old,having # N/F, requring DHS Surgery.pt. is a known case of HTN Since 15 yrs. and she is taking Tab Amlodepine-Atenolol combination. Patient has been investigated and diagnosed to have HOCM by 2D ECHO., how would you proceed for this case?

What would we the choice of Anaesthesia?

? Spinal? Epidural? General anaesthesia

I planned Epidural for this patient.Pt.taken in OT. Venous access with two peripheral lines. Oxygen started and connected with monitor. First dose inj.xylocaine 2% 15 cc given. Sooner after this dose, inj. Noradrenaline infusion started @

1ml/hr.(4mg/50cc)It was incresed to 2ml/hr.as per need. (dose of Norad. is 0.04-0.4 mcg/kg/min) IV fluids inj.Hydrxyethyl starch 500 ml and one unit of Blood. Oxygen @3-4 lit/min given continuously. inj.Antibiotic, patoprazole, ondansetron given. Second dose of Epidural inj.Bupivacaine 3 cc given. Patient remained stable intra and post op. Shifed to ICU ,Where oxygen continued with monitoring. Patient’s vitals were as follow:

TIME HEARTRATE

SYSTOLICBP

DIASTOLICBP

SPO2%

8:28 am 56 153 58 93

8:33 54 154 58 99

9:10 58 116 42 98

9:23 57 107 38 98

9:33 53 111 39 98

9:43 52 108 39 99

9:53 54 129 40 99

10:03 54 148 44 100

10:13 55 158 45 100

10:23 54 156 45 99

11:30 55 158 50 99

Vital parameters of patient : HOCM-DHS 10/1/2013

Comments: Any patient with HTN and ECG changes always get cardiac evaluation done.

Patients with HOCM ,presenting for surgery where regional anaes. is preferred,Always maintain Hemodynamics with vasopressors and fluids. Don’t give any Inotropic or chronotropic agents.

Keep Defibrillator available ,as pts. are highly prone for Arrythmias.

Pt’s preload should be maintained adequetely.

Thank you

spinal

EPIDURAL

G/A TAKE CARE OF ME

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Date post:	04-Jul-2015
Category:	Health & Medicine
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