Cardiomyopathy – anaesthetic challenges

Dr. S. Parthasarathy MD., DA., DNB, MD (Acu),

Dip. Diab. DCA, Dip. Software statistics, Phd (physio)

Mahatma Gandhi Medical college and research institute puducherry , India

Definition

• Cardiomyopathies are diseases of the heart muscle and

may present with cardiac dysfunction

• Classification

• Dilated

• Obstructive (HOCM)

• Restrictive

• Dilated cardiomyopathy (DCM) is defined by a large

heart cavity with impaired systolic function of one or

both ventricles.• (a). Fractional myocardial shortening < 25% and/or

ejection fraction < 45%; and • (b). left ventricular end diastolic diameter > 117%

Pathophysiology- systolic dysfunction

• Global reduction in myocardial contractility• Decreased LV ejection fraction • LV dilates • Increased LVEDV • Frank starling law – better contraction • Compensation fails • LVF• Diastolic dysfunction is trivial

Treatment

• sickle cell disease, muscular dystrophy, excess alcohol, hypothyroidism, and some chemotherapy agents

• Treat the cause if any• Warfarin ?? • Along with cardio active drugs

Clinical features

• fatigue,hypotension oliguria

• Pulmonary edema , orthopnea

• Ascitis ,Edema

• AV ring dilation and regurgitation

• Arrhythmias, LBBB and poor progression,

• ECHO

Forward failure

Backward failure LV / RV

Treatment

• ACE inhibitors • ARBs • Diuretics• Other therapies include beta-blockers, spirono

lactone, digoxin, biventricular pacing, and anticoagulants.

• Medical treatment –control of CCF - > 1 week.

Anaesthetic concerns 1) Myocardial depression should be avoided

2) normovolemia should be maintained

3) Avoid overdose of drugs during induction as

circulation time is slow.

4) Ventricular after load is avoided

5) Avoid sudden hypotension when regional

anaesthesia is a choice

Preoperative check up

• History and findings of CCF • Routine • ECHO – EF <25% , Regurgitant lesions- danger

signs • ACE inhibitors stop ?? • Electrolytes • Volume status , continue anti aryhthmics• Anxiolysis

Anaesthetic concerns

• Volume ( spinal . 10 % fall is significant in DCM ) • Rhythm ( ECG monitoring and control) • Less inhalational agents – more narcotics • Ketamine , etomidate in ideal doses • CVP – OK ?? Only RV preload• TEE • PAC – worth but outcomes similar !! • Hemoglobin

• Interest has been generated regarding use of xenon

in patients with DCM, because of its minimal effect

on heart rate, arterial and LV pressures, myocardial

contractility, and regional chamber stiffness

Postoperative period

• Post operative HDU • Oxygenation • volume • RA to counter pain • Anti arrhythmic to continue

Peripartum cardiomyopathy (PPCM)

• Peripartum cardiomyopathy (PPCM) has an incidence of 1 in

4000 live births, and has a quoted mortality of between

20% and 50%.

• PPCM usually presents post 36 weeks but may develop for

up to 5 months postpartum.

• It may recur in subsequent pregnancies;

• cardiology assessment should be performed prior to further

conceptions.

PPCM ( PCM) It is a diagnosis of exclusion.

• an idiopathic cardiomyopathy presenting with heart

failure secondary to left ventricular systolic

dysfunction towards the end of pregnancy or in the

months following delivery, where no other cause of

heart failure is found.

• The left ventricle may not be dilated but the ejection

fraction is nearly always reduced below 45%.

What is PPCM ??

• Non ischemic dilated cardiomyopathy

How does it happen ??

• 1 in 3000 – 4000 births

• Auto antibodies against fetal cells – myocardium• abnormal cardiac response to hemodynamic

changes associated with pregnancy. • Proinflammatory cytokines • Coronary microangiopathy

• Almost same symptoms • ACE inhibitors ?? • Amlodepine .diuretics, digoxin -- ok • LMWX – heparin OK • Levosimendan is used as an intravenous

infusion at the rate of 0.1–0.2 μg/kg/min in cardiac failure with or without a loading dose of 3–12 μg/kg over 10 minutes

Anaesthetic technique • Controlled GA with RSI, diuretics after delivery,

avoidance of methergin • Fetal safety • CSEA • Spinal bupi fentanyl • -- beware of anticoagulation • Epidural volume extension technique – • 1 ml spinal bupi + epidural saline 10 ml.

• Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy

• Hypertrophic cardiomyopathy (HCM) is an autosomal dominant condition.

• unexplained left ventricular hypertrophy which may be concentric or asymmetrical, diffuse or focal.

• Syncope, failure , hypotension

Hypertrophy of LV

Diastolic dysfunction and defective relaxation

Atrial kick needed

Increased LVEDP – CPP ?

Hypertrophied ventricle and more oxygen needed – ischemia

Increased contraction – LVOT obstruction – MR

HOCM

Anaesthetic concerns

• maintenance of sinus rhythm;• reduction in sympathetic activity to reduce

chronotropy and inotropy;• maintenance of left ventricular filling;• the maintenance of systemic vascular

resistance.

Morphine , atracurium

• Symptomatic patients

• Major surgery

• IBP, TEE included

Chamber size (DCM) Vs

Wall thickness (HOCM)

Cardiac arrest in HCM

• The use of inotropic agents is contraindicated if the

arrest is thought to be due to LVOT obstruction as

this will only increase the obstruction.

• Alpha -Agonists, i.v. fluids, and rapid correction of

arrhythmias are more appropriate measures.

• The application of external defibrillator pads is

recommended before induction of anaesthesia.

Use vasopressors than inotropes in HOCM

• Restrictive• cardiomyopathy

Restrictive cardiomyopathy

• Endomyocardial fibrosis • Idiopathic

• Amyloidosis, sarcoidosis, haemachromatosis, and eosinophilic endocarditis

What happens ??

• Diastolic dysfunction • Both LV and RV-- but RV more • Normal systolic function • No enlargement• Elevated pressures and backward failure

Goals

• to maintain adequate filling pressures;• sinus rhythm to be maintained if possible;• to manage electrolyte disturbances;• to maintain SVR in the presence of relatively

fixed cardiac output.

Cardiac grid

• We have to understand

the basic of ragaa and

tune our technique to

suit the disease and

surgery

Arrhythmogenic Right Ventricular Cardiomyopathy

• progressive fibro fatty replacement of RV

myocardium, initially with typical regional and later

global RV and some LV involvement, with relative

sparing of the septum.

• CHF and arrhythmia are the factors

Thank you all !!

Understand the principles