cardiomyopathy & anaesthesia

CARDIOMYOPATHY & ANAESTHESIA DR. ABHIJIT S. NAIR Consultant Anaesthesiologist, Basavatarakam Indo-American Cancer Hospital & Research Institute, Hyderabad.

Cardiomyopathy = heart muscle disease

EXTRINSIC

INTRINSIC

SYSTOLIC

DIASTOLIC

• deterioration of the function of the myocardium for any reason • Risk of dysrhythmias or sudden cardiac death

Pathophysiology • Systolic dysfunction • Diastolic dysfunction

TYPES:  Dilated: • Ischemic, valvular • Non-ischemic infections, chemotherapeutic agents, drug abuse, alcohol, peripartum, hypothyroidism, Sickle cell disease, Muscular dystrophies Hypertrophic:(septal hypertrophy-idiopathic hypertrophic, Secondary to Hypertension) Restrictive Takotsubo

DCM

Infections • • • • • • • •

HIV Coxsackie virus CMV Toxoplasmosis Chagas’ disease Trichinosis Leptospirosis Lyme disease

Abuse • • • •

Alcohol Cocaine Methamphetamines Heroin

Drug induced

Anthracyclines

A drop in LVEF of >10% or to 30 mm) • Unexplained syncope • Non-sustained VT

HOCM

Management • • • •

Beta blockers Anti-Arrhythmics AICD Myomectomy

LVOTO • Common at IVS • dynamic LVOTO in sub-aortic region during systole • exacerbated when there is under filling of LV with forceful sub-aortic narrowing • velocity of blood in the outflow tract draws the anterior mitral valve leaflet towards IVS • SAM: Anterior leaflet pulled from posterior MV leaflet—> obstruction

Anaesthesia goals • Sinus rhythm • Low heart rate • Reduction in sympathetic activity to reduce chronotropy and inotropy • Maintain LV filling • maintenance of SVR • Invasive monitoring

• “ Defibrillator paddles throughout surgery”

Alerts/ contraindications • Inotropic agents : if the arrest is thought to be due to LVOT obstruction as this will only increase the obstruction • Regional Anaesthesia • Vasodilators

Restrictive • • • • • •

Idiopathic Endomyocardial fibrosis Amyloidosis(common) Sarcoidosis Haemachromatosis Eosinophilic endocarditis

Presentation • SOB • Biventricular dysfunction( Diastolic more common) • Low volume pulse • Regurgitant murmurs • IIIrd heart sound

Management • Lower the elevated filling pressures caused by low ventricular compliance without reducing cardiac output • ACEI or β-blockade/ diuretics • Anti-arrhythmics • Anticoagulants • Disease modifying drugs • Heart transplantation!

Cardiac Resynchronization Therapy

Alerts • Digoxin relatively contraindicated in amyloidosis ( arrhythmogenic) • Cardioversion of patients in AF : complete heart block due to existing intrinsic pacemaker damage

Anaesthesia goals: • • • •

Adequate filling pressures Sinus rhythm Manage electrolyte disturbances Maintain SVR in the presence of relatively fixed cardiac output • KETAMINE!

Anaesthesia & RCM • vasodilatation, myocardial depression, reduced venous return, IPPV: Compromises CO • Spontaneous respiration desirable

Takotsubo cardiomyopathy • Transient, reversible, left ventricular dysfunction causing severe hypotension and can mimic an acute coronary event

Described by Sato et al in 1990

CAG: Normal

Management: • • • • •

No evidence-based guidelines Supportive Beta blockers, ACE inhibitors, diuretics Anticoagulation Possibility of recurrence in similar situation

Conclusion • • • • • • • •

Understand the pathology Avoid worsening of heart function Sinus rhythm Invasive monitoring Electrolyte imbalance/ arrhythmia Judicious use of vasopressor / inotrope Multimodal analgesia Look for DIASTOLIC DYSFUNCTION