Cardiomyopathies PDF

THE CARDIOMYOPAT HIESDR. A. T. ADENIYI Consultant Paediatrician/ Lecturer EKSUTH/EKSU  INTRODUCTION An array of disorders cardiac muscle of myocardial structure and functions Defined by the European Cardiac Society as; “a myocardial disorder...

THE CARDIOMYOPAT HIESDR. A. T. ADENIYI Consultant Paediatrician/ Lecturer EKSUTH/EKSU  INTRODUCTION An array of disorders cardiac muscle of myocardial structure and functions Defined by the European Cardiac Society as; “a myocardial disorder in which the heart muscle is structurally and functionally abnormal, in the absence of coronary artery disease, hypertension, valvular disease and congenital heart disease sufficient to cause the observed  INTRODUCTION Classified on the basis of aetiology into  Idiopathic  Primary  Secondary Classified on the basis of the predominant abnormality into Dilated Hypertrophic Restrictive Arrythmogenic right ventricular dysplasia SECONDARY CAUSES OF CM Secondary causes of CM include Viral myocarditis Endocrine disorders Metabolic disorders Nutritional deficiencies Drugs Hypersensitivity reactions  DILATED CARDIOMYOP ATHY  Epidemiology The most common form of cardiomyopathy in children Incidence is poorly defined in African children In developed countries, incidence is estimated to be 0.57 – 1.23/ 100,000 per year in children below 18 years affects all age groups In children, it’s more commonly diagnosed below 2 years of age in developed countries; averagely at 5 years in developing countries  The major abnormality is the dilatation of the ventricles, more prominently the left There is poor ventricular contractility, impaired systolic function and reduced ventricular wall thickness The LV systolic dysfunction is variable and progressive The dysfunction may involve the cardiac conducting system It is familial in 20-50% of cases When familial, can be inherited as AD (most common), AR, X-linked and mitochondrial  Aetiology of DCM Unknown in most cases Thought to be a common result of myocardial damage from many causes Etiologic factors include  viral illnesses: coxsackie B, measles, HIV, T. gondii, trypanosomiasis,  Nutritional deficiencies: thiamine, selenium, carnitine  Alcohol  Drugs: doxorubicin, anthracycline antibiotics  Endocrine disorders: hyperthyroidism, hypothyroidism, diaetes mellitus, phaeochromocytoma  Familial  Metabolic: haemosiderosis Pathophysiology of DCM  Clinical Features Heart failure Arrhythmia Thromboembolic events Sudden cardiac death Recurrent chest infections Exercise intolerance/ easy fatiguability  Irritability Poor growth, failure to thrive Weak peripheral pulses Narrow pulse pressure Displaced, diffuse apex beat  Investigations CXR Echocardiography ECG Genetic studies Cardiac MRI Endomyocardial biopsy Cardiac catheterization  Management Manage heart failure  Frusemide  ACE Inhibitors (captopril) are mainstay of management of HF  Inotropics: digoxin, dobutamine, milrinone  Beta blockers Manage cardiac arrhythmia: class III drugs Anticoagulants: warfarin, low dose heparin, aspirin, clopidrogel Heart transplant is the ultimate  Partial left ventriculectomy Left ventricular assist devices Multisite ventricular pacing  Prognosis Generally poor without cardiac transplant Death usually results from intractable heart failure, arrhythmia and thromboembolism HYPERTROPHIC CARDIOMYOPAT HY  Introduction Characterised by increased wall thickness in the absence of other recognisable causes (CoA, AoS, systemic HTN) Constitutes about 35 – 40% of paediatric CM Most often diagnosed in infancy and adolescence Family history is found in 50 – 60% of cases. Usually affects the LV; may infrequently affect the RV  Pathophysiology Characterized by disarray of the cardiac myofibrils and myofilaments, and sometimes fibrosis Diminished myocardial compliance with diastolic dysfunction Systolic function is preserved; may be hyperdynamic There may be asymmetric hypertrophy of the IVS and MV insufficiency  Pathophysiology Associated LV outflow tract (LVOT) obstruction – HOCM Increased O2 demand by hypertrophied myocardium results in progressive myocardial ischaemia Hypotension may occur during exercise as a result of reduced LV filling and SV Progressive atrial enlargement results from reduced compliance  Aetiology Genetic: AD inheritance Infant of diabetic mothers Neuromuscular disorders Inborn errors of metabolism (Pompes disease) Syndromic: Noonan, Beckwith-Wiedelman Glycogen storage disease  Clinical Features Mostly asymptomatic Weak, irregular pulses Precordial pain Hyperactive precordium Palpitations Precordial heave Dizziness Ejection systolic murmur over the aortic area Syncope Apical systolic murmur of MV insufficiency (usually Easy fatiguability absent if there is no LVOT obstruction) Dyspnoea  Workup ECG: prominent P waves, short PR intervals, widened QRS, ST segment and T wave abnormalities Holter monitoring; exercise ECG Echocardiography: LV/ septal wall thickness, outflow tract gradient, MV insufficiency CXR: normal/ slightly increased CTR, prominent LV  Cardiac catheterisation: LVOT gradient Cardiac CT/ MRI Genetic testing, metabolic screening EMB (rarely done)  Management Strenuous exercise prohibited Beta blockers: ↓ LVOT obstruction, ↓ HR thus improving LV filling, anti-arrhythmic, ↓ myocardial O2 demand Ca channel blockers: ↓ contractility Anti-arrhythmias Implantable cardioverter defibrillator (ICD)  Management Septal alcohol ablation Surgical septal myomectomy Mitral valve replacement Screen first degree relatives Heart transplant Manage HF  Prognosis Generally poor but highly variable Myocardium may thin out in long standing cases (about 10%) and present with features of DCM Risk of death highest in infants and adolescence Common causes of death: HF, Sudden cardiac death 20 arrhythmia (VT / VF)  Poor prognostic factors Family history Syncope Arrhythmias Exercise hypotension LV wall thickness > 30 mm LVOT gradient > 30 mmHg RESTRICTIVE CARDIOMYO  Introduction < 5 % of cardiomyopathies; F > M Mostly idiopathic; family hx in 25% Reduced ventricular compliance with diastolic dysfxn Normal ventricular wall thickness and dimensions Preserved systolic function Back pressure into the atrial; subsequent dilatation  Clinical Features Right hrt failure: tender hepatomegaly, pedal oedema, ascites Left hrt failure: cough, dyspnoea, pulmonary oedema No murmur Syncope; arrhythmias, MI, thromboembolism INVESTIGATIONS  ECG: prominent P waves, non-specific ST-T wave changes  ECHO: abn cardiac filling  Treatment Diuretics Antiarrhythmias Anticoagulants Pharmacologic treatment is difficult Prognosis poor without hrt transplant