4/11/2017
Cardiomyopathy
John Steuter, MD Bryan Heart
Disclosures No Conflicts
Cardiomyopathy
WHO Classification
Anatomy & physiology of the LV 1. Dilated • Enlarged • Systolic dysfunction 2. Hypertrophic • Thickened • Diastolic dysfunction 3. Restrictive • Diastolic dysfunction 4. Arrhythmogenic RV dysplasia • Fibrofatty replacement 5. Unclassified • Fibroelastosis • LV noncompaction Circ 93:841, 1996
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Dilated Cardiomyopathy
Dilation and impaired contraction of ventricles: Reduced systolic function with or without heart failure Characterized by myocyte damage Multiple etiologies with similar resultant pathophysiology
Many of the cases are idiopathic incidence of idiopathic dilated CM 5-8/100,000 incidence likely higher due to mild, asymptomatic cases 3X more prevalent among males and African-Americans
DCM: Etiology
Ischemic Valvular (aortic and mitral valve disease) Hypertensive (end stage) Familial Idiopathic Inflammatory Infectious Viral –Cox B, CMV, HSV, HIV Ricketsial - Lyme Disease Parasitic - Chagas’ Disease, Toxoplasmosis Non-infectious Collagen Vascular Disease (SLE, RA) Peripartum Toxic Alcohol, Anthracyclines (adriamycin), Cocaine Metabolic Endocrine –thyroid dz, pheochromocytoma, DM, acromegaly, Nutritional Thiamine, selenium, carnitine Neuromuscular (Duchene’s Muscular Dystrophy--x-linked)
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Ischemic Cardiomyopathy
Patients with history of MI or revascularization (CABG or PCI) Patients with >75% stenosis of the left main or proximal LAD Patients with >75% stenosis of two or more epicardial vessels
Prognosis depends on Etiology
1230 pts. referred for unexplained CM. Felker GM. NEJM 2000;342:1077
40 year old female presents with “crushing chest pain”
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Echo: EF 45% Inferior Wall hypokinesis
CATH: Normal Coronaries
Definition of mycocarditis
Inflammation of the heart muscle secondary to injury – Ischemic damage – Mechanical trauma – Genetic cardiomyopathies – Exposure to discrete external antigens • Viruses , bacteria, parasites, toxins drugs – Internal triggers • Autoimmune activation against self antigens
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Incidence
Difficult to ascertain, depends on criteria used Estimated 8 to 10 per 100,000 Unselected autopsy series as high as 1 to 4 per 100 Young adults with sudden cardiac death, estimated 8.6% Idiopathic dilated cardiomyopathy patients only 10-40% are secondary to myocarditis
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Population
Bimodal age distribution Young children and teenagers: acute presentation – Exuberant response to initial exposure of antigen Older adults: Subtle and insidious symptoms of dilated cardiomyopathy and heart failure – Mature immune system with greater tolerance
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Clinical presentation
Wide-ranging clinical presentation contributes to difficult diagnosis and classification – Asymptomatic ECG or echocardiographic abnormalities – Cardiac dysfunction, arrhythmias, heart failure and hemodynamic collapse
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Acute Myocarditis Presentation
Fatigue 82% Dyspnea on exertion 81% Arrhythmias 55% Palpitations 49% Chest pain at rest 26%
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Acute Myocarditis Presentation
Acute ischemic syndrome type symptoms – Elevated troponin – ST-segment elevation on ECG – Segmental wall motion abnormalities on echocardiography Viral prodrome symptoms 20-80% – Fever – Chills – Myalgias – Constitutional symptoms
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Fulminant Myocarditis Presentation
Abrupt onset within 2 weeks of a viral illness Hemodynamic compromise Hypotension requiring pressors and mechanical support Echocardiogram reveals diffuse global hypofunction Thickening of the ventricular wall probably due to myocardial edema from myocardial inflammation and cytokine release
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Endomyocardial biopsy in fulminant myocarditis • Typical and diffuse myocarditis in each histologic section
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Pathogenesis
Pathogenesis
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Diagnostics: Expanded Criteria for Diagnosis of Myocarditis Category I: Clinical Symptoms – Clinical heart failure – Fever – Viral prodrome – Fatigue – Dyspnea on exertion – Chest pain – Palpitations – Pre-syncope or syncope
Category II: Evidence of Cardiac Structural or Functional Perturbation in the absence of Regional Coronary Ischemia
Echocardiography evidence – Regional wall motion abnormalities – Cardiac dilation – Regional cardiac hypertrophy Troponin release – High sensitivity (>0.1 ng/mL) Normal coronary angiography or Absence of reversible ischemia by coronary distribution on perfusion scan
Category III: Cardiac Magnetic Resonance Imaging
Increased myocardial T2 signal on inversion recovery sequence Delayed contrast enhancement after gadolinium-DTPA infusion
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Category IV: Myocardial biopsy – Pathologic or Molecular Analysis
Pathology findings compatible with Dallas criteria Presence of viral genome of polymerase chain reaction or in situ hybridization – 80-100% specificity when performed from myocardial biopsy
Treatments/Therapeutic Approaches
Supportive Therapy Immunosuppression Interferon Intravenous Immune Globulin Immune Adsorption Therapy Hemodynamic Support Vaccination
Supportive Therapy
First-line therapy Only a small proportion of patient require hemodynamic support Treat this group same as for clinical heart failure – Diuretics – IV Vasodilators: Nitroglycerin, Nesiritide – ACEi, ARBs, B-blockers when stable • Anti-inflammatory properties
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Hemodynamic Support
Patients with fulminant myocarditis and cardiogenic shock may require – Intra-aortic balloon pump – Ventricular assist devices – Extracoporeal membrane oxygenation (ECMO)
Vaccination
Targeted vaccination in the future Patients genetically susceptible to myocarditis After the mumps vaccination – Disappearance of endocardial fibroelastosis causing dilated cardiomyopathy
Prognosis
Most patients with acute myocarditis and mild cardiac involvement recover without long-term sequelae Patient with advance cardiac dysfunction, varied outlook Patients with severe hemodynamic collapse at presentation actually have a good prognosis – 93% transplant-free survival in 11 years 30% of those with chronic myocarditis may recover
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Prognosis Several studies have looked at clinical variables that predict adverse outcomes (death and transplantation) – Syncope – Bundle branch block – EF <40% Other factors – NYHA Class III or IV – PCWP <15mmHg – Immunopathologic evidence of myocardial inflammation – Failure to use B-blockers – BiV failure – Giant cell or viral genome on biopsy
DCM: toxic
Alcoholic cardiomyopathy Chronic use
Mechanism?: – Myocyte cell death and fibrosis – Directly inhibits: • mitochondrial oxidative phosphorylation • Fatty acid oxidation
Relative Risk of Mortality Risk vs intake 2
1.5
1 RR
0.5
0 0 1-6d7-13d 14- 28- 42- >69d 27d 41d 69d Drinks/week
PBRC 2010
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Treatment
Guideline directed medical therapy Reversible with abstinence
Questions
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