Flashcards in Myocarditis/ Cardiomyopathy Deck (11):
1. Explain the theory proposed for myocyte injury in acute viral myocarditis.
viral infection causes myocyte necrosis and macrophage activation which causes cytokine expression and an inflammatory response
2 Differentiate the roles of direct viral injury, injury due to inflammation and secondary effects caused by the immune system on myocytes in the pathophysicology of viral myocarditis
macrophage activation causes an infiltration of monouclear cells and cytokine expression incites natural killer cells in the viral clearing phase
3. Describe the basic genetic abnormailities that result in hypertrophic cardiomyopathy.
1/500 people have autosomal dominant, mutations are in sarcomeric proteins; most common myosin heavy chain (beta myosin mutation aparent by age 20, tropnin T by age 40, myosin binding protein C by age 60
4. Describe the clinical presentation of hypertrophic cardiomyopathy.
disproportionate and inapporpriate hypertrophy of the LV, often septum is invovled (asymmetric septal hypertrophy) which leads to diastolic dysfunction
5. Explain how the hemodynamic abnormailites associated with hypertrophic cardiomyopathy may limit exercise capacity.
hypderdynamic systolic function, impaired relaxation and increased stiffness, arrhthmogenicity (fibrosis) mitral valve apparatus dysfunction--- lead to lesser cardiac output which worsens with exercise
exercise can increase preload which will worsen symptoms
6. Contrast the structural abnormalities of dilated cardiomyopathy with hypertrophic cardiomyopathy.
dilated abnormalities are connected to abnormalities in cytoskeleton while hypertrophic cardiomyopathy is due to mutations in the sarcomeric proteins
What are the three current theories regarding the damage during chronic phase of myocarditis.
chronic immune activation (cytotoxic T ; persistent viral infection, virus-induced apoptosis
Describe the clinical presentation and treatment for myocarditis.
viral syndrome (fatigue, fever, myalgias) chest pain, dyspnea, palpitations, syncope and sudden cardiac death; tx. Within 24 hrs with antivirals, immunosuppression , and bed rest with Bblockers and ACEI
Describe the signs that accompany hypertrophic cardiomyopathy.
signs include bisferiens pulse, S4 or systolic ejection murmur due to obstruction of mitral valve
Describe the medical and device therapies for hypertrophic cardiomyopathy.
negative inotropic agents to relieve outflow tract obstruction: Beta blockers, Verapamil, Disopyramide
implantable cardioverter-defibrillator can reduce sudden cardiac death
non-surgical septal reduction