CVPR 04-03-14 09-10am Myocarditis and Cardiomyopathy - Horwitz

Question 1

Acute myocarditis – defn

Answer 1

An inflammatory disease of the myocardium that usually attacks a healthy child or adult and is often viral in origin

Question 2

Acute myocarditis – presentation

Answer 2

Wide range: Often presents w/in 2 wks after a URI or flu-like syndrome w/fever & chills or GI symptoms…… If concurrent pericarditis is present, pts may have chest pain and ECG changes as well…. Adult cases often present w/HF with or without cardiogenic shock….. Arrhythmias w/palpitations or syncope are sometimes the presenting symptoms & may cause sudden death.

Question 3

Causes of myocarditits

Answer 3

Many viruses cause myocarditis…..Hypersensitivity to drugs (anthracyclines & other chemo agents most common)…..Systemic inflammatory diseases (SLE) ….. Certain bacterial, fungal or other infectious diseases are among less common causes

Question 4

Peripartum cardiomyopathy

Answer 4

Begins the last month of pregnancy or w/in 5 months after pregnancy….. Poorly understood…..Often resolves but may proceed to a serious cardiomyopathy.

Question 5

Mechanism of virally-induced cardiomyopathy

Answer 5

In cases of viral etiology, an immune-related process rather than direct damage from the actual pathogen may be the major mechanism of injury…… Certain viruses (like Coxsackie B) have a relatively high incidence of myocarditis; However, in any viral epidemic only a very small % of victims are afflicted by clinically detectable myocarditis for an unknown reason (genetic predisposition?)

Question 6

Myocarditis & Autoimmunity

Answer 6

Myocarditis is often an autoimmune reaction….. Certain viruses (coxsackie B) have regions (epitopes) immunologically similar to cardiac myosin.

Question 7

Physical findings in Myocarditis

Answer 7

S3…Pulmonary congestion or peripheral edema…If cardiac dilation is present, mitral or tricuspid insufficiency murmurs…..Increased troponins ressembling findings in acute MIs may be present

Question 8

ECG changes in Myocarditis

Answer 8

A variety of nonspecific ECG changes may occur, including patterns suggestive of pericarditis or acute MI…..

Question 9

Echocardiograms in Myocarditis

Answer 9

Often demonstrate global or diffuse ventricular dysfunction & are very useful in confirming that a myocardial process is present

Question 10

Biopsies in Myocarditis

Answer 10

Rarely done, but show focal or diffuse necrosis & myocyte swelling w/inflammatory changes.

Question 11

Asymptomatic Myocarditis

Answer 11

A large % of myocarditis cases w/minimal or absent symptoms (other than evidence of an acute viral infection) probably go unrecognized…… Some such cases may eventually develop a dilated cardiomyopathy

Question 12

Myocarditis w/HF - outcomes

Answer 12

Myocarditis cases presenting w/heart failure may resolve w/out apparent injury, may proceed rapidly downhill to death or may evolve into a chronic dilated cardiomyopathy.

Question 13

Myocarditis w/HF - therapy

Answer 13

If HF is present, usual methods for this condition are applicable to treatment, esp. diuresis, low dose BBs & ACE-Is (and occasionally inotropic agents)

Question 14

Nonviral Infectious Myocarditis - treatment

Answer 14

If non-viral infections are involved, appropriate antimicrobial agents are used.

Question 15

Steroids to treat Myocarditis

Answer 15

In diseases in which steroids are known to effective (such as SLE), they are useful…. However, in viral or idiopathic cases steroids are controversial.

Question 16

Three types of cardiomyopathy

Answer 16

1. Most common = Dilated Cardiomyopathy….. 2. Rare = Hypertrophic cardiomyopathy….. 3. Rare = Restrictive cardiomyopathy

Question 17

Dilated cardiomyopathy

Answer 17

Left ventricle is always involved, but often all 4 heart chambers are dilated…..Mild hypertrophy w/increased cardiac mass is usual (may be same thickness as normal, but now covers more area b/c of dilation, so more total mass)

Question 18

Hypertrophic cardiomyopathy

Answer 18

Left ventricle is hypertrophied but not dilated, and there often is disproportionate hypertrophy of the septum….. may cause obstruction & problems w/diastolic filling

Question 19

Restrictive cardiomyopathy

Answer 19

Infiltration or fibrosis of the ventricles, usually without dilatation.

Question 20

Causes of dilated cardiomyopathy

Answer 20

Clinical distinction often made between “ischemic” (due to CAD) and “nonischemic” dilated cardiomyopathy….. Dilation may be present w/out development of HF in mild cases or early stages of the disease.

Question 21

Dilated cardiomyopathy – Clinical manifestations

Answer 21

1. Most common to detect this condition when severe Heart Failure is present (Cardiomegaly on chest films, ECHO: Dilated ventricles w/impaire systolic function & low EF = confirm the Dx)….. 2. Arrhythmia (injury, fibrosis, dilation; may cause sudden death)….. 3. Thromboembolism (dilation, poor contraction, abnormal surface)

Question 22

Dilated cardiomyopathy – Presentation

Answer 22

HF w/large silent [i.e., asymptomatic] heart w/impaired systolic function

Question 23

Dilated cardiomyopathy – Etiology

Answer 23

Usually idiopathic…. Also: Ischemia, Familial, Viral, Alcohol abuse, etc.

Question 24

Dilated cardiomyopathy – Treatment

Answer 24

1. Treatment of HF: Usually diuretics, ACE-Is, & BBs (BBs once stabilized/decongested); Also, digoxin, spironolactone, vasodilators, inotropes, biventricular pacing if refractory ventricular asynchrony present (often due to left bundle branch block)….. 2. Anticoagulation to prevent emboli (esp. if A fib present)….. 3. Anti-arrhythmic agents – drugs & implantable defibrillators (to prevent sudden death)….. 4. Last resorts: Implantable left ventricular devices (LVADs) or Heart transplant

Question 25

Hypertrophic cardiomyopathy - presentation

Answer 25

Left ventricle is hypertrophy (often eccentric) but NOT dilated… Disorganized muscle fibers & collagen matrix, esp. in septum (which is often disproportionately thickened)….. Predominant diastolic disfunction, w/normal or enhanced systolic function….. Septal thickening + hyperdynamic contraction may cause aortic outflow tract obstruction (LV pressure»Aortic pressure )

Question 26

Hypertrophic obstructive cardiomyopathy – symptoms/outcomes

Answer 26

Dyspnea (increase LV filling pressure)….. Angine (hyprtrophic lV, increase systolic LV pressure)…..Especially w/obstruction, sudden death may occur w/exertion (arrhythmias), esp. common cause of sudden death in athletes

Question 27

Hypertrophic cardiomyopathy – etiology

Answer 27

Relatively rare & usually familial - Strong genetic component – Autosomal dominant inheritance

Question 28

Treatment of hypertrophic cardiomyopathy

Answer 28

If obstructive component present: 1. Decrease contractility may decrease outflow tract obstruction - If drugs (BBs, Verapamil) ineffective, surgical resection or percutaneous alcohol septal ablation in the outflow tract often relieves obstruction….. 2. Avoid extreme exertion (may prevent sudden death)….. 3. Ventricular pacing (ICD) may occasionally be useful for relief of obstruction or arrhythmia control

Question 29

Restrictive cardiomyopathy – presentation

Answer 29

Impaired ventricular filling due to stiff (non-compliant) ventricles….. Systolic function often normal & ventricles usually NOT dilated

Question 30

Restrictive cardiomyopathy – Dx & Treatment

Answer 30

Dx via echocardiography w/Doppler assessment of ventricular filling….No real treatment

Question 31

Restrictive cardiomyopathy – prognosis & etiology

Answer 31

Rare & w/poor prognosis (Intractable failure and fatal arrhythmias may occur)….. An infiltrative disease, most commonly due to amyloidosis & sarcoidosis

Question 32

Brain natriuretic peptide (BNP) test

Answer 32

To decide if there is HF or not (very good at ruling out HF): If BNP low (500, usually in 1000s), probably is HF….. Also useful in monitoring therapy for HF pt