Pericarditis and myocarditis


























Viral
Bacterial
Fungal
Parasitic
Radiation induced
Drug induced
Neoplastic
Systemic inflammatory disease
Myocardial infarction/Dressler syndrome (pericarditis)
Traumatic (pericarditis)
Metabolic (pericarditis)
Peripartum (myocarditis)



Myocarditis


  • Myocarditis is an inflammatory disorder of the cardiac muscle characterized by infiltration of the myocardium by immune cells, and myocyte necrosis.
  • The inflammation may be focal or diffuse.

    • Any or all cardiac chambers may be involved.
    • It may result in regional or global contractile impairment, chamber stiffening, or conduction system disease.
    • Clinical manifestation are highly variable depending upon the region of involvement, and include chest pain, acute heart failure, or cardiac arrhythmias.

  • Viral illnesses (coxsackievirus, parvovirus, and human herpes virus 6) are the most common causes of myocarditis in the United States.
  • Diphtheria is the most common bacterial cause worldwide.

Presentation


Pericarditis

Classic presentation


  • Chest pain: sharp, pleuritic, and worse with recumbency (95%).
  • Pericardial friction rub heard over the left sternal border (15–30%).
  • ECG changes: diffuse ST elevations, PR depression in the lateral leads.
  • Pericardial effusion.

Critical presentation


  • Hemodynamic instability secondary to cardiac tamponade.
  • Patients may complain of chest pain and dyspnea.
  • Heart sounds may be muffled.
  • Jugular venous distension.
  • ECG demonstrating electrical alternans.
  • Large effusion with diastolic right ventricular collapse on bedside echocardiogram.

Myocarditis

Classic presentation


  • Chest pain that may mimic cardiac ischemia.
  • Heart failure: dyspnea, fatigue, orthopnea, exercise intolerance.

Critical presentation


  • Fulminant decompensated heart failure.
  • Dysrhythmias, including complete heart block.
  • Syncope and sudden cardiac death.

Diagnosis and evaluation


Pericarditis


  • Acute pericarditis is largely a clinical diagnosis.
  • Two of the following four criteria should be met:

    • Classic chest pain (sharp, pleuritic, and worse with recumbency).
    • Pericardial friction rub.
    • ECG changes with new diffuse ST elevation or PR depression in the lateral leads (Table 26.2; Figure 26.1).

      • The ST elevations associated with pericarditis can be differentiated from those seen with ST elevation myocardial infarction.

        • ST elevations in pericarditis rarely exceed 5 mm.
        • ST elevations are diffuse rather than in a vascular distribution.
        • Reciprocal ST depression and PR elevation should only be seen in leads aVR and V1.
        • Associated temporal changes, such as hyperacute T-waves or Q-waves, are not typically seen in pericarditis.

    • Pericardial effusion (Figure 26.2):

      • Presence of effusion confirms the diagnosis, though absence does not exclude it.

  • Chest radiograph: enlarged cardiac silhouette if effusion is present.
  • Inflammatory markers: leukocytes may be normal or elevated, ESR is usually elevated although it is not specific.
  • Cardiac markers: may be elevated in myocarditis or postinfarction pericarditis.
  • Echocardiogram:

    • Normal wall motion.
    • Evaluate for coexisting effusion; effusion size can be estimated by the distance between the epicardium and the pericardium (<0.5 cm = small effusion; 0.5–2 cm = moderate effusion; >2 cm = large effusion).
    • Presence of a large effusion on a bedside echocardiogram with RV collapse during diastole should prompt consideration of impending tamponade.

Feb 17, 2017 | Posted by in CRITICAL CARE | Comments Off on Pericarditis and myocarditis

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