Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android


The myocardium can be affected by genetic, inflammatory, metabolic, infiltrative, ischemic, or primary disease processes, with significant overlap for many of them (Table 483-1). Myocardial diseases may present acutely, with signs of decompensated heart failure: tachypnea, tachycardia, an enlarged heart, soft heart sounds that may have a tictoc rhythm, cardiac gallop cadence, and either no murmurs or systolic murmurs of mitral or tricuspid regurgitation or aortic or pulmonary stenosis/outflow tract obstruction. Alternatively, they may present chronically with failure to thrive, decreased exercise tolerance, and more subtle findings of heart failure. Occasionally, the predominant process may be an arrhythmia, either atrial or ventricular tachycardia/fibrillation, or bradycardia/heart block. These present clinically with palpitations, syncope, or sudden death.


The electrocardiogram and chest x-ray are useful in suggesting heart disease but are rarely diagnostic. In acute presentations, the chest x-ray usually shows diffuse cardiac enlargement, passive pulmonary congestion, and interstitial edema; the electrocardiogram shows normal or reduced ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.