In deciding that a heart is enlarged by noting the apex beat,
percussion dulness, and by fluoroscopy, it should be remembered that
the apex beat may be several centimeters to the left from the actual
normal point, and yet the heart not be enlarged.

The necessity of protecting the heart in acute infections, and the
seriousness to the heart of infections are emphasized by the present
knowledge that tonsillitis, acute or chronic, and mouth and nose
infections of all kinds can injure the heart muscle. In probably
nearly every case of diphtheria, unless of the mildest type, there
is some myocardial involvement, even if not more than 25 percent of
such cases show clinical symptoms of such heart injury. Tuberculosis
of different parts of the body also, sooner or later, injures the
heart; and the effect of syphilis on the heart is now well
recognized.


SYMPTOMS AND SIGNS OF CARDIAC DISTURBANCE

It is now recognized that any infection can cause weakness and
degeneration of the heart muscle. The Streptococcus rheumaticus
found in rheumatic joints is probably the cause of such heart injury
in rheumatism. That prolonged fever from any cause injures heart
muscle has long been recognized, and cardiac dilatation after severe
illness is now more carefully prevented. It is not sufficiently
recognized that chronic, slow-going infection can injure the heart.
Such infections most frequently occur in the tonsils, in the gums,
and in the sinuses around the nose. Tonsillitis, acute or chronic,
has been shown to be a menace to the heart. Acute streptococcie
tonsillitis is a very frequent disease, and the patient generally,