through the coronary arteries and the vessels of the heart,
impairing its nutrition or causing it to tire more readily, may be
the cause of these cardiac pains, distress or discomfort.

Palpating the radial artery is not absolutely reliable in all cases
of auricular fibrillation, or in another form of arrhythmia called
auricular flutter or tachysystole. James and Hart [Footnote: James
and Hart: Am. Jour. Med. Sc., 1914, cxlvii, 63.] have found that the
pulse is not a true criterion of the condition Of the circulation.
There is always a certain amount of heart block associated with
auricular fibrillation so that not all of the auricular stimuli pass
through the bundle of His. James and Hart determine the heart rate
both at the radial pulse and at the apex, the difference being
called the pulse deficit. They use this deficit as an aid in
deciding when to stop the administration of digitalis. When the
pulse deficit is zero, the digitalis is stopped. In this connection
they also find that, even though the pulse deficit may be zero,
there may be a difference in force and size of the waves at the
radial artery. This can be demonstrated by the use of a cuff around
the brachial artery and by varying the pressure. It will be found
that the greater the pressure, the fewer the number of beats coming
through.

Besides the instruments of precision referred to above, more careful
percussion, more careful auscultation, more careful measurements,
roentgenoscopy and fluoroscopic examination of the heart, and a
study of the circulation with the patient standing, sitting, lying
and after exercise make the determination of circulatory ability a
specialty, and the physician who becomes an expert a specialist. It
is a specialization needed today almost more than in any other line