Electrocardiography is a mature discipline, so familiar to both doctors
and patients that it's hardly noticed, one of those tests that have
always been there, like the white count and hemoglobin, not something
one has to think about much, or question. To some extent this view is
valid, but it overlooks some important points. Like the white count and
hemoglobin, electrocardiograms are produced by technicians using
mechanical devices that turn out numbers, but there is a difference. The
white count and hemoglobin are reported as single values to be
interpreted by the doctor who knows the patient and ordered the test,
but the graph produced by an EKG machine represents millions of numbers
displayed as XY plots, a message written in a language different from
one's own. It requires transla- tion, and this means that the translator
must not only know the lan- guage, but also be able to assess the
effects on it of the many factors that may have modified its meaning
between origin and delivery. There is potential for harm to the patient,
as well as for help, in every facet of the process, and to lose sight of
this, to see the tracing as a single whole, would be like seeing words
as units without con- sidering the letters that compose them. When we
read, we do recog- nize whole words, patterns, but, having learned the
letters first, revert to this base intuitively when we encounter a new
word, or one that is misspelled.
