Biografía Inge Edler

Eur J Echocardiography (2001) 2, 3–5
doi:10.1053/euje.2001.0082, available online at http://www.idealibrary.com on

BIOGRAPHY
Inge Edler and the Origins of Clinical
Echocardiography
A. G. Fraser, on behalf of colleagues and friends in the Working Group on
Echocardiography of the European Society of Cardiology
University of Wales College of Medicine, Cardiff, U.K.

Introduction
Manycardiologists know that Inge Edler and Hellmuth
Hertz started clinical echocardiography in 1953, but few
know how their collaboration came about.
Edler was working as Director of the Cardiovascular
Laboratory at the University Hospital in Lund in the
south of Sweden, and one of his duties was to refer
patients with rheumatic mitral disease for closed valvotomy. He aimed to select only those withpure mitral
stenosis, but sometimes the results were poor and the
clinical consequences disastrous. Surgery for this condition had been started in the early 20th century, but
largely abandoned due to mortality rates as high as
88%[1]. After the Second World War there was a renaissance of interest in heart surgery, following the experience gained in treating wounds of the heart, but theresults for mitral stenosis remained poor, with a mortality of 66% reported in 1950[2]. Edler wondered how

Figure 1. Inge Edler (right) and Hellmuth Hertz photographed when attending a congress on echocardiography
in Rotterdam in 1979 (courtesy of Professor Dr
J. R. T. C. Roelandt).
1525-2167/01/010003+03 $35.00/0

patients could be identified more carefully so that the
results would not beunpredictable.

The First Echocardiograms
As a young man Edler had wanted to study engineering
at university, but competition was hard and he was
unsuccessful. He therefore studied medicine instead, but
he retained his interest in new engineering techniques.
When considering the problem of patients with mitral
valve disease, he thought of using either radar (which
had also been developedduring the Second World War)
or ultrasound to study the heart. He did not know if
either would work, so he spoke to his clinic nurse
because her husband, Jan Cederlund, was a physicist. He
in turn thought of a friend who had been interested in
ultrasound systems, and knew that one was being used
for non-destructive testing in the Kockum shipyards in
Malmo, and so this friend — Hellmuth Hertz —was
¨
contacted. Hertz arranged to meet Inge Edler, who had
in fact seen him once before when Hertz had consulted
him as a patient with headaches.
Edler explained the clinical problem to Hertz, who
thought there was a 50% chance that ultrasound might
work. Radar would be ineffective because of its high
frequency. Hertz visited the testing company (Tekniska
Rontgencentralen) in Malmo andused their ultrasonic
¨
reflectoscope on himself. Since he obtained some
moving signals, he and Edler (Fig. 1) were sufficiently
encouraged to agree to work together.
They borrowed the ultrasound machine from the
shipyard for one weekend in May 1953. Edler used it on
himself and on some patients; he obtained a moving
signal at a depth of about 10 cm from the transducer,
which he suspectedmight be from the posterior wall of
the heart. This first A-mode scan on a cathode ray
oscilloscope has since been published[3]. By chance,
Edler and Hertz had borrowed a transducer with a
 2001 The European Society of Cardiology

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A. G. Fraser

Figure 2. The first echocardiographic recording obtained by Inge Edler and Hellmuth Hertz, displayed as an
M-mode trace on photographic film,which they interpreted as showing echoes from the left ventricular
posterior wall (courtesy of Professor Inge Edler).

frequency appropriate for transthoracic imaging; if it
had been either much lower or much higher they might
have been discouraged and could have abandoned their
efforts.
The father of Hellmuth Hertz, Gustav Hertz, had
worked as director of research for Siemens at Erlangen...