A concise history of echocardiography: timeline, pioneers, and landmark publications

Abstract

Echocardiography is less than 70 years old, and many major advances have occurred within living memory, but already some pioneering contributions may be overlooked. In order to consider what circumstances have been common to the most successful innovations, we have studied and here provide a timeline and summary of the most important developments in transthoracic and transoesophageal ultrasound imaging and Doppler techniques, as well as in intravascular ultrasound and imaging in paediatric cardiology. The entries are linked to a comprehensive list of first publications and to a collection of first-hand historical accounts published by early investigators. Review of the original manuscripts highlights that it is difficult to establish unequivocal precedence for many new imaging methods, since engineers were often working independently but simultaneously on similar problems. Many individuals who are prominently linked with particular developments were not the first in their field. Developments in echocardiography have been highly dependent on technological advances, and most likely to be successful when engineers and clinicians were able to collaborate with open exchange between centres and disciplines. As with many other new medical technologies, initial responses were sceptical and introduction into clinical practice required persistence and substantial energy from the first adopters. Current developments involve advances in software as much as in equipment, and progress will depend on continuing collaborations between engineers and clinical scientists, for example to identify unmet needs and to investigate the clinical impact of particular imaging approaches.

Keywords: echocardiography; history; key publications‌; pioneers.

Graphical Abstract

Selected principal milestones in the development of echocardiography. Details and references can be found in the text, timeline, and references.

Figure 1

Timeline of key insights from physics that remain important for current echocardiographic practice.

Figure 2

The first photographic film of M-mode echocardiography that was exposed by Edler and Hertz in October 1953, digitally scanned and then displayed as a continuous contact print. (courtesy of Professor Lars Edler)

Figure 3

(A) frame 15; and (B) frame 19A; selected from the M-mode echocardiographic film of the heart (shown in Figure 1).

Figure 4

Early 2-dimensional images of the heart and mitral valve, from (A) Hertz 1964 and (B) Hertz 1967, both obtained with a mirror system and recorded on 16 mm film at 7 frames per second; and (C) from Roelandt (1980; page 33) recorded about 1971 and described as ‘Stop-frame from the first two-dimensional ultrasonic image obtained from a patient with severe pericardial effusion; aHW = anterior heart wall.’ In this display, the transducer is along the left side of the image, and the echo-free space to the left of the arrow was interpreted as pericardial fluid in front of the heart.

Figure 5

Early monoplane transoesophageal probe and images (courtesy of Professor Peter Hanrath).

Figure 6

Left: 32-element phased-array 5.6 MHz intravascular ultrasound imaging (IVUS) of a basket (1972). Right: Single element rotating 30 MHz IVUS image of an artery containing atherosclerotic plaque (asterisk, and arrowed) (1992). From Bom N, Lancée CT, Rijsterborgh H, ten Hoff H, Roelandt JRTC. From idea to clinical application. in Intravascular Ultrasound, Roelandt, Gussenhoven, Bom Eds. Kluwer Academic Publishers, 1993.