Echocardiography History and Development Notes

Early Echocardiography

• Initial Ultrasonoscope: Edler and Hertz developed an ultrasonoscope for early echocardiograms.

  • FIGURE 1.1: Image of the initial Ultrasonoscope used by Edler and Hertz.

• Helmut Hertz's Contribution:

  • Focused on recording ultrasonic signals.

  • Developed ink-jet technology.

  • Spent a few years in cardiac ultrasound before dedicating his career to ink-jet technology.

  • Advised Siemens against entering cardiac ultrasound, believing it had limited potential (Effert, personal communication, 1996).

• Edler's Focus:

  • Concentrated on echocardiography for mitral stenosis and, to a lesser degree, mitral regurgitation until his retirement in 1976.

  • Did not engage with newer techniques for pericardial effusion or ventricular function.

• Early Use in China (1960s):

  • Investigators in Shanghai and Wuhan used ultrasonic devices to examine the heart.

  • Started with A-mode ultrasound and developed an M-mode recorder.

  • Confirmed Edler and Effert's findings on mitral stenosis.

  • Unique contributions:

    • Fetal echocardiography.

    • Contrast echocardiography using hydrogen peroxide and then carbon dioxide.

• Introduction in the United States:

  • John J. Wild, H. D. Crawford, and John Reid examined the excised heart.

  • Identified myocardial infarction and published their findings in 1957 in the American Heart Journal.

  • Neither Wild nor Reid was a physician; Reid was an engineer.

  • Reid collaborated with Claude Joyner (cardiologist) to duplicate the work on mitral stenosis by Edler and Effert.

  • Their work, published in Circulation in 1963, marked the first American clinical effort using pulsed reflected ultrasound to examine the heart.

• This technique paved the way for further advancements in echocardiography, influencing subsequent research and clinical practices in cardiac imaging.

Personal Involvement and Early Discoveries

• Interest in Echocardiography (1963):

  • Motivated by frustration with limitations of cardiac catheterization and angiography.

  • Inspired by an advertisement claiming an instrument could measure cardiac volumes with ultrasound (though the claim was unfounded).

  • Observed a moving echo from the posterior wall of the heart, similar to Hertz and Edler's findings.

• Key Experiment and Discovery:

  • Borrowed an ultrasonoscope from neurologists (used for detecting the midline of the brain).

  • Recorded echoes from the back wall of the left ventricle in multiple individuals.

  • Observed two echoes separated by an echo-free space in a patient with pericardial effusion.

    • Posterior echo was stationary, while the anterior echo moved with cardiac motion.

  • Findings confirmed in an animal laboratory.

• Publication:

  • Initial paper on pericardial effusion published in JAMA in 1965.

• Simultaneous Work in Japan:

  • Japanese investigators (Satomura, Yoshida, and Nimura) at Osaka University used Doppler technology to examine the heart in the mid-1950s.

  • Their work laid the basis for modern Doppler ultrasound techniques.

• Collaborative Development:

  • The field of cardiac ultrasound has evolved through collaboration among physicists, engineers, and clinicians over the past 50 years.