A new technique for measuring thickness of the left ventricular wall utilizes pulsed reflected ultrasound and can be performed at the bedside in a matter of minutes without discomfort or risk. A group of echoes from a portion of the left ventricle are recorded and the ultrasound energy is reduced so that a single echo is recorded from the pericardium-lung interface. As the tracing is being inscribed, energy is suddenly increased and echoes anterior and posterior to the pericardial echo are recorded. The width of the band of myocardial echoes anterior to the pericardial echo represents left ventricular wall thickness. Accuracy of this technique was confirmed in 25 normal subjects and in 35 patients in whom left ventricular wall thickness was measured either at necropsy or during openheart surgery.
Feigenbaum H, Popp RL, Chip JN, Haine CL. Left Ventricular Wall Thickness Measured by Ultrasound. Arch Intern Med. 1968;121(5):391-395. doi:10.1001/archinte.1968.03640050001001