In the EDITORIAL, "Nontraumatic Approaches to Assessing Cardiac Performance," published June 21 (216:-2007-2008, 1971), a simple diagram was used to illustrate the systolic time intervals. The illustration depicted the Q-S2 period as extending to the end of S2. The Q-S2 interval should have been shown to end at the initial high-frequency vibration of the second heart sound, ie, the beginning of S2.
Diagram Inaccurate. JAMA. 1971;217(9):1197. doi:10.1001/jama.1971.03190090019005