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By John Gorcsan III, William A. Mandarino, Lee G. Deneault, Shigeki Morita, Akihiko Kawai, Bartley P. Griffith, Robert L. Kormos. The International Journal of Cardiac Imaging 10, 103–111, June 1994. Publisher title, full byline, author affiliations and abstract verified at link.springer.com/article/10.1007/BF01137705 . Abstract: six excised dog hearts were perfused ex vivo; an intraventricular balloon supplied volume and a micromanometer catheter supplied pressure. Automated echocardiographic borders measured mid-ventricular short-axis area. Three volume runs in 1 mL increments per heart yielded 1,080 simultaneous observations. The experiment compared pressure-area with pressure-volume relationships; it did not establish clinical validation. Full article not inspected.

William A. Mandarino is a named coauthor of the 1994 study estimating ventricular compliance from automated echocardiography and pressure measurements in an isolated-heart preparation. The full publisher byline establishes this identity and the shared contribution; it does not assign a separate experimental task to each coauthor.^[ref]

The method pairs image-derived ventricular area with simultaneously acquired pressure, using a balloon volume as an experimental reference. A micromanometer's pressure zero and the chamber's external pressure are different inputs to interpreting that relation.

For an original measurement model, suppose the recorded pressure is $p_m=p+b$, with constant offset $b$. Then $d{p}_m/dV=dp/dV$: a fixed zero offset moves a curve vertically without changing its local derivative. By contrast, a gain error $p_m=gp+b$ givesIf $g=1.10$, inferred ventricular compliance is about 9.09% low even though the curve retains the same qualitative shape. These stipulated errors explain why measurement calibration matters; they are not errors reported for Mandarino's apparatus.

The study's repeated paired measurements therefore concern a quantitative mapping, not just acquisition of a recognizable heart image. Its experimental results support the tested preparation, while the abstract explicitly reserves validation in clinical use.^[ref]