CARDIOVASCULAR ANESTHESIA (Society of Cardiovascular Anesthesiologists) - The In Vitro Effects of Remifentanil, Sufentanil, Fentanyl, and Alfentanil on Isolated Human Right Atria - IMPLICATIONS: In isolated human right atria, remifentanil, sufentanil, and fentanyl did not modify inotropic variables in isometric conditions. In contrast, alfentanil induced a concentration-dependent negative inotropic effect possibly related, at least in part, to a decrease in Ca2+ inward transient. None of these opioids altered lusitropic variables./