Peripheral saline contrast with Valsalva and a modified Müller's maneuver may improve detection of atrial level right‐to‐left shunts: A preliminary observation

: As part of an evaluation for source of embolism, transthoracic echocardiography with peripheral saline contrast injection during normal respirations and also Valsalva release is routinely performed to evaluate for an atrial level shunt. We present a preliminary observation of addition of a modified Muller's maneuver early during the Valsalva release. The Muller's maneuver has been described to occur with sleep apnea and will increase right-to-left shunting through a PFO. Of 34 patients, 24 were negative for a right-to-left shunt with normal respiration or Valsalva release. Of these 24 patients, 8 were then positive for a shunt by addition of a modified Muller's maneuver. One additional patient could not perform the modified Muller's maneuver. This preliminary observation suggests that in patients referred to an echocardiography laboratory for evaluation of source of embolism, adding the modified Muller's maneuver to those negative for shunting during normal respirations and Valsalva release may yield an increase in right-to-left atrial level shunt detection.