AIM To analyze the differences of different Valsalva maneuver (VM) in contrast transthoracic echocardiography (cTTE) screening for patent foramen ovale (PFO), and the application of simple breathing trainers in standardizing of VM and cTTE.

METHODS Randomly selected 146 patients who were suspected PFO to underwent cTTE in the Department of StructuralHeart Disease, the First Affiliated Hospital of Xi’an Jiaotong University from June to September 2022, and completion rate, RLS positive quantitative grading, the detection rate of grade III RLS, number of VM performed, and the time required for examination were compared under the breath-holding method, pressure gaugemethod, and simple breathing trainers method.

RESULTS The positive rates of RLS in resting state, breath holding method, pressure gauge method, and simple breathing trainer method were 33.6%, 52.3%, 64.1%, and 62.5%, respectively; The positive rates of Level III RLS (RLS Level III indicates the presence of high-risk patent foramen ovale) were 3.9%, 25.0%, 39.1%, and 37.5%, respectively. The positive rates of resting state RLS and grade III RLS were significantly lower than those of breath holding method, pressure gauge measurement method, and simple breathing trainer method (all P<0.05). The positive rates of RLS and Level III RLS using the breath holding method were significantly lower than those using the pressure gauge method and the simple breathing trainer method (both P<0.05); The difference in RLS positive rate and level III RLS positive rate between the pressure gauge method and the simple breathing trainer method is not statistically significant; The number of times VM was performed under the breath holding method was higher than that using the pressure gauge method (3.1 ± 0.8) times vs. (2.8 ± 0.7) times and the breathing trainer method (3.1 ± 0.8) times vs. (2.6 ± 0.6) times, both P<0.05. The average examination time of the breath holding method was significantly longer than that of the pressure gauge method (336 ± 46) s vs. (311 ± 45) s and the breathing trainer method (336 ± 46) s vs. (301 ± 36) s, both P<0.05, but there was no statistical difference between the pressure gauge method and the simple breathing trainer method.

CONCLUSION Standardizing VM and standard devices reduce the number of VM and shorten inspectionexamination time without affecting the PFO detection rate. Simple breathing trainer improves the examination completion rate and is widely used in clinical work.