Introduction <p>Valsalva maneuvers are the initial line in management of paroxysmal supraventricular tachycardia in hemodynamically stable children. This study aimed to compare the efficacy of modified versus standard Valsalva maneuvers on the clinical outcomes and satisfaction of children with paroxysmal supraventricular tachycardia.</p> Methods <p>The study used randomized controlled trial and recruited ninety children with paroxysmal supraventricular tachycardia from Pediatric Emergency Department and Pediatric Cardiac Intensive Care Unit at Tanta University Hospitals, El-Gharbia Governorate, Egypt. The researchers divided the studied children into three equal groups of thirty. A control group that received conventional hospital care, an intervention group I that received modified Valsalva maneuver plus conventional hospital care, and an intervention group II that received standard Valsalva maneuver plus conventional hospital care. The primary outcome was the return to sinus rhythm within the first 5&#xa0;min of admission and the secondary outcomes were decreased dyspnea, decreased antiarrhythmic therapy use, length of stay time in hospital as well as children’s satisfaction.</p> Results <p>More than half (53.3%) of the children who received the modified Valsalva maneuver returned to sinus rhythm within the first five minutes post-implementation compared to 33.3% of the children who received the standard Valsalva maneuver. Children within modified Valsalva maneuver group had a mean satisfaction score of 25.56 ± 1.67 that was significantly higher than those in the standard Valsalva maneuver group’s score of 20.10 ± 2.57 (<i>P</i> = 0.0001).</p> Conclusion <p>The modified version of the Valsalva maneuver was significantly more effective than the standard Valsalva maneuver in terminating supraventricular tachycardia and improving children’s clinical outcomes. This included a decrease in the degree of dyspnea within the first minute from severe to moderate and reducing the need for administering antiarrhythmic drugs for management of SVT episodes. Additionally, children in the MVM group had a higher mean satisfaction score than those in the SVM group, with highly statistically significant differences.</p> Trial registration <p>PACTR202407479098909. Registered 15/07/2024.</p>