Background: Supraventricular tachycardia (SVT) is a common cause of emergency room 
visits. Modified Valsalva maneuver (MVM) is proven to be safe to some extent, effective in 
terminating SVT episodes and can be easily performed by critical care nurses. Aim: -This 
study aimed to evaluate the effect of modified Valsalva maneuver on clinical outcomes for 
patients with acute supraventricular tachycardia. Design: Quasi-experimental research design. 
Setting: - This study was conducted in cardiac emergency unit at Tanta Main University 
Hospital. Subjects: - A purposive sample of 80 patients diagnosed with acute 
supraventricular tachycardia divided into two equal groups, control group received routine 
care for reversion of SVT by cardiac nursing staff and study group managed by modified 
Valsalva maneuver with routine hospital care that implemented by the researcher. Tools: 
Two tools were used in this study, tool I Supraventricular Tachycardia Patient's Assessment 
Tool and tool II. Patient's clinical outcomes included hemodynamic parameters assessment, 
electrocardiography (ECG) rhythm monitoring, and numeric rating scale for measuring 
nausea and modified Borg dyspnea scale.  Results:  Study group showed significant 
difference regarding hemodynamic parameters, heart rhythm, and severity of nausea and 
dyspnea throughout the periods of intervention. In addition, there was significant difference 
between control and study groups in relation to hemodynamic parameters and ECG rhythm, 
but it was not significant in relation to the severity of nausea and dyspnea. Conclusions:  The 
present study's results suggest that modified VM therapy was more effective for terminating 
SVT. The modified VM therapy also indirectly reduced the need for anti-arrhythmic 
medication and decrease severity of nausea and dyspnea. Recommendations: - Modified 
Valsalva maneuver should carry out as first-line therapy for patients with stable SVT.