Modified Valsalva Maneuver for PSVT

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Modified Valsalva Maneuver for PSVT

​This modified Valsalva Maneuver is a simple yet effective technique used to treat stable PSVT.

Phase 1: Increasing Intrathoracic Pressure.

• The first phase involves the patient performing a standardized "strain" by blowing into a 10mL syringe for approximately 15 seconds while sitting up or in a semirecumbent position.
• This action contracts the thoracic and abdominal muscles, causing a drop in blood flow back to the heart (decreased preload) and the brain.
• This drop stimulates the baroreceptor reflex, triggering the sympathetic nervous system (stress response) to raise blood pressure, cardiac output, and peripheral vascular resistance.

Phase 2: Sudden Drop in Intrathoracic Pressure.

• After the 15-second strain, the patient stops blowing into the syringe just before being laid flat (or simultaneously).
• This sudden decrease in intrathoracic pressure increases blood flow back to the heart, leading to an opposite effect of phase 1.
• The body compensates by increasing parasympathetic (vagal) activity, decreasing heart rate, and promoting a relaxation response.

Phase 3: Laying Flat and Raising Legs to 45 Degrees.

• The patient is then laid flat while raising their legs to 45 degrees.
• This postural modification further increases blood flow back to the heart, boosting stroke volume and cardiac output.
• This triggers even more vagal stimulation, causing a decrease in heart rate, potentially converting the patient back into sinus rhythm.

In conclusion, by manipulating the nervous system and leveraging physiology, this maneuver is a safe, simple, and cost-free treatment to treat PSVT.