I have tried many vagal maneuvers (coughing, straining, ice water to the face, carotid massage, and others) over the years to break paroxysmal supraventricular tachycardia (PSVT) in otherwise healthy patients, all with little success. I discovered a maneuver, however, that has a far higher rate of success. It is relatively simple and works in approximately 20 to 30 seconds.
Have the patient lie flat on his back and raise his feet over his head as far as he can. (Pictured.) The knees can be bent. Increase the effectiveness of this maneuver by having the patient take a breath and strain while in this position. As with any other medical intervention, this maneuver has some risk, such as back injury, neck injury, spinal cord injury with paralysis, and stroke, to name a few. Do not do this maneuver if your patient's rapid heart rate is from a different cause.
Reentrant PSVT (also called AV nodal reentry tachycardia) is the most common type among all patients with a regular PSVT. Electrophysiologic studies have demonstrated that PSVT (also termed PAT) is a nodal reentry tachycardia in the majority of cases of healthy patients with no structural heart disease. The patients most likely to respond to vagal maneuvers are those with paroxysmal reentry nodal tachycardia because vagal stimulation prolongs AV nodal conduction time and can terminate arrhythmias, which depend on AV nodal reentry for their continuation. Vagal maneuvers would not be expected to work and may be dangerous in patients whose arrhythmia is secondary to a cause such as hypovolemia, hypoxia, sepsis, drugs, and many others.
Vagal maneuvers increase vagal tone via multiple mechanisms, two of which are increasing intrathoracic pressure and increasing blood pressure. I would suggest that the maneuver described in this article works better simply because it causes a greater rise in blood pressure and intrathoracic pressure and causes greater vagal stimulation than other vagal maneuvers. Increasing arterial blood pressure stretches the baroreceptors (high pressure receptors) in the large arteries of the upper body, most notably in the aortic arch and the internal carotid artery just above the carotid bifurcation (carotid sinus). When baroreceptors are stimulated, nerve impulses enter the brain and result in increased vagal output and inhibition of sympathetic nervous system output.
The blood pressure and intrathoracic pressure of patients in the position pictured probably rise more than when they are straining in the supine or sitting position. Holding the legs above the head also increases venous return to the heart and adds to the rise in blood pressure that one experiences in this position.