During the prodromal phase of a vasovagal syncope, blood pressure falls markedly; this fall usually precedes the decrease in heart rate, which may be absent at least at the beginning of this phase. Hypotension is caused by vasodilatation in the skeletal muscles due to inhibition of sympathetic vasoconstrictive activity. Acute tilt studies (1,2) showed that isometric manoeuvres of the arms or of the legs are able to induce an abrupt significant blood pressure increase during the phase of impending vasovagal syncope, which is already evident after 10 s, and allow the patient to avoid or delay losing consciousness in most cases. This effect seems to be mediated largely by sympathetic nerve discharge and vascular resistance increase during manoeuvres and to to mechanical compression of the venous vascular bed in the legs and abdomen. Consequently, symptoms of impending syncope disappear in many patients or remain unchanged in others, and syncope is aborted even when the patient remains in the standing position.
Instruction Counterpressure Manoeuvres
Three manoeuvres have been validated.
Arm-tensing consists of the maximum tolerated isometric contraction of the two arms achieved by gripping one hand with the other and contemporarily abducting (pushing away) the arms.
Handgrip consists of the maximal voluntary contraction of a rubber ball (approximately of 5-6 cm diameter) taken in the dominant hand for the maximum tolerated time or till to complete disappearance of symptoms.
Leg crossing consists of leg-crossing combined with maximum tensing of leg, abdominal and buttock muscles
Patients are instructed to maintain the manoeuvre they choose as long as possible and eventually move on to the second manoeuvre if useful. A session protocol (maximum duration of 1 hour) consists of: explanation of purpose and session-program; explanation of simple physiology and vasovagal reflexes; demonstration and explanation of the 3 manoeuvres; practising of the 3 manoeuvres using the beat-to-beat blood pressure recordings and electrocardiographic monitoring as biofeedback signal.
Vasovagal syncope is a benign condition. According to the recent recommendations of the ESC Guidelines on Syncope (3) the patients who seek medical advice after having experienced a vasovagal faint require principally reassurance and education regarding the nature of the condition. In general, initial ‘treatment’ of all forms of neurally-mediated reflex syncope comprises education regarding avoidance of triggering events (e.g., hot crowded environments, volume depletion, effects of cough, tight collars, etc.), recognition of premonitory symptoms, and manoeuvers to abort the episode. Non-pharmacological “physical” treatments are arising as a new first choice treatment of vasovagal syncope in patients who have vasovagal syncope preceded by prodromal symptoms and age <65 years. This approach seems to be very helpful in real life. In 2 follow-up studies (1,2), the manoevres were self-administered by these patients in >95% of cases and were able to abort syncope in >95% of patients. No patients had injury or other adverse morbidity related to the relapses. The treatment was easy to perform, reliable, safe and well accepted by the patients, who expressed good satisfaction.
The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.