Background: It is known that approximately two-thirds of patients with vasovagal syncope have prodromal symptoms and when these start, physical maneuvers that can increase venous return may abort the syncopal attack. The aims of this study were to evaluate the effects of 3 physical maneuvers, squatting, leg-crossing with muscle tensing, and handgrip, on improving hemodynamic status, and to compare the effect of each on aborting or preventing vasovagal syncope.
Methods and results: Of 50 patients who underwent the head-up tilt test (HUT) to evaluate syncope, 27 patients with positive HUT were classified as group I (14 men, 13 women; mean age 44.5+/-15.3 years), 23 patients with negative HUT were classified as group II (13 men, 10 women; mean age 41.2 +/-16.7 years), and 21 normal subjects were classified as group III (10 men, 11 women; mean age 28.6+/-6.3 years). The effects of the physical maneuvers were evaluated in 21 patients from group I who underwent a repeat HUT 1 week after the initial test. Leg-crossing significantly increased systolic blood pressure (SBP) in all 3 groups (8.0+/-5.8 mmHg in group I, 7.0+/-8.5 mmHg in group II, 8.7+/-5.7 mmHg in group III; p < 0.05), but not diastolic blood pressure (DBP). Squatting significantly increased SBP and DBP in all 3 groups (7.1 +/-5.1, 4.6+/-5.8 mmHg in group I, 7.8+/-5.9, 4.3+/-4.7 mmHg in group II, 6.5+/-5.0, 3.7+/-3.9 mmHg in group III; p < 0.05). However, handgrip did not exert any significant influence on the hemodynamics in any group nor did heart rate change significantly during the physical maneuvers in any group. During the repeat HUT, prodromal symptoms with hypotension developed in 13 of the 21 patients and of these 5 fainted immediately after and were not able to do the physical maneuvers. Squatting and leg-crossing aborted syncope in 7 of 8 patients, but handgrip aborted syncope in only 1 patient.
Conclusion: Squatting and leg-crossing with muscle tensing improved the hemodynamics of normal subjects as well as those of patients with vasovagal syncope. Squatting and leg-crossing can be used as a simple and effective preventive maneuver in patients with vasovagal syncope.