PO-05-237 A NOVEL STRATEGY OF AUTONOMIC REHABILITATION THERAPY FOR POSTURAL ORTHOSTATIC TACHYCARDIA SYNDROME

Abstract

Postural Orthostatic Tachycardia Syndrome (POTS) is defined as a sustained increase in HR (>30 bpm) in upright position, orthostatic intolerance, and absence of hypotension. POTS is underdiagnosed and associated with functional disability. Its mechanisms include autonomic denervation, genetic disease, hypovolemia, hyperadrenergic status and deconditioning. POTS patients (pts) have difficulty to perform strengthening exercises for lower limbs and abdominal muscles due to fatigue, pain and comorbidities that make certain movements impractical without supervision. Therefore, they are unable to perform conventional free or supervised training programs. To evaluate the feasibility of a novel training protocol named as Autonomic Rehabilitation Program (ARP) and to report the outcome of patients who completed the program. Five POTS pts were studied–history, physical examination and autonomic tests. All pts were under conventional treatment with no improvement and underwent the specially designed physiotherapy program. The protocol consists in applying peripheral muscle electrostimulation with different frequencies, ranging from 5 to 50 Hertz, aiming to promote pumping contractions at 5Hz and evolving to 50Hz bands to increase the capacity for resisted contractions. We initially stimulated the bilateral antigravity muscle groups, with a 4-channel device, starting contractions promoted only by the device, with the pt completely passive. From the moment the pt felt confortable, active-assisted contractions (pt's exercises together with stimulation) were started isometrically, progressing to eccentric exercises and then to concentric and concentric-resisted exercises. Orthostatic intolerance, functional capacity,and HR before and post-ARP were evaluated. Five pts (5 females, 1 male) with an average age of 32 yo, completed ARP. Before therapy, they presented reduction of systolic index, increased HR (> 30 beats/min in relation to supine position) and low increment of TPR in upright position in the autonomic tests. After a mean follow-up of 8.6 weeks, all of them presented reduction of HR, reported significant improvement of symptoms (one of them referred total remission) and were able to initiate free conventional exercises.The ARP was well tolerated. These exercise adaptation ramps using the peripheral electrostimulation device seem to be more efficient than conventional physiotherapy. Further studies are needed to evaluate the long-term benefit of this strategy