Researchers: Studies Show Beta Blockers Help Children With POTS

Heart rate variability may pinpoint who will benefit

Postural orthostatic tachycardia syndrome (POTS) is fairly common in children, but because of complex factors (hypovolemia and autonomic dysfunction, for example), children with the condition often have a hard time making normal adjustments through cardiac output compensation, say researchers from Peking University in Beijing. POTS can have serious effects, including recurrent syncope attacks that lead to physical and psychological damage.

Randomized trials have supported using beta blockers to treat adult patients with POTS, but findings have been inconsistent on that treatment for children. The researchers analyzed eight studies comparing the beta blocker metoprolol with conventional treatments (such as oral rehydration salts or patient education) in 340 children. They reported their results in Frontiers in Pediatrics

Symptoms improved in 198 children given metoprolol and 142 children on conventional treatment, but the effective rate at the end of short-term follow-up was significantly higher in the metoprolol group (79.5 versus 57.3).

There were no reported severe adverse events.

Other researchers at Peking University conducted a separate study, which included 45 children with POTS who received metoprolol and 17 healthy controls. Their results are evidence that only some children wilh POTS will benefit from beta blockers and, furthermore, that beta blockers may impair exercise intolerance. But they also found that baseline heart rate variability indicators predicted the drug’s efficacy.Their study provides noninvasive and easy-to-use ways to help identify who might respond best to therapy.

Baseline triangular index ≤ 33.7 and standard deviation of all normal-to-normal intervals index ≤ 79.0 ms were the most useful. Combining the two indices as the cut-off values had sensitivity of 85.3, specificity of 81.8, and accuracy of 84.4%.