TUESDAY, Aug. 12, 2025 (HealthDay News) -- Ivabradine lowers heart rate (HR) and relieves symptoms of postural orthostatic tachycardia syndrome (POTS), according to a study published online in the July issue of the Journal of Cardiovascular Pharmacology.Michele Marchetta, M.D., from the University of Virginia in Charlottesville, and colleagues reported the effects of HR lowering with ivabradine, a selective If channel blocker, on symptom burden in patients with POTS. The analysis included 10 patients (average age, 28 years) with POTS.The researchers found that after ivabradine treatment, there was a significant reduction in the change in HR with standing in all patients from 40 to 15 bpm, without significant changes in blood pressure. Additionally, in all patients, the Malmö score was significantly reduced from 86 to 39. There was a correlation between change in HR with standing and the change in Malmö score (R = +0.828; R2 quadratic = 0.635). Patients also reported improvement in "feeling faint," which decreased by 69 percent, and "chest pain," which decreased by 66 percent."The mechanisms controlling heart rate with standing appear to be dysfunctional, leading to an excessive increase in heart rate, which is in turn sensed by the brain as a 'danger' signal leading to further release of stress hormone, norepinephrine, and to symptoms that resemble anxiety and panic attacks," coauthor Antonio Abbate, M.D., Ph.D., also from University of Virginia, said in a statement. "When the heart rate is controlled with ivabradine, the loop is inhibited, and patients feel better."One author disclosed ties to Kiniksa, Monterosa Tx, and Novo Nordisk.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter