CARDAMYST NASAL SPRAY APPROVED TO TREAT ACUTE SVT

Intranasal etripamil offers a new self-administered option for rapid PSVT conversion in select patients

Straight Healthcare
March 2026

Paroxysmal supraventricular tachycardia (PSVT) is common in outpatient and emergency practice, with a prevalence in the U.S. of roughly 168 to 332 per 100,000 (about 2.29 per 1,000 persons). Women account for most diagnosed cases, and risk rises substantially with age, with adults older than 65 years carrying several-fold higher risk than younger adults. In ablation series, AV nodal reentrant tachycardia (AVNRT) is the dominant mechanism, followed by AV reentrant tachycardia and focal atrial tachycardia. During acute episodes, vagal maneuvers, such as the Valsalva maneuver, remain first-line therapy because they are rapid, low-cost, and immediately available. However, the success rate of vagal maneuvers is low, only 5 - 20% in clinical practice.

Cardamyst® (etripamil) is a short-acting intranasal L-type calcium channel blocker recently approved by the FDA for conversion of acute symptomatic PSVT to sinus rhythm in adults. It works by reducing calcium influx in AV nodal tissue, thereby interrupting AV nodal-dependent reentry and facilitating rhythm termination. In its pivotal trial, 184 patients with confirmed atrioventricular-nodal-dependent PSVT were randomized to Cardamyst or placebo during symptomatic events. Conversion to sinus rhythm within 30 minutes occurred in 64% of the Cardamyst group versus 31% in the placebo group (hazard ratio 2.62; 95% CI 1.66 to 4.15; p<0.0001). Median time to conversion was 17.2 and 53.5 minutes, respectively. The most common adverse reactions were local nasal effects, including nasal discomfort (28%), nasal congestion (14%), and rhinorrhea (12%). Cardamyst is contraindicated in patients with heart failure (NYHA Class II-IV), pre-excitation syndromes such as Wolff-Parkinson-White (WPW), sick sinus syndrome, and advanced heart block.

While catheter ablation, which has a success rate exceeding 94%, remains the curative first-line therapy for recurrent symptomatic PSVT, Cardamyst provides a crucial non-invasive alternative. For patients with nodal reentrant SVT who are not ideal surgical candidates or who choose to defer invasive procedures, this "pill-in-the-pocket" nasal spray offers a reliable method for self-management outside the hospital setting. By facilitating rapid conversion at home, Cardamyst may reduce the frequency of ED visits and the need for intravenous pharmacotherapy, thereby providing patients with greater autonomy in managing their condition. As clinicians integrate this therapy into practice, it will likely serve as a bridge or alternative for those seeking to avoid the risks associated with catheter-based interventions.