Safety Study of Intranasal Etripamil for the Termination of Spontaneous Episodes of Paroxysmal Supraventricular Tachycardia (PSVT). NODE-302

The NODE-302 study is an extension of the NODE-301 efficacy study. It is a multi-centre, open label study designed to evaluate the safety of etripamil NS 70 mg when self-administered by patients for spontaneous episodes of PSVT in an outpatient setting. All patients randomized in the NODE-301 study and who meet the inclusion and exclusion criteria of the NODE-302 study are eligible for the NODE-302 study. After each episode of PSVT, patients will have the option to continue in the NODE-302 study and manage subsequent episodes of PSVT with etripamil NS 70 mg if they do not meet any withdrawal criteria. Each episode of PSVT will be documented by an ambulatory cardiac monitoring system (CMS) that will be placed on the chest by the patient or caregiver when symptoms begin, and will record at least 5 hours of continuous ECG. The study will include a Qualification Visit, a Treatment Period(s) , a Follow-up Visit(s) ,a Final Study Visit and if necessary an Early Termination Visit if the patient withdraws from the study after taking etripamil NS 70 mg and had a Follow-up Visit, or the patient withdraws from the study and did not take etripamil NS 70 mg.