NASVAL-SVT: Nasal Swab Versus Modified Valsalva for Supraventricular Tachycardia (NCT07617077) | Clinical Trial Compass
RecruitingNot Applicable
NASVAL-SVT: Nasal Swab Versus Modified Valsalva for Supraventricular Tachycardia
Turkey (Türkiye)60 participantsStarted 2026-05-01
Plain-language summary
Supraventricular tachycardia (SVT) is a common heart rhythm disorder seen in emergency departments, causing a rapid heartbeat (typically 150-250 beats per minute). The current best non-drug treatment, the modified Valsalva maneuver (mVM), successfully restores normal rhythm in about 43% of cases. When these maneuvers fail, intravenous adenosine is used, which, while effective, can cause brief but distressing side effects such as chest tightness, shortness of breath, and intense anxiety.
During the COVID-19 pandemic, some patients briefly fainted during nasal swab collection. This happens because inserting a swab into the back of the nasal cavity (nasopharynx) stimulates the trigeminal nerve, which then activates the vagus nerve and slows the heart - a phenomenon called the trigeminocardiac (or nasocardiac) reflex. One published case report described a patient whose SVT was terminated within 10 seconds using a nasal swab.
This study compares the nasal swab technique with the modified Valsalva maneuver in patients presenting to the emergency department with SVT. Patients are randomly assigned to one of two groups. The primary outcome is whether a normal heart rhythm is restored within 1 minute of the procedure. Patient comfort and satisfaction are also measured.
The study is conducted in two phases. The first (pilot) phase (30 patients per group) will assess whether the study can be successfully conducted and collect data to finalize the required sample size. The second (main) phase will use the pilot phase's actual data to determine the final number of participants needed.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Age 18 years or older
* Electrocardiographically confirmed supraventricular tachycardia (SVT): narrow QRS complex (≤120 ms), regular rhythm, rapid ventricular rate, documented on 12-lead ECG or continuous cardiac monitoring
* Hemodynamic stability, defined as ALL of the following simultaneously present:
* Systolic blood pressure ≥90 mmHg
* Diastolic blood pressure ≥60 mmHg
* Alert and oriented mental status (GCS 15)
* No signs of acute end-organ dysfunction
* Ability and willingness to provide written informed consent
Exclusion Criteria:
* Age younger than 18 years
* Pregnancy (known or suspected)
* Inability to confirm SVT diagnosis by ECG criteria
* Delta wave or pre-excitation pattern on ECG (Wolff-Parkinson-White syndrome or asymptomatic pre-excitation) - due to risk of ventricular fibrillation with vagal maneuvers
* Wide QRS tachycardia (QRS ≥120 ms) where ventricular tachycardia cannot be excluded
* Absolute contraindication to modified Valsalva maneuver (inability to assume supine position or passive leg elevation)
* Contraindication to nasal swab (nasal surgery within 30 days, active epistaxis, visible nasal polyp or mass)
* Hemodynamic instability requiring immediate synchronized cardioversion
* Prior enrollment in this study (re-presentation with SVT)
* Refusal to participate
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Sinus Rhythm Conversion Rate at 1 Minute
Timeframe: 1 minute after procedure completion
Trial details
NCT IDNCT07617077
SponsorMarmara University Pendik Training and Research Hospital