• Posted September 27, 2023

Fast-Acting Nasal Spray May Ease Rapid Heartbeat

Up to 2 million people in the U.S. experience rapid-fire heartbeats from time to time, and many end up in the hospital for treatment.

But an investigational nasal spray may help folks with paroxysmal supraventricular tachycardia (PSVT) safely and quickly slow their heart rate on their own.

"Currently, PSVT is treated with intravenous medication administered in the emergency room or by paramedics when vagal maneuvers are not effective, which is the majority of cases,"said study leader Dr. James Ip, an associate professor of clinical medicine at Weill Cornell Medical Center in New York City.

Vagal maneuvers are physical actions such as bearing down that make the vagus nerve slow your heart down.

At 160 to 250 heartbeats a minute, Ip said PSVT can be scary, but it isn't usually life-threatening.

When self-administered as a nasal spray, etripamil can slow heart rate in 30 minutes, according to a clinical trial funded by its maker, Milestone Pharma. Etripamil is a calcium channel blocker, a class of drugs known to slow down heart rates.

No medications are currently approved to treat PSVT without direct medical supervision, researchers said in background notes.

"This is a game changer because patients can now treat their own PSVT episode by themselves and avoid calling an ambulance or going to the emergency room,"Ip said.

The study was published Sept. 27 in the Journal of the American Heart Association. Milestone Pharma plans to submit a new drug application to the U.S. Food and Drug Administration in October.

The new research is an extension of a previous trial of the nasal spray. Folks were 58 years old, on average, and had experienced 9.7 PSVT episodes in the previous year. Most were taking long-acting medications to prevent rapid heartbeats.

They wore an electrocardiogram (ECG) patch linked to a cellphone to transmit data about their symptoms. During PSVT episodes, they did a vagal maneuver, and self-administered the nasal spray if the rapid heartbeat continued. They kept the ECG patch on for five hours after the episode.

Of the 169 participants, 105 self-administered at least one dose of etripamil over seven months. Etripamil restored heart rate to normal within 30 minutes in 60% of 188 PSVT episodes, and within an hour in 75% of the episodes, the study showed.

Of 40 participants who self-treated two PSVT episodes, 63% responded to the medication within 30 minutes. What's more, people were good at detecting when they were experiencing these rapid heart rhythms, with 92 having one or more episodes confirmed by their ECG patch.

Ip said there were no serious heart-related adverse effects from the drug, and the most common side effects were nasal congestion or runny nose.

"The safety has been consistently demonstrated as a single dose, after a repeat dose after 10 minutes [if the first dose doesn't work], and after repeat dosing for multiple events,"he said.

By contrast, oral medications take longer to work and may be associated with safety concerns such as fainting and low blood pressure, Ip said.

The drug is also being studied in people with a common heart rhythm disorder called atrial fibrillation (a-fib) and in children aged 6 to 17.

Outside experts agree that if approved, this nasal spray could be a game changer for the millions of people who experience rapid heartbeats.

"In the future, this could be a very effective and safe way for patients to treat themselves for this bothersome condition,"said Dr. Deepak Bhatt, director of Mount Sinai Heart and professor of cardiovascular medicine at the Icahn School of Medicine in New York City.

Current treatment options for PSVT aren't always ideal, added Dr. Javier Banchs, director of electrophysiology and pacing at Baylor Scott & White Health in Dallas.

Catheter ablation uses a narrow plastic tube to kill cells responsible for the heart rhythm problems and is highly effective, but not everyone is a candidate or wants to undergo the procedure, he said.

Vagal maneuvers like straining, washing your face, drinking ice-cold water, or lying on your back with the legs elevated above the heart level don't always work either, Banchs said.

"A drug called adenosine, which can only be given through intravenous access, has been the pharmacological treatment of choice, but the success of a drug like etripamil in clinical trials has been long waited for," he said.

Dr. Adam Shapira , a cardiac electrophysiologist at Baylor Scott & White Health in Dallas, agreed.

"Having a safe, effective and self-administered pharmacological agent to terminate PSVT is a breakthrough," he said. "This agent will likely become the treatment of choice."

More information

The U.S. National Library of Medicine has more on paroxysmal supraventricular tachycardia (PSVT).

SOURCES: James Ip, MD, associate professor, clinical medicine, Weill Cornell Medical Center, New York City; Deepak Bhatt, MD, MPH, director, Mount Sinai Heart, professor, cardiovascular medicine, Icahn School of Medicine, New York City; Javier Banchs, MD, director, electrophysiology and pacing, Baylor Scott & White Health, Dallas; Adam Shapira, MD, cardiac electrophysiologist, Baylor Scott & White Health; Journal of the American Heart Association, Sept. 27, 2023