Paroxysmal supraventricular tachycardia symptoms and causes
“PSVT is an abnormally fast heart rhythm that involves the upper chambers (the atria) of the heart. The rates can range anywhere from 100 beats per minute to over 200 beats per minutes,” Emory cardiologist and arrhythmia expert Michael Lloyd, MD, explains. “Technically, if a person were to go on a run and get their natural heart rate to over 100, this could be interpreted as a form of SVT, but doctors distinguish a naturally fast heart rate from fear, stress, and exercise as a normal sinus tachycardia which is different than PSVT. We use the term PSVT (paroxysmal SVT) to describe the fact that true PSVT usually starts and stops suddenly and abruptly. The symptoms usually feel like a fluttering in the chest. Many patients describe being able to see their shirt move due to the rapid beating of the heart.”
Episodes can last for minutes to hours and, while they usually stop on their own, if the episodes continue unabated, medical intervention using an intravenous medicine called adenosine can interrupt the PSVT, according to Lloyd.
“In most cases, PSVT is simply from an abnormal electrical connection within the heart's conduction (electrical system). It’s analogous to being born with a freckle or mole on a certain part of the body. That is, it’s usually a sporadic, innocent developmental variation that isn't rigidly passed down through families,” Lloyd explains. “PSVT is typically associated with an otherwise normal heart and does not increase the risk of heart attack, or future heart disease.”
However, while it isn’t life-threatening, the condition can threaten quality of life if it goes undiagnosed and untreated.
“The random, sporadic nature of PSVT makes it very hard to capture or demonstrate to healthcare providers,” says Lloyd, who is an electrophysiologist, a specialist in the treatment of heart rhythm disorders. “Unfortunately, this leads to the episodes being misdiagnosed as anxiety or panic attacks.”
The confusion is understandable because panic disorder is common, affecting about three percent of Americans, according to the National Institutes of Mental Health. And, like PSVT, panic attacks can come on suddenly and be accompanied by fast heartbeats and feelings of intense fear.
However, the switch-like turning on and off of the racing heartbeats can be an important clue that PSVT is behind the symptoms. And technology is helping make the diagnosis of the condition easier with smartphone apps that capture arrhythmias outside the doctor’s office.
“Luckily, smartphones now have empowered patients to have a readily available monitoring system to allow better capture and diagnosis of the episodes,” Lloyd says.
March 02, 2020
Christopher Nystuen, MD, MBA