Rapid, Erratic Heart Rate: Is It Supraventricular Tachycardia (SVT)?

What is a Supraventricular Tachycardia?

Supraventricular Tachycardia (SVT), also called paroxysmal SVT (PSVT), is an umbrella term for episodes of rapid, erratic heartbeats that start and stop without warning. SVT is caused by signaling issues originating above the heart’s ventricles, which trigger a premature atrial beat and result in heart rates jumping quickly to over 100 bpm and often in the range of 150-220 bpm.

Like other arrhythmias, early and accurate identification and effective management contribute to improved patient outcomes and better quality of life.

How Prevalent is SVT?

SVT can occur at any age, and prevalence is approximately 1 in 300. Patients who are female and those who are older have higher rates,¹ with older adults being 5x more likely to experience SVT than individuals who are younger.^2,3

People at greater risk for SVT have coronary heart disease, hypertension, congenital heart disease, thyroid disease, and sleep apnea, as are those with anxiety, who drink more alcohol than recommended, smoke or use tobacco, or ingest large quantities of caffeine.

Types of SVT

• PSVT: paroxysmal supraventricular tachycardia, which often affects young people who are training or exercising hard
• AVNRT: atrioventricular nodal reentrant tachycardia, which is common in young adults and the elderly
• Accessory pathway tachycardia (e.g., Wolff-Parkinson-White syndrome) is common in those younger than 1
• PACs: premature atrial contractions
• Atrial tachycardia
• Atrial fibrillation
• Atrial flutter

Symptoms of SVT

While rarely life-threatening, SVT can significantly impact a patient’s life. While some patients may be asymptomatic, others experience mild symptoms and episodes that are infrequent and relatively short in duration. Another set of patients face a multitude of symptoms and/or long-duration episodes that alter sleep, affect the ability to stay active and enjoy daily activities, impact work, lead to potential risk for injury if syncope is involved, and necessitate visits to the emergency department.

SVT symptoms may last for a few seconds or even several hours. Severe or long-lasting symptoms may require medical attention.

Typical SVT Symptoms:

• Very rapid pulse (>100 bpm)
• Fluttering or pounding in the chest (palpitations)
• Pounding sensation in the neck
• Chest pressure or pain
• Shortness of breath
• Lightheadedness, dizziness
• Syncope
• Weakness or fatigue
• Anxiety

SVT Diagnosis and Treatment

Due to its intermittent nature, diagnosis of PSVT can be challenging, but early diagnosis may lead to reduced symptom burden and improved quality of life. Even when a patient’s episodes of SVT are frequent, it may be difficult to definitively diagnose if the symptoms do not occur while the patient is being monitored in the clinical setting.

Most patients with SVT do not have underlying heart disease. SVT is often misdiagnosed as panic or stress.

In addition to a thorough health and family history, SVT diagnosis may include:

• Blood tests to identify potential causes of a fast heartbeat, such as thyroid issues
• Short-term rate and rhythm assessments: ECG/EKG, Holter monitor, event recorder
• Implantable loop recorder to record heartbeat for a period of up to 3 years
• Echocardiogram to assess how blood flows through the heart and valves
• Stress test to see if exercise triggers an SVT episode or makes it work
• Tilt table test to determine if elevated heart rate leads to fainting
• Electrophysiological (EP) study to identify where the erratic heartbeat originates

If SVT happens often, it may lead to dilated cardiomyopathy—but some or all of the damage may be reversed with treatment.

Once SVT has been identified, treatment is determined based largely on whether the patient is hemodynamically stable. Treatment for stable patients typically starts with less invasive, non-pharmacologic interventions, including vagal maneuvers, carotid sinus massage, or placing the face in ice water.

If these options are unsuccessful, the next step is the use of IV medications to control heart rate (chemical cardioversion). A direct current cardioversion can be performed if the patient is unstable, or if previous measures are not effective.

Catheter ablation is curative and a fairly low-risk treatment with a success rate of up to 98%.

Depending upon the circumstances, patients may be better suited for long-term pharmacotherapy instead of ablation. Medications (pill, nasal spray) may be taken all the time, or only as needed for acute needs.

Quality of Life with SVT

While SVT symptoms may not occur frequently, and may resolve on their own in minutes, the uncertainty about the timing and location of recurrence may cause a significant burden for patients. Ongoing worries—whether an event will take place in a location such as work or while driving, or the prospect of an emergency room visit with the associated costs and complexities—can lead to long-term stress and other related health issues.

Encouragement, support and reassurance from family, friends, and healthcare professionals, as well as other patients, can help mitigate fear and lead to greater confidence and feelings of well-being by patients with SVT.

Helping patients understand the disease and its management may lead to increased implementation of self-care and lifestyle modifications to help reduce symptoms and increase medication adherence.

Clinical Takeaways

1. Patient and provider awareness of SVT helps increase diagnosis and effective treatments.
2. Symptom tracking by patients can be helpful in effective management
3. A combination of lifestyle modifications, pharmacotherapies, and procedures may be used to treat SVT.
4. Patients should know what symptoms should lead them to seek help in the Emergency Department or trigger a call to their healthcare team.
5. Open communication between the patient and their healthcare team ensures that worsening symptoms or decreasing treatment effectiveness can be addressed promptly.

SVT Resources

PCNA has a series of informational resources for healthcare professionals and patients.

Videos

• PSVT: Barriers and Solutions to the Disease Burden for Patients – Symptoms and quality of life for patients with PSVT, and best practices to reduce burden from the perspective of both clinicians and patients.
• PSVT Strikes Any Time, Any Place – Capturing a conversation between a health care professional (HCP) and a patient with SVT—who is also a nurse—this 11-minute video focuses on the patient’s journey.

Podcast Episodes

• PSVT: Exploring Treatment Options for Paroxysmal Supraventricular Tachycardia – Review of clinical trial data, and current and future treatment options
• PSVT: Spotlight on Transitions of Care Across Settings – Discussion of trends of patients seeking care in outpatient and emergency department settings, and best practices for closing the gap in disparities to care
• Episodic Rapid Heart Rates—PSVT, AFib, and More – Pathophysiology, prevalence, symptoms, and disparities related to diagnosis and treatments, and helpful resources for providers and patients
• Living with PSVT: A Patient-Centered Care Plan -Learn about the patient journey for those living with PSVT, including the challenges that can delay diagnosis, as well as the importance of patient-centered care in and beyond the healthcare setting
• Treatment for PSVT – A discussion of traditional pharmacologic and non-pharmacologic treatment options, plus research into additional treatments –