What is the approach to evaluating Non-Sustained Ventricular Tachycardia (NSVT)?

From the Guidelines

The workup of non-sustained ventricular tachycardia (NSVT) should include a minimum of a 12-lead ECG, stress test, echocardiography, and a 24-hour ambulatory monitor, as recommended by the American Heart Association and American College of Cardiology 1.

Key Components of the Workup

• A 12-lead ECG to assess for underlying cardiac abnormalities
• Stress test, including echocardiography, to evaluate for ischemia and cardiac function
• A 24-hour ambulatory monitor to characterize the frequency and nature of arrhythmias
• The patient should be instructed to perform their usual levels of exercise with the monitor in place

Considerations for Athletes

• Athletes with NSVT at rest that is suppressed with exercise and who have no evidence of structural heart disease, molecular/genetic disorders, or transient abnormalities at the time of evaluation can be cleared for competitive athletics without limitations 1
• If structural heart disease is identified, the athlete should be limited to class IA competitive sports

Additional Considerations

• The presence of PVCs, including NSVT, has been associated with increased cardiovascular risk and mortality, particularly in patients with underlying heart disease 1
• The detection of PVCs, particularly if multifocal and frequent, is generally considered a risk factor for adverse cardiovascular outcomes, and such patients should be evaluated to ensure they do not have underlying conditions that warrant further treatment
• Treatment decisions, including antiarrhythmic medications or implantable cardioverter-defibrillator placement, should be based on the underlying etiology and risk stratification, taking into account the potential risks and benefits of treatment, as outlined in the 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1

From the Research

Diagnostic Approach

To work up NSVT, the following steps can be taken:

• Identify the presence of structural heart disease, as NSVT in patients with coronary artery disease is associated with an increased risk of sudden and nonsudden cardiac death 2
• Determine left ventricular function, as patients with left ventricular ejection fraction (LVEF) < 40% may be at higher risk 2
• Use diagnostic tools such as programmed electrical stimulation to identify low- and high-risk patients 3
• Consider the frequency of NSVT, as a higher frequency may indicate a higher risk of sudden death in patients with nonischemic dilated cardiomyopathy 3

Risk Stratification

Risk stratification is crucial in managing NSVT:

• Patients with a history of NSVT or monomorphic VT are more likely to benefit from antitachycardia pacing (ATP) therapy 4
• A history of NSVT or MVT is a significant predictor for appropriate and successful ATP therapy 4
• Patients with hypertrophic cardiomyopathy and NSVT may be at higher risk for cardiac arrest 3
• Patients with normal hearts and NSVT usually have a benign prognosis 5

Management

Management of NSVT depends on the individual patient's risk profile:

• Beta-blockers may be used as first-line therapy to control symptoms 2, 6
• Antiarrhythmic drugs, such as class III anti-arrhythmic agents, may be effective in certain patients 6
• Implantable cardiac defibrillators (ICDs) may be indicated in patients with a high risk of sudden cardiac death 6, 4
• Catheter ablation may be considered in patients with symptomatic NSVT or those who have not responded to medical therapy 6, 5