Non-sustained Ventricular Tachycardia: An Overview

What Is Non-sustained Ventricular Tachycardia?

Non-sustained ventricular tachycardia (NSVT) is defined as a sequence of three or more consecutive ventricular beats that occur at a rate greater than 100 beats per minute and last less than 30 seconds. Nonsustained ventricular tachycardia (NSVT) has been observed in a variety of settings, ranging from healthy people to patients with serious cardiac disease. The predictive value of NSVT is questionable in the absence of heart disease. When NSVT is identified after exercise, particularly during the recovery phase, it suggests a higher risk of cardiovascular death in subsequent years.

What Are the Symptoms of Non-sustained Ventricular Tachycardia?

NSVT symptoms may differ on an individual's age, underlying medical conditions, and the presence of structural heart disease. Typical signs and symptoms include:

• Heart palpitations.

• Shortness of breath.

• Chest pain.

• Fainting.

• Feeling dizziness or lightheadedness.

• Nausea.

What Is the Diagnosis of Non-sustained Ventricular Tachycardia?

Patients who do not exhibit any signs of NSVT may still be tested for other causes. Physicians can recommend various tests to determine the underlying reason for a patient's symptoms. These include,

• An electrocardiogram (ECG) looks for heart electrical activity abnormalities.

• Exercise stress testing evaluates the heart's activity during physical activity.

• An echocardiogram employs ultrasonography to create heart pictures showing its anatomy and functionality.

• Coronary angiography uses X-rays to examine the heart's blood vessels.

• Blood tests to determine the electrolyte levels.

• CT and MRI scans for the heart.

• Genetic testing assesses if a patient inherits a certain heart problem.

NSVT can be detected by instruments not designed to diagnose ventricular tachycardia. Pacemakers and implantable cardiac monitors are examples of equipment causing NSVT. Ambulatory ECG devices monitor the heart's electrical activity for several days, weeks, or years. A longer monitoring period makes it possible to observe and record rare cardiac arrhythmias such as NSVT. The Holter monitor is an ambulatory ECG device. This portable, lightweight monitor is wired to tiny discs called electrodes and is placed on the chest. The Holter monitor is worn for 24 to 48 hours to record the cardiac rhythm.

What Is the Treatment of Non-sustained Ventricular Tachycardia?

NSVT does not necessarily require treatment. The underlying etiology and symptoms will determine its management. Treatment for patients without heart disease consists of routine follow-up visits with the doctor and notifying any changes. NSVT in individuals with a healthy heart is regarded as benign and does not require medical attention.

• Medications: Medications such as beta-blockers, calcium channel blockers, or Amiodarone may be effective with symptoms of NSVT. Amiodarone is an antiarrhythmic medication that helps to maintain the heart's rhythm. Antiarrhythmic medications such as Sotalol and Flecainide are not advised for the treatment of non-sustained ventricular tachycardia (NSVT), particularly in cases of severe cardiac events followed by NSVT. Antiarrhythmic medications can help treat severe symptoms.

• Ablation Therapy: Ablation therapy may be a viable alternative for individuals experiencing severe symptoms or who are not responding to anti-arrhythmic medications. This treatment employs heat or cold energy to treat the heart area responsible for aberrant electrical signals. About 80 percent of cases of NSVT are successfully treated with ablation therapy.

• Implantable Cardioverter-Defibrillator: When NSVT coexists with heart failure or coronary artery disease, it increases the chance of cardiac arrest and sudden death in people with hypertrophic cardiomyopathy. In these cases, the risk is primarily decreased blood flow from the left ventricle (ejection fraction) rather than NSVT. An implantable cardioverter-defibrillator (ICD) may be advised to lower the risk. An ICD is a battery-powered device inserted beneath the skin on the chest. It monitors the cardiac rhythm and sends minimal electrical shocks or currents if it becomes abnormal.

How Does Non-sustained Ventricular Tachycardia Affect Other Diseases?

• NSVT and Heart Failure: NSVT was linked to an increase in the rate of new-onset heart failure. NSVT may result in vagally-mediated late heart rate decline through the autonomic nervous system. This condition may be caused by increased oxygen consumption or ventricular dyssynchrony. Ventricular dyssynchrony also modifies myocardial blood flow and asymmetrical thickening of the walls. Moreover, recurrent dyssynchrony may worsen calcium levels and lead to aberrant contractions.

• NSVT and Stroke: NSVT is a separate risk factor for the occurrence of TIA (transient ischemic anemia) and stroke. NSVT induces ventricular dyssynchrony and may lead to mechanical anomalies in the left atrial appendage, which could explain the increased risk of stroke or thromboembolic event. NSVT in a structurally normal heart was a sign of other stroke-causing illnesses.

• NVST and Systemic Hypertension: There is a correlation between the degree of subendocardial fibrosis and cardiac hypertrophy in patients with arterial hypertension and NSVT. NSVT affects 12 percent to 28 percent of patients with hypertension and LV hypertrophy compared to patients with hypertension alone. The specific mechanism of ventricular arrhythmia in patients with hypertension or valve dysfunction is unknown.

How to Prevent Non-sustained Ventricular Tachycardia?

Certain heart diseases can be prevented, while NSVT cannot. However, some actions can be taken to lower the NSVT risk factors. Making the following lifestyle adjustments can improve heart health and reduce the chance of NSVT:

• Engage in moderate-intense physical exercise for at least 150 minutes a week (such as brisk walking) or vigorous-intense physical activity for at least 75 minutes (such as jogging).

• Consume a diet high in fruits, whole grains, vegetables, lean protein, nuts, and seafood to ensure optimal health.

• Reduce the consumption of processed meats, red meat, refined carbohydrates (such as white rice and pasta), and sugary drinks.

• Achieve and maintain a healthy weight.

• Quit smoking and avoid secondhand smoke.

• Regular check-ups with the doctor can identify heart health risk factors like high blood pressure, high cholesterol, and type 2 diabetes.

Conclusion:

NSVT can be observed in a variety of settings, from people with severe cardiac disease to healthy individuals. Depending on the underlying illness, its prognostic relevance varies and is unknown in different clinical scenarios. Treating the underlying heart condition is the goal of managing patients with non-sustained ventricular tachycardia (NSVT) unless there are severe symptoms.