Supraventricular Tachycardia vs. Ventricular Tachycardia

Attribute	Supraventricular Tachycardia	Ventricular Tachycardia
Location of origin	Above the ventricles	In the ventricles
Heart rate	Usually 150-250 bpm	Usually 100-250 bpm
QRS complex	Narrow	Wide
Causes	Can be triggered by stress, caffeine, alcohol, etc.	Often caused by heart disease or previous heart attack
Symptoms	Palpitations, dizziness, shortness of breath	Chest pain, fainting, sudden cardiac arrest

Introduction

Supraventricular tachycardia (SVT) and ventricular tachycardia (VT) are both types of abnormal heart rhythms that can cause rapid heart rates. While they may sound similar, there are key differences between the two conditions that affect their diagnosis, treatment, and prognosis.

Causes

SVT is typically caused by abnormal electrical pathways in the heart that lead to rapid heart rates. These pathways can be present from birth or develop later in life. Common triggers for SVT include stress, caffeine, and certain medications. On the other hand, VT is often associated with heart disease, such as a previous heart attack or cardiomyopathy. It can also be caused by electrolyte imbalances or certain medications.

Symptoms

Both SVT and VT can cause symptoms such as palpitations, dizziness, chest pain, and shortness of breath. However, SVT tends to come on suddenly and may resolve on its own, while VT is more likely to be sustained and can be life-threatening. In severe cases, VT can lead to loss of consciousness or cardiac arrest.

Diagnosis

Diagnosing SVT and VT typically involves an electrocardiogram (ECG) to record the heart's electrical activity. In SVT, the ECG will show a rapid heart rate originating above the ventricles. In VT, the ECG will show a wide QRS complex, indicating that the rapid heart rate is originating in the ventricles. Additional tests, such as a Holter monitor or electrophysiology study, may be needed to confirm the diagnosis.

Treatment

Treatment for SVT and VT varies depending on the underlying cause and severity of the condition. In SVT, maneuvers such as Valsalva maneuver or carotid massage may help restore normal heart rhythm. Medications, such as beta-blockers or calcium channel blockers, may also be used to control heart rate. In some cases, catheter ablation may be recommended to eliminate the abnormal electrical pathways. On the other hand, VT may require more aggressive treatment, such as antiarrhythmic medications, implantable cardioverter-defibrillator (ICD) placement, or even cardiac ablation.

Prognosis

The prognosis for SVT and VT varies depending on the underlying cause, response to treatment, and presence of other medical conditions. In general, SVT is considered to have a better prognosis than VT, as it is less likely to be life-threatening. With appropriate treatment, most people with SVT can lead normal, healthy lives. VT, on the other hand, can be more challenging to manage and may require ongoing monitoring and treatment to prevent complications.