Ventricular Tachycardia on ECG: Symptoms and Characteristics

Ventricular tachycardia (VT) is a type of rapid heart rhythm that originates in the ventricles and is defined as three or more consecutive premature ventricular contractions occurring at a heart rate typically exceeding 100 beats per minute. This condition can present in various forms, including monomorphic or polymorphic patterns, and is often associated with hemodynamic instability, especially in patients with underlying heart disease.

ECG Features of Ventricular Tachycardia

On an electrocardiogram (ECG), ventricular tachycardia is characterized by a sequence of three or more wide QRS complexes, each typically lasting longer than 0.12 seconds. These QRS waves appear broad and abnormal in shape, with no preceding P waves visible, indicating that the impulse is not originating from the atria.

Key Diagnostic Criteria

One of the hallmark signs of VT on ECG is the presence of a wide QRS complex tachycardia. Additionally, secondary ST-T wave changes are commonly observed, which reflect the altered ventricular repolarization patterns. The heart rate during an episode of VT usually ranges between 100 and 200 beats per minute, and the rhythm may be either regular or slightly irregular, depending on the subtype.

Clinical Significance and Urgency

Ventricular tachycardia is considered a medical emergency and is one of the most critical arrhythmias encountered in cardiology. It can lead to serious complications such as reduced cardiac output, loss of consciousness, and even progress to ventricular fibrillation if not promptly treated. Therefore, immediate recognition and intervention are essential in managing this condition.