The ECG Rhythms content is currently under development and is being updated by medical professionals.
Ventricular tachycardia (VTach) is a heart rhythm disorder characterized by a rapid sequence of three or more consecutive premature ventricular contractions (PVCs) originating from the ventricles. This rapid rhythm, typically exceeding 100 beats per minute, arises due to abnormal electrical activity within the ventricles.
Analogy: “A rapid, intense drum solo taking over the song’s rhythm.”
On an ECG, ventricular tachycardia is identified by a rapid heart rate, usually greater than 100 beats per minute and often ranging from 150 to 250 bpm. The QRS complexes are wide, with a duration of 0.12 seconds or greater (more than 3 small squares), and they lack a preceding P wave, indicating their ventricular origin. The morphology of the QRS complexes can be uniform from beat to beat (monomorphic ventricular tachycardia), suggesting a single origin in the ventricles, or it can vary (polymorphic ventricular tachycardia), indicating multiple ventricular foci or a re-entrant circuit. The rhythm in ventricular tachycardia is usually regular, although some beat-to-beat variability may be present. In some cases, there may be atrioventricular (AV) dissociation, where the atria and ventricles beat independently of each other. Ventricular tachycardia can be sustained, lasting for more than 30 seconds, or non-sustained, lasting for less than 30 seconds.
The symptoms of ventricular tachycardia can vary depending on the rate of the tachycardia and its duration. Individuals may experience palpitations, feeling their heart racing or pounding. Other symptoms can include dizziness, lightheadedness, and shortness of breath. Chest pain, also known as angina, may occur. In more severe cases, particularly with sustained ventricular tachycardia, individuals may experience fainting (syncope) or even loss of consciousness. Ventricular tachycardia is a potentially life-threatening arrhythmia that can lead to ventricular fibrillation or sudden cardiac arrest if not treated promptly. It is often associated with underlying heart disease, such as ischemic heart disease or cardiomyopathy, as well as acute myocardial infarction or electrolyte imbalances.
“Like a runaway engine speeding out of control, the ventricles are beating rapidly and ineffectively.”