Ventricular tachycardia overview: Difference between revisions
| Line 21: | Line 21: | ||
===Prognosis=== | ===Prognosis=== | ||
Sustained ventricular tachycardia in general carries a poor prognosis due to an increased risk of [[sudden cardiac death]]. | Sustained ventricular tachycardia in general carries a poor prognosis due to an increased risk of [[sudden cardiac death]]. | ||
==Diagnosis== | |||
===Chest X Ray=== | |||
Chest X rays are done only when ventricular tachycardia leads to [[congestive heart failure]] or if a secondary pathological disease is suspected as the cause of ventricular tachycardia. | |||
==Treatment== | ==Treatment== | ||
Revision as of 17:26, 15 January 2013
|
Ventricular tachycardia Microchapters |
|
Differentiating Ventricular Tachycardia from other Disorders |
|---|
|
Diagnosis |
|
Treatment |
|
Case Studies |
|
Ventricular tachycardia overview On the Web |
|
Risk calculators and risk factors for Ventricular tachycardia overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2], Avirup Guha, M.B.B.S.[3]
Overview
Ventricular tachycardia is a tachycardia, or fast heart rhythm that originates in one of the ventricles of the heart. This is a potentially life-threatening arrhythmia because it may lead to ventricular fibrillation and sudden death.
Classification
Ventricular tachycardia refers to a rhythm with a heart rate in excess of 100 (and in some definitions 120) beats per minute that arises distal to the bundle of His. Ventricular tachycardia can be classified under three main categories. Firstly, The morphology of the QRS complexes on the EKG (monomorphic ventricular tachycardia vs polymorphic ventricular tachycardia). Secondly, The duration of the episode. Thirdly, The symptoms associated with the episode.
Pathophysiology
The underlying mechanism of VT is due to automaticity arising in either the myocardium or in the distal conduction system. The most common underlying substrate for ventricular tachycardia is ischemic heart disease. The morphology of ventricular tachycardia often depends on its cause.
Causes
Common causes of ventricular tachycardia include ischemic heart disease, illicit drugs (cocaine and methamphetamine), structural heart disease (including congenital heart diseases such as Tetralogy of Fallot), inherited channelopathies, drug toxicity (digoxin, drugs that prolong the QT interval) and electrolyte disturbances(such as hypokalemia, hypomagnesemia, and hypocalcemia).
Differentiating Ventricular Tachycardia from other Disorders
Ventricular tachycardia must be distinguished from a variety of electrocardiographic abnormalities with similar appearance.
Risk Factors
Reversible/preventible risk factors for ventricular tachycardia include electrolyte disturbances such as hypokalemia, digitalis toxicity, antiarrhythmic use, pulmonary artery catheter placement and illicit drug use such as cocaine. Irreversible causes include structural heart disease and inherited channelopathies.
Screening
In a young patient with lone atrial fibrillation, short QT syndrome should be excluded. In a patient with a family history of sudden cardiac death a physical examination should be performed.
Natural History, Complications and Prognosis
Prognosis
Sustained ventricular tachycardia in general carries a poor prognosis due to an increased risk of sudden cardiac death.
Diagnosis
Chest X Ray
Chest X rays are done only when ventricular tachycardia leads to congestive heart failure or if a secondary pathological disease is suspected as the cause of ventricular tachycardia.
Treatment
Therapy may be directed at either terminating an episode of the arrhythmia or for suppressing a future episode from occurring. The treatment is tailored to the specific patient, with regard to how well the individual tolerates episodes of ventricular tachycardia, how frequently episodes occur, their comorbidities, and their wishes.