Tachycardia: Difference between revisions
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→Ventricular tachycardia
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==Ventricular fibrillation== | ==Ventricular fibrillation== | ||
VF is | Ventricular fibrillation (VF) is identified by the complete absence of properly formed QRS complexes and no obvious P waves. Instead of uniform activation of the ventricular myocardium, there are uncoördinated series of very rapid, ineffective contractions of the ventricle caused by many chaotic electrical impulses. In recent onset VF the QRS complexes are of high amplitude at rates greater than 320 bpm, which manifest random changes in morphology, width and height. It appears as a completely chaotic rhythm. If VF continues, the fibrillatory waves become fine and can resemble asystole in these cases. | ||
===Treatment=== | ===Treatment=== | ||
Electrocardioversion is the only treatment for ventricular fibrillation. | VF is lethal if the patient is not treated immediately. It gives rise to a mechanical standstill of the heart, because the heart is not able to pump normally anymore. Electrocardioversion is the only treatment for ventricular fibrillation. | ||
==Accelerated idio-ventricular rhythm== | ==Accelerated idio-ventricular rhythm== | ||
Accelerated idioventricular rhythm (AIVR) is a relatively benign form of ventricular tachycardia. It is (mostly) a regular repetitive ventricular rhythm rate around 60-120 bpm, but mostly 80-100. It is the result of an enhanced ectopic ventricular rhythm, which is faster than normal intrinsic ventricular escape rhythm (<40 bpm), but slower than ventricular tachycardia (over 100-120 bpm). It often occurs during reperfusion after a myocardial infarction. AIVR is not predictive marker for early VF; however, recent debate has started whether among patients with successfull coronary intervention, AIVR is a sign of ventricular dysfunction and therefore a slightly worde prognosis. | |||
AIVR can also occur in infants. By this definition, this is a ventricular rhythm of no more than 20% faster than the sinus rate and occuring in the absence of other heart disease. This arrhythmia typically resolves spontaneously during the first months of life (in contrast to an infant with incessant VT which can be due to discrete myocardial tumors or congenital cardiomyopathy). | |||
===Treatment=== | |||
AIVR is generally a transient, self-limiting rhythm and resolves as sinus rate surpasses the rate of AIVR. It rarely causes hemodynamic instability and rarely requires treatment. | |||
==Torsades de Pointes== | ==Torsades de Pointes== | ||