[Ventricular tachycardia of ischemic cardiomyopathies].
Ventricular tachycardia in patients with ischemic heart disease are almost always observed after myocardial infarction without preservation of the border zone (thrombolysis or early angioplasty). Monomorphic tachycardias are related to permanent electrophysiological substrate with a zone of slow conduction. This may be affected by initiating factors such as extrasystoles, especially with alternating long and short cycles, and the sympathetic nervous system before the appearance of clinical tachycardia. Cardiac mortality is mainly due to sudden death after an initial episode of sustained monomorphic ventricular tachycardia. The prognostic value of left ventricular function as assessed by the ejection fraction is essential: the 5-year mortality is 30% if LVEF is > 0.3 compared with 51% if LVEF is < 0.3 (p < 0.01). On the other hand, the frequency of spontaneous VT and VT induced by programmed stimulation does not affect the prognosis. The mortality after an initial episode of syncopal tachycardia is greater than after a well tolerated tachycardia. This is why the clinical history of the patient is essential to guide management. The persistence of inducible VT despite antiarrhythmic therapy increases the mortality; it is therefore important to find a drug which prevents induction VT. The patient is then classified as "responder". The number of "responders" patients, however, is low when the ejection fraction is < or = 0.30. The choice of treatment seems important when the ejection fraction is < or = 0.30: in this case, patients receiving Class I antiarrhythmics have a higher mortality and those taking betablockers have a reduced mortality. After polymorphic VT, if VT or VF is inducible, the risk of mortality is very high.(ABSTRACT TRUNCATED AT 250 WORDS)
Leclercq
J F
JF
Clinique cardiologique, hôpital Lariboisière, Saint-Cloud.
D016757:Death, Sudden, Cardiac / Q000209:etiology; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000150:complications* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D013318:Stroke Volume; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy
Les tachycardies ventriculaires des cardiopathies ischémiques.