Sudden cardiac death and polymorphous ventricular tachycardia in pationts with normal QT intervals and normal systolic cardiac function

摘要: This study delineates the clinical spectrum of 15 patients with polymorphic ventricular tachycardia and normal QT intervals in absence apparent structural heart disease, adverse drug effects, or electrolyte disturbances. Patients presented either palpitations (n = 2), presyncope 5), syncope 4), no symptoms 1), aborted sudden death 3). Mean age was 41 years (range 20 to 64), mean follow-up 38 months 4 109). Left function as determined by echocardiogram 9) left ventriculography 9). Episodes (VT) were analyzed terms preceding interval, relation initiating coupling interval (coupling interval/QT VT index). The for group a whole 0.41 ± 0.02 second. could be separated into 3 distinct groups. Four had reproducibly induced exercise initiated fate-coupled brats (mean index 1.27±0.21). Isoproterenol patients, all responded chronic β blockade. Two during episodes coronary artery spasm, both calcium channel Polymorphic unrelated exertion vasospasm occurred 9 patients. Tachycardia onset closely coupled beats 0.95±0.16), preceded pause 5 Sudden shortest indexes. Drug therapy pacing not reliable preventing death. Invasive eicectrophysiologk studies, including use monophasic action potential recordings, useful evaluation management these Appropriate presenting exercise- vasospasm-induced is usually associated good prognosis. Conversely, spontaneous short-coupled have high incidence death, should considered automatic implantable cardioverter defibrillator insertion.