Onset heart rate of microvolt-level T-wave alternans provides clinical and prognostic value in nonischemic dilated cardiomyopathy

Abstract

The OHR of TWA is of additional prognostic value in DCM.

Predicting Sudden Death Risk for Heart Failure Patients in the Implantable Cardioverter-Defibrillator Age

“…7 Nonsustained VT and frequent ventricular ectopy increase in prevalence with heart failure severity and have predicted sudden and non-sudden death. 3,11,12 ICDs did not improve survival compared with no antiarrhythmic therapy or with amiodarone in patients with nonischemic cardiomyopathy selected for nonsustained VT (S. Adam Strickberger, MD, Washington Hospital Center, Washington, DC, oral and electronic communication, 2001) or depressed ventricular function. 13 Invasive electrophysiological studies detect potential reentry circuits after myocardial infarction.…”

“…17 Detection of small oscillations in the T-wave amplitude (T-wave alternans) during exercise is linked to susceptibility to ventricular arrhythmias. 12 It is associated with high-risk groups and was a marker of risk in a prospective study of 85 patients with nonischemic cardiomyopathy. 12 Trials to determine if T-wave alternans testing can be used to select patients for ICD therapy are in progress.…”

“…12 It is associated with high-risk groups and was a marker of risk in a prospective study of 85 patients with nonischemic cardiomyopathy. 12 Trials to determine if T-wave alternans testing can be used to select patients for ICD therapy are in progress.…”

“…19 In heart failure populations, the predictive value of this test is unclear. 12,20 Neurohumoral activation is associated with heart failure severity and mortality; sympathetic activation promotes arrhythmias. 21,22 Heart rate variability reflects neurohumoral activity and its interaction with the sinus node.…”

Evidence regarding clinical use of microvolt T-wave alternans

“…Many studies conducted in patients without implanted ICDs have found MTWA to be a highly accurate risk stratifier and, in particular, have found that the rate of ventricular tachyarrhythmic events (VTEs) among patients who test MTWA negative is exceedingly low [1][2][3][4][5][6][7] suggesting that ICD therapy may not benefit such patients 8 . As a result, MTWA has been proposed as a means of guiding implantable cardioverter defibrillator (ICD) therapy in patients with risk factors for SCD but without a prior history of sustained VTEs (primary prevention patients).…”