Optimal Target Heart Rate for Exercise-Induced T-Wave Alternans

Drug-induced T wave alternans.

Computer Software tool for heart rate variability (HRV), T-wave alternans (TWA) and heart rate turbulence (HRT) analysis from ECGs

BACKGROUND This paper presents a software package for quantitative evaluation of heart rate variability (HRV), heart rate turbulence (HRT), and T-wave alternans (TWA) from ECG recordings. The software has been developed for the purpose of scientific research rather than clinical diagnosis. MATERIAL/METHODS The software is written in Matlab Mathematical Language. Procedures for evaluation of H...

Malignant T-wave alternans.

A36-year-old woman was referred after her son had syncopal episodes associated with a markedly prolonged QT interval, which was treated with b-blockers and a subsequent pacemaker. The mother had a history of “seizures” as a child that had been treated with various medications, which did not appear to affect her events. She continued to have episodes 2 to 3 times a year, and witnesses said she w...

The immediate reproducibility of T wave alternans during bicycle exercise.

A number of recent studies have demonstrated that the microvolt level T wave alternans measured during bicycle exercise can identify patients at high risk for developing malignant ventricular arrhythmias. However, little is known about the reproducibility of T wave alternans measured during bicycle exercise. The purpose of this study was to prospectively evaluate the immediate reproducibility o...

Microvolt t-wave alternans with exercise in pediatrics and congenital heart disease: limitations and predictive value.

BACKGROUND Microvolt t-wave alternans (TWA) in early exercise is a noninvasive marker of life-threatening ventricular arrhythmia in some adult cardiac populations. The incidence and potential significance of sustained TWA in pediatric and congenital heart disease (CHD) populations has not been well defined. METHODS TWA treadmill exercise studies in pediatric patients with CHD, myopathy, poten...