Cardiac repolarization variability in patients with postural tachycardia syndrome during graded head-up tilt

- Baumert, Mathias, Lambert, Elisabeth, Vaddadi, Gautam, Sari, Carolina Ika, Esler, Murray, Lambert, Gavin, Sanders, Prashanthan, Nalivaiko, Eugene

Relation between QT interval variability and cardiac sympathetic activity in hypertension

- Baumert, Mathias, Schlaich, Markus P., Nalivaiko, Eugene, Lambert, Elisabeth, Sari, Carolina Ika, Kaye, David M., Elser, Murray D., Sanders, Prashanthan, Lambert, Gavin