Introduction
- the R on T phenomenon happens when a PVC (which represents the R) occurs at a region which is in a vulnerable phase of repolarization (represented by a T wave on ECG)
- this phenomenon has a potential to trigger ventricular arrhythmias such as Torsades des Pointes in specific situations
- R on T which triggers ventricular arrhythmias can happen in:
- patients with a prolonged QT interval which is either congenital or acquired (which can be caused by a number of drugs or electrolyte abnormalities)
- patients with normal QT interval but one of these conditions:
- myocardial ischemia, typically during the acute phase, although it may also occur during the healing phase of MI due to QT prolongation
- electrolyte abnormalities (such as hypokalemia)
- Brugada syndrome
- CPVT
- before the R on T phenomenon triggering TdP occurs, a pause or slowing of the rhythm can usually be observed and the TdP is described as pause-dependent
- VTs occurring as a result of acute MI without QT prolongation are not pause-dependent
ECG characteristics
- a PVC occurring during a T wave of the preceding beat
- can be followed by an onset of ventricular arrhythmia
ECG 1 The R on T phenomenon in this example occurs in precordial leads and does not trigger a TdP, however a TdP can be seen in limb leads on the left
References
- Oksuz, Fatih, Baris Sensoy, Ekrem Sahan, Fatih Sen, Kazım Baser, Hande Cetin, Sefa Unal, Ozcan Ozeke, Serkan Topaloglu, and Dursun Aras. 2015. “The Classical “R-On-T” Phenomenon”. Indian Heart Journal 67 (4): 392-394. https://doi.org/10.1016/j.ihj.2015.02.030.
- Liu, Michael B., Nele Vandersickel, Alexander V. Panfilov, and Zhilin Qu. 2019. “R-From-T As A Common Mechanism Of Arrhythmia Initiation In Long Qt Syndromes”. Circulation: Arrhythmia And Electrophysiology 12 (12). https://doi.org/10.1161/CIRCEP.119.007571.
Published by
Assoc. Prof. Michal Pazderník, MD, Ph.D. FESC
Introduction
- the R on T phenomenon happens when a PVC (which represents the R) occurs at a region which is in a vulnerable phase of repolarization (represented by a T wave on ECG)
- this phenomenon has a potential to trigger ventricular arrhythmias such as Torsades des Pointes in specific situations
- R on T which triggers ventricular arrhythmias can happen in:
- patients with a prolonged QT interval which is either congenital or acquired (which can be caused by a number of drugs or electrolyte abnormalities)
- patients with normal QT interval but one of these conditions:
- myocardial ischemia, typically during the acute phase, although it may also occur during the healing phase of MI due to QT prolongation
- electrolyte abnormalities (such as hypokalemia)
- Brugada syndrome
- CPVT
- before the R on T phenomenon triggering TdP occurs, a pause or slowing of the rhythm can usually be observed and the TdP is described as pause-dependent
- VTs occurring as a result of acute MI without QT prolongation are not pause-dependent
ECG characteristics
- a PVC occurring during a T wave of the preceding beat
- can be followed by an onset of ventricular arrhythmia
ECG 1 The R on T phenomenon in this example occurs in precordial leads and does not trigger a TdP, however a TdP can be seen in limb leads on the left
References
- Oksuz, Fatih, Baris Sensoy, Ekrem Sahan, Fatih Sen, Kazım Baser, Hande Cetin, Sefa Unal, Ozcan Ozeke, Serkan Topaloglu, and Dursun Aras. 2015. “The Classical “R-On-T” Phenomenon”. Indian Heart Journal 67 (4): 392-394. https://doi.org/10.1016/j.ihj.2015.02.030.
- Liu, Michael B., Nele Vandersickel, Alexander V. Panfilov, and Zhilin Qu. 2019. “R-From-T As A Common Mechanism Of Arrhythmia Initiation In Long Qt Syndromes”. Circulation: Arrhythmia And Electrophysiology 12 (12). https://doi.org/10.1161/CIRCEP.119.007571.
Published by
Assoc. Prof. Michal Pazderník, MD, Ph.D. FESC
