QRS complex and T wave planarity for the efficacy prediction of automatic implantable defibrillators

Katerina Hnatkova, Irena Andršová, Tomáš Novotný, Bert Vanderberk, David Sprenkeler, Juhani Junttila, Tobias Reichlin, Simon Schlögl, Marc A. Vos, Tim Friede, Axel Bauer, Heikki V. Huikuri, Rik Willems, Georg Schmidt, Christian Sticherling, Markus Zabel, Marek Malik

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Objective: To test the hypothesis that in recipients of primary prophylactic implantable cardioverter-defibrillators (ICDs), the non-planarity of ECG vector loops predicts (a) deaths despite ICD protection and (b) appropriate ICD shocks. Methods: Digital pre-implant ECGs were collected in 1948 ICD recipients: 21.4% females, median age 65 years, 61.5% ischaemic heart disease (IHD). QRS and T wave three-dimensional loops were constructed using singular value decomposition that allowed to measure the vector loop planarity. The non-planarity, that is, the twist of the three-dimensional loops out of a single plane, was related to all-cause mortality (n=294; 15.3% females; 68.7% IHD) and appropriate ICD shocks (n=162; 10.5% females; 87.7% IHD) during 5-year follow-up after device implantation. Using multivariable Cox regression, the predictive power of QRS and T wave non-planarity was compared with that of age, heart rate, left ventricular ejection fraction, QRS duration, spatial QRS-T angle, QTc interval and T-peak to T-end interval. Results: QRS non-planarity was significantly (p<0.001) associated with follow-up deaths despite ICD protection with HR of 1.339 (95% CI 1.165 to 1.540) but was only univariably associated with appropriate ICD shocks. Non-planarity of the T wave loop was the only ECG-derived index significantly (p<0.001) associated with appropriate ICD shocks with multivariable Cox regression HR of 1.364 (1.180 to 1.576) but was not associated with follow-up mortality. Conclusions: The analysed data suggest that QRS and T wave non-planarity might offer distinction between patients who are at greater risk of death despite ICD protection and those who are likely to use the defibrillator protection.

Original languageEnglish
Article number322878
StateAccepted/In press - 2023
Externally publishedYes


  • Biomarkers
  • Defibrillators, Implantable
  • Electrocardiography


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