Quantitative Assessment of Vectorcardiographic Loop Morphology

Golriz Sedaghat, Elyar Ghafoori, Jonathan W. Waks, Muammar M. Kabir, Alexei Shvilkin, Mark E. Josephson, Larisa G. Tereshchenko

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Vectorcardiography (VCG), developed 100 years ago, characterizes clinically important electrophysiological properties of the heart. In this study, VCG QRS loop roundness, planarity, thickness, rotational angle, and dihedral angle were measured in 81 healthy control subjects (39.0 ± 14.2y; 51.8% male; 94% white), and 8 patients with infarct-cardiomyopathy and sustained monomorphic ventricular tachycardia (VT) (68.0 ± 7.8y, 37.5% male). The angle between two consecutive QRS vectors was defined as the rotational angle, while dihedral angle quantified planar alteration over the QRS loop. In VT subjects, planarity index decreased (0.63 ± 0.22 vs. 0.88 ± 0.10; P = 0.014), and dihedral angle was significantly more variable (variance of dihedral angle, median (IQR): 897(575-1450) vs. 542(343-773); P = 0.029; rMSSD: 47.7 ± 12.7 vs. 35.1 ± 13.1; P = 0.027). Abnormal electrophysiological substrate in VT patients is characterized by the appearance of QRS loop folding, likely due to local conduction block. The presence of fragmented QRS complexes on the 12-lead ECG had low sensitivity (31%) for detecting QRS loop folding on the VCG.

Original languageEnglish (US)
Pages (from-to)154-163
Number of pages10
JournalJournal of Electrocardiology
Issue number2
StatePublished - Mar 1 2016
Externally publishedYes


  • Planarity
  • Vectorcardiography
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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