Exaggerated amplitude and peak location of Ta wave in tachycardia as an indicator for atrial disorders

Arya Bhardwaj, Bala Chakravarthy Neelapu, Kunal Pal, Sivaraman Jayaraman
National Institute of Technology Rourkela


In Standard Limb Lead (SLL) Electrocardiogram (ECG) of Sinus Rhythm (SR) volunteers, the atrial repolarization (Ta wave) as a possible indicator for atrial-related diseases is undermined. The presence of Ta wave in exercise stress ECG has been noted previously. However, manifestation of Ta wave in SR is limited using SLL. This study delineates and compares the characteristics of the Ta wave in Sinus Tachycardia (ST) with the SR in terms of amplitude and Ta peak location using the Modified Limb Lead (MLL) system. MLL was recorded for eight SR and fifteen ST volunteers (mean age of 24 years). P-R and S-T segment amplitudes were measured and analyzed. Ta wave-related impact on P-R and S-T segment have been noted and found a 41.60 % increase in P-RST to P-RSR and 49.60% in S-TST to S-TSR using absolute values of P-R and S-T. Moreover, the Ta wave peak can be predicted with the change in morphology and amplitude of the P-R and S-T segments. Determination of Ta wave peak may help delineate atrial-related disease conditions. A detailed study on S-T segment depression and elevation helps decrease the false-negative detection of myocardial infarction. Keywords: Atrial repolarization, Modified limb lead, Myocardial infarction, Sinus rhythm, Sinus tachycardia.