Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access
Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc
Journal website https://www.cardiologyres.org

Original Article

Volume 14, Number 1, February 2023, pages 45-53


Is T-Wave Alternans a Repolarization Abnormality Marker in COVID-19? An Investigation on the Potentialities of Portable Electrocardiogram Device

Figures

Figure 1.
Figure 1. STROBE diagram of the study.
Figure 2.
Figure 2. Initial regression model of TWA at discharge and clinical variables. TWA: T-wave alternans.

Tables

Table 1. Baseline Characteristics of Study Population
 
COVID-19 (n = 76)Non-COVID-19 (n = 34)P value
BMI: body mass index; Ca: calcium, CAD: coronary artery disease; CKD: chronic kidney disease; DBP: diastolic blood pressure; DM: diabetes mellitus; GFR: glomerular filtration rate; K: potassium; LOS: length of stay; Na: natrium; N/A: not applicable; SBP: systolic blood pressure; SD: standard deviation; COVID-19: coronavirus disease 2019.
Clinical variables
  Age (mean ± SD)41.70 ± 13.8038.35 ± 13.300.236
  Sex
    Male (n, %)33 (43.42)11 (32.35)0.274
    Female (n, %)43 (56.58)23 (67.65)
  BMI (mean ± SD)24.35 ± 3.5623.74 ± 4.540.5697
  SBP (mm Hg)122.17 ± 15.82130.31 ± 25.840.0478
  DBP (mm Hg)77.79 ± 11.1381.09 ± 11.760.1689
  D-dimer (mean ± SD)1.32 ± 2.221.18 ± 1.200.8109
  CRP (mean ± SD)43.39 ± 57.0150.12 ± 51.990.7637
  Na (mean ± SD)140.02 ± 22.60132.26 ± 28.330.2013
  K (mean ± SD)4.01 ± 0.734.33 ± 1.290.1661
  Ca (mean ± SD)8.52 ± 1.898.3 ± 1.080.6529
  LOS (mean ± SD)12.46 ± 6.768.77 ± 7.390.0151
Comorbidities
  Hypertension0 (0)0 (0)N/A
  CAD14 (18.42)3 (8.82)0.198
  CKD (GFR < 60 mL/min/1.73 m2)4 (5.26)0 (0)0.173
  Type 2 DM7 (9.21)3 (8.82)0.948
Medication
  Favipiravir10 (13.16)5 (14.70)0.827
  Azithromycin20 (26.31)9 (26.47)0.986
  Levofloxacin1 (1.32)0 (0)0.502

 

Table 2. TWA Profile on Admission and Discharge According to PCR Swab Result*
 
PCR resultAdmission, mean ± SD (µV)P valueDischarge, mean ± SD (µV)P value
*Independent t-test. TWA: T-wave alternans; PCR: polymerase chain reaction; SD: standard deviation.
PCR-positive (n = 76)42.47 ± 26.520.75753.45 ± 34.420.030
PCR-negative (n = 34)44.72 ± 38.2125.15± 17.64

 

Table 3. COVID-19 Patients Disease Severity and TWA
 
Disease severityn (%) admission, n = 62Admission TWA (µV), mean ± SDP valuen (%) discharge, n = 38Discharge TWA (µV), mean ± SDP value
COVID-19: coronavirus disease 2019; TWA: T-wave alternans; SD: standard deviation.
Mild illness47 (75.80)44.29 ± 27.140.341825 (65.79)49.47 ± 33.620.3303
Moderate illness15 (24.19)36.75 ± 24.4613 (34.21)61.09 ± 35.99

 

Table 4. Final Regression Model of TWA at Discharge and PCR Result
 
TWA (discharge)CoefficientStandard errorP>t95% CI
TWA: T-wave alternans; PCR: polymerase chain reaction; CI: confidence interval.
PCR18.2988.2340.0301.802 - 34.793
Constants35.1526.6670.00021.800 - 48.504