Electrocardiographic QRS Axis Shift ,Rotation and COVİD-19

The lung is the most seriously damaged organ in patients with coronavirus disease (COVID-19). In patients with advanced lung involvement, the alveoli are filled with fluid, white blood cells, mucus, and damaged lung cell debris [1].

The electrical position of the heart in the frontal plane is defined as normal, right, left, or northwest quadrant axis deviation, while its position in the horizontal plane is defined as clockwise rotation (Cwr), normal transition, or counterclockwise rotation (Ccwr)[2].

As respiratory disease progresses,rightward shift(Rws) of the frontal QRS axis can result from Cwr of the heart around its longitudinal axis as viewed from the apex, sudden increase in pulmonary vascular resistance causing right ventricle dilatation, or both [3].

Electrocardiographic changes should be monitored intermittently, as this disease progresses rapidly to near 50% mortality within 7-28 days [4].The aim of this study was to investigate whether easily detectable electrocardiographic axis and rotation changes could predict advanced lung involvement[4].

Methods Study design Records of 250 hospitalized patients with dyspnea and COVID-19 were analyzed retrospectively.Patients were excluded if they received positive pressurized oxygen therapy(n:25),underwent mechanical ventilation,(n:15)exhibited atrial fibrillation(n:10), conditions precluding the assessment of QRS transitional rotation ;complete bundle branch block(n:10), significant arrhythmias(n:5,complete atrioventricular block(n:2), polymorphic ventricular tachycardia(n:2), and ventricular fibrillation), Wolff-Parkinson-White syndrome(n:1), supraventricular tachycardia(n:4), or had unclear QRS axis orientation(n:20). The remaining160 patients who had electronic medical records, nursing records,at least three electrocardiographic recordings taken a few days apart, and laboratory and tomographic findings were included in the study.Patients with normal oxygen saturation (SpO2; ≥ 90%) who did not receive oxygen therapy and patients with low SpO2(<90%) who received nasal oxygen therapy were included in this study. Patients were divided into two groups: normal SpO2(NS,n = 80) and low SpO2(LS, n = 80).

Electrocardiographic measurements were performed as previously described.The Tpe (T peak to T end) interval was measured from precordial leads [5].The delta corrected QT interval(QTc) calculated as last electrocardiographic QTc minus first electrocardiographic QTc. Discrepancies between computerized electrocardiographic analysis and the mean of three computer-aided measurements(Adobe Photoshop program-300dpi resolution) by a researcher were resolved by consultation with a second researcher.

Using follow-up electrocardiography,according to the direction of QRS axis shift between the first and last electrocardiograms, both groups were divided into two main subgroups:patients with rightward shift (Rws) and patients with leftward shift(Lws) of the QRS axis.The patient numbers were as follows: NS Rws (n=37),NS Lws(n=43),LS Rws (n=40),andLS Lws (n=40). Based on electrocardiographic follow-up analyses,the two main groups were compared in terms of rotation condition (i.e., Cwr, normal transition, or CCwr), electrocardiographic intervals, and laboratory findings

Tomographic findings were evaluated in accordance with COVID-19 Reporting and Data System (CO-RADS)classification.CO-RADS scores are as follows: 1 (very low level of suspicion), 2 (low level of suspicion), 3 (equivocal), 4 (high level of suspicion),and 5 (very high level of suspicion)[6].