The Influence of Interatrial Conduction Disorders on Atrial Mechanical Function — Atrial Strain and Pulmonary Veins Reversal Flow in Patients with COVID-19

Figures

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  Fig. 1.. An exemplary image of ECG recordings, presenting normal (A), long and flat – low voltage (B), full Bachmann bundle block (C) P-wave morphologies. The ECG recording parameters were: speed 200 mm/s, gain 80 mm/mv. The ECG leads are II, III, aVF. The P-wave durations are as follows: (A) 110 ms, (B) 130 ms, (C) 166 ms. ECG, electrocardiography.

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  Fig. 2.. The changes in PALS among the patients with different P-wave morphologies, the presence of mitral regurgitation, HF and AFP. PALS, peak atrial longitudinal strain; PACS, peak atrial contraction strain; SE, standard error; HF, heart failure; AFP, paroxysmal atrial fibrillation.

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  Fig. 3.. The anatomic view of LA, with the approximate location of Bachmann and the septopulmonary bundle. Sanchez-Quintana originally used the photo in his research. This photo is used as a courtesy of the author [13]. LAA, left atrial appendage; SCV, superior vena cava; LS, left superior pulmonary vein; LI, left inferior pulmonary vein; RS, right superior pulmonary vein; RI, right inferior pulmonary vein; LA, left atrium.

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  Fig. 4.. The approximated differences in contraction profiles, based on analyzing LA regional strain, about P-wave morphologies. Numbers and colors represent the order of contraction. (A) Normal P-wave. (B) Long’n’flat P-wave, P-IAB (the red spot). (C) Positive-negative P-wave, with A-IAB (the red X) — i.e., the conduction in the region on the Bachmann bundle is completely blocked. P-IAB, partial interatrial block; A-IAB, advanced interatrial block; P-IAB, partial interatrial block; A-IAB, advanced interatrial block; LA, left atrium; LAA, left atrial appendage.

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  Fig. 5.. P-wave duration, age, PALS, PACS and LA volume in groups of patients with regard to P-wave morphology, and the results of tests of independence and multiple comparisons (post-hoc tests). We noted a significant difference in P-wave duration between normal conditions and P-IAB and A-IAB. No significant difference was observed between P-IAB and A-IAB. Differences in PALS and PACS were also statistically significant only between normal and abnormal P-wave morphologies. No statistical differences were present between P-IAB and A-IAB. PALS, peak atrial longitudinal strain; PACS, peak atrial contraction strain; LVEF, left ventricular ejection fraction; PV, pulmonary veins; LA volume, left atrial volume; SE, standard error; ANOVA, analysis of variance; P-IAB, partial interatrial block; A-IAB, advanced interatrial block.