Three-dimensional vectorcardiographic characteristics of breast cancer patients treated with chemotherapy

Background: Patients receiving chemotherapy for breast cancer (breast cancer) may develop cardiac electrophysiological abnormalities. The aim of this study is to examined possible alterations in cardiac electrophysiological parameters detected by three-dimensional vectorcardiograms (3D-VCGs) in breast cancer patients who received chemotherapy.

Methods: This was a prospective single-center cohort study conducted in Fourth Hospital of Hebei Medical University, China. Patients with breast cancer referred for chemotherapy from May 1, 2019, to October 1, 2019 were invited to participate in the study. 3D-VCGs and echocardiography were recorded at rest four times (baseline, after the first cycle, after third cycles and at the end of the regimen, respectively).

Results: A total of 63 patients were included. Compared with baseline, decreases in 3D maximum T vector magnitude (TVM) (0.29 ± 0.10 vs. 0.25 ± 0.10 mV; p < 0.05) and 3D T/QRS ratio (0.26 ± 0.11 vs. 0.21 ± 0.11; p < 0.05) were observed by the end of chemotherapy regimen, while echocardiographic parameters showed no significant variation before and after chemotherapy (all P > 0.05). Furthermore, after third cycles, maximum TVM were correlated with LVEF except in horizontal plane (3D: r = 0.33, p < 0.01; frontal plane: r = 0.34, p < 0.01; horizontal plane: r = 0.24, p = 0.06; right side plane: r = 0.30, p = 0.02). After completion of chemotherapy, maximum TVM were also positive correlated with LVEF (3D: r = 0.33, P < 0.01; frontal plane: r = 0.32, P = 0.01; horizontal plane: r = 0.27, P = 0.03, right side plane: r = 0.38, P < 0.01).

Conclusions: Along with chemotherapy, maximum TVM and T/QRS is lower in patients with breast cancer. After third cycles and after completion of chemotherapy, there is a positive correlation between maximum TVM and LVEF. 3D-VCGs can be used to detect electrophysiological abnormalities in breast cancer patients receiving chemotherapy.