Fig. 4
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12872-021-02076-5/MediaObjects/12872_2021_2076_Fig4_HTML.png)
Preoperative electrocardiogram in Case 2. Electrocardiogram (ECG) showing normal sinus rhythm with Q waves in leads II, III, and aVF, and ST segment depression in V5-V6
Preoperative electrocardiogram in Case 2. Electrocardiogram (ECG) showing normal sinus rhythm with Q waves in leads II, III, and aVF, and ST segment depression in V5-V6