Electrocardiographic Patterns and Ejection Fraction in Patients with Nonischemic Dilated Cardiomyopathy: A Cross-sectional Retrospective Study

Background::
The relationship between ECG changes in dilated nonischemic cardiomyopathy and ejection fraction (EF) is complex and poorly understood. Thus,
this study aimed to identify the most common patterns of ECG associated with dilated nonischemic cardiomyopathy and their relationship to EF.


Methods::
A retrospective cross-sectional study was conducted between 2019 and 2022, including 100 consecutive patients with nonischemic dilated
cardiomyopathy. ECG data were rate, axis, left (LBBB) and right bundle branch block (RBBB), first-degree heart block, premature ventricular
contractions, depth of S wave in leads V1 and V2, length of R wave in leads V2 and V6, the ratio of R/S in the lead V4, left ventricular
hypertrophy (LVH), maximum R wave length in leads I, II, and III, poor R wave progression, ST-segment elevation, and T wave inversion.


Results::
The most common ECG pattern associated with cardiomyopathy was T-wave inversion (47%). The EF was 23.9± 8.87% in patients with LBBB
and 25.5± 8.07% in patients without LBBB (P= 0.361). In patients with T-wave inversion, the EF was 23.4± 8.21%, and it was 26.28± 8.35% in
patients without T-wave inversion (P= 0.086). In patients with LVH, the EF was 23.89± 7.84%, and it was 25.5± 8.66% in patients without LVH
(P= 0.354). A negative nonsignificant correlation existed between SV1, SV2, RV2, RV6, R/S V4, and maximum R in I, II, III, and EF.


Conclusions::
The study showed that T-wave inversion was the most common pattern associated with dilated nonischemic cardiomyopathy. The study provided
insight into the negative correlation between EF and SV1, SV2, RV2, RV6, R/S V4, and maximum R in I, II, and III, although it did not reach a
significant level.