Not necessarily.
The ECG mainly reflects the activity of the cardiac muscle cells during contraction of their cardiac electrical vectors. In patients with an enlarged heart, the ECG may be abnormal due to inconsistent myocardial contraction, such as P waves suggesting atrial lesions and QRS wave clusters suggesting ventricular electrophysiological changes.
However, the ECG presents a holistic picture of the electrical activity of the heart, and if there are multiple lesions in the heart that cause the abnormal ECG vectors to cancel each other out, the ECG may be unremarkable. At the same time, the ECG can be misdiagnosed or missed due to its low sensitivity and specificity. Therefore, further evaluation of the condition in conjunction with other clinical investigations is required.