Left ventricular hypertrophy (LVH) detected by electrocardiography (ECG) is an independent cardiovascular risk factor. In hypertensive patients it represents the cardiac target organ damage. However, in clinical practice, the echocardiography is preferred for detection of left ventricular hypertrophy. Electrocardiographic findings, especially those so-called false negative results, are not considered for clinical decision making. The aim of this paper was to present current possibilities of ECG diagnostics in LVH detection, as well as to present a view on discrepant ECG findings in patients with increased left ventricular mass. The concept of the relative voltage deficit and the specific potential of myocardium is presented, in the context of the current knowledge on the structural and electrical remodeling of myocardium in left ventricular hypertrophy.