The role of ECG in the diagnosis of left ventricular hypertrophy

Abstract

The traditional approach to the ECG diagnosis of left ventricular hypertrophy (LVH) is focused on the best estimation of left ventricular mass (LVM) i.e. finding ECG criteria that agree with LVM as detected by imaging. However, it has been consistently reported that the magnitude of agreement is rather low as reflected in the low sensitivity of ECG criteria. As a result, the majority of cases with true anatomical LVH could be misclassified by using ECG criteria of LVH. Despite this limitation, it has been reported that the ECG criteria for LVH provide independent information on the cardiovascular risk even after adjusting for LVM. Understanding possible reasons for the frequent discrepancy between common ECG LVH criteria and LVH by echo or MRI would help understanding the genesis of ECG changes that occur as a consequence of increased LV mass.

Fig. (1)

In the 21^st century, the role of electrocardiography in assessment of left ventricular hypertrophy will move beyond the estimation of left ventricular mass and risk assessment to a deeper understanding of electrogenesis and electrical remodeling and its relation to ECG patterns.

Fig. (2)

Electrocardiography must use terminology consistent with the information it provides – information on impulse generation and propagation. The same alterations of electrical properties can be present with different clinical situations. Moreover, the clinical conditions are not “pure”. We deal with co-morbidities in the clinical practice. This is a major challenge for electrocardiography in the 21^st century in general, and for the diagnosis of left ventricular hypertrophy in particular.