Left ventricular hypertrophy: disagreements between increased left ventricular mass and ECG-LVH criteria: the effect of impaired electrical properties of myocardium

The classical paradigm of electrocardiographic diagnosis of left ventricular hypertrophy (LVH) is based on empirical finding of increased QRS voltage in cases of LVH and a continuous effort is devoted to finding ECG criteria that agree best with LVH classification according to an ECG-independent standard such as echocardiographic LVH (echo-LVH) based on increased left ventricular mass (LVM). Since there are more disagreements than agreements, this review is focused on discrepancies, i.e. false negative and false positive ECG findings. It summarizes the results of simulation studies on the effect of slowed conduction velocity and reduced intercellular coupling on the QRS pattern. The results from these simulation studies suggest that reduced myocardial conduction velocity which is either diffuse or regional, or reduced intracellular coupling, may account at least in part for the changes in the QRS patterns observed in patients with LVH.