Contents 1. Introduction
It is well recognized that there are numerous physiological and pathological factors that affect the ECG criteria of left ventricular hypertrophy (LVH) [1]. In 1960, Allenstein and Mori evaluated the ECG criteria that had been introduced for the diagnosis of LVH and they found that the literature at that time included over 30 ECG criteria [2]. However, in clinical practice, the voltage criteria are the most commonly used despite evidence that voltage ECG-LVH criteria are influenced by many factors that might commonly co-exist with LVH. A possible factor that might influence QRS voltages is the simultaneous presence of myocardial infarction (MI) and LVH. It is well known that MI affects the QRS voltages by either decreasing the amplitude of the R waves or through development of new Q waves [3]. Furthermore, Murphy et al [4] demonstrated that MI increased the sensitivity of BCG- LVH criteria. Theoretically, it is possible that deep QS deflections of anteroseptal MI might lead to potentiation of the amplitudes of R waves in leads V5 and/or V6 due to the lack of the cancellation of the oppositely directed electrical forces and thereby may produce false positive precordial voltage criteria of LVH. This study was designed to assess the influence of Q wave acute anteroseptal MI, in the absence of echo LVH, on the commonly used precordial and limb lead voltage criteria.
