Factors affecting the relationship between precordial electrocardiographic voltage and left ventricular wall thickness.

The relationship between left ventricular wall thickness and precordial electrocardiographic voltage was explored in thirty male subjects to determine the influence of two independent variables, precordial lead positions and skin thickness. The correlation coefficient of the relationship between SV2 + RV5 and mean left ventricular wall thickness was 0.41. When the precordial voltages were measured from two modified leads, one parasternal and one apical, whose positions were determined by locating the heart with ultrasound, the correlation coefficient was 0.57. Using multiple regression, a significant relationship was demonstrated between chest wall thickness and precordial voltage, and this relationship was explained by variations in skin thickness measured by calipers. The relationship between left ventricular wall thickness and precordial voltage is significantly influenced by skin thickness and lead placement.