Key Points
- To develop a clinical nomogram that quantitatively defines the normal limits of the mean electrical axis in electrocardiography based on age and relative body weight in healthy males.
- Assessed electrocardiographic limb leads to measure the frontal plane mean electrical axis in healthy adult males.
- Evaluated shifts in electrical axis relative to advancing age and variations in body habitus.
- Formulated mathematical standards to construct an accessible clinical nomogram.
- Both increasing chronological age and greater relative body weight qualitatively correlated with a significant leftward deviation of the mean electrical axis.
- Demonstrated that uniform clinical reference ranges misclassify physiologic leftward shifts in older or heavier individuals as abnormal.
- Derived quantitative nomographic limits to establish standardized, covariate-adjusted ranges of normal electrical axis orientation.
Structured PICO
OOutcomeMean electrical axis of the electrocardiogramsurrogate
The study aimed to develop a nomogram to define the normal limits of the ECG electrical axis adjusted for age and body habitus in normal males.