Designing Nomogram for Determining the Heart's QRS Axis
Journal of Clinical and Basic Cardiology 2011; 14 (1-4): 12-15
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Keywords: heart axis, nomogram, QRS
Background: Electrocardiogram is a recording of the heart’s electrical activity which could be very informative in the approach to patients with cardiac or non-cardiac problems. Determining the electrical axis of the heart (mainly QRS complex axis) is the first step in interpreting the electrocardiogram of a patient and has important applications in both clinical and epidemiological studies. Aim: This study was performed to design a nomogram for the exact determination of the heart’s QRS axis. Settings and Design: We used the corrected formula to determine the heart’s QRS axis. Materials and Methods: In order to calculate the electrical axis of the heart in the frontal plane, we used the combination of leads I and aVF. We used MATLAB m-code programming to design the nomogram according to the corrected formula. Results: Our work is a nomogram which uses leads I and aVF to calculate the heart’s electrical QRS axis. This nomogram covers the mean QRS complex between –30 and +30 small squares. Conclusion: This recording helps in the long-term assessment of physiological axis changes during treatment and followup. By means of this nomogram, the effects of pathological factors on the heart’s axis could be evaluated more accurately.
Journal of Clinical and Basic Cardiology 2011; 14 (1-4): 12-15
PDF Summary Figures
 |
Keywords: heart axis, nomogram, QRS
Background: Electrocardiogram is a recording of the heart’s electrical activity which could be very informative in the approach to patients with cardiac or non-cardiac problems. Determining the electrical axis of the heart (mainly QRS complex axis) is the first step in interpreting the electrocardiogram of a patient and has important applications in both clinical and epidemiological studies. Aim: This study was performed to design a nomogram for the exact determination of the heart’s QRS axis. Settings and Design: We used the corrected formula to determine the heart’s QRS axis. Materials and Methods: In order to calculate the electrical axis of the heart in the frontal plane, we used the combination of leads I and aVF. We used MATLAB m-code programming to design the nomogram according to the corrected formula. Results: Our work is a nomogram which uses leads I and aVF to calculate the heart’s electrical QRS axis. This nomogram covers the mean QRS complex between –30 and +30 small squares. Conclusion: This recording helps in the long-term assessment of physiological axis changes during treatment and followup. By means of this nomogram, the effects of pathological factors on the heart’s axis could be evaluated more accurately.