Conclusion
QRS axis is an important factor for risk stratification in
cardiovascular disease-free population with PR prolongation. The extent
to which this population with PR prolongation and QRS axis ≤37° is at
higher risk of death compared with the population without PR
prolongation. Assessment of the QRS axis is particularly necessary in
patients with prolonged PR on the ECG.
Acknowledgments: The authors thank all those who contributed to
this article.