The negative chronotropic effect during lumbar spine surgery: A systemic review and aggregation of an emerging model of spinal cardiac reflex.

Background: Hemodynamic perturbations in spine surgeries are predominantly reported in cervical and thoracic level procedures. The literature related to negative cardiovascular changes (decrease of heart rate and blood pressure) in lumbar spine procedures is still scarce and only highlighted in few case reports/letters until now.

Methods: With the help of a systematic literature review with predefined criteria, we, therefore, examined and synthesized here the probable underlying common cause of these hemodynamic disturbances in lumbar spine surgeries. Data aggregation to a model was done by a case survey method and established by a cause-effect relationship.

Results: There are only 5 cases that met our strict predefined criteria and that were aggregated to an emergent model of an autonomous reflex arc.

Conclusion: This review and consecutive data aggregation provides, for the first time, a concept of spinal cardiac reflex in lumbar spine surgeries.