Kinetics of the effect of the auricular heart point on the pressure-volume curve of the digital pulse

Introduction: The Heart auricular point has been shown to modify the characteristics of the digital pulse wave experimentally. However, kinetic studies have yet to widely evaluate its cardiovascular effects. The objective of this study was to propose an acukinetic model of the Heart auricular point effect using polynomial linear interpolation or spline. Methods: The digital volume pulse was recorded in healthy subjects. A photoplethysmography transducer was placed on the index finger of the right hand. The signal was modulated and amplified using the MP150 amplifier processor. A continuous 70-s recording was taken consisting of a 30-s baseline (1–30 s), a 10-s transacupuncture (31–40 s), and a 30-s post acupuncture periods (41–70 s). Participants received acupuncture at the Heart point of the right ear. The needle was inserted to a depth of approximately 3 mm, with no additional stimulation; and remained inserted for 10 s. Derivatives and integrals of each pulse cycle during transacupuncture periods were solved. The peak slope values and area under the curve of the transacupuncture period were used to construct an interpolated curve. Results: Analysis of spline curves during the transacupuncture period showed a decrease in their values in the initial period of auriculopuncture stimulation, with a recovery in the second part. These results may indicate that auriculopuncture initially reduced cardiac output, possibly causing a secondary sympathetic response mediated by baroreceptors. Conclusion: These results may indicate that auriculopuncture initially reduced cardiac output, possibly causing a secondary sympathetic response mediated by baroreceptors.