Page 45 - BH-1-2

Brain & Heart RDN guided by novel blood pressure responses

energy was 8–10 W for 60 s and increased to 12 W for compare BP and heart rate at baseline, 5 – 7 days, and 6
60 s if the SBP elevation was still evoked by the post- – 2 months. The other measurement data were compared
ablation electrical stimulation. The selection of exact by Student’s t-test. P < 0.05 was considered statistically
ablative powers depended on the impedance. The ablation significant. Data analysis was performed by SPSS 23.0
endpoint was defined as the disappearance or significant software (IBM Corporation, Armonk, New York).
blunting of the SBP-elevated response during the post-
ablation electrical stimulation. After the completion of all 3. Results
intra-arterial high-frequency electrical stimulation and A total of 14 patients who received selective RDN guided
radiofrequency ablation, bilateral renal arteriography was by RNS were included in this study. The patients were
performed repeatedly to evaluate for abnormalities such as relatively young (43 ± 9 years old), mostly male (11/14),
dissection, perforation, thrombosis, and other procedure- and not lean (BMI: 26.1 ± 2.2 kg/m ), with an ABP of 141 ±
2
related adverse events. 12/94 ± 8 mmHg and an OBP of 158 ± 24/101 ± 19 mmHg
2.3. Measurement at baseline. The remaining demographic data and clinical
characteristics are shown in Table 1.
The amplitude of beat-to-beat BP during the procedure
can be measured and stored automatically by the Lead The beat-to-beat SBPs at 260 RNS sites before RDN
Multi-channel Physiological Analysis software (Sichuan were obtained to analyze. The following 5 types of BP
Jinjiang Electronic Science and Technology Limited, responses were observed (Figure 2 and Table 2) and are
Chengdu, China). It could be regarded as unchanged when further elaborated below:
SBP fluctuation is in the vicinity (in the range of less than i. Type 1: BP persistently elevated above baseline.
5 mmHg) of baseline, based on the lower beat-to-beat SBP SBP in 74 sites (28.5%) continued to elevate during
variability (1.4–2.8 mmHg) with an invasive monitoring RNS. The peak SBP during the stimulation increased
technique . We used the intraoperative BP data observed significantly and exceeded the baseline by 14.3 ±
[20]
in an animal study to verify whether these possible trend 8.9 mmHg. The terminal SBP of the stimulation was
[18]
curves exist in humans. A quantitative method for judging still higher than the baseline by 11.6 ± 7.9 mmHg.
the trend of BP change during electrical stimulation was
used in this study. According to the change of specific ii. Type 2: BP dropped and then elevated above the
values, such as the maximum, minimum, and end values baseline.
during the stimulation from the pre-stimulation value, SBP in 47 sites (18.1%) dropped initially, then recovered
the fluctuating trend of an SBP curve can be preliminarily and exceeded the baseline during RNS. The valley SBP
determined. Thus, in this study, using 10 cardiac cycles dropped markedly, was lower than the baseline by
as a unit of measurement, we first identified the specific 14.0 ± 7.1 mmHg, and then recovered. The peak SBP
values containing the minimum SBP, the maximum SBP, increased significantly and exceeded the baseline by
the end-stimulation SBP, and their occurrence times. Then 13.2 ± 7.6 mmHg. The terminal SBP of the stimulation
we calculated the SBP change of these specific values from was still above the baseline by 8.3 ± 9.6 mmHg.
the pre-stimulation SBP to show and classify the trend of
BP at each stimulation site (a detailed process is shown iii. Type 3: BP dropped and then recovered but never
in Figure 1). ABP, average heart rate from the report of ABP went over the baseline.
monitoring, and anti-hypertensive medication regimens at SBP in 50 sites (19.2%) dropped initially and then
baseline, 5 – 7 days, and 6 – 12 months were collected. recovered but never went over the baseline during
2.4. Statistical analysis RNS. The valley SBP dropped markedly and was lower
than the baseline by 16.7 ± 8.4 mmHg, and the peak
Categorical variables were expressed as frequency or SBP recovered but never exceeded the baseline (−1.8 ±
percentage and statistically compared using the chi-square 5.9 mmHg). Terminal SBP was higher than the valley
or Fisher’s exact tests. The Shapiro-Wilk test was used to SBP by 13.1 ± 7.0 mmHg, which was -3.6 ± 5.6 mmHg
determine whether the measurement data had a normal of the baseline.
distribution. P > 0.05 was considered to conform to the
normal distribution, and then the measurement data were iv. Type 4: BP fluctuated in the vicinity of baseline.
expressed as the mean ± standard deviation. Non-normally SBP in 71 sites (27.3%) showed no observable change
distributed data were expressed as a median with the during RNS. BP fluctuated in the vicinity of the
interquartile range (IQR) (25% IQR, 75% IQR). Univariate baseline (−1.0 ± 2.1 mmHg at the valley and 1.3 ±
repeated measurement analysis of variance was used to 2.0 mmHg at the peak) during electrical stimulation.

Volume 1 Issue 2 (2023) 3 https://doi.org/10.36922/bh.0384