McLellan Alex J A, Schlaich Markus P, Taylor Andrew J, Prabhu Sandeep, Hering Dagmara, Hammond Louise, Marusic Petra, Duval Jacqueline, Sata Yusuke, Ellims Andris, Esler Murray, Peter Karlheinz, Shaw James, Walton Antony, Kalman Jonathan M, Kistler Peter M
Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Cardiology Department, Royal Melbourne Hospital, Victoria, Australia; Faculty of Medicine, Dentistry, and Health Sciences, University of Melbourne, Victoria, Australia.
Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Victoria, Australia; Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia; School of Medicine and Pharmacology-Royal Perth Hospital Campus, University of Western Australia, Perth, Australia.
Heart Rhythm. 2015 May;12(5):982-90. doi: 10.1016/j.hrthm.2015.01.039. Epub 2015 Jan 28.
Hypertension is the most common modifiable risk factor associated with atrial fibrillation.
The purpose of this study was to determine the effects of blood pressure (BP) lowering after renal denervation on atrial electrophysiologic and structural remodeling in humans.
Fourteen patients (mean age 64 ± 9 years, duration of hypertension 16 ± 11 years, on 5 ± 2 antihypertensive medications) with treatment-resistant hypertension underwent baseline 24-hour ambulatory BP monitoring, echocardiography, cardiac magnetic resonance imaging, and electrophysiologic study. Electrophysiologic study included measurements of P-wave duration, effective refractory periods, and conduction times. Electroanatomic mapping of the right atrium was completed using CARTO3 to determine local and regional conduction velocity and tissue voltage. Bilateral renal denervation was performed, and all measurements repeated after 6 months.
After renal denervation, mean 24-hour BP reduced from 152/84 mm Hg to 141/80 mm Hg at 6-month follow-up (P < .01). Global conduction velocity increased significantly (0.98 ± 0.13 m/s to 1.2 ± 0.16 m/s at 6 months, P < .01), conduction time shortened (32 ± 5 ms to 27 ± 6 ms, P < .01), and complex fractionated activity was reduced (37% ± 14% to 19% ± 12%, P = .02). Changes in conduction velocity correlated positively with changes in 24-hour mean systolic BP (R(2) = 0.55, P = .01). There was a significant reduction in left ventricular mass (139 ± 37 g to 120 ± 29 g, P < .01) and diffuse ventricular fibrosis (T1 partition coefficient 0.39 ± 0.07 to 0.31 ± 0.09, P = .01) on cardiac magnetic resonance imaging.
BP reduction after renal denervation is associated with improvements in regional and global atrial conduction and reductions in ventricular mass and fibrosis. Whether changes in electrical and structural remodeling are solely due to BP lowering or are due in part to intrinsic effects of renal denervation remains to be determined.
高血压是与心房颤动相关的最常见的可改变危险因素。
本研究的目的是确定肾去神经支配后血压降低对人体心房电生理和结构重塑的影响。
14例难治性高血压患者（平均年龄64±9岁，高血压病程16±11年，服用5±2种抗高血压药物）接受了基线24小时动态血压监测、超声心动图、心脏磁共振成像和电生理研究。电生理研究包括测量P波时限、有效不应期和传导时间。使用CARTO3完成右心房的电解剖标测，以确定局部和区域传导速度及组织电压。进行双侧肾去神经支配，并在6个月后重复所有测量。
肾去神经支配后，6个月随访时24小时平均血压从152/84 mmHg降至141/80 mmHg（P<.01）。整体传导速度显著增加（6个月时从0.98±0.13 m/s增至1.2±0.16 m/s，P<.01），传导时间缩短（从32±5 ms至27±6 ms，P<.01），复杂碎裂电位减少（从37%±14%至19%±12%，P=.02）。传导速度的变化与24小时平均收缩压的变化呈正相关（R²=0.55，P=.01）。心脏磁共振成像显示左心室质量显著降低（从139±37 g降至120±29 g，P<.01），弥漫性心室纤维化减轻（T1分配系数从0.39±0.07降至0.31±0.09，P=.01）。
肾去神经支配后血压降低与区域和整体心房传导改善以及心室质量和纤维化降低有关。电和结构重塑的变化是仅由血压降低引起还是部分归因于肾去神经支配的内在作用仍有待确定。
