Efectos beneficiosos de la simpatectomía renal sobre el remodelado vascular pulmonar en la hipertensión arterial primaria experimental / Beneficial effects of renal denervation on pulmonary vascular remodeling in experimental pulmonary artery hypertension

Introducción y objetivos. La activación tanto del sistema nervioso simpático como del sistema renina-angiotensina-aldosterona está estrechamente relacionada con la hipertensión arterial pulmonar. Nuestra hipótesis era que la simpatectomía renal reduce la actividad del sistema renina-angiotensina-aldosterona e inhibe la progresión de la hipertensión arterial pulmonar. Métodos. Se asignó aleatoriamente a un total de 22 perros beagle a tres grupos de estudio. Se efectuaron determinaciones de la dinámica pulmonar de esos animales antes y 8 semanas después de la inyección de 0,1 ml/kg de dimetilformamida (perros de control) o de 2 mg/kg de deshidromonocrotalina (perros con hipertensión arterial pulmonar y perros con hipertensión arterial pulmonar + simpatectomía renal). Ocho semanas después de la inyección, se determinaron las concentraciones de neurohormonas y se evaluó la morfología del tejido pulmonar. Resultados. Se observó un aumento significativo de la concentración de angiotensina II y endotelina-1 en plasma después de 8 semanas en los perros con hipertensión arterial pulmonar, y los valores obtenidos en los tejidos pulmonares de estos animales eran superiores a los de los perros del grupo de control y el grupo de simpatectomía renal (medias: angiotensina II, 65 ± 9,8 frente a 38 ± 6,7 y 46 ± 8,1; endotelina-1, 96 ± 10,3 frente a 54 ± 6,2 y 67 ± 9,4; p < 0,01). La deshidromonocrotalina aumentó la presión arterial pulmonar media (16 ± 3,4 frente a 33 ± 7,3 mmHg; p < 0,01), y la simpatectomía renal evitó que se produjera este aumento. La proliferación celular del músculo liso pulmonar fue mayor en los perros con hipertensión arterial pulmonar que en los animales de los grupos de control y de hipertensión arterial pulmonar + simpatectomía renal. Conclusiones. La simpatectomía renal atenúa el remodelado vascular pulmonar y reduce la presión arterial pulmonar en la hipertensión arterial pulmonar experimental. El efecto de la simpatectomía renal puede contribuir a reducir las concentraciones de neurohormonas (AU)

Introduction and objectives. Activation of both the sympathetic nervous system and the renin-angiotensin-aldosterone system is closely associated with pulmonary arterial hypertension. We hypothesized that renal denervation decreases renin-angiotensin-aldosterone activity and inhibits the progression of pulmonary arterial hypertension. Methods. Twenty-two beagles were randomized into 3 groups. The dogs’ pulmonary dynamics were measured before and 8 weeks after injection of 0.1 mL/kg dimethylformamide (control dogs) or 2 mg/kg dehydromonocrotaline (pulmonary arterial hypertension and pulmonary arterial hypertension + renal denervation dogs). Eight weeks after injection, neurohormone levels and pulmonary tissue morphology were measured. Results. Levels of plasma angiotensin II and endothelin-1 were significantly increased after 8 weeks in the pulmonary arterial hypertension dogs and were higher in the lung tissues of these dogs than in those of the control and renal denervation dogs (mean [standard deviation] angiotensin II: 65 [9.8] vs 38 [6.7], 46 [8.1]; endothelin-1: 96 [10.3] vs 54 [6.2], 67 [9.4]; P < .01). Dehydromonocrotaline increased the mean pulmonary arterial pressure (16 [3.4] mmHg vs 33 [7.3] mmHg; P < .01), and renal denervation prevented this increase. Pulmonary smooth muscle cell proliferation was higher in the pulmonary arterial hypertension dogs than in the control and pulmonary arterial hypertension + renal denervation dogs (AU)

Beneficial Effects of Renal Denervation on Pulmonary Vascular Remodeling in Experimental Pulmonary Artery Hypertension.

INTRODUCTION AND OBJECTIVES: Activation of both the sympathetic nervous system and the renin-angiotensin-aldosterone system is closely associated with pulmonary arterial hypertension. We hypothesized that renal denervation decreases renin-angiotensin-aldosterone activity and inhibits the progression of pulmonary arterial hypertension. METHODS: Twenty-two beagles were randomized into 3 groups. The dogs' pulmonary dynamics were measured before and 8 weeks after injection of 0.1mL/kg dimethylformamide (control dogs) or 2mg/kg dehydromonocrotaline (pulmonary arterial hypertension and pulmonary arterial hypertension + renal denervation dogs). Eight weeks after injection, neurohormone levels and pulmonary tissue morphology were measured. RESULTS: Levels of plasma angiotensin II and endothelin-1 were significantly increased after 8 weeks in the pulmonary arterial hypertension dogs and were higher in the lung tissues of these dogs than in those of the control and renal denervation dogs (mean [standard deviation] angiotensin II: 65 [9.8] vs 38 [6.7], 46 [8.1]; endothelin-1: 96 [10.3] vs 54 [6.2], 67 [9.4]; P < .01). Dehydromonocrotaline increased the mean pulmonary arterial pressure (16 [3.4] mmHg vs 33 [7.3] mmHg; P < .01), and renal denervation prevented this increase. Pulmonary smooth muscle cell proliferation was higher in the pulmonary arterial hypertension dogs than in the control and pulmonary arterial hypertension + renal denervation dogs. CONCLUSIONS: Renal denervation attenuates pulmonary vascular remodeling and decreases pulmonary arterial pressure in experimental pulmonary arterial hypertension. The effect of renal denervation may contribute to decreased neurohormone levels.

Evaluation of the synchrony of heart after catheter-based renal denervation by two dimensional strain imaging / 中华超声影像学杂志

Objective To evaluate the synchrony of heart after catheter-based renal denervation by two dimensional speckle tracking imaging.Methods Each renal sympathetic nerve of 20 dogs were ablated,and the index of heart and blood pressure were detected 6 weeks later.Standard 2D images were acquired in the 2-,3-and 4-apical views.The times from QRS onset to peak-systolic strain rate and to peak-diastolic strain rate were measured for the longitudinal 16-segments in Qlab software,and the standard deviation were calculated.The time to peak longitudinal strain rate and time to peak contraction strain rate of left atrium were measured for each segment contained septal,latera,anterior and posterior in the level of the basal segments,middle sections and apical in Qlab software,and the standard deviation were calculated.Parameters were compared among the before and after of the ablation.Results The systolic pressure and diastolic pressure had no changes after the ablation of renal sympathetic nerve (P ＞ 0.05).The R-R showed a increasing trend,but no significant differences(P ＞0.05).The peak time of LV systolic and diastolic strain rate had a extended trendency too,but no differences(P ＞0.05),and standard deviations of the peak times had no significant differences(P ＞0.05).The peak time of LA longitudinal strain rate and contraction strain rate had a extended trendency,but no obvious change (P ＞0.05),and the standard deviations of the peak times had no significant differences (P ＞0.05).The size of the heart cavity had no differences(P ＞0.05).Conclusions The systolic pressure and diastolic pressure have no changes after the ablation of renal sympathetic nerve,and the synchrony parameters of LV and LA have no significant differences,demonstrate that the synchrony of heart is not affected by the renal sympathetic denervation.

Evaluation of the security of catheter-based renal denervation by two dimensional speckle tracking imaging / 中华超声影像学杂志

Objective To evaluate the security of catheter-based renal denervation by two dimensional speckle tracking imaging.Methods 20 dogs was ablated,whose indicies of heart and blood pressure were detected 6 weeks later.Standard 2D images were acquired in the 2-,3-and 4-apical views as well as the parasternal short-axis views at the level of the mitral valve and papillary muscles.The time to peak-systolic strain of each segment in the level of the mitral valve and papillary muscles,the standard deviation of the time to peak-systolic strain,the peak strain of the longitudinal 12-segment were recorded.Parameters were compared among the before and after ablation.Results Compared with before ablation of renal sympathetic nerve,the systolic pressure and diastolic pressure didn't reduced significantly after the ablation of renal sympathetic nerve (P ＞ 0.05),while there were no significant difference in the peak strain of the longitudinal 12-segment,the dyssychrony parameters and the size of the heart cavity before and after ablation(P ＞0.05).Conclusions The pressure had no change after the ablation of renal sympathetic nerve while without harmful effect on the the size of the heart cavity,the function of the myocardial contraction and the dyssychrony parameters.The ablation of renal sympathetic nerve can' t lower the normal blood pressure and be safe for heart at the same time.