Renal sympathetic denervation
Hypertension is a major global health public health concern. However, the treatment of hypertension remains suboptimal. In 14-24% of the patients being treated for hypertension, blood pressure continued to be higher than treatment targets. In the search for new modalities to lower blood pressure renal sympathetic denervation (RDN) has been developed; the renal nerves play an important role in hypertension. With this treatment the renal nerves around the renal arteries are ablated with radio frequency energy. The initial results showed impressive lowering of blood pressure. However, the results of the blinded, randomized studies were a bit disappointing. Therefore, the last years studies have been focusing on improving the technique and selecting the right hypertensive patients. This thesis have focused on using renal nerve stimulation (RNS) before and after RDN to improve the denervation technique. With RNS we stimulate in the renal arteries in order to find the exact place of the nerves; stimulation at the place of the renal nerves leads to blood pressure increase. Afterwards we ablate that points, and thereafter we check with RNS if no blood pressure increase is observed. We have shown the acute effects on hemodynamics and heart rate variability of renal nerve stimulation during RDN. Moreover, we have shown that the patients with no RNS-induced blood pressure increase after RDN have better blood pressure lowering at follow-up compared to patients with any RNS-induced blood pressure increase. Finally, we discuss the role of RDN in the treatment of hypertension and possibly other cardiovascular disease.