Resistant hypertension (RH) is a powerful risk factor for cardiovascular morbidity and mortality. Among the characteristics of patients with RH, obesity, obstructive sleep apnea, and aldosterone excess are covering a great area of the mosaic of RH phenotype. Increased sympathetic nervous system (SNS) activity is present in all these underlying conditions, supporting its crucial role in the pathophysiology of antihypertensive treatment resistance. Current clinical and experimental knowledge points towards an impact of several factors on SNS activation, namely, insulin resistance, adipokines, endothelial dysfunction, cyclic intermittent hypoxaemia, aldosterone effects on central nervous system, chemoreceptors, and baroreceptors dysregulation. The further investigation and understanding of the mechanisms leading to SNS activation could reveal novel therapeutic targets and expand our treatment options in the challenging management of RH.

In treated hypertensive patients, among prospective RHT dynamic patterns, persistent RHT is frequent and independently associated with adverse cardiovascular prognosis.

Transluminal renal sympathetic denervation (RDN) reduces blood pressure (BP) in patients with drug-resistant uncontrolled hypertension. We assessed the effect of RDN on heart rate, supraventricular and ventricular ectopic activity and indexes of heart rate variability in 14 patients with drug-resistant uncontrolled hypertension who were all responders to RDN (defined as a reduction in office systolic BP ⩾ 10 mm Hg) at baseline and at 1 and 6 months after the procedure using the multielectrode EnligHTN ablation catheter (St Jude Medical). Office and 24-h systolic and diastolic BP were significantly reduced both at 1 and 6 months after RDN and all patients were office BP responders. There was a trend toward office heart rate reduction (by 6.9 b.p.m., P=0.064) at 1 month and a significant reduction by 10 b.p.m. (P=0.004) at 6 months. Mean 24-h Holter monitoring heart rate was reduced by 6.7 b.p.m. (P=0.022) at 1 month and by 5.3 b.p.m. (P=0.010) at 6 months after RDN. The total number of premature supraventricular and ventricular contractions was significantly decreased and time- and frequency- domain indexes were increased both at 1 and at 6 months after RDN (P<0.05 for both cases). Apart from the substantial BP lowering, RDN results in significant reduction of mean heart rate and arrhythmia burden, restoring autonomic balance in responder patients with drug-resistant uncontrolled hypertension.