Renal denervation as a second-line option in a patient with electrical storm resistant to medical treatment and conventional radiofrequency catheter ablation.

Electrical storm (ES) represents a critical state of electrical instability. We describe a patient with coronary artery disease, mechanical aortic valve replacement, and reduced left ventricular function with recurrent ICD shocks. Despite medical treatment with beta-blocker and amiodarone, and after successful ablation of different VT morphologies in combination with substrate modification, ES could not be controlled. We performed renal denervation (RDN) to reduce arrhythmic burden. Thereafter, patient remained free from sustained and non-sustained VTs at 6-month follow-up. RDN is an effective second-line treatment option in patients in whom conventional catheter ablation and medical treatment failed to control the VTs.

Predictors of future arrhythmic events in patients with unexplained syncope.

AIMS: The purpose of this study was to examine the usefulness of implantable loop recorders (ILRs) for symptom-rhythm correlation and to identify predictors of future arrhythmic events. PATIENTS AND METHODS: In our dual-centre study, we analysed ILR data of 189 patients (mean age 67.4 ± 15.2 years, 114 male) with unexplained syncope (single syncope 21 patients, recurrent 168 patients, traumatic injury 43 patients). Patients had severe comorbidities such as hypertension (n = 127), coronary artery disease (n = 31), diabetes mellitus (n = 33) and chronic renal insufficiency (n = 18). The median ILR usage was 29 months (M), with a range between 1 and 46 M. RESULTS: Forty-nine (26%) patients experienced syncope during the study, with a median of 8 M to first recurrence of syncope. In 43 patients, pacemaker implantation was performed because of sinus node disease (n = 29), high-degree AV-block (n = 6) or atrial fibrillation with slow ventricular rate (n = 8). In five patients, an ICD was implanted because of documented ventricular tachycardia (n = 4) or left ventricular ejection fraction <35% (n = 1). One patient received ablation of the cavotricuspid isthmus because of documented atrial flutter. Concerning the clinical course, in five patients explantation of the ILR was necessary due to pocket infection. Three patients died due to non-cardiac causes. Logistic regression analysis revealed that older patients had a significantly higher risk for future arrhythmic events (OR 1.3, p = .039). CONCLUSIONS: ILR monitoring is effective in indicating causes of unexplained syncope by providing symptom-rhythm associations. Only age was a predictor of future arrhythmic events. The mortality in patients with unexplained syncope was very low.

Optimization of the atrioventricular delay during cardiac resynchronization therapy using a device for non-invasive measurement of cardiac index at rest and during exercise.

AIMS: It is not clear whether cardiac resynchronization therapy (CRT) should only be optimized at rest or whether it is necessary to perform CRT optimization during exercise. Our study aims to answer this question by using an inert gas rebreathing method (Innocor®). METHODS AND RESULTS: Twenty-seven patients with congestive heart failure and implanted CRT devices were included in the study. The aetiology of the heart failure was ischaemic in nine (33%) patients. Patients had low left ventricular ejection fraction (29 ± 8%) and enlarged LV end-diastolic diameters (63 ± 7 mm). Atrioventricular delay (AVD) was optimized at rest according to cardiac index (CI), measured by inert gas rebreathing (Innocor®). Thereafter, patients performed standardized, steady-state bicycle exercise at 30 W in sitting body position. Three AVDs were tested during exercise in a random sequence: optimized resting AVD (AVD(opt)) according to baseline measurement; AVD(opt) - 30 ms; and AVD(opt) + 30 ms. Cardiac index was measured in each AVD by inert gas rebreathing. Cardiac index increased significantly during exercise. However, neither AVD(opt) shortening nor prolongation during exercise had significant effect on CI (shortening of AVD(opt) - 30 ms was accompanied by a reduction of CI of 4.8%, prolongation of AVD(opt) + 30 ms was accompanied by a reduction of CI of 7.7%). CONCLUSION: Shortening or lengthening of the AVD during exercise has no impact on CI in CRT patients. On the basis of our results, we conclude that in CRT patients the AVD should be programmed, fixed even during exercise.

Multidimensional ECG-based analysis of cardiac autonomic regulation predicts early AF recurrence after electrical cardioversion.

BACKGROUND: Heart rate turbulence, deceleration capacity (DC), and symbolic dynamics (SD) are promising novel domains of autonomic indices representing the multidimensional qualities of autonomic heart rate dynamics. PURPOSE: The aim of this study was to test the impact of these novel indices in predicting early AF recurrence within the first month after electrical cardioversion (CV). METHODS: In 45 patients with AF, standard Holter recordings were commenced immediately after CV. Holter-based indices were retrospectively analyzed using computerized algorithms. The best indices were applied in a multivariate model to select the optimal combination set that correctly classified patients who developed early AF recurrence. RESULTS: Early AF recurrence occurred in 25 vs 20 patients with stable sinus rhythm. The set with the highest predictive power consisted of DC, turbulence onset, VLF/P, and PTH19 as a parameter of SD. The receiver operating curve analysis applied to this optimum set produced an area under the curve of 0.86, thus correctly classifying patients with 95.0% specificity and 76.0% sensitivity. CONCLUSION: The analysis of novel multidimensional Holter-based autonomic indices after CV appears of clinical value because the procedure identifies patients with high risk of early AF recurrence. Furthermore, it indicates a substantial alteration of autonomic regulation.

Cardiac magnetic resonance imaging as a tool to link cardiac conduction disease to myocarditis with minimal left ventricular impairment.

Myocarditis is an injury of the myocardium caused by a variety of agents. Conduction disturbances such as complete atrioventricular block (AV block) may occur as an infrequent but serious complication of myocarditis. Early detection and accurate diagnosis of myocarditis are still unresolved challenges. We present 2 cases of otherwise mild myocarditis complicated by high-degree AV block in combination with isolated delayed uptake of contrast at the septal regions in the cardiac magnetic resonance imaging. Because the AV block was persistent in both cases, permanent pacemaker implantation was necessary. Delayed enhancement in the septal area in myocarditis might be predictive of infra-Hisian AV block.

Supra-additive expression of interleukin-6, interleukin-8 and basic fibroblast growth factor in vascular smooth muscle cells following coinfection with Chlamydia pneumoniae and cytomegalovirus as a novel link between infection and atherosclerosis.

BACKGROUND: Chlamydia pneumoniae and human cytomegalovirus (HCMV) may be involved in the pathogenesis of atherosclerosis. Prospective studies indicate an increased risk for cardiovascular events in patients with evidence of multiple infections. OBJECTIVE: To determine whether there is a synergistic effect of coinfection with C pneumoniae and HCMV on expression of selected growth factors and cytokines. METHODS: The production of interleukin (IL)-6, IL-8, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), and 'regulated on activation normal T-cell expressed and secreted' (RANTES) was measured in coinfected aortic smooth muscle cells (AoSMC). RESULTS: Using reverse transcription polymerase chain reaction and immunoassays, it was demonstrated that the expression of IL-6, IL-8, RANTES and bFGF was stimulated in a dose- and time-dependent fashion in C pneumoniae and also in HCMV-infected cultures. In contrast, the expression of PDGF-AA was only stimulated following HCMV infection. Coinfection with C pneumoniae and HCMV resulted in a supra-additive stimulation of IL-6 (30% increased expression, P≤0.05) at 48 h, IL-8 (137% increased expression, P≤0.001) at 24 h and bFGF (209% increased expression, P≤0.01) at 48 h following infection. CONCLUSIONS: The findings of the present study show that C pneumoniae and HCMV are able to act in synergy in coinfected AoSMC. The supra-additive induction of AoSMC growth factors and cytokines indicates a novel molecular link between infection and vascular disease development.

HISTORIQUE: Le Chlamydia pneumoniae et le cytomégalovirus humain (CMVH) participent peut-être à la pathogenèse de l'athérosclérose. Selon des études prospectives, le risque d'événements cardiovasculaires est plus important chez les patients présentant des manifestations d'infections multiples. OBJECTIF: Déterminer si la co-infection par le C pneumoniae et le CMVH a un effet synergétique sur l'expression de facteurs de croissance et de cytokines précises. MÉTHODOLOGIE: Les chercheurs ont mesuré la production d'interleukine (IL)-6, d'IL-8, du facteur de croissance basique des fibroblastes (FCbF), du facteur de croissance dérivé des plaquettes (FCDP) et de la protéine RANTES régulée à l'activation, exprimée par les lymphocytes T normaux et sécrétée en présence de co-infection des cellules des muscles lisses de l'aorte (CMLA). RÉSULTATS: Au moyen de la réaction en chaîne de la polymérase à transcription inverse et du dosage immunologique, les chercheurs ont démontré que l'expression de l'IL-6, de l'IL-8, de la protéine RANTES et du FCbF étaient stimulés selon la dose et le délai dans les cellules infectées par le C pneumoniae ainsi que par le CMVH. Par contre, l'expression du FCDP-AA n'était stimulée qu'après une infection par le CMVH. Une co-infection par le C pneumoniae et le CMVH entraînait une stimulation supra-additive de l'IL-6 (expression accrue de 30 %, P≤0,05) 48 heures après l'infection, de l'IL-8 (expression accrue de 137 %, P≤0,001) 24 heures après l'infection et du FCbF (expression accrue de 209 %, P≤0,01) 48 heures après l'infection. CONCLUSIONS: Les résultats de la présente étude démontrent que le C pneumoniae et le CMVH peuvent agir en synergie en cas de co-infection des CMLA. L'induction supra-additive des facteurs de croissance des CMLA et des cytokines laisse supposer un nouveau lien moléculaire entre l'infection et l'apparition d'une maladie vasculaire.

Ordinary AV Nodal Reentry Tachycardia-Unusual Ablation: A Case Report and Review of the Literature.

A 72-year-old woman was referred to us with typical symptoms of paroxysmal supraventricular tachycardia for electrophysiological diagnostics and catheter ablation. During the first session of catheter ablation, a probing of the right ventricle was not successful. Therefore, an angiography of the central veins was performed. A rare anatomical variation with atresia of the inferior vena cava below the hepatic veins with azygos persistence was detected. The blood of the lower half of the body was drained via the dilated azygos into the superior vena cava; the blood of the liver veins enters into the right atrium directly. By atypical catheter placement over the azygos vein in the right ventricle and coronary sinus, an AV nodal reentry tachycardia (AVNRT) could be confirmed as the mechanism of tachycardia. However, a stable position of the ablation catheter could not be achieved by the femoral approach, so the successful AV node modulation with ablation of the slow pathway was performed via jugular access.

QRS duration and QTc interval are predictors of risk for ventricular arrhythmias during cardiac resynchronization therapy.

BACKGROUND AND OBJECTIVES: QRS duration (QRSd) and prolonged corrected QT interval (QTc) are associated with ventricular arrhythmic events. This study was designed to determine whether CRT by means of biventricular pacing alters the QTc and QRSd, and whether such changes are related to the risk of sustained ventricular tachyarrhythmias (sVTA). METHODS AND RESULTS: A total of 127 patients (102 men, mean age 63.9 +/- 8.9 years) with drug-resistant heart failure and QRS duration > or = 130 ms underwent CRT/CRT-ICD. The aetiology of the heart failure was ischaemic in 41 patients (32.3%). After a median follow-up of 24 months, 42 sVTA occurred in 35 patients (27.6%). Twenty-nine patients had a single sVTA, in five patients two sVTA and in one patient three sVTA occurred. The paced QTc was longer in sVTA patients (505 +/- 55 ms) compared with no sVTA patients (486 +/- 44 ms, P < or = 0.003). Similar responses for paced QRSd were observed (182 +/- 27 ms in sVTA patients vs 167 +/- 27 ms in no-sVTA patients, P < or = 0.03). This effect was independent from intrinsic QTc and QRSd and the aetiology of the heart failure. The mortality rate was significantly higher in patients with ventricular fibrillation and fast VT (P < or = 0.004) who experienced shock therapies. However, the sVTA were not the immediate cause of death. CONCLUSIONS: A pacing-induced increase in QTc and QRSd is related to sVTA in patients with CRT. Further studies are needed to determine whether optimization of CRT with the goal to achieve a narrow paced QRSd can reduce the occurrence of sVTA.

Combination of cardiac conduction disease and long QT syndrome caused by mutation T1620K in the cardiac sodium channel.

AIMS: The aim of the present study was to elucidate the molecular mechanism underlying the concomitant occurrence of cardiac conduction disease and long QT syndrome (LQT3), two SCN5A channelopathies that are explained by loss-of-function and gain-of-function, respectively, in the cardiac Na+ channel. METHODS AND RESULTS: A Caucasian family with prolonged QT interval, intermittent bundle-branch block, sudden cardiac death, and syncope was investigated. Lidocaine (1 mg/kg i.v.) normalized the prolonged QT interval and rescued bundle-branch block. An SCN5A mutation analysis was performed that revealed a C-to-A mutation at position 4859 (exon 28), predicted to change a highly conserved threonine for a lysine at position 1620. Mutant channels were characterized both in Xenopus oocytes and HEK293 cells. The T1620K mutation remarkably altered the properties of Nav1.5 channels. In particular, the voltage-dependence of the current decay time constants was largely lost. As a consequence, mutant channels inactivated faster than wild-type channels at potentials negative to -30 mV, resulting in less Na+ inward current (loss-of-function), but significantly slower at potentials positive to -30 mV, resulting in an increased Na+ inward current (gain-of-function). Moreover, we found a hyperpolarized shift of steady-state activation and an accelerated recovery from inactivation (gain-of-function). At the same time, channel availability was significantly reduced at the resting membrane potential (loss-of-function). CONCLUSION: We conclude that lysine at position 1620 leads to both loss-of-function and gain-of-function properties in hNav1.5 channels, which may consequently cause in the same individuals impaired impulse propagation in the conduction system and prolonged QTc intervals, respectively.

Efficacy of temperature-guided cryoballoon ablation without using real-time recordings - 12-Month follow-up.

BACKGROUND: We sought to evaluate a temperature-guided approach of cryoballoon (CB) ablation without visualization of real-time recordings. METHODS AND RESULTS: We analysed 166 patients (34.9% female, 60 ±â€¯11 years) with paroxysmal or short-term persistent atrial fibrillation (AF). Comorbidities included diabetes mellitus (n = 28), coronary artery disease (n = 24), hypertension (n = 122), previous stroke or TIA > 3 months (n = 12). Cryoablation of the pulmonary veins (PV) was performed using first-generation (n = 78) and second-generation CB (n = 88). Two 5-minute freezes were performed for the first-generation and two 4-minute freezes for the second-generation CB with the intention to achieve a temperature drop below -40 °C. At 12-month follow-up, we observed overall freedom from AF in 92 patients (56.6%, mean time to AF recurrence 3.4 ±â€¯2.9 months). There was a significant difference in freedom from AF between first-generation CB (45%) and second-generation CB (67%; p < 0.005). Complications were groin hematoma (4.8%) and phrenic nerve palsy (PVP) (2.4%). PVP disappeared after 12 months in all patients. Three patients developed cardiac tamponade (1.8%) that resolved without further sequelae after pericardiocentesis. Multivariate analysis revealed that only the achieved temperature in the right inferior PV (RIPV) was a predictor of long-term freedom from AF (OR 0.9; p = 0.014). Female gender was a predictor of AF recurrence (OR 6.1; p = 0.022). CONCLUSION: Temperature-guided CB ablation without real-time recordings is feasible and safe without reducing the efficacy if second-generation CB is used. Deep nadir temperatures especially in the RIPV are necessary for long term-success.

Transesophageal left ventricular posterior wall potential in heart failure patients with biventricular pacing.

INTRODUCTION: Biventricular (BV) pacing is an established therapy for heart failure (HF) patients with intraventricular conduction delay, but not all patients improved clinically. We investigated the interventricular delay (IVD) by means of the transesophageal left ventricular posterior wall potential (LVPWP). MATERIALS AND METHODS, AND RESULTS: A total of 18 HF patients (age 62+/-9 years; 15 males) with NYHA class 3.1+/-0.3, LV ejection fraction 22+/-7%, left bundle branch block and a QRS duration (QRSD) of 171+/-27 ms were analyzed using transesophageal LVPWP before implantation of a BV pacing device. The median follow up was 14+/-14 months. In 14 responders, IVD was 81+/-25 ms with a QRSD/IVD ratio of 2.2+/-0.3 with reclassification of NYHA class 3.1+/-0.3 to 2.0+/-0.5 (p<0.001) and an increase in LV ejection fraction from 22+/-7% to 36+/-11% (p=0.001) during long-term BV pacing. In four non-responders, transesophageal IVD was significantly smaller at 30+/-11 ms (p=0.001). CONCLUSION: Transesophageal IVD may be a useful method to detect responders to BV pacing. Transesophageal LVPWP may be a simple and useful technique to detect clinical responders to BV pacing in HF patients.

Termination of atrial flutter by directed transesophageal atrial pacing during transesophageal echocardiography.

INTRODUCTION: The purpose of this study was to evaluate termination of atrial flutter (AFL) by directed rapid transesophageal atrial pacing (TAP) with and without simultaneous transesophageal echocardiography (TEE) performed using a novel TEE tube electrode. MATERIALS AND METHODS, AND RESULTS: A total of 16 AFL patients (age 63+/-12 years; 13 males) with mean AFL cycle length of 224+/-24 ms (n=12) and mean ventricular cycle length of 448+/-47 ms (n=12) were analyzed using either an esophageal TO electrode (n=10) or a novel TEE tube electrode consisting of a tube with four hemispherical electrodes that is pulled over the echo probe (n=6). AFL could be terminated by directed rapid TAP using an esophageal TO electrode, leading to induction of atrial fibrillation (AF) (n=6), induction of AF and spontaneous conversion to sinus rhythm (SR) (n=3), and with conversion to SR (n=1). AFL could also be terminated by directed rapid TAP using the TEE tube electrode, with induction of AF (n=3) or induction of AF and spontaneous conversion to SR (n=3). CONCLUSION: AFL can be terminated by directed rapid TAP with hemispherical electrodes with and without simultaneous TEE. TAP with the directed TEE tube electrode is a safe, simple, and useful method for terminating AFL.

[Acute chest pain and new ECG changes in pacemaker patients : A clinical challenge]. / Akuter Thoraxschmerz in Verbindung mit neuen EKG-Veränderungen bei Schrittmacherpatienten : Eine klinische Herausforderung.

We report the case of a 82-year-old woman who was admitted to our institution with acute chest pain, nausea, and vomiting. Because of atrial fibrillation with intermittent bradycardia, a single-chamber pacemaker was implanted 4 years ago. The initial 12-lead ECG showed atrial fibrillation with a heart rate of 70 bpm, narrow QRS, and T­wave inversions in the inferolateral leads. Coronary artery disease was excluded by immediate cardiac catheterization. A subsequent ECG three hours later showed a ventricular paced rhythm. During the subsequent clinical course, cardiac injury markers remained normal. However, serum amylase and lipase levels were 5 times above the normal range. According to these clinical findings, acute pancreatitis was the most likely diagnosis. Abdominal ultrasound excluded pancreatic necrosis and gallstones. Initial treatment consists of fasting, pain control, and intravenous fluids with resolution of symptoms after a few days. The patient could be discharged 7 days later. In conclusion, the observed ECG findings in combination with chest pain are suggestive for myocardial ischemia mandating immediate cardiac catheterization. However, acute pancreatitis might present with the aforementioned ECG changes and symptoms. The case was further complicated by a distinct electrocardiographic memory effect due to intermittent ventricular pacing.

ST-segment Elevation Following Cardioversion of Atrial Fibrillation in the Emergency Department: Unmasked Myocardial Infarction due to Left Main Coronary Artery Plaque Rupture or Unspecific Finding?

Atrial fibrillation (AF) is a frequent reason for emergency department visits. According to current guidelines either rate- or rhythm-control are acceptable therapeutic options in such situations. In this report, we present the complicated clinical course of a patient with AF and a rapid ventricular response. Because of paroxysmal AF, the patient was on chronic oral anticoagulation therapy with warfarin. Pharmacological treatment was ineffective to control ventricular rate, and immediate synchronized electrical cardioversion was performed. One hour later, the patient complained of chest pain in combination with marked ST-segment elevation in the anterior leads. Cardiac catheterization with optical coherence tomography disclosed plaque rupture in the left main coronary artery without other significant stenosis. Stent implantation was performed successfully. During the course of the hospital stay, the patient remained asymptomatic and the ST-segment elevations resolved. However, despite treatment with amiodarone it was not possible to keep the patient permanently in sinus rhythm. Therefore, a biventricular pacemaker was implanted and AV node ablation performed.

Prevention of lesion recurrence in chronic total coronary occlusions by paclitaxel-eluting stents.

OBJECTIVES: The aim of this research was to assess the efficacy of paclitaxel-eluting stents in chronic total coronary occlusions (CTO). BACKGROUND: Percutaneous coronary interventions for CTOs are characterized by a high target vessel failure rate. METHODS: In 48 consecutive patients, paclitaxel-eluting stents (Taxus, Boston Scientific Corp., Natick, Massachusetts) were implanted after successful recanalization of a CTO (duration >2 weeks). Patients underwent an angiography after 6 months and were followed clinically for 12 months. They were compared with 48 lesion- and risk-matched patients with CTOs treated with bare metal stents (BMS). Primary clinical end point was the one-year incidence of major adverse cardiac events (MACE) (death, myocardial infarction, repeat revascularization); secondary end points were the rate of restenosis and re-occlusion. RESULTS: In-hospital MACE was 4.2% with Taxus, and 2.1% with BMS (p = NS). The one-year MACE rate was 12.5% in the Taxus group, and 47.9% in the BMS group (p < 0.001), which was due to a reduced need for repeat revascularization. The angiographic restenosis rate was 8.3% with Taxus versus 51.1% with BMS (p < 0.001). There was only one late re-occlusion with Taxus (2.1%) as compared with 23.4% with BMS (p < 0.005). The late loss was reduced in the Taxus group by 84% as compared with BMS. All nonocclusive restenoses in the Taxus group were focal and successfully treated by implanting an additional Taxus stent. CONCLUSIONS: The treatment of CTOs with a paclitaxel-eluting stent drastically reduces MACE and restenosis, and almost eliminates re-occlusion, which is typically frequent with BMS in CTOs. Chronic total coronary occlusion should be a preferred indication for drug-eluting stents.

Toxic Epidermal Necrolysis During Dronedarone Treatment: First Report of a Severe Serious Adverse Event Of A New Antiarrhythmic Drug.

A 77-year-old female patient with symptomatic atrial fibrillation with fast ventricular rate despite conventional antiarrhythmic therapy was treated with dronedarone. Five days later, she developed a maculopapulous exanthema and small flaccid blisters, which spread over the common integument predominantly located on the dorsal trunk. Over few days, the patient showed a severe epidermal necrolysis of approximately 30 % of the body area and ultimately died in multiorgan failure. Here, we report a rare case of toxic epidermal necrolysis during treatment with dronedarone leading to patient death.

Increased production of matrix metalloproteinases 1 and 3 by smooth muscle cells upon infection with Chlamydia pneumoniae.

Atherosclerosis has been linked to Chlamydia pneumoniae infection. In atherosclerotic arteries chlamydiae infect macrophages, endothelial cells, and smooth muscle cells (SMC). It has been suggested that the proteolysis of the extracellular matrix by matrix metalloproteinases (MMPs) is involved in the destabilisation and rupture of atherosclerotic plaques. In this study we investigated the expression of several MMPs and tissue inhibitors of MMP (TIMPs) in C. pneumoniae-infected SMC using reverse transcription-polymerase chain reaction analysis. Chlamydial infection of SMC up-regulated the mRNA levels of MMP-1 (interstitial collagenase) and MMP-3 (stromelysin) but did not affect the expression of MMP-2 and -9 (gelatinases). Additionally, the levels of TIMP-1 and -2 mRNA remained unchanged upon infection. Cells infected with C. pneumoniae secreted increased quantities of MMP-1 and -3 proteins as demonstrated by enzyme-linked immunosorbent assays. The ability of C. pneumoniae to stimulate the production of MMP-1 and -3 by SMC may be important for its pathogenic role in the progression of atherosclerotic disease.

Renal denervation with cryoenergy as second-line option is effective in the treatment of resistant hypertension in non-responders to radiofrequency ablation.

AIMS: Renal denervation (RDN) with radiofrequency (RF) is being used to treat resistant hypertension (rHTN). As 15-30% of treated patients are non-responders to RDN, we investigated whether RDN with cryoenergy can serve as a second-line option. METHODS AND RESULTS: Ten non-responder patients (mean age 55 years, six male) with rHTN were treated with cryoenergy for RDN. In order to qualify as non-responders, patients had to show systolic 24 hr ambulatory BP (ABP) ≥150 mmHg (median ABP 183/102 mmHg, median office- based BP [OBP] 191/108 mmHg) despite treatment with ≥4 different antihypertensive drugs (mean 6), and further not show a reduction of systolic ABP ≥10 mmHg at ≥3 months after RDN with RF. The three/six/12-month follow-up (FU) comprised clinical and biochemical evaluation, OBP and ABP measurement. Additionally, at six months, duplex sonography was performed. Cryoablation with a 7 Fr cryoablation catheter (Freezor® Xtra; Medtronic, Minneapolis, MN, USA) was performed in all patients without complications (four applications in both renal arteries, every four minutes, temperature -75°C). At three, six, and 12 months we found a reduction in systolic OBP of -41/-47/-61 mmHg (n=10/7/6; p=0.044 for all), diastolic OBP of -18/-14/-34 mmHg, systolic ABP of -38/-35/-52 mmHg (n=9/7/6, p=0.014 for all), and diastolic ABP of -20/-13/-18 mmHg (p=0.043 for all), respectively. During FU, no complications occurred and the renal function remained unchanged. CONCLUSIONS: The significant reduction in systolic OBP and ABP observed qualifies RDN with cryoenergy as an effective second-line therapeutic option in non- responders to RDN with RF.

Renal denervation in the treatment of drug-resistant hypertension: current knowledge and future perspectives.

Resistant hypertension remains a challenging issue even for modern medicine. Therefore, research is focusing on the development of new technologies to optimize the treatment of this condition. It has been demonstrated that the dysfunction of the sympathetic nervous system is crucial in the development and maintenance of advanced stages of hypertension. Based on these findings, clinical trials have recently shown that catheter-based percutaneous renal denervation therapy is safe and effective in the treatment of resistant hypertension. This review discusses the current scientific knowledge of renal denervation therapy in resistant hypertension, including the different methods that have been described in the literature so far, as well as limitations of the available data. Furthermore, new potential targets for this fascinating therapy will be addressed.