Catheter ablation vs. antiarrhythmic drug therapy in patients with symptomatic atrioventricular nodal re-entrant tachycardia: a randomized, controlled trial.

AIMS: To conduct a randomized trial in order to guide the optimum therapy of symptomatic atrioventricular nodal re-entrant tachycardia (AVNRT). METHODS AND RESULTS: Patients with at least one symptomatic episode of tachycardia per month and an electrophysiologic diagnosis of AVNRT were randomly assigned to catheter ablation or chronic antiarrhythmic drug (AAD) therapy with bisoprolol (5 mg od) and/or diltiazem (120-300 mg od). All patients were properly educated to treat subsequent tachycardia episodes with autonomic manoeuvres or a 'pill in the pocket' approach. The primary endpoint of the study was hospital admission for persistent tachycardia cardioversion, during a follow-up period of 5 years. Sixty-one patients were included in the study. In the ablation group, 1 patient was lost to follow-up, and 29 were free of arrhythmia or conduction disturbances at a 5-year follow-up. In the AAD group, three patients were lost to follow-up. Of the remainder, 10 patients (35.7%) continued with initial therapy, 11 patients (39.2%) remained on diltiazem alone, and 7 patients (25%) interrupted their therapy within the first 3 months following randomization, and subsequently developed an episode requiring cardioversion. During a follow-up of 5 years, 21 patients in the AAD group required hospital admission for cardioversion. Survival free from the study endpoint was significantly higher in the ablation group compared with the AAD group (log-rank test, P < 0.001). CONCLUSIONS: Catheter ablation is the therapy of choice for symptomatic AVNRT. Antiarrhythmic drug therapy is ineffective and not well tolerated.

Spot drug-eluting stenting for long coronary stenoses: long-term results of a randomized clinical study.

BACKGROUND: Preliminary results of a randomized trial have suggested that total lesion coverage with drug-eluting stents (DES) is not necessary in the presence of diffuse disease of nonuniform severity. In the present study, we report long-term results of this trial. METHODS: Consecutive, consenting patients with a long (>20 mm) coronary lesion of nonuniform severity and indication for percutaneous coronary intervention were randomized to full stent coverage of the atherosclerotic lesion with multiple, overlapping (full DES group, n = 90) or spot stenting of the hemodynamically significant parts of the lesion only (defined as diameter stenosis > 50%) (spot DES group, n = 89). RESULTS: At a follow-up of 2-7 years, 30 patients with full DES (33.3%) and 12 patients (13.5%) with spot DES had a major adverse cardiac event (MACE) (P = 0.015). Cox proportional hazard model showed that the risk for MACE was almost 65% lower among patients who were subjected to spot DES compared to those who underwent full DES (HR = 0.35, 95% CI = 0.18-0.68, P = 0.002). This association remained significant even after controlling for age, sex, and lesion length, and the type of stent used (HR = 0.41, 95% CI = 0.20-0.81, P = 0.011). CONCLUSIONS: In the presence of diffuse disease of nonuniform severity, selective stenting of only the significantly stenosed parts of the lesion confers better long-term results compared to total lesion coverage with DES.

Use of a circular mapping and ablation catheter for ablation of atypical right ventricular outflow tract arrhythmia.

A new technique for ablation of persistent ectopic activity with atypical electrocardiographic characteristics at the vicinity of the right ventricular outflow tract is described. A new circular mapping and ablation catheter initially designed for pulmonary vein ablation was used. Abolition of ectopic activity was achieved with minimal fluoroscopy and ablation times.

Complex fractionated atrial electrograms at anatomic sites of ganglionated plexi in atrial fibrillation.

AIMS: To investigate the relationship of complex fractionated atrial electrograms (CFAEs) with the activity of the ganglionated plexi (GP) in the cardiac autonomic nervous system. METHODS AND RESULTS: Thirty-two patients (aged 55 +/- 10 years, five females) scheduled for circumferential ablation for paroxysmal atrial fibrillation (AF) were studied. Mapping of CFAEs during AF was performed at the left atrium (LA) and pulmonary vein-atrial junctions, particularly at the locations where GP are commonly located. Complex fractionated atrial electrograms were identified at >or=1 GP site in 22 of 32 patients (68.8%) and >or=1 LA wall site in 11 patients (34.4%, P < 0.001). In the 10 patients without CFAEs at the GP site, only one patient displayed CFAEs at the LA site. At the site of the left superior GP, CFAEs were recorded in 17 of 32 patients (53.1%), and in 14 (43.8%), 10 (31.3%), 13 (40.6%), and 19 (59.4%) patients at the sites of left inferior, right anterior, right inferior GP, and crux GP, respectively. Ten of 11 patients with CFAEs recorded in the LA wall also displayed CFAE in at least one GP. This association was statistically significant (P = 0.05). In 7 of these 11 patients, CFAEs were also recorded in the LA wall sites adjacent to a GP that also displayed CFAEs. CONCLUSION: Complex fractionated atrial electrograms at presumed anatomic sites of GP were identified in 68.8% patients with paroxysmal AF. In 11 patients without CFAE at the GP, CFAEs were recorded in the LA wall only in one patient. These findings suggest an association between CFAEs and GP.

Anatomic approach for ganglionic plexi ablation in patients with paroxysmal atrial fibrillation.

There is evidence that parasympathetic denervation may prevent atrial fibrillation (AF) recurrences. This study aimed at applying an anatomic approach for ablation of atrial ganglionic plexi (GPs) in patients with paroxysmal AF. Nineteen patients with symptomatic, paroxysmal AF underwent anatomically guided radiofrequency ablation at the location of the 4 main left atrial GPs and were prospectively assessed for recurrence of AF or other atrial arrhythmia. This group was compared with 19 age- and gender-matched patients who previously underwent conventional circumferential pulmonary vein ablation. All ablation procedures were uneventful. Circumferential and GP ablations were accomplished with a radiofrequency delivery time of 28 +/- 5 versus 18 +/- 3 min (p <0.001) and a fluoroscopy time of 31 +/- 5 versus 18 +/- 5 min (p <0.001), respectively. Parasympathetic reflexes during radiofrequency ablation were elicited in 4 patients (21%). Arrhythmia recurred in 7 patients (37%) with circumferential ablation and 14 patients (74%) with GP ablation, during 1-year follow-up (p for log-rank test = 0.017). In 2 patients with GP ablation, left atrial flutters were documented in addition to AF during follow-up. Patients who underwent GP ablation had an almost 2.5 times higher risk of AF recurrence compared with those who underwent circumferential ablation (hazard ratio 2.6, 95% confidence interval 1.0 to 6.6, p = 0.038). In conclusion, anatomically guided GP ablation is feasible and safe in the electrophysiology laboratory, but this approach yields inferior clinical results compared with circumferential ablation.

Regional endocardial left atrial voltage and electrogram fractionation in patients with atrial fibrillation.

INTRODUCTION: Heterogeneities in electrophysiological properties may contribute to the development of atrial fibrillation, and regional disparities in endocardial voltage in the left atrium have been related to arrhythmogenic mechanisms. This study aimed at investigating endocardial voltage in different regions of the left atrium in patients with atrial fibrillation (AF). METHODS AND RESULTS: Thirty-six patients (aged 56 +/- 7 years, 10 female) scheduled for circumferential ablation for paroxysmal AF were studied. Voltage measurements were performed during AF and with constant right ventricular pacing in the anterior, posterior, superior and inferior walls outside the antrum of the left (LPV), and right (RPV) pulmonary veins, by means of electroanatomical mapping. There was a high agreement among measurements performed in the endocardium of the posterior atrial wall (ICC > 0.70), and moderate agreement among measurements performed in the superior and inferior walls (0.50 < ICC< 0.70), outside both PV antra. The posterior left atrial wall demonstrated significantly higher voltages both outside the LPV antrum (1.29 +/- 1.36 mV) and the RPV antrum (1.20 +/- 0.63 mV) compared to the inferior, anterior and superior walls (0.47 +/- 0.49, 0.68 +/- 0.69, and 0.61 +/- 0.83 mV outside the LPV antrum, and 0.39 +/- 0.23, 0.65 +/- 0.49, and 0.49 +/- 0.24 mV outside the RPV antrum, respectively). Fractionated electrograms were mainly identified at the posterior left atrial wall, outside the right PV antrum. CONCLUSION: During AF, the posterior wall displays significantly higher voltage and electrogram fractionation compared with other parts of the left atrial endocardium outside the antra of both pulmonary veins in patients with paroxysmal AF.

Long-term follow-up after radiofrequency catheter ablation for atrial fibrillation.

AIMS: Data on long-term follow-up of patients who have undergone catheter ablation for atrial fibrillation (AF) are very limited. This report aimed at presenting clinical outcome and AF-free survival after pulmonary vein (PV) isolation over an extended (>3 years) follow-up period. METHODS AND RESULTS: Thirty-nine patients subjected to PV isolation for paroxysmal AF were followed-up for at least 3 years according to a strict protocol. Fourteen patients (35.8%) had one, 19 patients (50%) had two, and 6 patients (15.4%) had three ablation procedures. At end of follow-up (42.2 +/- 6.0 months), 17 patients (43.5%) were completely free of AF or other atrial arrhythmia, and 26 patients (66.6%) had symptomatic improvement. The long-term success rate was 21.4% for patients subjected to a single ablation procedure, 52.6% for patients subjected to two catheter ablation procedures, and 66.7% for patients who underwent three ablation procedures (P = 0.094). There was also a trend for patients who underwent a combination of different ablation procedures (ostial, antral, and/or circumferential) to have a higher AF-free survival when compared with patients subjected to the same procedure (P-value for log-rank test = 0.036). CONCLUSION: Catheter ablation does not eliminate paroxysmal AF in up to 56% of patients in the long term, despite the use of two or three ablation procedures in two-thirds of them. However, it confers symptomatic improvement in 67% of treated patients.

Clinical outcome of left atrial ablation for paroxysmal atrial fibrillation is related to the extent of radiofrequency ablation.

BACKGROUND: The exact mechanism of eliminating atrial fibrillation (AF) by catheter ablation techniques is not known. We investigated whether the extent of atrial damage conferred by radiofrequency lesions is a predictor of success after ablation, regardless of the method employed for ablation. METHODS: Ninety consecutive patients with paroxysmal AF subjected to ostial-antral pulmonary vein isolation (n = 41) or circumferential (n = 49) catheter ablation were studied. RESULTS: At 1 year follow-up, 16 out of 41 patients (39%) with ostial-antral ablation and 16 out of 49 patients (32.6%) with circumferential ablation had AF recurrences (p = 0.5). The mean duration of radiofrequency ablation lesions was statistically significantly shorter in patients with recurrence of AF compared to those with sinus rhythm 1 year after ablation (22.3 +/- 4.2 min vs. 27.2 +/- 4.5 min, respectively, p value < 0.001). Radiofrequency ablation time was inversely associated with the risk of recurrence of AF 1 year after ablation and this relationship remained even after adjustment for potential confounding factors such as age, sex, left atrial size, and type of ablation technique (ostial-antral or circumferential; HR = 0.80, 95% CI: 0.72-0.87, p < 0.001). CONCLUSIONS: Duration of radiofrequency energy delivery is an independent predictor of clinical outcome at 1 year follow-up both among patients undergoing circumferential as well as ostial-antral ablation.

Handgrip-enhanced myocardial fractional flow reserve for assessment of coronary artery stenoses.

BACKGROUND: Fractional flow reserve (FFR) may yield false-negative results in up to 12% of lesions tested, and there is a zone of uncertainty at borderline values. METHODS: Forty-eight patients were investigated by means of dobutamine stress echocardiography (DSE), coronary angiography, and FFR assessment of 48 coronary lesions before, during, and immediately after handgrip exercise. RESULTS: Mean FFR values were lower during and immediately after handgrip exercise as compared with baseline (0.86 +/- 0.09 vs 0.87 +/- 0.08 vs 0.88 +/- 0.08, P < .05, respectively). The sensitivity of FFR < or = 0.75 for predicting myocardial ischemia on DSE was 17.6% before handgrip exercise, 52.9% during, and 35.5% immediately after exercise. The specificity of FFR < or = 0.75 before, during, and immediate after exercise was 100%, 93.5%, and 96.8%, respectively. In 10 patients, FFR values > 0.75 before handgrip became < or = 0.75 during or immediately after handgrip exercise (P = .01). All these patients had angina and/or DSE indicating ischemia in the territory of the vessel studied, and underwent coronary intervention. At 6 months follow-up, all patients were asymptomatic with negative DSE tests. CONCLUSIONS: The addition of handgrip exercise can significantly lower the FFR and potentially improve its ability to detect physiologically significant stenoses.

Effect of slow pathway ablation in atrioventricular nodal reentrant tachycardia on the electrophysiologic characteristics of the inferior atrial inputs to the human atrioventricular node.

The inferior atrial extensions of the atrioventricular (AV) node have been related to the anatomic substrate of the slow pathway, but their role in AV nodal reentrant tachycardia (AVNRT) is unknown. Ten patients with slow-fast AVNRT were studied before and after successful slow pathway ablation. Simultaneous His bundle recordings from the right and left sides of the septum were made during right and left inferoparaseptal pacing. Longer stimulus to His (St-H) intervals were measured during right inferoparaseptal pacing than during left inferoparaseptal pacing (284 +/- 55 vs 246 +/- 46 ms, p = 0.005 for right His recordings and 283 +/- 56 vs 244 +/- 46 ms, p = 0.005 for left His recordings) at similar coupling intervals during AVNRT induction. After ablation, the St-H intervals at the maximum AV nodal conduction decrement were similar during right inferoparaseptal and left inferoparaseptal pacing (217 +/- 32 vs 207 +/- 21 ms, p = 0.10 for right His and 215 +/- 32 vs 206 +/- 20 ms, p = 0.13 for left His) at similar coupling intervals. The difference (DeltaSt-H) between St-H intervals during AVRNT induction or at the maximum conduction decrement and during constant pacing for right His recordings with right inferoparaseptal pacing were significantly greater than DeltaSt-H measured with left His during left inferoparaseptal pacing (173 +/- 64 vs 137 +/- 55 ms, p = 0.005) before ablation, but not after (117 +/- 39 vs 100 +/- 40 ms, p = 0.44). Resetting of AVNRT with delivery of left inferoparaseptal extrastimuli was achieved in 7 of 10 patients. In conclusion, the electrophysiologic characteristics of the right and left inferior atrial inputs to the human AV node in patients with AVNRT and their response to slow pathway ablation provide further evidence that the inferior nodal extensions represent the anatomic substrate of the slow pathway.

Atrial arrhythmias following ostial or circumferential pulmonary vein ablation.

AIMS: The incidence, clinical significance and optimum treatment of AF ablation-induced proarrhythmia is not entirely known. This report describes the incidence and management of atrial arrhythmias occurring after various techniques for the ablative therapy of atrial fibrillation (AF). METHODS: Five hundred and forty-four patients with paroxysmal atrial fibrillation were subjected to ostial pulmonary vein (PV) (n = 204), antral (n = 300), or circumferential (n = 40) ablation around the PV ostia. RESULTS: Atrial tachycardia or flutter during the first 6 months after AF ablation was detected in 14 patients and was more common among patients subjected to circumferential or circumferential and linear ablation (18% and 22%, respectively) than to other techniques (p < 0.001). The risk of atrial tachycardia or flutter among patients who underwent ostial, ostial with lines and antral ablation was 1%, 8% and 1%, respectively. No difference was observed in the risk of atrial arrhythmia between patients who underwent ablation with or without additional lines, either ostial (p = 0.17) or circumferential (p = 0.99). Re-ablation was performed in patients with sustained atrial arrhythmia (11 out of 14 patients). At 6 months, no recurrence was seen in 10 of these patients as well as in 3 patients with non-sustained atrial tachycardia or flutter. CONCLUSIONS: The incidence of atrial tachycardia or flutter following AF ablation is lower for ostial than circumferential ablation. The addition of lines along the mitral isthmus and between the superior PVs does not significantly affect the risk of ablation-induced arrhythmia. Non-sustained atrial tachycardia or flutter following AF ablation procedures does not always require additional ablation.

Latent arterial hypertension in apparently lone atrial fibrillation.

INTRODUCTION: Longitudinal studies on lone AF are rare and the incidence of hypertension in this population unknown. This study aimed at investigating the incidence of arterial hypertension in patients with apparently lone atrial fibrillation (AF). METHODS AND RESULTS: Out of 292 consecutive patients presented with permanent or paroxysmal AF, 32 patients were diagnosed as having lone AF according to strict criteria. Three patients were subjected to ablation of the ligament of Marshall, 14 patients to pulmonary vein isolation, and the remainder were treated with beta blockade. Patients were followed-up for a 1-3 year period. During follow-up, 14 patients were diagnosed as having arterial hypertension. Thirteen of them had recurrent AF despite ligament of Marshall ablation (1 patient), pulmonary vein isolation (4 patients) and beta blockade (8 patients). Cox regression analysis revealed that the only significant predictor of development of hypertension was complete or partial response to antiarrhythmic therapy (beta=3.82, S.E.=1.22, exp(b)=45.63, 95% C.I.=4.17-499.2, p=0.001), independent of age (beta=-0.01, p=0.74), sex (beta=-0.91, p=0.28), left ventricular ejection fraction (beta=0.06, p=0.52), left atrial size (beta=0.58, p=0.7) and kind of antiarrhythmic therapy (ablation or drug therapy) (beta=1.36, p=0.09). In patients with lone AF that did not respond at all to antiarrhythmic therapy, there was a 45.6 times higher risk of diagnosing hypertension during the next 3 years as compared to responders. CONCLUSION: Approximately 44% of patients with an initial diagnosis of lone AF may represent occult cases of arterial hypertension. In these patients hypertension may affect AF recurrence and treatment outcomes, regardless of the mode of antiarrhythmic therapy used.

Patient dosimetry during coronary interventions: a comprehensive analysis.

BACKGROUND: We performed a detailed analysis of patient radiation during coronary interventions, comparing dose measurements to established dose reference levels, assessing coronary artery doses, and estimating total radiation risk of fatal cancer. METHODS: We prospectively examined 281 patients who were subjected to 307 percutaneous coronary interventions. RESULTS: The mean kerma area product (KAP) per procedure was 82.1 +/- 47.9 Gy x cm2. Corresponding values for fluoroscopy and digital cineangiography were 28.3 +/- 25.5 Gy x cm2 and 53.8 +/- 35.5 Gy x cm2, respectively, and exposure times were 13.1 +/- 6.8 minutes (87%) and 2.0 +/- 1.5 minutes (13%), respectively. The right anterior oblique caudal and left anterior oblique cranial projections accounted for the highest amount of KAP (24.0% and 23.1%, respectively) compared with other projections. The maximum recorded skin-dose was 182 mGy. Performing a representative procedure on a phantom, the effective dose was 14.9 mSv. The mean coronary dose was 61.7 +/- 38.2 mGy, with a highest calculated dose of 220.1 mGy. The third quartile of KAP measurements was 105 Gy x cm2, the 95th percentile was 175 Gy x cm2, and the mean value of KAP measurements was 82 Gy x cm2. The total risk for the development of fatal cancer was calculated as 83 cases for every 100,000 patients subjected to coronary intervention. CONCLUSIONS: A detailed analysis of patient radiation during coronary interventions is presented. Coronary doses and total radiation risk of fatal cancer are also calculated, and a method for establishing dose reference level values is proposed.

Comparison of effectiveness of carvedilol versus bisoprolol for maintenance of sinus rhythm after cardioversion of persistent atrial fibrillation.

Ninety patients who underwent cardioversion of persistent atrial fibrillation (AF) were randomized to bisoprolol 5 to 10 mg once daily or carvedilol 12.5 to 25 mg twice daily. Using intention-to-treat analysis, 23 patients (46%) in the bisoprolol group and 17 patients (32%) in the carvedilol group relapsed into AF during the 1 year of total follow-up (p = 0.486). Patients treated with carvedilol had a 14% (hazard ratio 0.86) lower risk of relapse of AF compared with patients in the bisoprolol group, although results were statistically insignificant (p = 0.661) after controlling for patient age, gender, baseline heart rate, and left atrial diameter.

Right and left inferior extensions of the atrioventricular node may represent the anatomic substrate of the slow pathway in humans.

OBJECTIVES: The purpose of this study was to investigate the electrophysiologic characteristics of the inferior extensions of the human atrioventricular (AV) node and their possible relationship to slow pathway conduction. BACKGROUND: The human heart contains right and left inferior extensions of the AV node that relate to right and left atrial inputs. METHODS: Fourteen patients admitted for catheter ablation of left-sided accessory pathways were studied. Atrial pacing was performed from multiple sites in both atria, and simultaneous His-bundle recordings from right and left sides of the septum were made. RESULTS: Significant differences of A-H and stimulus to His (St-H) intervals with pacing at various sites were found. St-H intervals were similar during constant pacing from the low right atrium or the left inferoparaseptal area (112 +/- 28 ms vs 112 +/- 26 ms, P = .8, for right His recordings and 114 +/- 23 ms vs 111 +/- 25 ms, P = .9, for left His recordings). At maximum decrement, there were significantly shorter St-H intervals during left inferoparaseptal pacing compared to low right atrial pacing (201 +/- 24 ms vs 218 +/- 44 ms, P = .02, for right His recordings, and 200 +/- 24 ms vs 219 +/- 41 ms, P = .009, for left His recordings). Differences on right His recordings between St-H intervals at maximum decrement and at constant pacing from the low right atrium were significantly higher than corresponding differences on left His recordings during pacing from the left inferoparaseptal area (P = .035). CONCLUSIONS: Our findings support the concept that the right and left inferior extensions of the human AV node may represent the anatomic substrate of the slow pathway as defined electrophysiologically.

Medical personnel and patient dosimetry during coronary angiography and intervention.

Percutaneous coronary interventions are associated with increased radiation exposure compared to most radiological examinations. This prospective study aimed at (1) measuring entrance doses for all in-room personnel, (2) performing an assessment of patient effective dose and intracoronary doses, (3) investigating the contribution of each projection to kerma-area product (KAP) and irradiation time, (4) comparing results with established DRL values in this clinical setting and (5) estimating the risk for fatal cancer to patients and operators. Measurements were performed during 40 consecutive procedures of coronary angiography (CA), half of which were followed by ad hoc coronary angioplasty (PTCA). KAP measurements were used for patients and thermoluminescent dosimetry for the in-room personnel. The mean KAP value per procedure for CA was 29 +/- 9 Gy cm2. Thirty four per cent of KAP was due to fluoroscopy, whereas the remainder (66%) was due to digital cine. Accordingly, the mean KAP value per PTCA procedure was 75 +/- 30 Gy cm2, and contribution of fluoroscopy is 57%. Effective dose per year was estimated to be 0.04-0.05 mSv y(-1) for the primary operator, and 0.03-0.04 mSv y(-1) for those assisting. Corresponding measurements for radiographer and nurse were below detectable level, implying minimal radiation hazards for them. Regarding radiation exposure, coronary intervention is considered a quite safe procedure for both patients and personnel in laboratories with modern equipment and experienced operators as long as standard safety precautions are considered. Exposure optimization though should be constantly sought through continuous review of procedures.

Conduction patterns in the cardiac veins: electrophysiologic characteristics of the connections between left atrial and coronary sinus musculature.

INTRODUCTION: Fractionated electrograms and double potentials have been well described within the coronary sinus (CS) in humans. The pattern of circumferential activation in the CS has not been investigated. Furthermore, no data exist on conduction characteristics within the great cardiac vein (GCV) or the middle cardiac vein (MCV). METHODS AND RESULTS: Twenty patients underwent catheter mapping of the CS, the MCV, and the GCV. Anatomical areas were verified by cannulation of the left superior pulmonary vein. The pattern of circumferential muscle activation within the proximal CS was also studied with a circular mapping catheter (Lasso 12 mm). At conventional mapping during sinus rhythm and high right atrial pacing, discrete double potentials or fractionated electrograms were recorded during left, right atrial and CS pacing at the CS ostium, mid-CS, and distal CS-ligament of Marshall area, in 2 (10%), 1 (5%), and 9 (45%) patients, respectively, whereas no patient displayed such signals in the MCV or GCV ( p < 0.001). Proximal CS mapping with the Lasso was accomplished in 10 patients, 7 of whom had no evidence of multicomponent potentials in the CS at conventional mapping. Specific CS potentials dissociated from the atrial electrograms were recorded in all patiens with the use of circumferential mapping. The perimetric distribution of electrograms within the CS suggested an oblique course of conduction across the CS musculature. CONCLUSION: Potentials representing activation of the CS musculature, with an oblique course of conduction across the CS, can be recorded in human CS but not in the GCV or MCV. This is compatible with anatomical observations of sinus venosus musculature covering the CS but not other cardiac veins, and supports the rationale for the role of CS musculature in the generation of atrial arrhythmias.

Renal denervation for resistant hypertension: acute results and long-term follow-up.

INTRODUCTION: Renal sympathetic hyperactivity is vital for the maintenance and progression of essential hypertension. Catheter-based renal denervation is an evolving concept with favourable results regarding the control of hypertension; however, clinical experience is still limited. METHODS: We enrolled 15 patients with resistant hypertension who underwent percutaneous, catheter-based radiofrequency treatment for renal artery denervation. Patients were followed up for 4 to 13 months. RESULTS: Baseline mean blood pressure was 169/96 mmHg (SD 9/11), and patients were receiving a mean 3.9 ± 0.8 antihypertensive medications. Blood pressure values were reduced to 136/79 mmHg (SD 10/7), and antihypertensive medications to 2.9 ± 0.8 at 6.9 ± 3.4 months after the procedure. All procedures were uneventful and technically easy. The only drawbacks of the procedure are pain that the patient may feel during energy delivery, and the inability to obtain a sustained impedance reduction that allows completion of radiofrequency current delivery at some sites in the renal artery. CONCLUSIONS: Renal denervation facilitates control of resistant hypertension with reduction of medication, and appears to be a safe and technically easy procedure to accomplish.