Renal nerve stimulation identifies aorticorenal innervation and prevents inadvertent ablation of vagal nerves during renal denervation.

PURPOSE: Recently we reported the use of renal nerve stimulation (RNS) during renal denervation (RDN) procedures. RNS induced changes in blood pressure (BP) and heart rate are not fully delineated yet. We hypothesized that electrical stimulation of the sympathetic nerve tissue in the renal artery would lead to an increase in BP and vagal stimulation would cause a decrease in BP. We report the different patterns of BP and heart rate responses elicited by RNS prior to RDN. METHODS: 35 patients with drug-resistant hypertension were included. RNS was performed under general anesthesia at four sites in the right and left renal arteries, both before and immediately after RDN. RNS-induced BP and heart rate changes were monitored. RESULTS: A total of 289 RNS sites in 35 patients were analyzed. An increase in systolic BP of >10 mmHg was regarded as a positive BP response to RNS. This pattern of response was observed in 180 sites (62%). 86 RNS sites (30%) showed an indifferent response with BP changes ≤10 mmHg. At 13 sites (4.5%) RNS elicited a decrease in BP up to -8 mmHg. However, 10 RNS sites (3.5%) showed a pronounced vagal response with hypotension and sinus cycle lengths ranging between 4224-10272 milliseconds. These sites were distributed among two patients. CONCLUSION: RNS identified sympathetic and parasympathetic nerve tissue in the renal arteries. RNS can be potentially used to map nerve bundles and guide selective ablation of sympathetic nerve fibers and prevent inadvertent ablation of parasympathetic nerve tissue during RDN.

Mechanical power sheath mediated recanalization and lead implantation in patients with venous occlusion: Technique and results.

INTRODUCTION: Chronic venous occlusion hampers lead revisions and upgrades in patients with a cardiac implantable electronic devices (CIEDs). This can make cardiothoracic surgery, venoplasty, or contra-lateral implantation of leads with tunneling necessary. A technique using venous recanalization may be a preferred alternative. We assessed the efficacy and safety of this new technique. METHODS AND RESULTS: From 2009 to 2016, all consecutive patients planned for lead revision or upgrade with known chronic venous occlusion were studied. All patients underwent extraction of an existing malfunctional or functional CIED lead with the Cook Evolution mechanical power sheath. By using the lumen of the sheath, endovascular access to the heart was obtained for new leads. Forty-two patients (107 leads, 2.6 ± 1.1) were included. The indication for this procedure was replacement of malfunctional leads (n = 35, 83%) or device upgrade (n = 7, 17%). In total, 77 leads were extracted (30 leads stayed in situ) with a mean age at time of extraction of 8.4 years. Because of damage to bystander leads during extraction, two additional leads (one RA lead, one LV lead) were extracted. Clinical success was achieved in 41 patients (97%) and complete success in 39 patients (93%). There were two minor complications (two pocket hematomas, managed conservatively) and one major complication (tamponade, needing thoracotomy). Mean procedure time was 3.0 hours (median, 2.0; range, 1:28-5:35 hours) with a mean fluoroscopy time of 14.9 ± 12.5 minutes. CONCLUSIONS: The technique of Evolution-mediated recanalization in case of lead revisions or upgrades is feasible with an acceptable safety profile and high efficacy.

Apical rocking is predictive of response to cardiac resynchronization therapy.

Identification of patients who will benefit from cardiac resynchronization therapy (CRT) is challenging. "Apical rocking" is frequently observed in asynchronously contracting ventricles and small studies suggested that it may predict CRT response. We assessed the predictive value of LV apical rocking on echocardiographic and clinical response to CRT in a large cohort of patients treated with CRT. Echocardiography was performed in 137 consecutive patients prior to CRT, and repeated during follow-up. Apical rocking was defined as motion of the left ventricular (LV) apical myocardium perpendicular to the LV long axis. Echocardiographic response to CRT was defined as a reduction in LV end-systolic volume ≥15% and clinical response as survival without heart failure hospitalization. All echocardiograms were assessed by independent cardiologists, blinded for baseline, clinical and follow-up data. Multivariable analyses were performed to adjust for potential confounders. Mean echocardiographic and clinical follow-up was 22 ± 8 and 57 ± 12 months respectively. Apical rocking was present in 49% of the patients. Apical rocking was more common in females, younger patients, and in patients with non-ischemic cardiomyopathy. Echocardiographic response to CRT was observed in 69%, clinical response in 77% of the patients. Apical rocking was associated with both echocardiographic response (OR 10.77, 95% CI 4.12-28.13) and clinical response to CRT (HR 2.73, 95% CI 1.26-5.91). Also after multivariable analyses, apical rocking was associated with both echocardiographic (OR 9.97, 95% CI 3.48-28.59) and clinical response to CRT (HR 2.13, 95% CI 0.94-4.83). Apical rocking is independently associated with both echocardiographic and clinical response to CRT.

Conventional radiofrequency catheter ablation compared to multi-electrode ablation for atrial fibrillation.

BACKGROUND: Limited data is available on long-term atrial fibrillation (AF) free survival after multi-electrode catheter pulmonary vein isolation (PVI). The aim of this study was to compare point-by-point PVI to multi-electrode PVI in terms of procedural characteristics and long-term AF free survival. METHODS AND RESULTS: 460 consecutive patients were randomly allocated: 230 patients underwent conventional, point-by-point ablation with a radiofrequency ablation catheter (cPVI group) and 230 patients underwent multi-electrode, phased radiofrequency ablation (MER group). Median follow-up was 43 months. Mean age was 56 years, 82% of patients had paroxysmal AF. Baseline characteristics did not differ among catheter groups. Acute electrical PVI was achieved in 99.7% of pulmonary veins, with no differences among catheter groups. Procedure time and ablation time were significantly shorter in the MER group. There were significantly less complications in the MER group (4.8% vs. 1.3%, P=0.025). After a mean of 1.5 procedures, AF free survival without the use of antiarrhythmic drugs was 74% at 1 year and 46% at 5 years follow-up and did not differ among catheter groups (cPVI group 45%, MER group 48%, P=0.777). In multivariate analysis, BMI, AF duration and CHADSVASc score were predictors of AF free survival. CONCLUSION: Multi-electrode ablation was superior in procedure duration and ablation time, with less complications. However, both conventional point-by-point PVI and multi-electrode PVI achieved a high acute PVI success rate and showed a comparable long-term AF free survival.

Pulmonary vein isolation to treat paroxysmal atrial fibrillation: conventional versus multi-electrode radiofrequency ablation.

PURPOSE: For patients with symptomatic atrial fibrillation (AF), a curvilinear multi-electrode ablation (MEA) catheter has been reported to be successful to achieve pulmonary vein (PV) isolation. However, this approach has not been compared prospectively with conventional PV isolation (CPVI) using a standard circular mapping catheter and 3D electro-anatomic mapping. In this prospective non-randomized study, we compared the efficacy of these two techniques. METHODS: Of 185 consecutive patients, age 54.6 ± 10.1 years, with symptomatic paroxysmal AF (PAF), 96 patients underwent PV isolation by CPVI and 89 patients underwent MEA to isolate the PVs. CPVI was performed by encircling the left- and right-sided PVs. During MEA, the PV ablation catheter (Medtronic, USA) was used to isolate PVs with duty-cycled radiofrequency energy. RESULTS: The mean procedure time was 171.73 ± 52.87 min for CPVI and 133.25 ± 37.99 min for MEA, respectively (P < 0.001). The mean fluoroscopy time was 31.07 ± 14.97 for CPVI and 30.07 ± 11.45 min for MEA (P = 0.651). At 12 months, 80% of patients who underwent CPVI and 82% of patients who underwent MEA were free of symptomatic PAF off antiarrhythmic drug therapy (P = 0.989). Among the variables of age, gender, duration and frequency of PAF, left ventricular ejection fraction, left atrial size, structural heart disease, and the ablation technique, only an increased left atrial size was an independent predictor of recurrent PAF. Left atrial flutter occurred after CPVI in two patients and after MEA ablation in three patients. CONCLUSION: In patients undergoing catheter ablation for PAF, MEA and CPVI proved equally efficacious.

Upgrading to biventricular pacing guided by pressure-volume loop analysis during implantation.

INTRODUCTION: cardiac resynchronization therapy (CRT) may improve prognosis in patients with chronic right ventricular (RV) pacing, and optimal lead position can decrease nonresponders. We evaluated the clinical and echocardiographic response to CRT in patients with previous chronic RV pacing, using pressure-volume loop analyses to determine the optimal left ventricular (LV) lead position during implantation. METHODS AND RESULTS: In this single-blinded, randomized, controlled crossover study, 40 patients with chronic RV apical pacing and symptoms of heart failure, decreased LV ejection fraction (LVEF) or dyssynchrony were included. During implantation, stroke work (SW), LVEF, cardiac output, and LV dP/dt(max) were assessed by a conductance catheter. Clinical and echocardiographic response was studied during a 3-month period of RV pacing (RV period, LV lead inactive) and a 3-month period of biventricular pacing (CRT period). At the optimal LV lead position, SW (37 ± 41%), LVEF (16 ± 13%), cardiac output (29 ± 16%), and LV dP/dt(max) increased (11 ± 11%) significantly during biventricular pacing compared to baseline. Additional benefit could be achieved by pressure-volume loop guided selection of the best left-sided pacing location. RV outflow tract pacing did not improve hemodynamics. During follow-up, symptoms improved during CRT, VO(2,max) increased 10% and significant improvements in LVEF, LV volumes, and mitral regurgitation were observed as compared to the RV period. CONCLUSIONS: CRT in patients with chronic RV pacing causes significant improvement of both LV function as measured by pressure-volume loops during implantation and clinical and echocardiographic improvement during follow-up. Pressure-volume loops during implantation may facilitate selection of the most optimal pacing site.

Dominant frequency of atrial fibrillation correlates poorly with atrial fibrillation cycle length.

BACKGROUND: Localized sites of high frequency during atrial fibrillation (AF) are used as target sites to eliminate AF. Spectral analysis is used experimentally to determine these sites. The purpose of this study was to compare dominant frequencies (DF) with AF cycle length (AFCL) of unipolar and bipolar recordings. METHODS AND RESULTS: Left and right atrial endocardial electrograms were recorded during AF in 40 patients with lone AF, using two 20-polar catheters. Mean age was 53+/-9.9 years. Unipolar and bipolar electrograms were recorded simultaneously during 16 seconds at 2 right and 4 left atrial sites. AFCLs and DFs were determined. QRS subtraction was performed in unipolar signals. DFs were compared with mean, median, and mode of AFCLs; 4800 unipolar and 2400 bipolar electrograms were analyzed. Intraclass correlation was poor for all spectral analysis protocols. Best correlation was accomplished with DFs from unipolar electrograms compared with median AFCL (intraclass correlation coefficient, 0.67). A gradient in median AFCL of >25% was detected in 16 of 40 patients. In 13 of 16 patients (81%) with a frequency gradient of >25%, the site with highest frequency was located in the left atrium (posterior left atrium in 8 patients). The site with shortest median AFCL and highest DF corresponded in 25% if unipolar and in 31% if bipolar electrograms were analyzed. CONCLUSIONS: DFs from unipolar and bipolar electrograms recorded during AF correlated poorly with mean, median, and mode AFCL. If a frequency gradient >25% existed, the site with highest DF corresponded to the site of shortest median AFCL in only 25% of patients. Because spectral analysis is being used to identify ablation sites, these data may have important clinical implications.

Long-term clinical response of cardiac resynchronization after chronic right ventricular pacing.

Chronic right ventricular (RV) pacing might elicit unpredictably deleterious effects on left ventricular (LV) function similar to that of native left bundle branch block (LBBB). The objective of the present study was to evaluate the clinical and echocardiographic response to cardiac resynchronization therapy after years of chronic RV pacing. In this prospective observational study of 284 consecutive patients, cardiac resynchronization therapy was performed in 194 patients (68%) with a native LBBB and in 90 patients (32%) with a pacing-induced LBBB after chronic RV pacing (upgraded group). Echocardiographic and clinical parameters were evaluated in both groups at baseline and during 2 years of follow-up. The clinical response was defined as survival with improvement of > or =1 in the New York Heart Association class without heart failure hospitalization. Reverse LV remodeling was defined as LV end-systolic volume reduction of > or =15%. At baseline, the New York Heart Association class, quality of life, and exercise capacity were comparable but the LV ejection fraction was significant greater and the LV volumes were significant smaller in the upgraded group. Changes with time in the clinical parameters, echocardiographic parameters, and clinical response were not significantly different between the 2 groups. Reverse LV remodeling was observed in 86% in the upgraded group versus 78% of the native LBBB group after 1 year (p = 0.39). Survival was not significantly different between the 2 groups. In conclusion, comparable clinical and echocardiographic improvement was seen when resynchronization therapy was applied in patients with preceding chronic RV pacing compared with patients with a native LBBB.

Intermediate to long-term results of radiofrequency modified Maze procedure as an adjunct to open-heart surgery.

BACKGROUND: Of patients scheduled for elective open heart surgery, a substantial number of patients have preoperative atrial fibrillation (AF). The cut-and-sew Maze procedure and variant Maze procedures abolish AF in 45% to 95% during short- to intermediate-term follow-up. Limited data are available about maintenance of sinus rhythm during intermediate- to long-term follow-up. The objective of the present study was to assess the association between postoperative rhythm and mortality and stroke. METHODS: From November 1995 to November 2003, 258 patients with structural heart disease and permanent AF with a duration of longer than 12 months were scheduled for elective cardiac surgery and included in a registry. They underwent a radiofrequency modified Maze procedure as an adjunct to the open heart operation. Patients were followed in the outpatient clinic, and follow-up data were obtained from medical correspondence of attending physicians. For this paper, follow-up ended November 2006; however, patients are being followed in an ongoing registry. RESULTS: Two hundred fifty-eight patients (mean age, 68.1 +/- 9.5 years) with permanent AF underwent cardiac surgical procedures and concomitant radiofrequency Maze surgery; 213 patients (82.5%) underwent more than one procedure. Mean duration of permanent AF was 66.6 +/- 69.8 months (range, 16 to 96). Preoperatively, 82.9% of patients were in New York Heart Association class III. In-hospital mortality was 3.9% (10 patients), and during a mean follow-up of 43.7 +/- 25.9 months (range, 27 to 114), 73 patients (28.3%) died. Left ventricular ejection fraction was normal in 44.6%, moderately decreased in 42.5%, and poor in 12.9% of patients. Sustained sinus rhythm, including atrial rhythm or an atrial-based paced rhythm was present in 69% of patients at 1 year, in 56% at 3 years, in 52% at 5 years, and in 57% of patients at the latest follow-up. Antiarrhythmic drugs were used by 64% of survivors who were free of atrial fibrillation. Oral anticoagulation therapy was taken by 99% of patients. Stroke was reported in 4 patients (1.6%). CONCLUSIONS: The RF modified Maze procedure abolishes AF in the majority of patients with structural heart disease and longstanding permanent AF. Postoperative rhythm was not predictive of all-cause mortality, cardiac mortality, and stroke, neither in the whole group nor in the subgroups defined by preoperative left ventricular ejection fraction and New York Heart Association class. The stroke rate was very low in this group with longstanding AF.

Predictive factors of sustained sinus rhythm and recurrent atrial fibrillation after a radiofrequency modified Maze procedure.

BACKGROUND: Preoperative atrial fibrillation (AF) in patients scheduled for elective open-heart surgery is a well-known phenomenon. The cut and sew Maze procedure or variant Maze procedures abolish AF in 45-95% of patients during short- to intermediate-term follow-up. We determined preoperative and postoperative factors predictive of sustained sinus rhythm (SR) and recurrent AF in an elderly cohort of patients with structural heart disease who underwent cardiac surgery. PATIENTS AND METHODS: From November 1995 to November 2003, 285 patients with structural heart disease and permanent AF were scheduled for elective cardiac surgery. All patients underwent a radiofrequency (RF) modified Maze procedure as an adjunct to the open-heart operation. Patients were followed in the outpatient clinic or follow-up data were obtained from attending doctors. Patients are being followed in an ongoing registry; however for the patients who are the subject of this paper follow-up ended November 2006. Preoperative factors predicting recurrent AF postoperatively were assessed, as were factors associated with sustained SR. RESULTS: Two hundred and eighty-five patients (mean age 68.0+/-9.6 years) underwent a total of 655 open-heart procedures and concomitant RF Maze surgery. In-hospital mortality was 4.6% (13 patients). Mean and median duration of AF were 60.9+/-68.7 months and 26 months (range 6-396), respectively. Median follow-up was 36.5 months (range 27-114 months). Sustained SR, including atrial rhythm or an atrial-based paced rhythm was present in 59% of patients at 1 year, in 54.4% at 3 years, in 53.4% at 5 years and in 57.1% of patients at the latest follow-up. Stroke was reported in six patients (2.1%). Factors predictive of postoperative AF recurrence were duration of permanent AF, preoperative atrial fibrillation wave and preoperative left atrial (LA) size. Postoperative angiotensin converting enzyme (ACE) inhibitor therapy was associated with SR during follow-up. LA size decreased during follow-up in patients with sustained SR, whereas LA size increased in case of recurrent AF. CONCLUSIONS: In this group of elderly patients with permanent AF in the setting of structural heart disease who underwent cardiac surgery and a RF Maze procedure as a concomitant procedure, the duration of AF, preoperative atrial fibrillation wave and preoperative LA size were predictive of recurrent AF, whereas left ventricular ejection fraction, left ventricular diameters and invasive hemodynamic parameters were not. Postoperative ACE inhibitor therapy was associated with sustained SR. Furthermore, sustained SR after RF Maze surgery was associated with decreased LA dimensions.

Clinical response of cardiac resynchronization therapy in the elderly.

BACKGROUND: Although prevalence of heart failure increases with age, in most clinical trials of cardiac resynchronization therapy (CRT), older patients are not included. Observational studies of effects of CRT in older patients had a small sample size. In the present study, the clinical and echocardiographic response to CRT in a larger group of elderly (age > 75 years) patients was evaluated. METHODS: In this prospective observational study of 266 consecutive patients, CRT was performed in 107 elderly patients (40%) and 159 (60%) younger patients (age < or = 75 years). Echocardiographic and clinical parameters were evaluated at baseline and at 3, 12, and 24 months. RESULTS: In the elderly group, mean age was 79 years compared with 67 years in patients aged < or = 75 years. Clinical baseline characteristics between the 2 groups were comparable. During follow-up, there was a comparable and sustained improvement in both groups according to New York Heart Association (NYHA) class, quality of life score, and left ventricular (LV) ejection fraction. Clinical response, defined as survival with improvement (> or = 1 score) of NYHA class without hospital admittance for heart failure, was seen in 67% and 69% (group aged < or = 75 years) versus 65% and 60% (group aged > 75 years) after 3 months and 1 year, respectively. Reverse LV remodeling defined as LV end-systolic volume reduction > or = 10% was seen in 79% and 87% (group aged < or = 75 years) versus 71% and 79% (group aged > 75 years) after 3 months and 1 year, respectively. Hospitalization for heart failure decreased significantly in both groups in the year after CRT. A subgroup analysis of 39 octogenarians (> 80 years) also showed a significant improvement in NYHA class and LV ejection fraction in this subgroup. Also, LV reverse remodeling occurred in a similar extent (75% and 84%) after 3 months and 1 year, respectively. CONCLUSIONS: This study shows a clinical and echocardiographic improvement of CRT in patients aged > 75 years and even so in octogenarians.

Comparison of usefulness of cardiac resynchronization therapy in patients with atrial fibrillation and heart failure versus patients with sinus rhythm and heart failure.

The prevalence of atrial fibrillation (AF) in patients with heart failure is high, but data about the effects of cardiac resynchronization therapy (CRT) in patients with chronic AF are scarce. In this prospective observational study of 263 consecutive patients, CRT was performed in 96 patients (37%) with chronic AF and 167 patients (63%) with sinus rhythm (SR). Echocardiographic and clinical parameters were evaluated at baseline and 3 and 12 months. Reverse left ventricular (LV) remodeling is defined as LV end-systolic volume decrease > or =10%. Hospitalization rates for heart failure in the year before and after implantation were compared. Baseline characteristics between patients with and without AF were similar, but the AF group had smaller LV end-systolic and end-diastolic volumes and larger left atrial dimensions. New York Heart Association class, 6-minute walking distance, quality-of-life score, LV ejection fraction, and mitral regurgitation improved significantly at 3 and 12 months in both groups, and the changes were similar. Reverse LV remodeling after 3 and 12 months was 74% and 82% (AF group) versus 77% and 83%, respectively (SR group, p = 0.79). After 1 year, cardioversion had occurred in 25% of patients with AF. In the year after implantation, significant decreases in hospitalizations for heart failure in both groups (84% and 90%) were documented. Long-term mortality was almost equal in both groups. In conclusion, this large-scale study shows that the benefit of CRT in patients with chronic AF and heart failure is similar to that in patients with SR. Patients with chronic AF and heart failure should be considered candidates for CRT.

Sustained benefit of cardiac resynchronization therapy.

INTRODUCTION: Most data on cardiac resynchronization therapy (CRT) are from trials with highly selected patients, with limited long-term echocardiographic data. This study was performed to evaluate long-term echocardiographic remodeling after CRT in daily practice. METHODS AND RESULTS: A biventricular pacemaker was implanted in 130 patients with advanced heart failure who met the general accepted criteria for CRT or in heart failure patients with a conventional pacemaker indication. Two years echocardiographic follow-up was available. Mean age (73 years) was higher than in the randomized trials. Forty-one patients (32%) died during the 2 year follow-up period. Mortality was higher in males, in patients with increased NT-proBNP, renal dysfunction, or left atrial dilatation before implantation. Echocardiographic response (LVEF improvement of 5% or more) was documented in 69, 88, and 91% of the survivors, after 3 months, 1 year, and 2 years, respectively. Echocardiographic response after 3 months was associated with a significantly higher long-term survival (P = 0.04). Mean LVEF was 22% at baseline compared to 31.8, 38.3, and 39.7% after 3 months, 1 year, and 2 years, respectively (P < 0.01). Reverse remodeling (a reduction of LV end systolic volume of more than 10%) was observed in 70.7, 81.0, and 91.7% of the survivors after 3 months, 1 year, and 2 years, respectively. Long-term LV improvement was more pronounced in patients with nonischemic cardiomyopathy. CONCLUSION: LV reverse remodeling and beneficial echocardiographic changes were sustained during 2 years follow-up. A 5% or more increase in LVEF after 3 months was associated with a better long-term survival.

Successful radiofrequency ablation in patients with previous atrial fibrillation results in a significant decrease in left atrial size.

BACKGROUND: The objective of the present study was to evaluate the relation between freedom from atrial fibrillation (AF) and left atrial (LA) size in patients who underwent circumferential pulmonary vein (PV) isolation and LA ablation. METHODS AND RESULTS: One hundred five consecutive patients with symptomatic and drug-refractory paroxysmal or persistent AF were included in the present study. The mean age was 52+/-9.5 years (range, 27 to 75 years); 74 patients (70%) were male. Paroxysmal AF was present in 52 (49.5%) and persistent AF in 53 (50.5%) patients. Mean AF duration was 6.0+/-5.1 years in the paroxysmal AF group and 7.6+/-6.0 years in the persistent AF group. A 3D electroanatomic map of the LA including the PV ostia was constructed with a nonfluoroscopic navigation system (Carto, Biosense Webster). Left- and right-sided PVs were encircled by continuous radiofrequency ablation lines. We performed 128 ablation procedures in 105 patients, ie, 23 redo procedures. The mean long-term follow-up duration was 14.6+/-4.9 months (range, 6 to 24 months). Sinus rhythm was present in 45 patients (86.5%) in the paroxysmal AF group and in 41 patients (77.3%) in the persistent AF group at the latest follow-up. Six months after ablation, LA dimension in the persistent AF subjects who remained in sinus rhythm decreased from 44.0+/-5.8 to 40+/-4.5 mm (range, 31 to 51 mm). In contrast, in patients with recurrences of AF, LA dimension increased from 45+/-6.5 to 49+/-5.4 mm (range, 32 to 59 mm). In the successfully treated paroxysmal AF group, LA dimension decreased from 40.5+/-4.4 to 37.5+/-3.5 mm (P<0.01). CONCLUSIONS: In radiofrequency ablation of AF using an electroanatomic approach, there is a statistically significant relationship between medium-term procedural success and LA size: persistent sinus rhythm is associated with reduced and recurrent AF with increased LA dimensions.