Right Ventricular Lead Research Articles

0446: Septal right ventricular lead positioning and optimized DDD pacing versus intrinsic conduction in sinus node disease: an echocardiographic study. The optimist trial

Preserved intrinsic conduction in paced sinus node disease (SND) patients seems to be associated with a better outcome when compared with apical right ventricular (RV) DDD pacing.The prospective, multicenter, randomized OPTIMIST study was designed to compare RV lead positioning in the septum to preserved intrinsic conduction in chronically paced SND patients. SND patients with a class I indication were implanted with a DDD pacemaker (St. Jude medical), the RV lead being located in the midseptum. The algorithm VIP™ (Ventricular Intrinsic Preference) was programmed « on » in all patients at hospital discharge. After a 6 weeks observational period, patients with a ventricular pacing percentage inferior to 10% were randomized in 2 parallel groups: VIP « on » (preserved natural conduction - group 1) or « off » with AV delay optimization (RV pacing - group 2). Patients were followed every 6 months with echocardiography through 18 months. The primary endpoint was the left ventricular end-systolic diameter (LVESD) (Corelab analysis), with a non inferiority hypothesis. 216 patients mean age 76.07±9.45 were included and 167 randomized. The baseline characteristics were comparable in group 1 and 2 including left ventricular ejection fraction, LVEF (62.4±12.6 vs 64.4±8.7%), LVESD (32.7±8.5 vs 32.5±9.3mm) and 6 weeks RV pacing percentage (1.81±1.92 vs 2.15±2.07%). At the end of FU, as expected the percentage of RV pacing was significantly higher in group 2 (78.9±31.6 vs 7.9±17.4%). The LVEF was 62.3±10.1% in group 1 and 60.9±10.9% in group 2 (NS) and the LVESD was 31.9±7.23mm in group 1 and 31.26±7.21mm in group 2 (NS).The non-inferiority hypothesis was validated (p=2.572e-06 for a delta = 4.785). AF burden was not different between the 2 groups. When implanting the RV lead in the midseptum, DDD pacing with high percentage of RV capture was not associated with LV echocardiographic deterioration as compared to preserved intrinsic conduction pacing mode. January 17 th , Saturday 2015

Exercise Training and Pacing Status in Patients With Heart Failure: Results From HF-ACTION

BackgroundWe sought to determine if outcomes with exercise training in heart failure (HF) vary according to ventricular pacing type. Methods and ResultsHeart Failure: A Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION) randomized 2,331 outpatients with HF and left ventricular ejection fraction ≤35% to usual care plus exercise training or usual care alone. We examined the relationship between outcomes and randomized treatment according to ventricular pacing status with the use of Cox proportional hazards modeling. In HF-ACTION 1,118 patients (48%) had an implanted cardiac rhythm device: 683 with right ventricular (RV) and 435 with biventricular (BiV) pacemakers. Patients with pacing devices were older, more frequently white, and had lower peak VO2 (P < .001 for all). Peak VO2 improved similarly with training in groups with and without pacing devices. The primary composite end point—all-cause death or hospitalization—was reduced only in patients randomized to exercise training without a device (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.67–0.93 [P = .004]; RV lead: HR 1.04, 95% CI 0.84–1.28 [P = .74]; BiV pacing: HR 1.05, 95% CI 0.82–1.34 [P = .72]; interaction P = .058). ConclusionsExercise training may improve exercise capacity in patients with implanted cardiac devices. However, the apparent beneficial effects of exercise on hospitalization or death may be attenuated in patients with implanted cardiac devices and requires further study.

Left and right ventricular lead positions are imprecisely determined by fluoroscopy in cardiac resynchronization therapy: a comparison with cardiac computed tomography

Fluoroscopy is the routine method for localizing left ventricular (LV) and right ventricular (RV) lead positions in cardiac resynchronization therapy (CRT). However, the ability of fluoroscopy to determine lead positions in a standard ventricular segmentation is unknown. We aimed to evaluate the accuracy and reproducibility of fluoroscopy to determine LV and RV lead positions in CRT when compared with cardiac computed tomography (CT). Fifty-nine patients undergoing CRT were included. Bi-plane fluoroscopy and cardiac CT were evaluated in all patients. Pacing lead positions were assessed in a standard LV 16-segment model and in a simplistic RV 8-segment model. Four patients with LV lead displacement were excluded from the agreement analysis of LV lead position. Agreement of LV lead position between fluoroscopy and cardiac CT was observed in 19 (35%) patients with fluoroscopy demonstrating a 1-segment and ≥2-segment error in 30 (55%) and 6 (11%) patients, respectively. Agreement of RV lead position was found in 13 (22%) patients with fluoroscopy showing a 1-segment and ≥ 2-segment error in 28 (47%) and 18 (31%) patients, respectively. The interobserver agreement on LV and RV lead positions was poor for fluoroscopy (kappa 0.20 and 0.23, respectively) and excellent for cardiac CT (kappa 0.87 and 0.85, respectively). Fluoroscopy is inaccurate and modestly reproducible when assessing LV and RV lead positions in a standard ventricular segmentation when compared with cardiac CT. Cardiac CT should be applied to determine the exact pacing site in future research evaluating the optimal pacing lead position in CRT.

Universal Algorithm for Diagnosis of Biventricular Capture in Patients with Cardiac Resynchronization Therapy

An accurate and universal method for diagnosis of biventricular (BiV) capture using a standard 12-lead electrocardiogram (ECG) would be useful for assessment of cardiac resynchronization therapy (CRT) patients. Our objective was to develop and validate such an ECG method for BiV capture diagnosis that would be independent of pacing lead positions-a major confounder that significantly influences the morphologies of paced QRS complexes. On the basis of an evaluation of 789 ECGs of 443 patients with heart failure and various right ventricular (RV) and left ventricular (LV) lead positions, the following algorithm was constructed and validated. BiV capture was diagnosed if the QRS in lead I was predominantly negative and either V1 QRS was predominantly positive or V6 QRS was of negative onset and predominantly negative (step 1), or if QRS complex duration was <160 ms (step 2). All other ECGs were classified as loss of LV capture. The algorithm showed good accuracy (93%), sensitivity (97%), and specificity (90%) for detection of loss of LV capture. The performance of the algorithm did not differ among apical, midseptal, and outflow tract RV lead positions and various LV lead positions. LV capture leaves diagnostic hallmarks in the fused BiV QRS related to different vectors of depolarization and more rapid depolarization of the ventricles. An accurate two-step ECG algorithm for BiV capture diagnosis was developed and validated. This algorithm is universally applicable to all CRT patients, regardless of the positions of the pacing leads.

First experience of intraoperative echocardiography-guided optimization of cardiac resynchronization therapy delivery

Insufficient correction of mechanical dyssynchrony is a cause of non-response to cardiac resynchronization therapy (CRT). To determine if CRT delivery could be optimized during the implantation procedure by choosing the number and location of pacing sites using echocardiography guidance. In patients with a QRS ≥ 150 ms or a QRS < 150 ms and criteria for mechanical dyssynchrony, the objective of the implantation procedure was to shorten the left pre-ejection interval (LPEI), measured online, by at least 10 ms compared with standard biventricular configuration, by moving the right ventricular (RV) lead at different locations and, if necessary, by adding a second RV lead. Ninety-one patients (70 men; mean age 73 ± 10 years; left ventricular [LV] ejection fraction 29 ± 10%) were included. The final pacing configuration was standard biventricular in 15 (17%) patients, optimized biventricular in 22 (24%) and triple-site ventricular in 54 (59%). LPEI was shortened by ≥ 10 ms compared with standard biventricular stimulation in 73 (80%) patients. Compared with standard biventricular pacing, the final optimized pacing configuration improved global intraventricular synchrony (decreasing LPEI from 158 ± 36 ms to 134 ± 29 ms; P<0.001), LV systolic efficiency (decreasing LPEI/LV ejection time from 0.58 ± 0.18 to 0.46 ± 0.13; P<0.001) and LV filling (increasing LV filling time/RR from 44 ± 8% to 47 ± 7%; P<0.001) and decreased mitral valve regurgitation. Intraoperative echocardiography-guided placement of RV lead(s) during CRT implantation is feasible and acutely improves LV synchrony compared with standard biventricular stimulation.

Abstract 18402: Outcomes of Pacing in Patients With Cardiac Amyloidosis - A Single Center Experience

Background: Cardiac amyloidosis (CA) is associated with sinus node dysfunction (SND) and conduction system disease (CSD) yet data on pacing indications and outcomes is scarce. Methods: Retrospective review of patients (pts) with CA who had device implantation due to pacing indication at our institution. Results: At total of 51 (mean age 67.2±9.2 years, 90.2% male) pts with immunoglobulin light chain (n=27, 52.9%), hereditary transthyretin (n=7, 13.7%) and wild-type transthyretin (n=17, 33.3%) CA were included. Indication for pacing was exercise intolerance (n=16, 31.4%), syncope (n=16, 31.4%), congestive heart failure (n=5, 9.8%) and palpitation (n=2, 3.9%) with SND (n=23, 45.1%), CSD (17=33.3%) and uncontrolled atrial fibrillation (n=11, 21.6%). 16 (31.4%) pts received defibrillators (ICD) for primary prevention, of whom 8 (15.7%) had left ventricular ejection fraction (LVEF) ≤35%. Atrial (P wave: 1.7±1.2mV, threshold: 1.1±0.5mV/0.5±0.2ms) and right ventricular (RV) (R wave: 7.9±3.8mV, threshold: 0.8±0.4mV/0.4±0.1ms) lead parameters were satisfactory at implantation. During follow-up (mean 36.6±33.6 months), 26 (51%) pts reported symptomatic improvement (SI). Syncope was the only predictor of SI (OR 16.4, 95%CI 1.8-145.2, p=0.01) while exercise intolerance was not (OR 0.09, 95%CI 0.02-0.44, p=0.003). First-time life-threatening ventricular arrhythmias (VA) occurred in 6 (11.8%) pts, 3 (5.9%) had ICD implanted for LVEF ≤35%, 3 (5.9%) without ICD and LVEF ≥35%. Syncope was not predictive of first-time VA. RV lead noise led to inappropriate ICD shocks in 1 patient. Atrial lead sensing failure occurred in 6 (11.8%) and loss of capture in 5 (9.8%). Conclusion: Device implantation in patients with cardiac amyloidosis is safe but atrial lead failure is common. Syncope usually improves with pacing whereas other factors should be considered in those presented with exercise intolerance. Selection of pts who need pacing for prophylactic ICD implantation is challenging as neither left ventricular ejection fraction nor syncope are predictive of arrhythmic events.

Validation of Conventional Fluoroscopic and ECG Criteria for Right Ventricular Pacemaker Lead Position Using Cardiac Computed Tomography

It is hypothesized that pacing the right ventricular (RV) septum is associated with less deleterious outcomes than RV apical pacing. Our aim was to validate fluoroscopic and electrocardiography (ECG) criteria for describing pacemaker and implantable cardioverter defibrillator RV "septal" lead position against the proposed gold standard: cardiac computed tomography (CT). Using the conventional fluoroscopic criteria, we intended to place RV nonapical leads on the interventricular septum. Lead positions were later retrospectively analyzed with CT and correlated with ECGs and fluoroscopic projections: posterior-anterior, 40° left anterior oblique (LAO), 40° right anterior oblique (RAO), and left lateral. Only 21% (nine of 35) of presumed "septal" RV nonapical leads using the conventional fluoroscopic criteria were on the true septum. A schema developed to define septal position in the RAO fluoroscopic view had high agreement with CT images. ECG criteria had only fair to moderate agreement with CT. The paced QRS duration was significantly longer (P < 0.001) with RV apical pacing (176 ± 10.7 ms), compared to RV nonapical pacing (144.5 ± 14.3 ms). Using the conventional fluoroscopic criteria, only a minority of RV leads were implanted on the true RV septum. Instead, aiming for the middle of the cardiac silhouette in the RAO fluoroscopic view, confirming rightward orientation in the LAO view, and having a paced QRS duration <140 ms may allow the implanting cardiologist a simple, more accurate method to achieve true RV septal lead positioning.

Impact of the right ventricular lead position on clinical outcome and on the incidence of ventricular tachyarrhythmias in patients with CRT-D

Data on the impact of right ventricular (RV) lead location on clinical outcome and ventricular tachyarrhythmias in cardiac resynchronization therapy with defibrillator (CRT-D) patients are limited. To evaluate the impact of different RV lead locations on clinical outcome in CRT-D patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial. We investigated 742 of 1089 CRT-D patients (68%) with adjudicated RV lead location enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial to evaluate the impact of RV lead location on cardiac events. The primary end point was heart failure or death; secondary end points included ventricular tachycardia (VT), ventricular fibrillation (VF), or death and VT or VF alone. Eighty-six patients had the RV lead positioned at the RV septal or right ventricular outflow tract region, combined as nonapical RV group, and 656 patients had apical RV lead location. There was no difference in the primary end point in patients with nonapical RV lead location versus those with apical RV lead location (hazard ratio [HR] 0.98; 95% confidence interval [CI] 0.54-1.80; P = .983). Echocardiographic response to CRT-D was comparable across RV lead location groups (P > .05 for left ventricular end-diastolic volume, left ventricular end-systolic volume, and left atrial volume percent change). However, nonapical RV lead location was associated with significantly higher risk of VT/VF/death (HR 2.45; 95% CI 1.36-4.41; P = .003) and VT/VF alone (HR 2.52; 95% CI 1.36-4.65; P = .002), predominantly in the first year after device implantation. Results were consistent in patients with left bundle branch block. In CRT-D patients, there is no benefit of nonapical RV lead location in clinical outcome or echocardiographic response. Moreover, nonapical RV lead location is associated with an increased risk of ventricular tachyarrhythmias, particularly in the first year after device implantation.

Chronic Implantation of Intravascular Cardioverter Defibrillator in a Canine Model: Device Stability, Vascular Patency, and Anchor Histology

A percutaneously placed implantable intravascular defibrillator (PICD) has been developed with a right ventricular (RV) single-coil lead and titanium electrodes in the superior vena cava (SVC) and the inferior vena cava (IVC). This study evaluated implant techniques, device stability, and anchor histology of the PICD over 9 months in a canine model. Twenty-four hounds (wt = 30-55 kg) were anesthetized and a custom sheath introduced into the right femoral vein. The PICD was advanced over a wire and positioned with the titanium electrodes (cathodes) in the SVC and the IVC. A nitinol anchor secured the device in the jugular. The RV lead was positioned in the RV apex and screwed into place. The catheters, wires, and sheath were removed with an average implant time of 14 minutes. In one group of animals (n = 13), serial venograms were performed at 7 days, 14 days, and 28 days. In a second group (n = 6) and third group (n = 5), venograms were also performed at 90 days and 270 days, respectively. Six canines were sacrificed and anchor histologic examination done at 90 days. All implants were successful with no surgical complications observed. Devices (N = 24) remained appropriately positioned with no anchor migration. Histology at 90 days showed 98% endothelialization of the anchor. Venograms revealed patent IVC and jugular veins in all animals at every time point examined. The PICD can be rapidly and chronically implanted in animals. Long-term intravascular defibrillator placement is feasible in a canine model.

Implantable Cardioverter Defibrillator Malfunction Following LVAD Implantation

Implantable cardioverter defibrillator (ICD) lead malfunction has been reported after left ventricular assist device (LVAD) implantation, however the incidence and mechanism are not known. The mechanism of RV lead malfunction following LVAD implantation may be related to changes in LV and RV geometry, rather than decrease in LV mass. In this prospective single center study, we collected ICD lead data before, during and after LVAD implantation, including 12 time points during implantation. Data were collected prospectively on 29 patients, including 24 patients undergoing LVAD implantation (ICD implanted 35±34.9 months earlier) and 5 control patients who had LVAD implanted initially followed by ICD implantation. Of the 24 LVAD patients, 17 were male, 15 had coronary artery disease, 15 had LVAD implanted as destination therapy, and mean age was 57.6±13 years. Fifty-four leads were tested before, during, 1 week and 3 months after LVAD implantation, including 18 right atrial, 24 right ventricular (RV), and 12 left ventricular (LV) leads. In 16 patients, ICD leads were tested at 12 intraoperative steps. RV sensing was >50% decreased from baseline in 6 patients (25%) immediately post-op, with RV sensing improving at 1 week in 3 patients (50%). In 2 patients (8%) who also had decreased sensing, RV pacing threshold was >50% elevated from baseline immediately post-op (n=1) and at 1 week (n=1). One RV pacing threshold returned to baseline at 3 months. Of the 4 patients with significant decreases in RV sensing in whom lead function was tested at serial time points during VAD implantation, an RV sensing decrease was not detected until immediately following weaning off cardiopulmonary bypass. One RV lead was turned off and one was replaced due to non-capture. Time from lead implant to LVAD was 77.6±57.9 months in the patients with decreased RV lead sensing (n=6) vs. 33.3±43 months in patients with no decreased RV sensing (n=18). Post-operatively, 14 (58%) patients had ventricular arrhythmias, new onset in 8 (33%); and 15 (63%) had atrial arrhythmias, new onset in 7 (29%). On ECG, sensed QRS width decreased after LVAD (126.5±36.7 vs. 100±35.5ms). Of the 5 control patients, none had >50% decreased RV sensing and 1 had >50% elevation in pacing threshold from the day of implant to 1 year post-implant. Of 29 patients, 6 died (4.9±6.8 months) and 1 underwent cardiac transplant (3 months). ICD lead malfunction can occur following LVAD implantation, but may improve over time. Intraoperative RV sensing problems were not detected until weaning of cardiopulmonary bypass, suggesting the mechanism of RV lead malfunction may be related to changes in LV and RV geometry from LVAD implantation. Ventricular arrhythmias are common in the LVAD population, even in patients who did not have them pre-operatively.

Double left ventricular pacing following accidental malpositioning of the right ventricular electrode during implantation of a cardiac resynchronization therapy device

Accidental malpositioning of a right ventricular (RV) electrode has not been previously reported in the context of cardiac resynchronization therapy (CRT).The case of a 75-year old male patient with dilative cardiomyopathy, left ventricular (LV) ejection fraction 23%, New York Heart Association functional heart failure status stage III, left bundle branch block (LBBB) with QRS width of 136 ms, and misplacement of the RV lead to the LV apex during implantation of a CRT defibrillator is described.Following unremarkable implantation, routine interrogation of the CRT device on the first day after the implantation revealed uneventful technical findings. The 12-lead surface electrocardiogram (ECG) showed biventricular stimulation featuring a narrow QRS complex with incomplete right bundle branch block (RBBB) and R>S in V1. The biplane postoperative chest X-ray was graded normal. On routine follow-up one month later, a transthoracic echocardiogram revealed an increased ejection fraction of 51% but the RV lead was placed in the LV apex. An additional transesophageal echocardiogram exhibited an Eustachian valve guiding the lead via the patent foramen ovale through the mitral valve into the LV apex. Operative revision was scheduled and the active fixation lead was uneventful removed from the LV. A new electrode was inserted and placed in the RV apex.Accidental malplacement of the RV electrode to the LV may be difficult to diagnose in the context of CRT patients as a stimulated biventricular ECG with incomplete RBBB appearance is expected in this situation. Careful analysis of lateral radiographic views during the operation is important to ensure correct lead positioning. As timely revision is the preferred procedure, early routine transthoracic echocardiography may be considered for detection of malplacement.

Larger Interventricular Conduction Time Enhances Mechanical Response to Resynchronization Therapy

Previous studies have reported that the left ventricular (LV) pacing site is a major determinant of the hemodynamic response to cardiac resynchronization therapy (CRT). However, lead positioning in a lateral or posterolateral cardiac vein may not be optimal for every patient. The objective of this study was to assess the relationship between the right ventricular (RV)-to-LV conduction time and the systolic function during CRT on the basis of changes to LV pressure-volume loops. Left ventricular pressure and volume data were determined using a conductance catheter during CRT device implantation in 10 patients. Four endocardial LV sites were systematically assessed at four atrioventricular delays. The RV-to-LV conduction time was measured as the time interval between spontaneous peak R waves, recorded through the RV lead and the LV catheter. The optimal pacing site varied among patients. However, the pacing site associated with the maximum RV-to-LV conduction time resulted in a stroke volume improvement comparable to the pacing site identified through individual hemodynamic optimization (41 ± 17 mL vs 44 ± 18 mL, P = 0.266). Moreover, the RV-to-LV conduction time recorded at each endocardial pacing site correlated positively with the increase in stroke volume (r = 0.537; P < 0.001), stroke work (r = 0.642; P < 0.001), and the pressure-derivative maximum (r = 0.646; P < 0.001) obtained with CRT. An optimal acute response to CRT can be obtained by positioning the LV lead at the site associated with the maximum RV-to-LV conduction time. A significant correlation appears to exist between RV-to-LV conduction time and the improvement in systolic function with CRT.

Transatrial Antegrade Approach for Double Mitral and Tricuspid “Valve-in-Ring” Implantation

Within the last 5 years, the number of transcatheter aortic valve implantation (TAVI) procedures has increased continuously and, in parallel, the indications for TAVI have expanded (eg, failing surgical valves and rings). Furthermore, alternative TAVI access routes such as transaxillary and transaortic have been applied successfully. We report on, to our knowledge, the first-in-human case of a combined off-pump antegrade transatrial implantation of a transcatheter valve within a mitral and tricuspid annuloplasty ring through an anterolateral minithoracotomy. The patient showed severe mitral valve and tricuspid valve stenosis and regurgitation 15 years after mitral valve repair and 7 years after aortic valve replacement and tricuspid valve repair.

Right ventricular lead adjustment in cardiac resynchronization therapy and acute hemodynamic response: a pilot study

Optimal left ventricular (LV) lead position has emerged as an important determinant of response after cardiac resynchronization therapy (CRT). Comparatively, strategy for right ventricular (RV) lead optimization remains uncertain. Three variations of RV lead position (apex, mid-septal, and high septal) were tested in seven consecutive patients. At each location, intra-procedural measurement of LV lead electrical delay (LVLED) was obtained during intrinsic rhythm and RV pacing (RV-LVLED). Simultaneous cardiac output assessment was performed using the LiDCO™ (lithium chloride indicator dilution) system. Final RV lead location was selected based on best-measured cardiac output. Clinical and echocardiographic outcomes were assessed at baseline and 6 months. Adjustment of RV lead position after securing a LV lead site led to an incremental change of 30 ± 18 % (range, 7-52 %) in the cardiac index (CI). There was substantial variation in acute hemodynamic response (∆CI, 14 ± 13 %; range, 3-41 %) seen with pacing from each patient's worst to best RV lead position; no single RV lead position emerged as optimal across all patients. Paced RV-LVLED was not correlated with percent change in CI (r = 0.18; p = NS). LV ejection fraction (LVEF) increased significantly (28 ± 4 to 40 ± 8 %, p = 0.006) at 6 months. LVLED measured during intrinsic rhythm, but not during RV pacing, correlated with percent change in LVEF (r = 0.88, p = 0.02). RV lead position adjustment can be used to enhance acute hemodynamic response during CRT. Measurement of paced RV-LVLED, however, does not reliably predict change in cardiac output.

Implantation of a Right Ventricular Implantable Cardioverter-Defibrillator Lead in the Right Ventricular Outflow Tract in a Patient with Ebstein Anomaly and Right Ventricular Lead Dislocation

An 80-year-old patient with Ebstein anomaly and prior implantable cardioverter-defibrillator (ICD) implantation was sent to our heart center because of right ventricular (RV)-ICD lead dislocation. Positioning of the new RV lead was difficult, no stable position could be found, and sensing and threshold measurements showed weak results in the RV basis, apex, and septum. So, we conducted positioning of the lead in the RV outflow tract where a stable position with good sensing and threshold parameters was found.

Percutaneous pacemaker or implantable cardioverter-defibrillator lead removal in an attempt to improve symptomatic tricuspid regurgitation

Pacemaker and implantable cardioverter-defibrillator (ICD) leads can cause tricuspid valve regurgitation (TR). Few data are available on the best management of significant TR that develops after pacemaker or ICD implantation and regarding any benefits of right ventricular (RV) lead extraction. We sought to determine the impact of RV lead removal on lead-induced TR. We reviewed all patients between 1 January 2000 and 31 December 2010 at the tertiary care hospital who had a preoperative indication of TR and underwent percutaneous extraction of an RV lead with the intent of trying to correct moderate or severe TR. Pre- and post-procedure echoes and clinical data were retrospectively reviewed. In the four patients identified, the RV lead was removed and placed in the coronary sinus to try to improve moderate or severe TR due to lead impingement. There was no significant improvement in the degree of TR except one patient where TR improved slightly from moderate to mild-moderate. All patients had a dilated tricuspid valve annulus by the time of lead extraction. Tricuspid annulus dilatation appeared to account for the persistent TR after RV lead removal. A greater degree of tricuspid valve annulus dilatation may be a marker and mechanism for irreversible lead-induced TR. Further studies are needed to determine whether surgical tricuspid valve repair or replacement combined with RV lead extraction would result in better outcomes than a percutaneous lead extraction approach.

Novel tips for engaging the coronary sinus guided by right ventricular lead

This study investigated the relationship between the ostia of the coronary sinus (CS) and the tricuspid annulus (TA) for CS cannulation using a right ventricular (RV) lead, which could map out the TA by forming a curve when placed at the apex or low septum. Seventy patients (45 males, 67 ± 12 years) who were admitted for CRT device implant were included in the evaluation of the relationship between the CS ostia and TA. An electrophysiological (EP) mapping catheter was used to probe the CS. The ostium was shown by the CS venography at the left anterior oblique (LAO) 20° and caudal 20°. Local electrograms were collected with CS catheters in the CS or RV. Transthoracic echocardiography was evaluated before each procedure. All CS ostia were located within 3.75 cm around the tip of TA. Sixty-two subjects (Group I, 89%) had CS ostia located under the TA. Eight patients (Group II) with CS ostia over the TA revealed larger left ventricular (LV) size and a smaller ratio of left atrium (LA)/LV size. LV enlargement predicted the presence of CS ostia over the TA. Typical CS electrograms were used to further confirm if the EP catheter was in the CS in all the subjects. Use of the RV lead revealed that the CS ostia had a close relationship with the TA.

Inappropriate Mode Switching in a Dual-Chamber Defibrillator System

A 22-year-old man with a history of arrhythmogenic right ventricular (RV) cardiomyopathy with involvement of the left ventricle on noninvasive imaging, symptomatic bradycardia, and frequent ventricular ectopy underwent placement of a dual-chamber implantable cardioverter-defibrillator for the primary prevention of sudden cardiac death. The device was a model 2231-40 Fortify DR, with a model 1999 atrial lead and 7120 dual-coil RV lead (St. Jude Medical, Sylmar, CA). Device interrogation performed 1 month postimplant revealed numerous mode-switch episodes. Representative electrograms are shown in Figure 1. Results of the interrogation also showed lead values within acceptable limits (P-wave sensing, 1.2 mV; R-wave sensing, 12 mV; pacing impedance of 350 Ω in the atrium, 490 Ω in the ventricle; high-voltage lead impedance 36 Ω; pacing thresholds of 200 bpm. The automatic mode switch (AMS) trigger was programmed nominally at 180 bpm. Figure 1. Stored electrogram of a representative automatic mode switch (AMS) episode. AS indicates atrial sensed; VIP, ventricular intrinsic preference (algorithm to …

Accuracy of Fluoroscopic and Electrocardiographic Criteria for Pacemaker Lead Implantation by Comparison with Three-Dimensional Echocardiography

Fluoroscopic and electrocardiographic (ECG) criteria for the documentation of pacing lead positioning (apical and alternative sites) have been described, but data regarding their accuracy are lacking. Fifty patients (27 men; mean age, 76 ± 9 years) with permanent right ventricular (RV) pacing leads were included. RV lead position was classified as apical, mid septal, mid RV free wall, RV outflow tract (RVOT) septal, or RVOT free wall. Exact anatomic lead position was documented using three-dimensional (3D) transthoracic echocardiography (TTE). Cohen's κ coefficient was used to assess agreement between fluoroscopic or ECG criteria and 3D TTE. True lead positions were as follows: 15 apical, 24 mid septal, three mid RV free wall, and eight RVOT septal wall; no leads were implanted into the RVOT free wall. Fluoroscopy (κ = 0.56; 95% confidence interval [CI], 0.37-0.76) and electrocardiography (κ = 0.43; 95% CI, 0.25-0.60) had moderate overall agreement with 3D TTE. Fluoroscopy had moderate agreement with 3D TTE for apical (κ = 0.57; 95% CI, 0.32-0.83), mid septal (κ = 0.48; 95% CI, 0.25-0.72), and mid free wall sites (κ = 0.54; 95% CI, 0.08-1.00) and moderate to good agreement for the RVOT septal wall (κ = 0.61; 95% CI, 0.30-0.90). Fluoroscopy misclassified as mid septal six of the 15 RV apical leads. ECG criteria had moderate agreement with 3D TTE for apical positions (κ = 0.55; 95% CI, 0.34-0.77) and RVOT sites (κ = 0.47; 95% CI, 0.21-0.73). Electrocardiography misclassified as apical 10 and as RVOT six of the 24 mid septal leads. Fluoroscopic and ECG criteria are only moderately accurate in discriminating between RV apical, mid septal, mid free wall, and RVOT pacing sites. These data suggest that both fluoroscopy and electrocardiography may not be adequate techniques for the correct documentation of RV pacing lead position for routine clinical practice or research purposes.

The “rope and stick” and the “safety snare”: Two new techniques for tricky lead extractions

A 77-year-old pacemaker-dependent male was referred to our institution for extraction of a single-chamber pacing system for device infection. He received in 1998 a dual-chamber pacemaker with two passive leads (Pacesetter membrane-E 1450 T/1420 T) for complete atrio-ventricular block. After device-replacement he developed a pocket infection managed with antibiotic, removal of the device and excision of almost all the extravascular portion of the two leads and re-implant of a single-chamber device (year 2009) on the opposite site (the patient was in permanent atrial fibrillation). After many local revisions of the residual left pocket the patient was referred to our hospital. We decided to perform full extraction of all the leads and the device (increased C-reactive protein and blood samples positive for S. epidermidis). The procedure was carried out under conscious sedation in a hybrid-room with an active surgical back-up. After heavy debriding we obtained only few centimeters of the abandoned right-ventricular (RV) lead. However, it was enough to advance a locking stylet (LLD, Spectranetics Corporation, Colorado Springs, USA) to the lead tip. Manual traction was ineffective and a 14F laser-sheath (Spectranetics Corporation, Colorado Springs, USA) was advanced until the space between the clavicle and the first rib. Thereafter it was not possible to further advance the sheath, but a new attempt of manual traction was effective in freeing the right ventricular lead (Fig. 1-A). However, the left superior route proved to be ineffective for reaching the intravascular atrial lead. Considering the closeness of the proximal-edge of the atrial lead to the area which prevented laser sheath advancement, we feared that the same heavy adhesions could prevent percutaneous lead extraction by any approach. We advanced a medium curl 7F ablation catheter into the right atrium through an 18F femoral introducer and after many attempts, we were able to border the atrial lead (Fig. 1-B). In the meantime a 20-snare (Andrasnare: Andramed GmbH, Reutlingen, Germany) was advanced through a second femoral introducer to reach the tip of the ablation catheter and stabilize it (Fig. 1-C,D). A combined traction of both the ablation catheter and the snare (i.e. respectively the “stick” and “rope” of the title) was able to free both the proximal portion of the atrial lead and the distal end of the more recently implanted RV lead (Fig. 2-E). The RV lead was then effortlessly extracted from the subclavian access. Instead, the atrial lead appeared heavily trapped inside the atrial appendage. In order to avoid an atrial tear by insisting with simple traction we stabilized the lead with the first 20-snare while the 14F laser sheath was advanced into the inferior vena cava through a femoral introducer with a second 20-snare inside, which was used to secure the terminal part of the broken lead (Fig. 2-F). The laser sheath was then advanced over the secured lead up to the right atrial appendage while the first snare was maintained loosely around the system as a safety measure (“safety snare”). After few further laser bursts the outer insulation of the lead suddenly broke and came out of the sheath leaving the inner conductor, connected to the tip of the lead, exposed inside the laser sheath (Fig. 2-G). The presence of the “safety snare” allowed to stabilize once more the remaining part of the lead which was again reached by the second snare inside the 14F laser sheath permitting to free it in few further laser burst (Fig. 2-H). In view of the pacemaker-dependency and the double sub-clavicle access we implanted an epicardial pacemaker via sub-xyphoid route. Fig. 2After stabilizing the ablation catheter (arrow 5) with the snare (arrow 6), a combined traction was effective in freeing both the proximal portion of the atrial lead (arrow 3) and the terminal portion of the last RV lead (arrow 4, the screw mechanism was jammed). In the meantime a bipolar catheter (arrow 7) was advanced into the RV in view of pacemaker dependency of the patient (Panel E). After ineffective traction of the atrial lead by the snare, the laser sheath was advanced over a second snare (arrow 8) through the 18F femoral introducer (arrow 9) (Panel F). After reaching the tip of the atrial lead we delivered laser bursts with caution, the first snare was advanced outside the laser sheath as a safety measure (the “safety snare”, arrow 6). However, the outer insulation suddenly broke after few laser bursts leaving the inner conductor alone (panel G) inside the laser sheath (3a tip of atrial lead, 3b exposed inner conductor, 3c outer insulation). The “safety snare” was used to stabilize the inner conductor that was then reached with the second snare after completely removing the insulation. Few laser bursts were effective in freeing the tip of the atrial lead (3a, panel H). View Large Image Figure Viewer Download Hi-res image