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A 74-year-old with a history of sinus node dysfunction and intermittent AV block s/p permanent pacemaker implant 6 years prior, complains of one episode of dizziness.

Herein, we present a case of laser-assisted extraction of a retained lead remnant following incomplete removal of an implantable cardiac defibrillator system implanted via a left femoral approach.

As the coronavirus cases continue to surge, the urgent need for universal testing to identify positive cases for effective containment of this highly contagious pandemic has become the center of attention worldwide. However, in spite of extensive discussions, very few places have even attempted to implement it. We evaluated the efficacy of widespread testing in creating a safe workplace in our electrophysiology (EP) community. Furthermore, we assessed the new infection rate in patients undergoing EP procedure, to see if identification and exclusion of positive cases facilitated establishment of a risk-free operating environment. Viral-RNA and serology tests were conducted in 1670 asymptomatic subjects including patients and their caregivers and staff in our EP units along with the Emergency Medical Service (EMS) staff. Of 1670, 758 (45.4%) were patients and the remaining 912 were caregivers, EMS staff, and staff from EP clinic and lab. Viral-RNA test revealed 64 (3.8%) positives in the population. A significant increase in positivity rate was observed from April to June 2020 (p = 0.02). Procedures of positive cases (n = 31) were postponed until they tested negative at retesting. Staff testing positive (n = 33) were retested before going back to work after 2 weeks. Because of suspected exposure, 67 staff were retested and source was traced. No new infections were reported in patients during or within 2 weeks after the hospital-stay. Universal testing to identify positive cases was helpful in creating and maintaining a safe working environment without exposing patients and staff to new infections in the EP units. Trial Registration Number: clinicaltrials.gov : NCT04352764

BackgroundAs the coronavirus cases continue to surge, the urgent need for universal testing to identify positive cases for effective containment of this highly contagious pandemic has become the center of attention worldwide. However, in spite of extensive discussions, very few places have even attempted to implement it. We evaluated the efficacy of widespread testing in creating a safe workplace in our healthcare community including staff and patients.Furthermore, we assessed the rate of new infections in patients undergoing electrophysiology (EP) procedure, to see if identification and exclusion of positive cases facilitated establishment of a risk-free operating environment.MethodsUniversal testing was conducted in subjects with no symptoms of COVID-19 including patients and their caregivers and staff in our electrophysiology units along with the Emergency Medical Service (EMS) staff (n=1670)ResultsOf 1670, 758 (45.4%) were EP patients, and the remaining 912 were caregivers, EMS staff and hospital staff from EP clinic and lab. Viral-RNA test revealed 64 (3.8%) positives in the population. A significant increase in the rate of positives was observed from April to June, 2020 (p=0.02). Procedures of positive cases (n=31) were postponed until they tested negative at retesting on day 14. Staff testing positive (n=33) were retested before going back to work after 2 weeks. Because of suspected exposure, 67 staff were retested and source was traced. No new infections were reported in patients during the hospital stay or within 2-weeks after the procedure.ConclusionUniversal testing to identify positive cases was helpful in creating and maintaining a safe working environment without exposing patients and staff to new infections in the EP unit at the hospital.Trial Registration Numberclinicaltrials.gov: NCT04352764

Introduction The Medtronic Attain Stability Quad lead is a quadripolar left ventricular (LV) lead with an active fixation helix assembly designed to fixate the lead within the coronary sinus and pace nonapical regions of the LV. The primary objective of this study was to determine the safety and effectiveness of this novel active fixation quadripolar LV lead. Methods Patients with standard indications for cardiac resynchronization therapy (CRT) were enrolled. All patients were followed at 3 and 6 months post-implant and every 6 months thereafter until study closure. Pacing capture thresholds (PCTs) were measured at implant and each follow-up and adverse events (AEs) were recorded upon occurrence. Results Of the 440 patients who underwent implant procedures, placement of the Attain Stability Quad lead was successful in 426 (96.8%). LV lead-related complications occurred in 10 patients (2.3%), including LV lead dislodgement in three patients (0.7%). The percentage of patients with at least one LV pacing vector with a PCT ≤2.5 V at a 6-month follow-up was 96.3%. The LV lead was successfully fixated to the prespecified pacing location in 97.4% of cases. Conclusions This large, multinational study of the Attain Stability Quad lead demonstrated a high rate of implant success with a low complication rate. The active fixation mechanism allowed precise placement of the pacing electrodes at the desired target region with good PCTs and a very low dislodgement rate.

AIMS Antitachycardia pacing (ATP) is an effective treatment for ventricular tachycardia (VT) and can reduce the frequency of shocks in patients with an implantable cardioverter defibrillator (ICD). The association between survival and ATP, as compared to a shock, has not been confirmed in a large patient population. This study aims to determine if patients with an ICD receiving ATP have lower mortality, as compared to those receiving shock. METHODS Sixty-nine thousand three hundred and sixty-eight patients underwent ICD implantation between October 2008 and May 2013 and were enrolled in the remote monitoring network Merlin.net™ (St. Jude Medical, St. Paul, MN, USA). Patients were categorized into three groups based on the type of ICD therapy received during follow-up: no therapy (N = 47,927), ATP (N = 8,049), and shock (N = 13,392) groups. Survival was determined by linking implant records to the Social Security Death Index. RESULTS The no therapy (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.56-0.64, P < 0.001) and ATP (HR 0.70, 95% CI 0.64-0.77, P < 0.001) groups were associated with a lower mortality risk than the shock group. These results were unaffected by age, gender, device type, atrial fibrillation (AF) burden, or ventricular rate. ATP was effective in 85% of episodes and ATP effectiveness was dependent on the ventricular rate. CONCLUSIONS Mortality rates were higher in ICD patients who received only ATP compared to no therapy, but ICD patients who received a shock had higher mortality compared to both groups. Furthermore, the data suggest that age, gender, device type, AF burden, and rate of arrhythmia do not change the trend of higher mortality in patients receiving ICD shock compared to ATP alone.

There is increasing evidence that using frequent invasive measures of pressure in patients with heart failure results in improved outcomes compared to traditional measures. Admittance, a measure of volume derived from preexisting defibrillation leads, is proposed as a new technique to monitor cardiac hemodynamics in patients with an implantable defibrillator.The purpose of this study was to evaluate the accuracy of a new ventricular volume sensor (VVS, CardioVol) compared with 3-dimenssional echocardiography (echo) in patients with an implantable defibrillator.Twenty-two patients referred for generator replacement had their defibrillation lead attached to VVS to determine the level of agreement to a volume measurement standard (echo). Two opposite hemodynamic challenges were sequentially applied to the heart (overdrive pacing and dobutamine administration) to determine whether real changes in hemodynamics could be reliably and repeatedly assessed with VVS. Equivalence of end-diastolic volume (EDV) and stroke volume (SV) determined by both methods was also assessed.EDV and SV were compared using VVS and echo. VVS tracked expected physiologic trends. EDV was modulated -10% by overdrive pacing (14 mL). SV was modulated -13.7% during overdrive pacing (-6 mL) and increased over baseline +14.6% (+8 mL) with dobutamine. VVS and echo mean EDVs were found statistically equivalent, with margin of equivalence 13.8 mL (P.05). Likewise, mean SVs were found statistically equivalent with margin of equivalence 15.8 mL (P.05).VVS provides an accurate method for ventricular volume assessment using chronically implanted defibrillator leads and is statistically equivalent to echo determination of mean EDV and SV.

Antitachycardia pacing (ATP) is an effective treatment for ventricular tachycardia (VT) and can reduce the frequency of shocks in patients with an implantable cardioverter defibrillator (ICD). The association between survival and ATP, as compared to a shock, has not been confirmed in a large patient population. This study aims to determine if patients with an ICD receiving ATP have lower mortality, as compared to those receiving shock.Sixty-nine thousand three hundred and sixty-eight patients underwent ICD implantation between October 2008 and May 2013 and were enrolled in the remote monitoring network Merlin.net™ (St. Jude Medical, St. Paul, MN, USA). Patients were categorized into three groups based on the type of ICD therapy received during follow-up: no therapy (N = 47,927), ATP (N = 8,049), and shock (N = 13,392) groups. Survival was determined by linking implant records to the Social Security Death Index.The no therapy (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.56-0.64, P0.001) and ATP (HR 0.70, 95% CI 0.64-0.77, P0.001) groups were associated with a lower mortality risk than the shock group. These results were unaffected by age, gender, device type, atrial fibrillation (AF) burden, or ventricular rate. ATP was effective in 85% of episodes and ATP effectiveness was dependent on the ventricular rate.Mortality rates were higher in ICD patients who received only ATP compared to no therapy, but ICD patients who received a shock had higher mortality compared to both groups. Furthermore, the data suggest that age, gender, device type, AF burden, and rate of arrhythmia do not change the trend of higher mortality in patients receiving ICD shock compared to ATP alone.

Introduction: Closed-loop stimulation (CLS) is a form of rate-adaptive pacing capable of providing an effective pacing rate profile not only during physical exercise but also during mental stress. To test its effectiveness, CLS and accelerometer sensor (AS) rate response were compared intraindividually during a mental stress test (MST). Methods: Thirty-six patients (mean age 78.9 ± 6.4 years) implanted with a pacemaker with the CLS algorithm (Cylos, Biotronik, Berlin, Germany) underwent MSTs in different pacing configurations: nonrate-adaptive mode (VVI), AS mode (VVIR), and CLS mode, respectively. A modified Stroop test was used in order to induce mental stress. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure, and pacing percentage burden were collected for 5 minutes before, during, and 5 minutes after the test. Results: Mean peak-HR during MST was significantly higher in CLS configuration than in VVIR and VVI modes (92.8 ± 12.6 vs 78.9 ± 6.5 vs 77.8 ± 7.5; P ≤ 0.001). The average HR increase during MST was also higher in CLS configuration than in VVIR and VVI modes (22.7 ± 16.7 vs 8.2 ± 8.6 vs 6.6 ± 6.3; P ≤ 0.001). The percentage of pacing beats during MST was higher in CLS configuration than with the other two algorithms (48.4 ± 17.9 vs 27.4 ± 17.5 vs 25.8 ± 17.6; P ≤ 0.001). The average peak-SBP was significantly higher during MST in CLS mode than in VVIR and VVI configurations (172.6 ± 15.5 vs 156.7 ± 12.2 vs 145.5 ± 13.7; P ≤ 0.001). The mean SBP increase showed a similar behavior (51.8 ± 24.7 vs 18.4 ± 13.7 vs 16.4 ± 10.3; P ≤ 0.001). Conclusion: CLS algorithm in a single-chamber device is more effective than AS in detecting an hemodynamic demand due to an emotional stress and supplying a proper HR increase. These results are even more surprising compared to previous data in dual-chamber pacemakers, because they imply that CLS algorithm can provide an appropriate rate-modulation in patients with AF and chronotropic incompetence. (PACE 2012; 35:990–998)

Aims Functional mitral regurgitation (MR) could be managed by both cardiac resynchronization therapy (CRT) and mitral-valve surgery. Clinical decision making regarding the appropriateness of mitral-valve surgery vs. CRT is a challenging task. This study assessed the prevalence and prognosis of various degrees of functional MR in CRT candidates. Additionally, we sought to identify functional MR patients who either can be adequately managed by CRT only or will need surgery. Methods and results Cardiac resynchronization therapy recipients ( n = 794) were followed-up for 26 ± 18 months. Mitral regurgitation severity was quantified on scale 0–4. Cardiac resynchronization therapy responders were identified based on improvement in the New York Heart Association class and left-ventricular ejection fraction. Severity of MR and LV reverse remodelling were assessed at 3 and 12 months. Predictors of long-term MR change and CRT response were explored with multivariable models. Mitral regurgitation was present in 86%, with 35% prevalence of advanced MR (grade 3–4). Improvement of MR ≥1° after 12 months occurred in 46% of patients. It was relatively more frequent in patients with advanced MR at baseline (63%, P < 0.01). Baseline MR severity and change in MR at 3-month follow-up predicted response to CRT. Patients with ≥1° MR improvement at 12 months had more reverse remodelling compared with those with no change or worsening of MR. Conclusions Mitral regurgitation improvement at 3 months predicts CRT response and MR improvement at 12-month follow-up. This finding could have implications for subsequent MR surgical therapies.

Background— Obstructive sleep apnea (OSA) may be associated with pulmonary vein antrum isolation (PVAI) failure. The aim of the present study was to investigate if treatment with continuous positive airway pressure (CPAP) improved PVAI success rates. Methods and Results— From January 2004 to December 2007, 3000 consecutive patients underwent PVAI. Patients were screened for OSA and CPAP use. Six hundred forty (21.3%) patients had OSA. Patients with OSA had more procedural failures ( P =0.024) and hematomas ( P P P =0.001). At the end of the follow-up period (32±14 months), 79% of the non-CPAP and 68% of the CPAP group were free of atrial fibrillation ( P =0.003). Not using CPAP in addition to having non-PV triggers strongly predicted procedural failure (hazard ratio, 8.81; P Conclusions— OSA was an independent predictor for PVAI failure. Treatment with CPAP improved PVAI success rates. Patients not treated with CPAP in addition to having higher prevalence of non-PV triggers were 8 times more likely to fail the procedure.

To report survival rates in patients treated with pulmonary vein antrum isolation (PVAI), atrioventricular junctional ablation (AVJA), and antiarrhythmic and direct current cardioversion (A + DCCV) at 7 years follow-up. From February 2002–December 2004, 1,000 consecutive patients underwent PVAI or A + DCCV or AVJA. These patients were matched in a nested case-controlled methodology. Survival rates were compared at the end of 7 years. Three hundred and forty-five consecutive patients had undergone PVAI (34.5%), 157 (15.7%) consecutive patients AVJA, and 498(49.8%) A + DCCV. After matching the patients in a nested case-controlled methodology, 146 (32.3%) patients were in the PVAI group, 205 (59.4%) in the A + DCCV, and 101 (22.3%) in the AVJA. At 69 ± 27 months, 63 (13.9%) patients had died in the matched population. Three (2.1%) patients died in the PVAI group, 34 (16.5%) in the A + DCCV group, and 26 (25.7%) in the AVJA group. In multivariable analysis, treatment strategy was a significant predictor of mortality. Compared to patients with PVAI (reference group), those with A + DCCV (HR 4.9, p = 0.011) and AVJA (HR 10.6, p = 0.001) procedures had higher mortality risk. Compared to the other two procedures, patients with PVAI had the best survival rates at the end of 7 years. However, the observational case-control design of this study incurs the potential for confounding due to non-randomized treatment selection, and creates a major limitation in making valid generalization of the findings.

LV Lead Positioning Guided by ICE With Vector Velocity Imaging. Introduction: Intraoperative modality for “real-time” left ventricular (LV) dyssynchrony quantification and optimal resynchronization is not established. This study determined the feasibility, safety, and efficacy of intracardiac echocardiography (ICE), coupled with vector velocity imaging (VVI), to evaluate LV dyssynchrony and to guide LV lead placement at the time of cardiac resynchronization therapy (CRT) implant. Methods: One hundred and four consecutive heart failure patients undergoing ICE-guided (Group 1, N = 50) or conventional (Group 2, N = 54) CRT implant were included in the study. For Group 1 patients, LV dyssynchrony and resynchronization were evaluated by VVI including visual algorithms and the maximum differences in time-to-peak (MD-TTP) radial strain. Based on the findings, the final LV lead site was determined and optimal resynchronization was achieved. CRT responders were defined using standard criteria 6 months after implantation. Results: Both groups underwent CRT implant with no complications. In Group 1, intraprocedural optimal resynchronization by VVI including visual algorithms and MD-TTP was a predictor discriminating CRT response with a sensitivity of 95% and specificity of 89%. Use of ICE/VVI increased number of and predicted CRT responders (82% in Group 1 vs 63% in Group 2; OR = 2.68, 95% CI 1.08–6.65, P = 0.03). Conclusion: ICE can be safely performed during CRT implantation. “Real-time” VVI appears to be helpful in determining the final LV lead position and pacing mode that allow better intraprocedural resynchronization. VVI-optimized acute resynchronization predicts CRT response and this approach is associated with higher number of CRT responders. (J Cardiovasc Electrophysiol, Vol. 22, pp. 1034-1041, September 2011)

The Selection AFm Registry investigated the impact of pacemaker diagnostic data on the clinical management of patients with atrial arrhythmias, specifically atrial fibrillation (AF) through the use of advanced atrial arrhythmia monitoring features. Very few data on the clinical impact of such data has been reported in a real world setting.Patients with known or suspected AF with a Class I or Class II indication for a dual-chamber pacemaker received the Selection AFm pacemaker. These patients were prospectively followed at pacemaker follow-up visits, and data were collected on medications and device programming. Physicians identified which therapy changes were based upon the stored data within the pacemaker.Two hundred eighty-two patients were enrolled. A total of 119 patients had 311 changes made to either their medications or device programming after review of diagnostic pacemaker data. Changes involved rate and rhythm control, warfarin anticoagulation, and pacemaker programmed settings. Significantly, more changes were made in patients with documented atrial arrhythmias at follow-up.The atrial arrhythmia recording features were used by clinicians to guide therapy-related decisions in patients with paroxysmal AF. Such data represent an additional source of clinical information for AF disease management.

Objective To assess if patients treated with omega-3(n-3) polyunsaturated fatty acids (PUFAS) had lower procedural failure rates compared to an untreated population. Methods and Results From January 2004 to 2007, 1500 PVAI patients underwent catheter ablation. Two hundred and eighty five (19%) patients were treated with PUFAs. These patients were matched in a nested case controlled analysis. After matching, there were 129 patients in the PUFA group and 129 in the control group. Thirty-five (27.1%) patients in the study group had early recurrence vs. 57 (44.1%) in the control group p-value< 0.0001. Twenty-nine (23.2%) patients in the PUFA group vs. 41 (31.7%) in the non-PUFA group had procedural failure (p-value < 0.003). There were no significant differences in complications in the PUFA and non-PUFA groups. Conclusion Patients treated with PUFAs had lower incidences of early recurrence and procedural failure compared to an untreated population.

Background: Robotic catheter navigation and ablation either with magnetic catheter driving or with electromechanical guidance have emerged in the recent years for the treatment of atrial fibrillation. Objective: The aim of this study was to compare our center's experience of atrial fibrillation ablation using the Hansen Robotic Medical System with our current manual ablation technique in terms of acute and chronic success, as well as procedure time and radiation exposure to both the patient and the operator. Methods: A total of 390 consecutive patients with symptomatic and drug-resistant atrial fibrillation (289 males, 62 ± 11 years) were prospectively enrolled in the study. All patients underwent the procedure either with conventional manual ablation (group 1, n = 197) or with the robotic navigation system (RNS) (group 2, n = 193). Results: The success rate for RNS was 85% (164 patients), while for manual ablation it was 81% (159 patients) (p = 0.264) at 14.1 ± 1.3 months with AADs previously ineffective. Fluoroscopy time was significantly lower for RNS (48.9 ± 24.6 minutes for RNS vs. 58.4 ± 20.1 minutes for manual ablation, P < 0.001). Mean fluoroscopy time was statistically reduced after 50 procedures (61.8 ± 23.2 minutes for first 50 cases vs. 44.5 ± 23.6 minutes for subsequent procedures, P < 0.0001). Conclusion: Robotic navigation and ablation of atrial fibrillation is safe and effective. Fluoroscopy time decreases with experience.

In a series of 14 patients undergoing transseptal catheterization for ablation of left-sided accessory pathways, hydrogen appearance time was used to detect left-to-right shunting after removal of the catheter. Six of the 12 patients who had no evidence of shunt before catheterization had evidence of shunting after the procedure.

The use of non-thoracotomy endocardial implantable defibrillators with pacing capabilities has increased substantially over the past 2 years. This report demonstrates that the pacing threshold increases in some patients after endocardial defibrillation, and substantiates the practice of using maximal pacing output after endocardial defibrillation.