Lead Position Research Articles

The application of fluoroscopic criteria to define leadless pacemakers implant position and the effect of location on device performance.

Leadless pacemakers (LPs) were designed to avoid complications associated with transvenous pacing. To minimise risk of perforations, there is preference towards implanting LPs into the septum rather than the apex or free wall.An objective yet feasible way of characterising the LP location is currently lacking. We report a simple radiological method of defining LP position and our analysis of the impact of implantation site on performance of LPs. The first 100 LPs implanted at our UK centre were reviewed and the devices' positions in fluoroscopy images and X-rays based on conventional criteria for lead positions and conventional practice for LPs positioning were assessed. The devices' electrical parameters at implant and at the latest device follow-up were used to compare performance between implantation sites. 35.6% of implants were in the apex. 31.1% in mid-septum, 16.7% in apical septum, 15.5% on the septal right ventricular inflow and 1.1% in the septal RV outflow tract. We had no major complications.Thresholds, R-wave amplitudes, and impedance averaged at 0.67 ± 0.41 V, 10.64 ± 5.30 mV, and 777.67 ± 201.67 Ohms, respectively, at the time of implantation, and 0.66 ± 0.39 V, 14.08 ± 6.14 mV, and 564.29 ± 96.76 Ohms at the last device check. There was no difference in the pacing thresholds or impedance between implant sites. We propose a simple, reproducible way of defining the LP location which can help standardise the assessment of the device location sites across LP implantation centres. Emphasis on the safety and reliability of the leadless pacemakers in a real-world setting.Establishing the variation in the implantation sites for leadless pacemakers and reporting the effect of the implantation sites on the devices' performance.We propose a simple, reproducible way of defining the LP location which can help standardise the assessment of the device location sites across LP implantation centres.

Does targeted positioning of the left ventricular pacing lead towards the latest local electrical activation in cardiac resynchronization therapy reduce the incidence of death or hospitalization for heart failure?

Cardiac resynchronization therapy (CRT) improves symptoms, health-related quality of life and long-term survival in patients with systolic heart failure (HF) and shortens QRS duration. However, up to one third of patients attain no measurable clinical benefit from CRT. An important determinant of clinical response is optimal choice in left ventricular (LV) pacing site. Observational data have shown that achieving an LV lead position at a site of late electrical activation is associated with better clinical and echocardiographic outcomes compared to standard placement, but mapping-guided LV lead placement towards the site of latest electrical activation has never been investigated in a randomized controlled trial (RCT). The purpose of this study was to evaluate the effect of targeted positioning of the LV lead towards the latest electrically activated area. We hypothesize that this strategy is superior to standard LV lead placement. The DANISH-CRT trial is a national, double-blinded RCT (ClinicalTrials.gov NCT03280862). A total of 1,000 patients referred for a de novo CRT implantation or an upgrade to CRT from right ventricular pacing will be randomized 1:1 to receive conventional LV lead positioning preferably in a nonapical posterolateral branch of the coronary sinus (CS) (control group) or targeted positioning of the LV lead to the CS branch with the latest local electrical LV activation (intervention group). In the intervention group, late activation will be determined using electrical mapping of the CS. The primary endpoint is a composite of death and nonplanned HF hospitalization. Patients are followed for a minimum of 2 years and until 264 primary endpoints occurred. Analyses will be conducted according to the intention-to-treat principle. Enrollment for this trial began in March 2018, and per April 2023, a total of 823 patients have been included. Enrollment is expected to be complete by mid-2024. The DANISH-CRT trial will clarify whether mapping-guided positioning of the LV lead according to the latest local electrical activation in the CS is beneficial for patients in terms of reducing the composite endpoint of death or nonplanned hospitalization for heart failure. Results from this trial are expected to impact future guidelines on CRT. NCT03280862.

P256 AN UNUSUAL CASE OF PACEMAKER MALFUNCTION WITH NON COMMON ELCTROCARDIOGRAPHIC PRESENTATION AND UNEXPECTED ECHOCARDIOGRAPHIC FINDING

Abstract This clinical case shows the diagnostic challenge and the management of a 79 y–o male with recent hospitalization for infero–lateral STEMI undergoing primary PCI of Right Coronary Artery with 2 DES and following DDDR MRI PM (pacemaker) implantation due to the development of persistent 2:1 Atrio–Ventricular Block. One month later, admission at Emergency Department for syncope. Normal parameters were found at laboratory analyses. The electro–stimulator activity evaluation showed a PM malfunction with ventricular capture failure. Thus, the increase of PM output up to electric ventricular capture (8 Volt/120 msec) was performed, but the following Electrocardiogram showed a PM–induced rhythm with RBBB–morphology. Then, the bedside Echocardiogram showed an apparent presence of a linear hyper–echogenic image into left ventricle with no inter–ventricular septal defect neither inter–ventricular shunt, inter–atrial septal hypermobility with no evident inter–atrial shunt at rest; while a chest Radiography identified the atrial and ventricular leads with no accurate individuation of their position. The patient was admitted in Intensive Cardiac Care Unit with confirmation of intermittent failure to ventricular capture and RBBB–morphology during PM–induced rhythm at telemetry monitoring. Due to Electrocardiographic and Echocardiographic findings, a strong suspect of abnormal position of the ventricular lead into left ventricle through a possible PFO has been raised. A chest Computed Tomography was performed confirming the anomalous position of the ventricular lead: it reached the left atrium through an inter–atrial defect/patent foramen ovale (PFO), then crossing the mitral valve up to left ventricle. The PM–lead repositioning was scheduled two days after. After positioning of temporary stimulator lead in right ventricle, the ventricular lead has been withdrawn from left–side chambers and positioned into septal–apical right ventricle; furthermore, the position of right atrial lead has been optimized (because of frequent spontaneous passage to the left atrium through the PFO, during manual maneuvers) thus obtaining good stability of the device. During the following days, the telemetry monitoring showed a PM–induced rhythm, without capture nor sensing failure. The chest Radiography confirmed the correct position of leads and the pre–discharge Echocardiography showed a LVEF 57% with no valvular pathology and with atrial and ventricular leads into right–side chambers.

Association between left ventricular lead position and intrinsic QRS morphology with regard to clinical outcome in cardiac resynchronization therapy for heart failure.

Left ventricular (LV) lead position may be an important factor for delivering effective cardiac resynchronization therapy (CRT). We therefore aimed to evaluate the effects of LV lead position, stratified by native QRS morphology, regarding the clinical outcome. A total of 1295 CRT-implanted patients were retrospectively evaluated. LV lead position was classified as lateral, anterior, inferior, or apical, and was determined using the left and right anterior oblique X-ray views. Kaplan Meier and Cox regression were performed to evaluate the effects on all-cause mortality and heart failure hospitalization, and the potential interaction between LV lead position and native ECG morphologies. A total of 1295 patients were included. Patients were aged 69 ± 7 years, 20% were female, 46% received a CRT-Pacemaker (vs. CRT-Defibrillator), mean LVEF was 25% ± 7%, and median follow-up was 3.3 years [IQR 1.6-5-7 years]. Eight hundred and eighty-two patients (68%) had a lateral LV lead location, 207 (16%) anterior, 155 (12%) apical, and 51 (4%) inferior. Patients with lateral LV lead position had larger QRS reduction (-13 ± 27 ms vs. -3 ± 24 ms, p < .001). Non-lateral lead location was associated with a higher risk for all-cause mortality (HR 1.34 [1.09-1.67], p = .007) and heart failure hospitalization (HR 1.25 [1.03-1.52], p = .03). This association was strongest for patients with native left or right bundle branch block, and not significant for patients with prior paced QRS or nonspecific intraventricular conduction delay. In patients treated with CRT, non-lateral LV lead positions (including apical, anterior, and inferior positions) were associated with worse clinical outcome and less reduction of QRS duration. This association was strongest for patients with native LBBB or RBBB.

P416 A RARE CASE OF CHEST PAIN

Abstract 81–year–old woman, affected by arterial hypertension, paroxysmal atrial fibrillation treated with DOACs. She came to our emergency service for oppressive chest pain emerging after two weeks from the implantation of a dual–chamber pacemaker. The EKG showed 1 mm ST segment elevation in leads DII and aVL. Global and segmental function were normal, mild pericardial effusion along right chambers was reported on the echocardiogram. This case was managed as a STE–ACS and then the patient was given dual antiplatelet therapy and unfractioned heparin and taken to the cath lab. The coronary angiography didn’t show any significant stenosis. She was admitted to CCU, where pericardial effusion was noticed to be significantly increased. A CT scan revealed the ventricular pacemaker lead projecting into the pericardial sac with a 13 mm hemorrhagic pericardial effusion. Antithrombotic therapy was stopped and colchicine was started. The patient refused to undergo a trans–venous lead extraction. She was asymptomatic and hemodinamically stable at the time of discharge and was given a follow up program. This case shows a subacute complication of pacemaker implantation, in which antithrombotic agents administration made the real diagnosis to be shown after the increase of pericardial effusion. Ventricular lead perforation is a rare condition (0.1–0.8%). Some risk factors can be old age, female sex, anticoagulants, DMARDs and NSAIDs, the ventricular lead being positioned along the right ventricular free wall. Symptoms and signs depend on lead position. Diagnosis can be made by echocardiography, chest X–ray, CT scan. The best treatment for this patients is debated. In hemodinamically unstable patients an emergency treatment is recommended, while it is unclear which therapeutic option should be offered in the other cases. Lead perforation can be managed with transvenous or surgical lead extraction or a conservative treatment with a watchful waiting strategy can be performed. Acute, subacute and symptomatic perforations could better benefit from invasive strategies, otherwise chronic and asymptomatic cases could be followed up during time without invasive treatment.

PO-04-080 AN UNUSUAL CASE OF LEFT BUNDLE BRANCH AREA PACING LEAD MALFUNCTION

Left Bundle Branch Area Pacing (LBBAP) is being used for conduction system/physiological pacing. It is important to be aware of manifestations and causes of LBBAP lead malfunction. Identify set screw and connector block damage as a cause of LBBAP lead malfunction with varying pacing parameters. N/A 78 years old lady with dual chamber permanent pacemaker for sick sinus syndrome developed progressive rate related left bundle branch block with left ventricular (LV) systolic dysfunction. She underwent upgrade to a cardiac resynchronization therapy-pacemaker device with addition of LBBAP lead (SelectSecure 3830 Medtronic lead) with confirmation of lead position by typical LBBAP parameters and demonstration of optimal septal penetration on contrast administration (Figure). Unipolar and bipolar lead tip impedance was found to be extremely elevated at follow-up interrogation with elevated LBBAP threshold. Over the next few weeks, LBBAP lead impedance varied between 1000 to >3000 Ohms with variable capture threshold 1.2 to >5 Volt at 0.4 milliseconds (ms) (Figure). Bipolar pacing at capture threshold was septal morphology with only variable typical LBBAP pattern, consistent with anodal capture. LBBAP lead position appeared stable on chest X-ray and transthoracic echocardiogram without clear lead discontinuity. Available near-field electrogram (EGM) on device interrogation showed no noise with provocative maneuvers. Patient underwent elective lead revision. Trans esophageal echocardiogram (TEE) prior to pocket access confirmed stable lead position with adequate septal penetration without protrusion into LV (Figure). On opening the pocket, the 3830 lead was found to be minimally retracted in the header and was easily pulled out manually. Lead parameters including sensing, impedance and capture threshold were normal with selective LBBAP and local LBB potential (Figure). The lead remained loose within the header after set screw deployment. These findings were reproduced with right ventricular (model 5076) lead indicating set screw failure. A new pacemaker generator was implanted with consistently stable LBBAP parameters on follow-up. The explanted generator analysis showed LV setscrew socket and connector block damage (Figure). Set screw failure is a rare cause of pacemaker lead failure. LBBAP lead set screw failure may manifest in an atypical manner without lead noise and should be suspected in acute lead malfunction.

PO-03-200 THE RESPONSE TO AJMALINE PROVOCATION IN HEALTHY SUBJECTS

The electrocardiographic (ECG) response to diagnostic ajmaline provocation (AP) testing has been studied extensively in clinical cohorts. However, the healthy ECG response has not been described. We undertook a trial examining ECG changes in response to AP in a cohort of systematically recruited asymptomatic Caucasian healthy subjects with no family history of sudden death and normal baseline ECG and echocardiogram. Applicants responded to a national recruitment advertisement and completed an online medical questionnaire. Those fulfilling inclusion criteria were invited to undergo further evaluation with eligible subjects undergoing a diagnostic ajmaline challenge (1mg/kg, max. 100mg over 5 minutes). A continuous ECG was recorded in the standard and high right precordial lead (HRPL) position. Automated analysis of conventional and novel ECG measurements were made at baseline and at peak drug effect, which was defined as the point of maximum QRS duration (excluding precordial leads). One hundred healthy Caucasian subjects underwent AP. The mean age was 26.84 years (SD ± 8.01 years) and 52% were male. A drug induced type 1 Brugada pattern (DI-T1BP) was observed in 3/100 (3%) of the cohort. We performed a paired comparison of ECG measures at baseline versus peak drug effect (Table 1). AP had a similar effect on global QRS duration and global PR interval, with both increasing by 28%, mean delta 25.66ms and mean delta 43.36ms respectively. Changes in S wave parameters in lead II were pronounced, with a 97% increase in S wave duration and a 101% increase in S wave negative amplitude. ST-J point elevation in the anterior, inferior, and lateral regions was comparable, with a 57%, 51% and 57% increase in ST-J amplitude respectively. AP had a greater effect on cardiac conduction in females compared to males (Figure 1). In contrast, changes in STJ point amplitude and combined and segmented QRST segment area were greater in males. The healthy ECG response to AP elicits a pronounced effect on cardiac conduction, more so in females compared to males, whilst changes in STJ point amplitude and QRST area were greater in male subjects. A DI-T1BP is part of the healthy response to AP.Tabled 1Table 1. Paired analysis of baseline and peak ajmaline effect ECG characteristicsECG CharacteristicsMean at baseline (SD)Mean at Peak Ajmaline Effect (SD)Mean Delta = peak - baseline (SD)% ChangeP value*Global QRS duration ms90.42 (10.59)116.06 (12.06)25.66 (11.98)28.38<0.01Global T wave duration ms210.48 (24.96)225.48 (25.53)15.00 (20.53)7.13<0.01Global PR interval ms153.14 (19.45)196.50 (25.10)43.36 (17.27)28.31<0.01Global QT interval ms408.66 (33.03)414.38 (23.70)5.72 (18.62)1.40<0.01Global RR interval ms958.39 (197.57)813.98 (130.64)-144.41 (154.18)-15.06<0.01Global P wave duration ms102.74 (10.82)121.78 (13.58)19.04 (15.38)18.53<0.01Precordial Tpeak to Tend interval ms75.39 (27.28)81.88 (29.30)6.49 (39.29)8.610.07Precordial QRS duration ms85.59 (8.89)107.69 (11.10)22.10 (8.34)25.82<0.01Precordial T wave duration ms174.48 (24.53)199.81 (26.12)25.33 (26.33)15.00<0.01Anterior STJ amplitude uV47.97 (31.20)75.55 (48.44)27.58 (27.70)57.49<0.01Inferior STJ amplitude uV24.06 (21.97)36.46 (36.96)12.40 (26.33)51.54<0.01Lateral STJ amplitude uV34.45 (21.15)54.33 (30.79)19.89 (18.84)57.74<0.01Precordial QRS area mv/ms-409.59 (242.18)-613.71 (367.56)-204.12 (183.69)48.78<0.01Precordial QRST area mv/ms1481.06 (508.03)1838.87 (681.75)357.82 (278.89)24.32<0.01Precordial T wave area mv/ms483.66 (394.14)606.11 (453.04)122.45 (225.60)25.00<0.01Precordial STJ to Tpeak area mv/ms505.59 (230.36)543.71 (228.57)38.12 (103.28)8.00<0.01Precordial Tpeak to Tend area mv/ms258.31 (110.68)311.07 (147.60)52.76 (74.02)19.23<0.01S wave duration in lead I ms21.53 (15.55)36.01 (19.35)14.48 (14.07)67.25<0.01S wave duration in lead II ms17.34 (14.50)34.24 (20.33)16.90 (14.13)97.46<0.01S wave amplitude in lead I uV-189.09 (172.35)-290.47 (234.30)-110.38 (120.50)61.29<0.01S wave amplitude lead II uV-147.23 (197.92)-298.25 (255.25)-150.02 (155.93)101.89<0.01Inferior J wave amplitude uV43.31 (92.62)25.69 (57.06)-17.62 (68.55)-40.680.01Lateral J wave amplitude uV19.65 (41.36)10.18 (30.62)-9.47 (42.11)-48.190.03Anterior J wave amplitude uV0.77 (4.41)2.31 (7.42)1.55 (6.42)201.290.02 Open table in a new tab

PO-04-084 LOW SHOCK IMPEDANCE OF SUBCUTANEOUS IMPLANTABLE CARDIAC DEFIBRILLATOR (S-ICD) IN THE SETTING OF ACUTE DECOMPENSATED HEART FAILURE

Shock impedance represents the resistance between the coil and generator of subcutaneous ICDs. It is an important metric to predict device defibrillation success. Several factors have been implicated in determining system impedance of S-ICDs such as generator-lead distance, body habitus as well as generator position (subcutaneous vs. intermuscular pocket). We present a case report highlighting the impact of volume status on shock impedance. N/A A 60-year-old female presents to the office. She has a past medical history of obesity, Heart Failure with Preserved Ejection Fraction (HFpEF), ventricular fibrillation followed by implantation of transvenous ICD. This was complicated by device infection requiring device extraction and implantation of S-ICD. She has been having progressive shortness of breath with minimal exertion weeks prior to presentation. She denied chest pain, palpitations or dizziness but endorsed generalized fatigue as well as significant weight gain. She usually weighs around 165-170 lbs, but was 220 lbs on presentation. Her physical exam was remarkable for elevated jugular venous pressure, anasarca with crackles in the lung bases as well as abdominal ascites and lower extremity edema. Interrogation of her device was performed which showed no significant arrythmias. However, device detected low system impedance of <30 ohms. Her previous interrogation about 3 months earlier showed impedance of 50 Ohms. She was admitted for inpatient intravenous diuresis. Chest radiograph demonstrated normal position of the generator in the posterolateral chest wall and normal lead position in the parasternal area. Serial device interrogations were performed during the hospitalization showing gradual improvement in system impedance up to 45 Ohms once euvolemia was achieved (Figure 1). Due to improvement in shock impedance with diuresis, defibrillation threshold testing (DFT) was deferred and patient was discharged home in stable condition. Her repeat interrogation at follow up showed an impedance of 60 ohms. In the setting of heart failure exacerbation, excess fluid accumulation in the chest and abdominal cavities may result in a decrease in S-ICD shock impedance. Interpretation of device impedance should factor in patient’s volume status. Further studies are needed to ascertain if low impedance caused by fluid overload can impact device defibrillation success rate.

The role of contractile dyssynchrony in pacing-induced cardiomyopathy: detailed assessment using index of contractile asymmetry

AimsThe pathophysiological effects of chronic right ventricular pacing and the role of right ventricular lead position are not well understood. Therefore, we investigated the association between left ventricular contractile dyssynchrony and pacing-induced cardiomyopathy (PICM) in patients with chronic right ventricular pacing. Furthermore, we assessed the association between right ventricular lead location and left ventricular contractile dyssynchrony.MethodsThis was a retrospective study using data from 153 pacemaker patients with normal (≥ 50%) pre-implant left ventricular ejection fraction (LVEF). Baseline and follow-up echocardiograms were analyzed, and PICM was defined as LVEF < 50% with ≥ 10% decrease in LVEF after pacemaker implantation. Relative index of contractile asymmetry (rICA), a novel strain rate-based method, was calculated to quantify left ventricular contractile dyssynchrony between opposing walls in the three apical views. Right ventricular lead position was categorized into anterior septum, posterior septum, free wall, and apex based on contrast-enhanced cardiac computed tomography.ResultsForty-seven (31%) developed PICM. Overall contractile dyssynchrony, measured by mean rICA, was higher in the PICM group compared with the non-PICM group (1.19 ± 0.21 vs. 1.03 ± 0.19, p < 0.001). Left ventricular anterior-inferior dyssynchrony, assessed in the apical two-chamber view, was independently associated with PICM (p < 0.001). Thirty-seven (24%) leads were implanted anterior septal, 11 (7.2%) posterior septal, 74 (48.4%) apical, and 31 (20.3%) free wall. Left ventricular anterior-inferior dyssynchrony was significantly different between the four pacing lead locations (p < 0.01) with the highest rICA observed in the posterior septal group (1.30 ± 0.37).ConclusionsPICM is significantly associated increased contractile dyssynchrony assessed by rICA. This study suggests that especially left ventricular dyssynchrony in the anterior-inferior direction is associated with PICM, and pacing the right ventricular posterior septum resulted in the highest degree of anterior-inferior dyssynchrony. Quantification of left ventricular dyssynchrony by rICA provides important insights to the potential pathophysiology of PICM and the impact of right ventricular lead position.Graphical

PO-05-011 IMMUNOSUPPRESSIVE THERAPY WAS ASSOCIATED WITH LEAD DISLODGEMENT AFTER CARDIAC IMPLANTABLE ELECTRONIC DEVICE IMPLANTATION

Lead dislodgement is one of the severe complications in cardiac implantable electronic device (CIED) implantation. After CIED implantation, adhesions are formed between leads and tissues by inflammation, and as a result, leads are fixed in vessels. In patients with immunosuppressive therapy, such as steroids or immunosuppressant usage, adhesion is inhibited by anti-inflammatory effects. However, no studies have investigated the association between lead dislodgement and immunosuppressive therapy. We hypothesized that lead dislodgement more frequently occurs in patients with immunosuppressive therapy than those without. The purpose of this study was to investigate the association between lead dislodgement and immunosuppressive therapy. In total, 632 consecutive patients who underwent initial CIED implantation or lead addition (age, 76 ± 11 years; male, 365 [58%], high voltage device, 106 [17%], lead addition, 18 [3%]) were retrospectively enrolled. Lead placement was guided by fluoroscopy, and active fixation leads were used in all patients. Chest tape were removed at 1 week after the procedure. Lead dislodgement was defined as a change in the lead position requiring reoperation. As immunosuppressive therapy, 14 (2%) patients used steroids regularly, and 7 (1.1%) used immunosuppressant. Lead dislodgement occurred in 9 (1.4%) patients. Lead dislodgement more frequently occurred in patients with steroids usage than those without (7 (1%) versus 2 (14%), p<0.001). Similarly, lead dislodgement more frequently occurred in patients with immunosuppressant usage than those without (7 (1%) vs 2 (28%), p<0.001). In patients with CIED implantation or lead addition, lead dislodgement more frequently occurred in patients with steroids usage or immunosuppressant usage than those without.

ELFPIE: an error-laxity Fourier ptychographic iterative engine

We present a simple but efficient and robust reconstruction algorithm for Fourier ptychographic microscopy, termed error-laxity Fourier ptychographic iterative engine (Elfpie), that is simultaneously robust to (1) noise signal (including Gaussian, Poisson, and salt & pepper noises), (2) problematic background illumination problem, (3) vignetting effects and (4) misaligning of LED positions, without the need of calibrating or recovering these system errors. In Elfpie, we embed the inverse problem of FPM under the framework of feature extraction/recovering and propose a new image gradient-based data fidelity cost function regularized by the global second-order total-variation regularization. The closed-form complex gradient for the cost function is derived and is back-propagated using the AdaBelief optimizer with an adaptive learning rate. The Elfpie was tested on both simulation and experimental data. In general, compared against SOTA methods, the Elfpie is robust to Gaussian noise with a 100 times larger noise, salt & pepper noise with 1000 times larger noise and Poisson noise with 10 times larger noise. The Elfpie is able to reconstruct high-fidelity samples under LED position misalignments up to 2 mm. It can also bypass the vignetting effect, for which all SOTA methods fail to reconstruct the sample pattern. The MATLAB code for ELFPIE is available on Github.

Precision Mapping of Thalamic Deep Brain Stimulation Lead Positions Associated With the Microlesion Effect in Tourette Syndrome.

The microlesion effect refers to the improvement of clinical symptoms after deep brain stimulation (DBS) lead placement and is suggested to indicate optimal lead placement. Very few studies have reported its implications in neuropsychiatric disorders. To evaluate the magnitude of the microlesion effect in Tourette syndrome and the relationship between the microlesion effect and the anatomic location of implanted DBS leads. Six male patients were included. Their median age at surgery and follow-up period were 25 years (range, 18-47) and 12 months (range, 6-24), respectively. All patients were videotaped pre- and postoperatively, and tic frequencies were counted. We also analyzed the precision of lead placement and evaluated the normative connectome associated with the microlesion area. The microlesion effect was observed as an improvement in tic symptoms in all patients, and the long-term clinical outcomes were favorable. The median motor tic frequency was 20.2 tics/min (range, 9.7-60) at baseline and decreased to 3.2 tics/min (1.2-11.3) in patients on postoperative day 1 ( P = .043) and to 5.7 tics/min (range, 1.9-16.6) in patients on postoperative day 7 ( P = .028). Phonic tic tended to improve immediately after surgery although the changes were not significant. Image analyses revealed that the precise position of the electrode was directed toward the anteromedial centromedian nucleus. Normative connectome analysis demonstrated connections between improvement-related areas and wide areas of the prefrontal cortex. This study shows that the microlesion effect may seem as an immediate improvement after optimal DBS lead placement in patients with Tourette syndrome.

Minimally invasive epicardial left-ventricular lead implantation and simultaneous left atrial appendage closure.

Atrial fibrillation (AF) is common in patients with heart failure resulting in a high prevalence of AF in patients receiving Cardiac Resynchronization Therapy (CRT) implantation. In patients, unsuitable for transvenous left ventricular (LV)-lead implantation, epicardial LV-lead implantation represents a valuable alternative. Epicardial LV-lead placement can be achieved totally thoracoscopical or via minimally invasive left lateral thoracotomy. In patients with atrial fibrillation, concomitant left atrial appendage (LAA) clipping is feasible via the same access. Therefore, the aim of our study was the analysis of safety and efficacy of epicardial LV lead implantation and concomitant LAA clipping via minimally invasive left-lateral thoracotomy. Between December 2019 and March 2022, 8 patients received minimally invasive left atrial LV-lead implantation with concomitant LAA closure using the AtriClip. Transesophageal echocardiography (TEE) was performed to intraoperatively guide and control LAA closure. Mean patients age was 64 ± 11.2 years, 67% were male patients. Minimally invasive left-lateral thoracotomy was used in 6 patients while a totally thoracoscopic approach was performed in 2 cases. Epicardial lead implantation was successfully performed in all patients with good pacing threshold (mean 0.8 ± 0.2 V) and sensing values (10.1 ± 2.3 mV). Posterolateral position of the LV lead was achieved in all patients. Furthermore, successful LAA closure was confirmed during TEE in all patients. No procedure-related complications occurred in any of the patients. Two patients additionally received simultaneous laser lead extraction during the same procedure. Complete lead extraction was achieved in both patients. All patients were extubated in the OR and had an uneventful postoperative course. Our study highlights a novel treatment approach for patients with atrial fibrillation and the necessity of epicardial LV leads. Placement of a posterolateral LV lead position with concomitant occlusion of the left atrial appendage via a minimally-invasive left-lateral thoracotomy or even a totally thoracoscopic approach is safe and feasible with superior cosmetic result and complete occlusion of the left atrial appendage.

Long-term outcomes of pacemaker implantation in children with univentricular versus complex biventricular surgical repair.

Pacing in a univentricular circulation has been associated with worsened outcomes. We investigated the long-term outcomes of pacing in children with a univentricular circulation compared to a complex biventricular circulation. We also identified predictors of adverse outcomes. A retrospective study of all children with major congenital heart disease who underwent pacemaker implantation under the age of 18 years between November 1994 and October 2017. Eighty-nine patients were included; 19 with a univentricular and 70 with a complex biventricular circulation. A total of 96% of pacemaker systems were epicardial. Median follow up was 8.3 years. The incidence of adverse outcome was similar between the two groups. Five (5.6%) patients died and two (2.2%) underwent heart transplantation. Most adverse events occurred within the first 8 years after pacemaker implantation. Univariate analysis identified five predictors of adverse outcomes in the patients in the biventricular but none in the univentricular group. The predictors of adverse outcome in the biventricular circulation were a right morphologic ventricle as the systemic ventricle, age at first congenital heart disease (CHD) operation, number of CHD operations, and female gender. The nonapical lead position was associated with a much higher risk of an adverse outcome. Children with a pacemaker and a complex biventricular circulation have similar survival to the ones with a pacemaker and a univentricular circulation. The only modifiable predictor was the epicardial lead position on the paced ventricle, emphasizing the importance of apical placement of the ventricular lead.

Update in LV Only Fusion CRT Pacing: Annals and Future Perspectives.

Triple-chamber cardiac devices are utilized for cardiac resynchronization therapy (CRT) and is the standard-of-care therapy for heart failure (HF) patients in the current guidelines. In the setting of biventricular (BIV) pacing it involves a mandatory implantation of right ventricular (RV) lead that allows simultaneous BIV pacing with 0 ms VV (ventricular to ventricular) interval. Nevertheless, it seems that response to CRT is not related to RV lead position. RV pacing is known for deleterious effects on RV/Left Ventricle (LV) function and should not be used in persons with normal atrioventricular conduction (AV) and sinus rhythm. As it compensates for the additional asynchrony induced by unnecessary stimulation of RV pacing, only pacing the left ventricle (LV) may result in improved cardiac resynchronization therapy (CRT) outcomes and a decrease in the number of individuals who do not respond to the procedure. Furthermore, leadless LV fusion CRT pacing without RV lead could be a potential CRT therapy alternative to BIV pacing in nonischemic heart failure patients with preserved AV conduction. The aim of our study is to made an update in cardiac resynchronization therapy with LV only fusion pacing.

262 AN UNUSUAL CAUSE OF PACEMAKER MALFUNCTION WITH NON-COMMON ELECTROCARDIOGRAPHIC PRESENTATION AND UNEXPECTED ECHOCARDIOGRAPHIC FINDING

Abstract This clinical case shows the diagnostic challenge and the management of a 79 y-o male with arterial hypertension, tabagism, obesity and a recent hospitalization for infero-lateral STEMI undergoing primary PCI of Right Coronary Artery with 2 DES and following DDDR MRI PM (pacemaker) implantation (through left cephalic vein) due to the development of persistent 2:1 AV block (atrio-ventricular block). One month later, admission at Emergency Department for syncope. The admission therapy included Aspirin plus Clopidogrel, Ramipril, Atorvastatin. Normal parameters were found at laboratory analyses. The electro-stimulator activity evaluation showed a PM malfunction with ventricular capture failure. Thus, the increase of PM output up to electric ventricular capture (8 Volt/120 msec) was performed, but the following Electrocardiogram (ECG) showed a PM-induced rhythm with RBBB-morphology. Then, the bedside Echocardiogram showed an apparent presence of a linear hyper-echogenic image (lead?) into left ventricle with no inter-ventricular septal defect neither inter-ventricular shunt, inter-atrial septal hypermobility with no evident inter-atrial shunt at rest; while a chest Radiography identified the atrial and ventricular leads with no accurate individuation of their position. The patient was admitted in Intensive Cardiac Care Unit with confirmation of intermittent failure to ventricular capture and RBBB-morphology during PM-induced rhythm at telemetry monitoring. Due to Electrocardiographic and (above all) Echocardiographic findings, a strong suspect of abnormal position of the ventricular lead into left ventricle through a possible PFO has been raised. A chest Computed Tomography was performed confirming the anomalous position of the ventricular lead: the atrial lead was in the right atrium whereas the ventricular lead reached the left atrium through an inter-atrial defect/patent foramen ovale (PFO), then crossing the mitral valve up to left ventricle. The PM-lead repositioning was scheduled two days after. With intra-operative fluoroscopy, a further verify of leads position was observed (the ventricular one into left ventricle through PFO and mitral valve, the atrial one mildly displaced upwards) and the leads repositioning was performed. After positioning of temporary stimulator lead in right ventricle, the ventricular lead has been withdrawn from left-side chambers and positioned into septal-apical right ventricle; furthermore, the position of right atrial lead has been optimized (because of frequent spontaneous passage to the left atrium through the PFO, during manual maneuvers). Finally, the optimal stability of the device was obtained, as well as the optimal atrial and ventricular capture during stimulation test. During the observation in Cardiology Unit in following days, the telemetry monitoring and ECG showed a PM-induced rhythm, without capture nor sensing failure. The chest Radiography confirmed the correct position of atrial and ventricular leads. Finally, the pre-discharge transthoracic Echocardiography showed a LVEF 57% with no valvular pathology nor pericardial effusion, and with atrial and ventricular leads into right-side chambers.

571 SUCCESSFUL PERMANENT PACEMAKER IMPLANTATION IN A PATIENT WITH DEXTROCARDIA AND SITUS INVERSUS TOTALIS: LOOKING AT THE MIRROR.

Abstract Background Dextrocardia is a rare congenital condition with a prevalence of 0.83 per 10000 pregnancies. Its most common configuration is situs inversus totalis, also known as “mirror-image dextrocardia”. This case report presents a clinical case of symptomatic sinus node dysfunction requiring permanent pacemaker implantation (PPI) in a patient with mirror-image dextrocardia. Case summary A 81-year-old female patient with known situs inversus totalis presented with recurrent syncope. Sick sinus syndrome was diagnosed after documentation of critical pauses (&amp;gt;6.3”) at 24-hour Holter monitoring, giving indication to elective PPI. At admission, 12-lead ECG showed sinus bradycardia and right axis deviation on the frontal plane (standard peripheral leads position and precordial leads on the right side of the chest). Transthoracic echocardiography was performed prior to the procedure with the ultrasound probe flipped and placed on the patient's right side of the thorax, thus achieving standard echocardiography windows and images. A preserved biventricular systolic function and the absence of relevant valvular disease or cardiac malformations was documented. The next day, a dual-chamber pacemaker was implanted following standard technique with the operator standing on the right side of the patient and with right subclavian vein puncture; the pacemaker pocket was created in the right pectoral region. The entire procedure was performed under fluoroscopic guidance using horizontally 180° flipped views, therefore obtaining identical images to those of standard PPI procedures, helping the operator identify anatomical structures during lead positioning. [Fig. 1 a - b] Chest X-ray confirmed correct pacemaker lead placement and absence of procedure-related complications. Stable and satisfactory lead parameters were observed at follow-up. Discussion In literature there are only a few case reports on PPI in situs inversus totalis. The symmetrical disposition of the anatomy makes transvenous PPI technically demanding. In this case the challenge was overcome by using flipped fluoroscopy images, to facilitate lead positioning maneuvres. This technique can be considered only in situs inversus totalis and not in other forms of dextrocardia, such as dextroversion and destroposition, because it is the only situation in which the anatomy is the mirror image of the normal one.

Three-dimensional electroanatomical mapping guided right bundle branch pacing in congenitally corrected transposition of great arteries.

The ideal pacing strategy has been the Achilles' heel for patients with congenitally corrected transposition of great arteries (ccTGA) with bradycardia. Various pacing modalities were documented in the literature. This article describes a novel pacing strategy and its feasibility in ccTGA with an intact ventricular septum. We prospectively recruited three patients with ccTGA who presented with symptomatic complete heart block to our institute and were evaluated. All patients were planned for conduction system pacing. Those who had more than moderate or severe systemic atrioventricular regurgitation and systemic ventricular dysfunction were planned for conduction system pacing with an additional lead in the coronary sinus (CS) tributary, i.e. bundle branch pacing optimized cardiac resynchronization therapy with the intention to achieve incremental benefit. Since right bundle pacing is not described previously and in view of anatomical complexity in location, three-dimensional (3D) anatomical mapping was done with the EnSite system and later right bundle capture is identified conventionally as that of a left bundle in a normal heart. All three patients have stable lead positions and adequate thresholds at short-term follow-up. In this report, we demonstrated the feasibility of permanent physiological pacing of the systemic ventricle by capturing the right bundle with 3D anatomical mapping guidance, which results in physiological activation of the systemic ventricle.

Risk of Pacing-Induced Cardiomyopathy in Patients with High-Degree Atrioventricular Block-Impact of Right Ventricular Lead Position Confirmed by Computed Tomography.

Prospective studies applying fluoroscopy for assessment of right ventricular (RV) lead position have failed to show clear benefits from RV septal pacing. We investigated the impact of different RV lead positions verified by computed tomography (CT) on the risk of pacing-induced cardiomyopathy (PICM). We retrospectively included 153 patients who underwent routine fluoroscopy-guided pacemaker implantation between March 2012 and May 2020. All patients had normal pre-implant left ventricular ejection fraction (LVEF). Patients attended a follow-up visit including contrast-enhanced cardiac CT and transthoracic echocardiography. Patients were classified as septal or non-septal based on CT analysis. The primary endpoint was PICM (LVEF < 50% with ≥10% decrease after implantation). Based on CT, 48 (31.4%) leads were septal and 105 (68.6%) were non-septal. Over a median follow-up of 3.1 years, 16 patients (33.3%) in the septal group developed PICM compared to 31 (29.5%) in the non-septal group (p = 0.6). Overall, 13.1% deteriorated to LVEF ≤ 40%, 5.9% were upgraded to cardiac resynchronization therapy device, and 14.4% developed new-onset atrial fibrillation, with no significant differences between the groups. This study demonstrated a high risk of PICM despite normal pre-implant left ventricular systolic function with no significant difference between CT-verified RV septal or non-septal lead position.

Awake Versus Asleep Subthalamic Nucleus Deep Brain Stimulation in Parkinson’s Disease: Comparison of Normalised Target Accuracy and Clinical Outcomes

Traditionally, studies comparing awake and asleep Deep Brain Stimulation (DBS) for estimation of accuracy have measured the deviation of final lead position from the intended position, as opposed to the distance from actual target location. This allows introduction of bias in accuracy assessment.