Case report: Unusual cause of refractory hypoxemia after pacemaker lead extraction.

A 59-year-old woman with a history of a pacemaker implanted for III-degree atrioventricular block was admitted due to pocket infection. The atrial and ventricular leads were removed via the right femoral vein using a needle's eye snare. Hypoxemia was observed immediately after the removal of the lead. It was refractory to oxygen therapy. The pulse oxygen saturation (SpO2) showed 89% in the supine position and 77% in the upright position. However, the CTPA and pulmonary perfusion SPECT/CT imaging did not reveal any signs of pulmonary embolism. Pulmonary function tests and chest CT showed normal results. Transthoracic contrast echocardiography revealed a patent foramen ovale (PFO) and a right-to-left intracardiac shunt, no significant tricuspid regurgitation, without any signs of elevated right heart pressure or pulmonary hypertension. Hypoxemia was considered to be associated with the right-to-left shunt through PFO. The condition was relieved by percutaneous closure of the PFO. Refractory hypoxemia resulting from an intracardiac right-to-left shunt following pacemaker lead extraction is a rare but serious complication. Transthoracic contrast echocardiography helps in diagnosis. If the right-to-left intracardiac shunt through PFO persists irreversibly and the associated hypoxemic symptoms are significant, closure of the PFO is necessary. Transesophageal echocardiography also revealed the presence of a left-to-right shunt through PFO during cardiac systole. The closure of the PFO is also necessary to avoid long-term complications, such as chronic pulmonary hypertension and right heart failure.

The safety and efficiency of fluoroless site-specific transseptal puncture guided by three-dimensional intracardiac echocardiography.

BACKGROUND: Although fluoroless transseptal puncture (TSP) guided by intracardiac echocardiography (ICE) has been used for many years, there are no reports of an accurate site-specific method for TSP in detail, especially about the safety and efficiency of the method. This study aimed to compare the efficacy and safety of TSP guided by three-dimensional ICE using a fluoroless site-specific method with that of the conventional fluoroless method in patients with atrial fibrillation (AF). METHODS: This prospective study included 60 patients with AF scheduled for radiofrequency ablation who were assigned to undergo modified fluoroless site-specific TSP (SS-ICE group, n = 30) or conventional fluoroless TSP (C-ICE group, n = 30). TSP was guided by three-dimensional ICE in both study groups. RESULTS: All fluoroless TSP were performed successfully in both groups. There were no significant differences in patient characteristics, Pre-TSP time (11.3 ± 1.7 min vs. 11.1 ± 1.6 min, P = 0.822) and TSP time (3.4 ± 0.9 min vs. 3.5 ± 1.1 min, P = 0.772) between the SS-ICE group and the C-ICE group. The distance between the actual traversing point and the presetting point in the fossa ovalis was less than 5 mm in 87% of patients (26/30, 3.1 ± 1.2 mm) in the SS-ICE group. There were no TSP-related complications in either group. CONCLUSION: SS-ICE method is a simple, safe, and effective approach for fluoroless site-specific TSP.

Initial Experience in Transvenous Implantation of a Left Ventricular Lead With a Novel Venogram Balloon Catheter.

Aim: The most challenging and time-consuming stage of cardiac resynchronization therapy (CRT) device implantation is coronary sinus (CS) cannulation and left ventricular epicardial electrode implantation. This paper reports the initial clinical experience of CS cannulation and left ventricular lead implantation guided by a novel venogram balloon catheter (Lee's venogram balloon catheter). Methods and Results: Consecutive patients eligible for CRT were deemed suitable for this novel venogram balloon catheter. Parameters such as left ventricular lead implantation time, procedure time, and fluoroscopy time were recorded. CS cannulation with LV lead implantation guided by Lee's venogram balloon catheter was successful in all 5 patients, including 4 challenging cases. The total fluoroscopy and procedural durations were 5.0 ± 3.0 and 57.4 ± 12.5 min, respectively. No adverse catheter-related events occurred during the procedures. Conclusion: This initial study of an innovative venogram balloon catheter demonstrated that it greatly facilitated CS cannulation and successful LV lead placement in all patients undergoing CRT system implantation. This significantly shortened the learning curve and showed a decrease in left ventricular lead implantation time, procedure time, and fluoroscopy time.

Transfemoral extraction of pacemaker and implantable cardioverter defibrillator leads using Needle's Eye Snare: a single-center experience of more than 900 leads.

The femoral approach with the Needle's Eye Snare (NES) is often used for bailout after failure of the superior approach for transvenous lead extraction (TLE). The safety and efficacy of the NES as a first-line tool for TLE remain unclear. The medical records of patients who underwent TLE via the femoral approach utilizing the NES from May 2014 to June 2019 in Peking University People's Hospital were retrospectively reviewed. Nine hundred and eighty-five leads were extracted in 492 patients (369 men; mean age 72.8 ± 29.0 years). The median (range) number of leads extracted per patient was 2 (1-6). The mean indwelling time of all extracted leads was 112.6 ± 52.0 months. The complete procedure success rate, clinical success rate, and failure rate were 94.1% (463/492), 97.8% (481/492), and 1.1% (11/492), respectively. Major complications including death occurred in nine patients (1.9%), of whom eight developed cardiac tamponade. Among these eight patients, emergency pericardiocentesis followed by rescue surgical repair if necessary was successful in 6 (75.0%) and failed in 2 (25.0%). No significant differences were found in the clinical success rate or major complications rate between patients with pacemakers and implantable cardioverter defibrillators, or between patients with infected and uninfected leads. A femoral approach with the NES is safe and effective for TLE of both pacing and defibrillator leads and could be considered a first-line approach. Cardiac tamponade was the most frequent cardiovascular complication. A strategy of emergency pericardiocentesis followed by a rescue surgical approach seems to be reasonable technique to treat a cardiac tamponade.

Cardiac resynchronization therapy coronary venous left ventricular lead removal and reimplantation: Experience from a single center in China.

The present study aimed to investigate the success rate, methods and associated complications of left ventricular lead (LVL) extraction and venous pathway reimplantation in patients with cardiac resynchronization therapy device/defibrillator (CRT/CRTD). A retrospective analysis was performed in the patients who underwent CRT/CRTD extraction and reimplantation at our hospital from January 2012 to October 2018. The methods, patient complications and success rate of extraction and reimplantation of LVL were analyzed. A total of 54 patients underwent CRT/CRTD removal (pacemaker infection, n=51; LVL dysfunction, n=3; CRT/CRTD, 34/20). A total of 54 LVLs were removed (3 active electrodes and 51 passive electrodes). The average implantation duration of the LVL was 53.5 months (range, 1-204 months), whereas the success rate of the LVL extraction was 100% (94% completely removed and 6% clinically removed. A total of 6 patients (11%) were treated only by manual traction, whereas the remaining patients had their LVL successfully removed using extraction tools. In the peri-operative period, one fatality occurred (2%). The highest complication rate of the lead extraction was 2% and no minor complications were observed. A total of 36 patients were reimplanted on the right side, which was successful in 31 cases (success rate, 86.1%), whereas 3 cases were successfully reimplanted on the left side. The total success rate of LVL reimplantation was 87.2%. The procedure of the LVL removal and reimplantation exhibited a high success rate and a lower incidence of complications compared with that in patients with cardiac devices.

Remodeling of myocardial energy and metabolic homeostasis in a sheep model of persistent atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is the most common progressive cardiac arrhythmia and is often associated with rapid contraction in both atria and ventricles. The role of atrial energy and metabolic homeostasis in AF progression is under-investigated. OBJECTIVES: To determine the remodeling of energy metabolism during persistent AF and the effect of eplerenone (EPL), an aldosterone inhibitor, on metabolic homeostasis. METHODS: A nonsustained atrial pacing sheep model was developed to simulate the progression of AF from paroxysmal to persistent. Metabolomic and proteomic analyses at termination of the experiment were used to analyze atrial tissues obtained from sheep in sham, sugar pill (SP) and EPL-treated groups. RESULTS: Proteomic analysis indicated that compared to the sham group, in SP group, fatty acid (FA) synthesis, FA oxidation, tricarboxylic acid (TCA) cycle processes and amino acids (AAs) transport and metabolism were reduced, while glycolytic processes were increased. In metabolomic analysis, the levels of intermediate metabolites of the glycolytic pathways, including 2-phosphoglyceric acid (2 PG), 1,3-bisphosphoglyceric acid (1,3 PG), and pyruvate, HBP (uridine diphosphate-N-acetylglucosamine, UDP-GlcNAc), TCA (citrate) and AAs were greater while the levels of the majority of lipid classes, including phosphatidic acid (PA), phosphatidylcholine (PC), phosphatidylglycerol (PG), glycerophosphoglycerophosphates (PGP), glycerophosphoinositols (PI) and glycerophosphoserines (PS), were decreased in the atria of SP group than in those of sham group. EPL-pretreatment decreased the expression of glut4 and increased the content of acylcarnitines and lipids, such as lyso phospholipids, phospholipids and neutral lipids. CONCLUSION: In the metabolic remodeling during AF, glucose and lipid metabolism were up- and down-regulated, respectively, to sustain TCA cycle anaplerosis. EPL partialy reversed the metabolic shifting.

Snare sheath versus evolution sheath in transvenous lead extraction.

Lead extraction remains a challenging procedure with significant success. Owing to the increasing use of cardiac implantable electronic devices, there is a growing need for effective techniques management, to avoid the occurrence of device-related complications and lead dysfunction. We made a comparison of Evolution sheath and Needles Eye Snare sheath (abbreviated to Snare sheath) by analyzed the results using two kind of the methods in the Cardiology Center of Peking University People's Hospital. In the retrospective study we evaluated patients who underwent lead extraction from July 2013 to July 2014. Those who underwent lead removal without using evolution or snare were excluded. Primary endpoints included total exposure time, operation time, and complications. Data on clinical characteristics, indications, and outcomes were prospectively collected and analyzed. A total of 76 patients were included in the study (65.8% male; aged 68.1±14.34 years old). Snare and Evolution were used in 59 and 17 patients, respectively. A total of 134 leads were removed with 103 leads (76.87%) extracted using the Snare sheath. Lead age was 10.8±7.0 years. Complete extraction was observed in 67 patients of 124 leads. Evolution sheath was associated with significantly lower complication even after adjustment of the number of leads, type of leads, and lead age, compared to the Snare group (P<0.05). In the Snare sheath group, mortality rate was 1.69% and minor complication rate was 3.39%. When compared to the Snare sheath, lead extraction with the Evolution sheath has less X-ray exposure time and less operation time (P<0.05), while with a higher success rate (P<0.05). Besides, the Evolution group has fewer major and minor complications.

Prevalence of venous occlusion in patients referred for lead extraction: implications for tool selection.

AIMS: Data concerning the incidence of venous obstruction in patients referred for lead extraction is limited. Thus, we aimed to assess the incidence of venous obstruction in patients referred for lead extraction and the implications for tool selection. METHODS AND RESULTS: Contrast venography of the access vein was obtained in 202 patients (147 men; mean age, 62.4 ± 14.5 years) scheduled for lead extraction. The indication for lead extraction included infection (n = 145, 72%) and other causes (n = 57, 28%). Two patients with device infection had superior vena caval occlusion. Access vein occlusion occurred in 6 (11%) patients without infection vs. 46 (32%) patients with infection [P = 0.002; odds ratio (OR) 3.94; 95% confidence interval (CI) 1.58-9.87]. No significant differences between occluded and non-occluded patients were seen for age, sex, device type, number of leads, time from implant of the initial lead, or anticoagulation therapy (all P>0.05). Procedural duration and fluoroscopy exposure time were significantly lower in the open group than in the occluded group (P < 0.05). Patients with venous occlusion required more advanced tools for lead extraction, such as dilator sheaths, evolution sheaths, and needle's eye snares (P = 0.019). CONCLUSION: Both systemic and local infections are associated with increased risk of access vein occlusion. We found no support for the hypothesis that venous occlusion increases with the number of leads present. Lead extraction was more difficult in patients with venous occlusion, requiring advanced tools and more time.

Reuse of infected cardiac rhythm management devices in the same patients: a single-center experience.

BACKGROUND: In developing countries, patients with a cardiac rhythm management device (CRMD) that has become infected cannot always afford a new device, and reuse of the infected CRMD may be appropriate. To evaluate the safety of this practice, a cohort of consecutive patients with reused pacemakers was compared with a control group. METHODS: A single-center cohort of consecutive patients treated from 2007 to 2012 was analyzed in a two-way noninferiority study. Patients who had infected CRMDs removed at the Cardiovascular Center of The Peking University People's Hospital were enrolled, including those who had the same CRMD reimplanted and those who had a new CRMD implanted. RESULTS: This study included 212 patients, of who 99 (study group) had the same CRMD reimplanted, and 113 (control group) had a new CRMD implanted. During a mean follow-up period of 3.52 years (interquartile range: 2.1-4.7 years), 10 patients reached the primary end point of the study (infection, unexpected battery depletion, or device malfunction), including five (5%) in the study group and five (4.3%) in the control group. Recurrent infection occurred in three patients in the study group and two patients in the control group (3.0% vs 1.7%, relative risk: 1.29, 95% confidence interval: 0.62-2.29, P = 0.561). There were no cases of unexpected battery depletion in either group. CONCLUSIONS: Reuse of infected CRMDs in the same patients is noninferior to the implantation of new devices. In developing countries without full medical coverage, careful reuse of infected CRMDs can be considered.

Re-evaluation of transvenous lead extraction with modified standard technique: a prospective study in 229 patients.

As new-type powered sheaths are expensive and unavailable, the standard lead extraction techniques remain the mainstay in clinical applications in many countries. The purpose of this study was to re-evaluate the clinical application of the standard lead extraction techniques and equipment, and make some procedural modifications and innovations. In our center, between January 2006 and May 2012, 229 patients (median, 66 years) who underwent lead extraction due to infection and lead malfunction were registered and followed up prospectively with respect to clinical features, reasons for lead extraction, technical characteristics, and clinical prognosis. A total of 440 leads had to be extracted transvenously by using special tools from 229 patients (male, 72.1%). Vegetations ≥1 cm were detected in six patients. Locking Stylets were applied for 398 (90.5%) leads. Telescoping dilator polypropylene sheaths and counter traction technique were used for 202 (45.9%) leads due to lead adhesion, and the mean implant duration of the 202 leads was longer than the other 238 leads (48.9±22.6 vs. 26.6±17.8 months; P <0.01). In addition, modified isolation and snare techniques were used for 56 leads (12.7%). Minor and major procedure-related complications occurred in three (1.3%) and four (1.7%) cases respectively, including one death (0.4%). Severe lead residue occurred in one case. Complete procedural success rate was 96.1% (423/440), and clinical success rate was 98.9% (435/440). The median follow-up period was 18 (1-76) months. No infection- and procedure-related death occurred in our series. Our data demonstrated that high clinical success rate of transvenous lead extraction can be guaranteed by making full use of the standard lead extraction techniques and equipment with individualized modifications.

Implantable defibrillator lead extraction with optimized standard extraction techniques.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) leads might not be extracted especially in developing countries because of the high cost and lack of specialized tools. We aimed to evaluate transvenous extraction of ICD leads using optimized standard techniques. METHODS: We prospectively analyzed clinical characteristics, optimized extraction techniques and the feasibility of extraction for 40 patients (33 males; mean age 47.9 ± 16.1 years) with 42 ICD leads. RESULTS: Complete procedural success rate was 95.2% (40/42), and the clinical success rate was 97.6% (41/42). One ICD lead required cardiothoracic surgery. Minor complications occurred in three cases (7.5%), and no major complications or death occurred. Locking stylets were used to extract most leads (34, 81.0%) and almost half of the leads (20, 47.6%) required mechanical dilatation to free fibrotic adhesions; these leads had been implanted for a longer period of time than the others (43.7 ± 18.2 vs. 18.4 ± 13.4 months, P < 0.05). Three-quarters of the leads (30, 71.4%) were extracted with locking stylets plus manual traction (12, 28.6%), or mechanical dilatation with counter-traction (18, 42.8%) by the superior vena cava approach and one-quarter of the leads (11, 26.2%) were removed by optimized snare techniques using the femoral vein approach. Median extraction time was 20 min (range 2-68 min) per lead. Linear regression analysis showed that the extraction time was significantly correlated with implant duration (r = 0.70, P < 0.001). Median follow-up was 14.5 months (range 1-58 months), no infection, or procedure-related death occurred in our series. CONCLUSIONS: Our optimized procedure for transvenous extraction of ICD leads provides a practical and low-cost method for standard procedures.

Percutaneous extraction of leads from coronary sinus vein and branch by modified techniques.

BACKGROUND: Cardiac resynchronization therapy (CRT) device and coronary sinus (CS) lead extraction are required due to the occurrence of systemic infection, malfunction, or upgrade. Relevant research of CS lead extraction is rare, especially in developing countries because of the high cost and lack of specialized tools. We aimed to evaluate percutaneous extraction of CS leads by modified conventional techniques. METHODS: Of 200 patients referred for lead extraction from January 2007 to June 2011, 24 (12.0%) involved CS leads (24 CS leads). We prospectively analyzed clinical characteristics, optimized extraction techniques and feasibility of extraction. RESULTS: Complete procedural success was achieved in 23 patients (95.8%), and the clinical success in 24 patients (100.0%). The leading indication for CS lead extraction was infection (66.7%). Mean implant duration was (29.5 ± 20.2) months (range, 3 - 78 months). Sixteen CS leads (66.6%) were removed with locking stylets plus manual traction by superior transvenous approach. Mechanical dilatation and counter-traction was required to free fibrotic adhesions and extract 4 CS leads (16.7%), which had longer implant duration than other leads ((62.5 ± 12.3) vs. (22.9 ± 14.1) months, P < 0.05). Another 4 CS (16.7%) leads were removed by modified and innovative snare techniques from femoral vein approach. Median extraction time was 11 minutes (range, 3 - 61 minutes) per CS lead, which had significant correlation with implant duration (r = 0.8, P < 0.001). Sixteen patients (66.6%) were reimplanted with new devices at a median of 7.5 days after extraction. Median followed-up was 23.5 months (range, 8 - 61 months), three patients died due to sudden cardiac death (26 months), heart failure (45 and 57 months, respectively). CONCLUSION: The modified procedure was proved to be practical for percutaneous extraction of CS leads, especially in developing countries lacking expensive powered sheaths.