Thrombotic superior vena cava syndrome: a national emergency department database study.

Literature regarding etiology and trends of incidence of major thoracic vein thrombosis in the United States is limited. To study the causes, complications, in-hospital mortality rate, and trend in the incidence of major thoracic vein thrombosis which could have led to superior vena cava syndrome (SVCS) between 2010 and 2018. Data from the nationwide emergency department sample (NEDS) that constitutes 20% sample of hospital-owned emergency departments (ED) and in-patient sample in the United States were analyzed using diagnostic codes. A linear p-trend was used to assess the trends. Of the total 1082 million ED visits, 37,807 (3.5/100,000) (mean age 53.81 ± 18.07 years, 55% females) patients were recorded with major thoracic vein thrombosis in the ED encounters. Among these patients, 4070 (10.6%) patients had one or more cancers associated with thrombosis. Pacemaker/defibrillator-related thrombosis was recorded in 2820 (7.5%) patients, while intravascular catheter-induced thrombosis was recorded in 1755 (4.55%) patients. Half of the patients had associated complication of pulmonary embolism. A total of 59 (0.15%) patients died during these hospital encounters. The yearly trend for the thrombosis for every 100,000 ED encounters in the United States increased from 2.17/100,000 in 2010 to 5.98/100,000 in 2018 (liner p-trend < 0.001). Yearly trend for catheter/lead associated thrombosis was also up-trending (p-trend 0.015). SVCS is an uncommon medical emergency related to malignancy and indwelling venous devices. The increasing trend in SVCS incidence, predominantly catheter/lead induced, and the high rate of associated pulmonary embolism should prompt physicians to remain vigilant for appropriate evaluation.

Clinical performance of different DF-4 implantable cardioverter defibrillator leads.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) DF-4 connectors have been introduced to facilitate defibrillator lead connection and to reduce the size of device header. There are limited data regarding the overall performance of those leads and no comparison between different ICD DF-4 leads. METHODS: This is a cohort study of consecutive patients implanted with ICD DF-4 lead system at one University Centre between October 2010 and February 2015. A historical control group of patients with ICD DF-1 lead implantation was used for comparison. The following ICD DF-4 leads were evaluated: St. Jude Medical Durata 7122Q (St. Jude Medical, St. Paul, MN, USA), Medtronic Sprint Quattro Secure 6935 M (Medtronic Inc., Minneapolis, MN, USA), Boston Scientific Endotak Reliance 4-Site 0293 (Boston Scientific, Marlborough, MA, USA), and Boston Scientific Reliance 4-Front 0693. This study evaluated the acute and mid-term performances of those leads as well as complications. RESULTS: A total of 812 patients (age 63 ± 12 years, 80% male, left ventricular ejection fraction 31 ± 12%) underwent implantation of an ICD DF-4 lead. Acute and follow-up R-wave sensing and threshold were excellent. Compared to implantation, intrinsic R waves were higher at follow-up for Boston Scientific and Medtronic leads, and pacing lead impedances were lower for all leads at first follow-up (P < 0.001). The number of lead dislodgement or failure was similar between all leads. The estimated lead survival rates at 3 years were 95.6% for Boston Scientific Endotak 4-Site, 97.1% for Boston Scientific 4-Front, 97.7% for Medtronic Sprint Quattro, and 97.5% for St. Jude Durata (P  =  0.553). CONCLUSION: All ICD DF-4 leads had excellent acute and mid-term electrical performances. Longer follow-up will be necessary to confirm their sustained performance.

Clinical experience and procedural outcomes associated with the DF4 implantable cardioverter defibrillator system: the SJ4 postapproval study.

BACKGROUND: Current implantable cardioverter defibrillators (ICDs) employ two or three low- and high-voltage lead connectors, adding complexity and bulk, sometimes resulting in incorrect connections and adverse events. The SJ4 study evaluates the performance of a novel integrated single-lead DF4 connection system by characterizing lead measurements, handling characteristics, and outcomes. METHODS: Patients with standard guidelines-based ICD indications were enrolled and implanted with a St. Jude Medical™ DF4 system (St. Jude Medical, Sylmar, CA, USA; right ventricular high-voltage DF4 lead models 7120Q, 7121Q, 7122Q, or 7170Q with compatible ICD). Device electrical measurements, handling characteristics, and any adverse events were collected at implant and during each scheduled 6-month follow-up. RESULTS: Among 1,701 patients (65 ± 13 years, 72% male, left ventricular ejection fraction 29 ± 12%) enrolled at 58 centers, there were 1,697 successful implants (99.8% implant success; ICD; n = 999, cardiac resynchronization therapy-defibrillator n = 698). Implanting physicians reported that implantation of the DF4 lead was normal or easier than normal in 94% of cases with successful implant. These patients have been followed for 1.7 ± 0.5 years with a maximum follow-up of 2.5 years. The complication rate was 0.017 per patient year of follow-up (95% confidence interval: 0.013-0.023), which included abnormal defibrillation impedance, elevated pacing thresholds, failure to detect ventricular tachycardia/ventricular fibrillation, lead dislodgement, lead fracture, loss of capture, and lead perforation. There were no set screw-related complications at implant or during follow-up. CONCLUSION: The DF4 system overall performed very well with few complications at implant and in follow-up.

In vitro modeling accurately predicts cardiac lead fracture at 10 years.

BACKGROUND: Development of a cardiac lead fracture model has the potential to differentiate well-performing lead designs from poor performing ones and could aid in future lead development. OBJECTIVE: The purpose of this study was to demonstrate a predictive model for lead fracture and validate the results generated by the model by comparing them to observed 10-year implantable cardioverter-defibrillator lead fracture-free survival. METHODS: The model presented here uses a combination of in vivo patient data, in vitro conductor fatigue test data, and statistical simulation to predict the fracture-free survival of cardiac leads. The model was validated by comparing the results to human clinical performance data from the Medtronic Sprint Fidelis (Minneapolis, MN) models 6931 (single coil, active fixation) and 6949 (dual coil, active fixation), as well as the Quattro model 6947 (dual coil, active fixation). RESULTS: Median patient age in the single coil Fidelis 6931 population (64 years) was less than in the dual coil Fidelis 6949 and Quattro populations (68 years). Modeled and observed fracture-free survival for Quattro (>97%) was superior to that for Fidelis (<94%). The modeled survival agreed with the observed fracture-free survival data. The average model error was 0.3% (SD 1.2%). CONCLUSION: This model for cardiac lead fracture-free survival using in vivo lead bending measurements and in vitro bench testing can be used to predict lead performance as observed by alignment with field survival data.

Implantable Cardiac Defibrillator Lead Failure and Management.

The implantable-cardioverter defibrillator (ICD) lead is the most vulnerable component of the ICD system. Despite advanced engineering design, sophisticated manufacturing techniques, and extensive bench, pre-clinical, and clinical testing, lead failure (LF) remains the Achilles' heel of the ICD system. ICD LF has a broad range of adverse outcomes, ranging from intermittent inappropriate pacing to proarrhythmia leading to patient mortality. ICD LF is often considered in the context of design or construction defects, but is more appropriately considered in the context of the finite service life of a mechanical component placed in chemically stressful environment and subjected to continuous mechanical stresses. This clinical review summarizes LF mechanisms, assessment, and differential diagnosis of LF, including lead diagnostics, recent prominent lead recalls, and management of LF and functioning, but recalled leads. Despite recent advances in lead technology, physicians will likely continue to need to understand how to manage patients with transvenous ICD leads.

[Pacemaker and defibrillator lead extraction techniques - literature review and own results]. / Verfahren zur Extraktion von transvenösen Herzschrittmacher- und Defibrillatorsonden : Literaturübersicht und eigene Ergebnisse.

In the past, the application of continuous traction used to be the alternative to open surgical removal of impacted pacemaker leads. Today's state-of-the-art methods for lead extraction follow the principles of traction (by locking stylets) and countertraction (by outer sheaths). Technical advances with respect to outer sheath design - including the use of lasers or bipolar electrocautery - led to a higher success rate, particularly as far as the removal of endocardial defibrillator leads is concerned. From 1997 to 1999, we treated 31 patients (pts) who required lead extraction more than 6 months after lead implantation. In 16 pts pacemaker leads and in 15 pts endocardial defibrillator leads had to be removed. All but one infected lead could be extracted using the "Cook-Byrd-Method" described here. Incompletely extracted leads were more common in the patient group without infection. This may be the result of different levels of "aggressiveness" when removing leads in infected and non-infected cases, and a reflection of the different risks. We report on the technical principles of lead removal. Published methods and results are reviewed and compared. The laser sheath, recently favored by some authors, are not necessarily quicker, better and safer. New electrosurgical dissection sheaths seem to be promising in one study with just a small sample size. The results of the EXCL study (Electrosurgical Extraction of Cardiac Leads) will provide us with new data. Complete lead removal is mandatory, especially in systemically infected pacemaker systems, while it remains most important to prevent harm to the individual patient. The "aggressiveness" of each procedure should be related to the potential risk. However, the costs associated with each method may not be neglected.