Hands On
How to prevent, recognize, and manage complications of lead extraction. Part II: Avoiding lead extraction—Noninfectious issues
The first part of this review examined the infectious indications for lead extraction. This part discusses noninfectious indications for lead extraction and strategies for reducing the incidence of such indications.How to prevent, recognize, and manage complications of lead extraction. Part I: Avoiding lead extraction—Infectious issues
As the number of implanted devices continues to grow, so does the need for extraction of chronic endocardial leads. Extraction carries with it considerable risk of morbidity and mortality (both intraprocedure and postprocedure), even in experienced hands. Although the evolution of technology directed at this approach has facilitated the successful removal of leads, no evidence indicates that this technology has lessened the incidence or nature of adverse events. Risks associated with lead extraction include vascular and cardiac perforation, tricuspid valve injury, various arrhythmias, sepsis, pulmonary embolism, bleeding, stroke, and myocardial infarction.Percutaneous extraction of coronary sinus vein and branch leads
Extraction of cardiac leads and electrodes will continue to be a statistical necessity as electrode implant numbers and durations increase. Improved implant success and expanded indications in heart failure patients for left ventricular (LV) pacing electrodes via the coronary sinus (CS) and its branches have resulted in unique interactions among the leads, venous system, and epicardial heart that are not typically seen with traditional endocardial right heart cardiac electrodes. LV lead placement, as well as the myocardium’s response to it, requires continual evaluation to better understand the limitations that may be encountered during extraction of LV leads, especially as the mean duration of implant reaches beyond 1 year.European perspective on lead extraction: Part II
If manual extraction is not successful, a locking stylet is used after the inner lumen is reamed using another stylet to remove debris. Use of a locking stylet with a very flexible tip is essential so that a tortuous lead can be negotiated. Equally important is locking the stylet as close as possible to the lead tip and not allowing the stylet to slip during the procedure. The risk of severing the sometimes fragile interpolar section of encapsulated bipolar leads is high if a positive lock close to the lead tip cannot be achieved.A European perspective on lead extraction: Part I
The need for lead extraction has increased exponentially in the last decade due to greatly increased “total lead exposure time.” The increased total lead exposure time is the result of new indications for device treatment, device therapy involving more leads per patient, and longer average patient life. Improved general lead reliability noted over recent years may have decreased slightly the need for extraction; however, this effect is more than countered by recent advisories, recalls, and increased complication rates, probably related to many new centers offering device treatment.How to treat and identify device infections
The incidence of device-related infections depends directly on the definition employed. The lack of precision is also compounded by the latency between the initiation and manifestation of the infection. It is not rare for there to be some erythema at the incision site during the first week of healing, and it is not clear that this represents infection. Less frequent, but still common, there can be a small, superficial stitch abscess, which will respond to local measures. When the diagnosis of device system infection is made, it should be made on the basis of pocket cellulitis, erosion, abscess, persistent bacteremia, or endocarditis with or without vegetation on the lead.Lead extraction
Lead extraction has grown from a “niche” procedure practiced by a select few individuals to a fairly widely disseminated technique. With the apparent increase in device infections, occluded veins and the need for device “upgrades,” more physicians are attempting to extract chronically implanted pacing and implantable cardioverter-defibrillator (ICD) leads. Unfortunately, obtaining training for this procedure is difficult outside of a training program at a center with a physician experienced in lead extraction.Lead extraction using the femoral vein
Lead extraction using the femoral vein is an alternate approach for lead removal. It has often been dubbed “the inferior approach.” This is because today it is often reserved for use only after a failed primary approach via the implant vein. In reality it is the most versatile approach for lead removal. Prior to the advent of powered sheaths, it was frequently used as a primary approach. It is also the only approach, and the procedure of choice, for removal of broken or cut leads with free ends.How to select patients for lead extraction
The techniques and tools for percutaneous removal of transvenous leads have undergone substantial development over the past several decades. Although the use of locking stylets and powered sheaths to free leads from encapsulated scar tissue has improved the success rate, the procedure still carries a significant risk of morbidity and mortality even in the hands of experienced operators. The threshold for lead extraction continues to evolve. The initial use of the procedure was limited to patients with life-threatening infections because of limited tools, lower success rates and high complication rates.How to perform linear lesions
Atrial fibrillation (AF) is a particularly complex arrhythmia because the mechanisms leading to fibrillation are not fully understood. Accordingly, ablation strategies have evolved largely on an empirical basis. The creation of linear lesions is a fundamental strategy that is indispensable to an electrophysiology laboratory performing ablation for treatment of this arrhythmia.Pacing maneuvers for nonpulmonary vein sources: Part II
Superior vena caval (SVC) potentials are similar to pulmonary vein (PV) potentials. The concepts of multiple far-field electrograms and the use of perivenous pacing and specific site and simultaneous pacing described above are equally applicable to understanding the complex electrograms found within the SVC (Figure 1). Specific sites that require pacing to determine the components of a complex electrogram found in the SVC include the right atrium (RA), azygos vein, anomalous PVs draining into the SVC, and right upper PV; in some cases, an anomalous superior branch of the right inferior PV may be required.Pulmonary vein–related maneuvers: Part I
With the rapid evolution of atrial fibrillation ablation procedures, electrophysiologists have necessarily strived for simple and anatomic-based approaches. In all except the most straightforward procedures, however, questions regarding the significance of various potentials recorded on mapping and ablation catheters arise.1,2 Other articles in this series have described in detail the various approaches to atrial fibrillation ablation. In this article, the anatomic and electrophysiologic bases for pacing maneuvers used with a variety of ablation approaches are reviewed.How to determine and assess endpoints for left atrial ablation
Studies have demonstrated that myocardium surrounding pulmonary vein (PV) ostia plays an important role in the initiation and perpetuation of atrial fibrillation (AF).1,2 This important finding has led to the development of segmental PV ostial isolation, circumferential ablation, and isolation around the PVs using circular linear lesions guided by three-dimensional (3D) electroanatomic mapping. Substrate modification using limited linear ablation also has been demonstrated to improve the clinical outcome after PV isolation in patients with AF inducibility.How to recognize, manage, and prevent complications during atrial fibrillation ablation
Seminal observations by Haissaguerre et al1 demonstrating initiation of atrial fibrillation (AF) by pulmonary vein (PV) depolarizations led to the development of percutaneous catheter-based endocardial AF ablation procedure. Since its original description, the AF ablation procedure has evolved considerably. Currently, the most accepted ablation strategy involves creating circumferential radiofrequency (RF) ablation lesions around PV ostia (either individually or encircling wide areas around the left-sided and right-sided veins) with or without additional atrial lesions.How to use intracardiac echocardiography for atrial fibrillation ablation procedures
Intracardiac echocardiography (ICE) has been an important tool in the development of advanced catheter ablation procedures. ICE technology now allows complete echocardiographic interrogation of all four heart chambers from the right atrium. A list of the uses for ICE in ablation procedures is given in Table 1.How and when to ablate the ligament of Marshall
The ligament of Marshall is an epicardial vestigial fold that marks the location of the embryologic left superior vena cava. It contains the nerve, vein (vein of Marshall), and muscle tracts.1,2 The proximal portions of the muscle tracts connect directly to the coronary sinus myocardial sleeves. The distal portions of the muscle tracts extend upward into the pulmonary vein region. Figure 1 shows a postmortem human heart with the ligament of Marshall located between the left atrial (LA) appendage and left pulmonary vein.How to perform electrogram-guided atrial fibrillation ablation
Over the past decade, several mapping studies of human atrial fibrillation (AF) have made the following important observations: (1) Atrial electrograms during sustained atrial fibrillation have three distinct patterns: single potential, double potential, and complex fractionated potential(s) (CFAEs).1–3 (2) The distribution of these atrial electrograms during AF localizes to specific atrial sites, and these electrograms exhibit remarkable temporal and spatial stability.1,2 (3) The CFAE areas represent AF substrate sites and are important targets for AF ablation.How to perform encircling ablation of the left atrium
The purpose of this article is to describe the technique and results of circumferential pulmonary vein ablation (CPVA) in patients with atrial fibrillation (AF) as currently performed in Milan.1–14 Since a significant learning curve still exists with the standard procedure, we have recently developed a new system, called remote magnetic navigation and ablation, which can be performed by less experienced operators while at the same time still reducing complications.13 The results of our standard technique with manually deflectable catheters are based on about 10,000 patients with paroxysmal, persistent, or permanent AF, many of whom have structural heart disease.How to access the axillary vein
The axillary vein has become a desirable structure for venous access for implantation of defibrillator and pacemaker leads because the vein is large, easily accessed, and can accommodate multiple leads. Furthermore, axillary vein access is not associated with problems accompanying subclavian vein access, including pneumothorax and subclavian crush syndrome.1,2How to interpret electroanatomic maps
Electroanatomic mapping refers to the acquisition and display of electrical information combined with spatial localization. Technologies presently available include both contact and noncontact electroanatomic mapping. This review focuses on the creation and proper interpretation of contact electroanatomic maps, which involves the sequential recording of unipolar or bipolar electrograms with a catheter in contact with the endocardium or epicardium and display of this information on a three-dimensional navigation system.How to analyze T-wave alternans
Noninvasive detection of patients prone to ventricular tachyarrhythmias and sudden cardiac death using measurements of ventricular repolarization derived from the 12-lead surface ECG has received enormous interest. Among the methods introduced for this purpose are assessment of QT dispersion, determination of QT dynamics assessed from long-term ECG recordings, and morphologic assessment of T-wave patterns. Analysis of microvolt T-wave alternans has emerged as the most promising. Considerable experimental evidence links microvolt T-wave alternans to the genesis of life-threatening ventricular tachyarrhythmias.How to ablate left atrial flutter
Typical atrial flutter ablation has become an increasingly common indication for catheter ablation, with success rates routinely exceeding 90% in most laboratories. In contrast, catheter ablation of left atrial flutter is technically challenging, and high success rates are uncommon.How to ablate atrioventricular nodal reentry using cryoenergy
Most electrophysiologists are well acquainted with the technique of radiofrequency (RF) ablation of AV nodal reentrant supraventricular tachycardia (AVNRT). This familiarity has, in turn, translated into a high degree of efficacy and safety with this method of ablation. On the other hand, catheter cryoablation is a relatively new approach for treating patients with AVNRT.1,2 Although the two ablation methods have certain similarities, understanding the unique features of cryoablation is important so that the method can be optimally used.Atrial lead implantation in the Bachmann bundle
The search for alternative atrial pacing sites has been driven by the observation that atrial activation patterns can influence the incidence of atrial fibrillation (AF).1,2 One goal of atrial pacing is to prevent nonphysiologic delay between right and left atrial activation. Pacing from atrial sites that decrease dispersion of atrial refractoriness may decrease the incidence of AF.Using the twelve-lead electrocardiogram to localize the site of origin of ventricular tachycardia
The basis of this review is the underlying hypothesis that the QRS morphology on 12-lead ECG is, to a great extent, determined by the site from which a focal ventricular tachycardia (VT) arises or from which a reentrant circuit exits the central isthmus to activate the “normal” myocardium. The ability to localize or, at the very least, regionalize “the sites of origin” of VTs enables the electrophysiologist to concentrate mapping to a specific region. Several factors limit the ability of the QRS patterns to localize VT origin, including (1) presence and size of infarction, (2) degree of intramyocardial fibrosis, (3) shape of the heart (e.g., aneurysm) and its position within the chest cavity, (4) site and mechanism of VT within an infarct or scarred area, (5) influence of nonuniform anisotropy in affecting propagation from the site of the tachycardia, (6) effects of acute ischemia, antiarrhythmic drugs, or metabolic abnormalities on conduction, (7) integrity of the His-Purkinje system, (8) presence of increased myocardial mass, and (9) presence of structural abnormalities unrelated to tachycardia origin or mechanisms.
