New skin closure system facilitates wound healing after cardiovascular implantable electronic device surgery

The manuscript describes the efficacy of a new skin closure system(Zip Line?) for wound closure after pacemaker/implantable cardioverter defibrillator surgery. The system is particularly useful when wound healingis difficult with traditional methods and in patients at high risk for surgical site infections(SSIs). This skin closure option is easy and quick to apply and remove, and produces excellent cosmetic results. Although it is associated with a minimal expense upcharge, the benefits, including the potential for decrease in SSI, make it attractive and worth considering for skin closure in device patients, particularly those at increased risk of complications.

Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check:The role of highvoltage shock testing

AIM To describe our experience with shock testing for the evaluation of patients with Riata? leads.METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation(VF) induction and in 5 cases a R-wave-synchronized shock(> 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients(80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients(20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance(< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF.CONCLUSION In Riata? leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing.

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator(ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction(not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a nonprospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries(GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

Minimizing right ventricular pacing in sinus node disease: Sometimes the cure is worse than the disease

Traditional right ventricular(RV) apical pacing has been associated with heart failure, atrial fibrillation and increased mortality. To avoid the negative consequences of RV apical pacing different strategies have been developed, among these a series of pacing algorithms designed to minimize RV pacing. These functions are particularly useful when there is not the need for continuous RV pacing: intermittent atrioventricular blocks and, mainly, sinus node disease. However, in order to avoid RV pacing, the operationalfeatures of these algorithms may lead to adverse(often under-appreciated) consequences in some patients. We describe a case of a patient with sinus node disease, in whom right atrial only pacing involved long atrio-ventricular delay to allow intrinsic ventricular conduction, which led to symptomatic hypotension that could be overcome only by "forcing" also right ventricular apical pacing. We subsequently discuss this case in the context of current available literature.

Antitachycardia pacing programming in implantable cardioverter defibrillator:A systematic review

Implantable cardioverter defibrillator(ICD) programminginvolves several parameters. In recent years antitachycardia pacing(ATP) has gained an increasing importance in the treatment of ventricular arrhythmias, whether slow or fast. It reduces the number of unnecessary and inappropriate shocks and improves both patient's quality of life and device longevity. There is no clear indication regarding the type of ATP to be used, except for the treatment of fast ventricular tachycardias(188 bpm-250 bpm) where it has been shown a greater efficacy and safety of burst compared to ramp; 8 impulses in each sequence of ATP appears to be the best programming option in this setting. Beyond ATP use, excellent clinical results were obtained with programming standardization following these principles: extended detection time in ventricular fibrillation(VF) zone; supraventricular discrimination criteria up to 200 bpm; first shock in VF zone at the maximum energy in order to reduce the risk of multiple shocks. The MADIT-RIT trial and some observational registries have also recently demonstrated that programming with a widespread use of ATP, higher cut-off rates or delayed intervention reduces the number of inappropriate and unnecessary therapies and improves the survival of patients during mid-term follow-up.

Ticagrelor therapy and atrioventricular block:Do we need to worry?

Ticagrelor is a potent,direct P2Y12 antagonist with rapid onset of action and intense platelet inhibition,indicated in patients with acute coronary syndromes(ACS).This drug is usually well tolerated,but some patients experience serious adverse effects:Major bleeding;gastrointestinal disturbances;dyspnoea;ventricular pauses > 3 s.Given the unexpected high incidence of bradyarrhythmias,a PLATO substudy monitored this side effect,showing that ticagrelor was associated with an increase in the rate of sinus bradycardia and sinus arrest compared to clopidogrel.This side effect was usually transient,asymptomatic and not associated with higher incidence of severe atrioventricular(AV) block or pacemaker needs.A panel of experts from Food and Drug Administration did not consider bradyarrhythmias a serious problem in clinical practice and,accordingly,current labeling of the drug does not give any precaution or contraindication regarding this issue.However,recently some articles have described ACS patients with high-degree,life-threatening,AV block requiring drug discontinuation and,in some cases,pacemaker implantation.In this paper,we describe and discuss five published case reports of severe AV block following ticagrelor therapy and two other cases managed in our Hospital.The analysis of literature suggests that,although rarely,ticagrelor can be associated with lifethreatening AV block.Caution and careful monitoring are required especially in patients with already compromised conduction system and/or treated with AV blocking agents.Future studies,with long-term rhythm monitoring,would help to define the outcome of patients at higher risk of developing this complication.

Cardiac magnetic resonance imaging:Which information is useful for the arrhythmologist?

Cardiac magnetic resonance(CMR) is a non-invasive,nonionizing,diagnostic technique that uses magnetic fields,radio waves and field gradients to generate images with high spatial and temporal resolution.After administration of contrast media(e.g.,gadolinium chelate),it is also possible to acquire late images,which make possible the identification and quantification of myocardial areas with scar/fibrosis(late gadolinium enhancement,LGE).CMR is currently a useful instrument in clinical cardiovascular practice for the assessment of several pathological conditions,including ischemic and nonischemic cardiomyopathies and congenital heart disease.In recent years,its field of application has also extended to arrhythmology,both in diagnostic and prognostic evaluation of arrhythmic risk and in therapeutic decisionmaking.In this review,we discuss the possible useful applications of CMR for the arrhythmologist.It is possible to identify three main fields of application of CMR in this context:(1) arrhythmic and sudden cardiac death risk stratification in different heart diseases;(2) decisionmaking in cardiac resynchronization therapy device implantation,presence and extent of myocardial fibrosis for left ventricular lead placement and cardiac venous anatomy; and(3) substrate identification for guiding ablation of complex arrhythmias(atrial fibrillation and ventricular tachycardias).