Povidone-iodine Irrigation - A Possible Alternative To Lead Extraction

Pocket infection and erosion remain the commonest (class 1) indication for pacemaker (PM) or implantable cardiac defibrillator (ICD) lead extraction. However, tranvenous lead extraction is not without significant risk of serious complications, particularly in patients with chronically implanted leads or ICD leads specifically. The paucity of cardiologists adequately experienced to undertake this high-risk procedure also means that its availability is limited to relatively few specialist institutions, yet more conservative 'lead-preserving' treatment options have not been well-reported. We describe the first reported case of a chronically eroded and infected ICD generator, managed conservatively with 5-days of povidone-iodine closed irrigation, followed by re-implantation of a new ICD on the contralateral side. With satisfactory long-term follow-up, this successfully averted the need for lead extraction in our elderly patient. We advocate the need for formal prospective evaluation of conservative therapeutic strategies of PM and ICD pocket infections. Although not gold standard, it provides an important therapeutic alternative in resource-limited areas.     

Life-threatening perforation of a defibrillation lead

We describe cardiac perforation of a Riata implantable cardioverter defibrillator (ICD) shock lead in a 76-year-old male nine days after implantation of a prophylactic ICD. Since there are more reports of increased risk of cardiac perforations with the Riata lead, we advise cautious use of this lead. (Neth Heart J 2009;17:113–4.)     

Inappropriate ICD shocks for inappropriate reasons

ICD shocks can result from a variety of etiologies; determining the proper etiology of the inappropriate shock is essential for correction of the problem. Electromagnetic interference (EMI) can mimic cardiac signals and cause inappropriate defibrillator shocks. We present two cases of inappropriate ICD shocks due to EMI and reversal of the proximal and distal DF-1 lead terminals of the ICD lead. These are two unusual etiologies for inappropriate defibrillator shocks.     

New aspects of ICD therapy: from rhythm therapy to complex cardiac monitoring. Development of an implantable, ICD-assisted, intrathoracic 6-channel ECG for continuous monitoring of high infarct risk patients]

Implantable defibrillator systems (ICD) are therapy of choice for the treatment of life-threatening ventricular arrhythmias and in prevention of sudden cardiac death. In more than 80% of patients who receive an ICD, the underlying cardiac disease is a coronary heart disease. Since arrhythmogenic sudden cardiac death can be reliably prevented in these patients by the use of ICD technology, the cardiac prognosis for these patients is determined by the occurrence of myocardial ischemia and myocardial infarction, as well as from the heart failure which develops in consequence. An intrathoracic 6-channel ECG comparable to the standard surface ECG can be reconstructed by further technical development of the electrode configurations currently present in ICD systems. The importance of this development in early diagnosis of myocardial ischemias and myocardial infarction can hardly be adequately estimated at the moment. The chronic consequences of myocardial infarction can be completely prevented or at least greatly reduced by means of such diagnostics and inclusion of immediate initiation of effective, appropriate early therapeutic measures before more serious symptoms even occur. In the development and pilot studies thus far, it has been found that the intrathoracic 6-channel ECG which can be generated in the ICD is capable of reliably recognizing acute myocardial ischemia, irrespective of localization or extent earlier and better than the standard surface ECG. Continuous preventive ischemia monitoring using the implanted ICD thus appears possible in patients at risk of infarction.     

Cardiac sympathetic activity in chronic heart failure: cardiac <Superscript>123</Superscript>I-<Emphasis Type="Italic">m</Emphasis>IBG scintigraphy to improve patient selection for ICD implantation

Heart failure is a life-threatening disease with a growing incidence in the Netherlands. This growing incidence is related to increased life expectancy, improvement of survival after myocardial infarction and better treatment options for heart failure. As a consequence, the costs related to heart failure care will increase. Despite huge improvements in treatment, the prognosis remains unfavourable with high one-year mortality rates. The introduction of implantable devices such as implantable cardioverter defibrillators (ICD) and cardiac resynchronisation therapy (CRT) has improved the overall survival of patients with chronic heart failure. However, after ICD implantation for primary prevention in heart failure a high percentage of patients never have appropriate ICD discharges. In addition 25–50?% of CRT patients have no therapeutic effect. Moreover, both ICDs and CRTs are associated with malfunction and complications (e.?g. inappropriate shocks, infection). Last but not least is the relatively high cost of these devices. Therefore, it is essential, not only from a clinical but also from a socioeconomic point of view, to optimise the current selection criteria for ICD and CRT. This review focusses on the role of cardiac sympathetic hyperactivity in optimising ICD selection criteria. Cardiac sympathetic hyperactivity is related to fatal arrhythmias and can be non-invasively assessed with ¹²³I-meta-iodobenzylguanide (¹²³I-mIBG) scintigraphy. We conclude that cardiac sympathetic activity assessed with ¹²³I-mIBG scintigraphy is a promising tool to better identify patients who will benefit from ICD implantation.     

ICD discrimination of SVT versus VT with 1:1 V-A conduction: A review of the literature

Inappropriate ICD shocks are associated with increased mortality. They also impair patients'' quality of life, increase hospitalizations, and raise health-care costs. Nearly 80% of inappropriate ICD shocks are caused by supraventricular tachycardia. Here we report the case of a patient who received a single-lead dual-chamber sensing ICD for primary prevention of sudden cardiac death and experienced inappropriate ICD shocks. V-A time, electrogram morphology, and response to antitachycardia pacing suggested atrioventricular nodal reentry tachycardia, which was confirmed in an electrophysiology study. Inspired by this case, we performed a literature review to discuss mechanisms for discrimination of supraventricular tachycardia with 1:1 A:V relationship from ventricular tachycardia with 1:1 retrograde conduction.     

Incidence of lead dislodgement,malfunction and perforation during the first year following device implantation

Background

The number of cardiac rhythm device implantations has been growing fast due to expanding indications and ageing of the population. Complications of implantation were rare in the trials. However, these involved small numbers and selected patients. Prospective real-life data are necessary to assess cardiac device implantation procedure-related risks.

Objective

To determine the incidence and predictors of lead-related re-intervention in a Dutch high-volume teaching hospital.

Methods

Data from all patients who underwent cardiac rhythm device implantation between January 2010 and December 2011 were collected in a prospective registry. At least 1 year of follow-up regarding re-intervention was available for all patients. Lead-related reasons for re-intervention were categorised into lead dislodgement, malfunctioning or perforation.

Results

One thousand nine hundred twenty-nine devices including 3909 leads were implanted. In 595 patients (30.8 %) a CRT-D/P was implanted. Lead-related re-intervention was necessary in 86 (4.4 %) patients; it was more common in younger and male patients, and due to either lead dislodgement (66 %), malfunctioning (20 %) or perforation (18 %). Coronary sinus lead dislodgement or malfunctioning was 1.4 %. Right atrial dislodgement (1.9 %, p < 0.001) or ICD lead dislodgement (1.8 %, p = 0.002) was more common than right ventricular dislodgement (0.3 %). The incidence of lead malfunctioning was higher (0.8 %) in ICD leads. An apical position of the right ventricular lead and lateral wall position of the right atrial lead were related to cardiac perforation.

Conclusions

The incidence of lead-related re-intervention was comparable with the literature. The majority of re-interventions were due to lead dislodgements, particularly with right atrial and ICD leads. Re-intervention due to coronary sinus lead dislodgement was rare.     

The activity of mitochondrial enzymes in the muscles of rats subjected to physical training and subchronical intoxication with lead and zinc

The aim of this study was to evaluate the effect of lead and excess zinc on the adaptation of mitochondria from skeletal muscles to physical effort. Rats were intoxicated once a week for 12 weeks by subcutaneous injection of the solution containing 2 mg Zn+2 and/or 3 mg Pb2+ per kg of body weight. During the last 6 weeks, 6 times weekly, rats performed endurance training which involved swimming 15 minutes daily with additional load of 5% of the body weight. The activities of isocitrate (ICD), malate (SDH), succinate (MDH) dehydrogenases, cytochrome oxidase (COX) and protein content (PM) were determined in the mitochondrial fractions obtained from the soleus muscle (ST fibres), and from the superficial (FTb fibres) and deep (FTa fibres) parts of the gastrocnemius muscle. In the control group (C), which was injected with saline, higher activities of ICD and MDH were obtained in FTa and FTb fibres than in the ST fibres. SDH and COX had higher activities in FTa and ST compared to FTb fibres. Zinc treatment (Zn) caused diminution of ICD, SDH and COX activities in ST fibres. Lead intoxication (Pb) resulted in a decrease of MDH activity in all fibre types, and in a decrease of SDH activity in ST fibres. Simultaneous action of zinc and lead produced an increase in ICD activity and diminution of COX activity in FTb fibres. It also resulted in an increase of SDH and decrease of COX activity in ST fibres. These results suggest that the ST fibres are more susceptible to disturbances of adaptation to physical exercise caused by zinc and lead. There are no signs of uniform antagonism between zinc and lead action in the processes under investigation.     

The dawn of a new era in the struggle against sudden cardiac death

The year 2009 is important for Dutch cardiology. It marks not only the 75th anniversary of the Netherlands Society of Cardiology, but also the starting of ICD therapy, 25 years ago. The first ICD implant in the Netherlands was carried out in Utrecht by the cardiac surgeon Dr Penn with the technical assistance of Mr Seah Nisam in April 1984. The patient was referred from Maastricht by Professor Wellens. Referral was needed since Maastricht had no cardiac surgery department at that time.     

First experience with the wearable cardioverter defibrillator in the Netherlands

The implantable cardioverter defibrillator (ICD) has significantly improved survival in patients with an increased risk of sudden cardiac death (SCD). The wearable cardioverter defibrillator (WCD) is an alternative to the ICD in patients with a transient ICD indication or those in whom an ICD temporarily cannot be implanted. We describe here the technical details of the WCD and report three patients who were treated with a WCD in an outpatient setting. The WCD allowed the cardiac condition of two patients to improve to such an extent that permanent ICD implantation was deemed unnecessary. This new form of therapy may result in significant cost reduction, avoidance of unnecessary ICD implantation, and increased patient satisfaction.     

Psychological intolerance to implantable cardioverter defibrillator

Background: Implantable cardioverter defibrillators (ICD) are mobile implantable cardiac devices for immediate treatment of live threatening ventricular arrhythmias. However, these devices can affect patients, physiologically, psychologically and have effects on electrical devices. Case report: The case of a 61-year-old patient is reported. The patient came for regular 3-months visits with his ICD and complained about electromagnetic interference with all household electrical appliances, especially refrigerator and digital television set-top box. He described several phantom shocks when he came close to the electrical appliances. He noted the exact times and symptoms of the episodes but the device memory did not record anything. Conclusion: This case demonstrates the rare occurrence of psychological intolerance to implanted ICD shortly after implant. The device was programmed for higher sensitivity. The patient was calmed and reassured about the reprogramming.     

Rate and predictors of electrical failure in non-recalled defibrillator leads

BackgroundImplantable cardioverter defibrillator (ICD) leads are considered as the ‘weakest link’ in defibrillator systems due to FDA recalls and advisories involving popular lead models from major manufacturers. The rate of electrical failure of ICD leads not implicated in a recall is however not well determined.MethodsMedical records of patients implanted with ICDs at hospitals of the University of Pittsburgh Medical Center between 2002 and 2014 were analyzed. Leads were classified as having electrically failed if removed or replaced for reasons other than infection or heart transplantation. Patients were followed to endpoint of death or electrical lead failure.Results2410 consecutive ICD recipients (mean age 66 ± 13 years, women 22%, single/dual/biventricular-ICD 20%/44%/36%) were included. During a mean follow-up of 3.9 ± 3.3 years, 1272 patients (53%) died, 55 patients (2.3%) had ICD lead electrical failure, and 1052 (44%) patients were alive with functional leads at the time of last follow-up. Patients with failed leads had higher BMI (p = 0.07), better functional status (p = 0.04), higher serum creatinine (p = 0.004), wider QRS complex (p = 0.01), higher number of implanted leads (p = 0.06) and were more likely to have ischemic cardiomyopathy (p = 0.03). After adjusting for these variables in a binary logistic regression model, only a lower BMI, presence of non-ischemic cardiomyopathy, and a better functional status remained independently predictive of electrical failure.ConclusionsOnly 2.3% of non-recalled ICD leads experience electrical failure (annual failure rate of 0.6%). A higher patient functional status, lower BMI, and non-ischemic etiology of cardiomyopathy are independently associated with higher rates of ICD lead failure.     

Normal pacing function with normal impedance trends despite evident lead fracture in an implantable defibrillator – What is the mechanism?

A 63-year-old lady with a high-grade atrioventricular (AV) block and a structurally normal heart underwent permanent pacemaker implantation (dual chamber, Medtronic Ltd) 8 years back. On follow up, she had a recurrence of syncope after 3 years. The device interrogation at that time had revealed ventricular tachycardia (VT) for which she underwent implantable cardioverter defibrillator (ICD, Medtronic Ltd, Egida DR, DF1) upgradation at another center (electrograms not available). Now, she presents with episodes of presyncope after another 5 years. The Echocardiography was unremarkable. The ICD was interrogated & there was a stored ventricular fibrillation (VF) episode. But the electrograms suggested noise over a true VF electrogram noted in both near and far-field. In all probability, the VF was not a true one which might have arisen from some lead noise or from an electromagnetic interference (EMI). Fluoroscopy revealed an evident lead fracture near the superior vena cava (SVC) coil. The stored electrogram (EGM) characteristics also suggested possible lead noise rather than a true VF. She was advised for lead revision. Interestingly, all pacing parameters were normal along with normal impedance despite the evident lead fracture. This happened due to the ICD lead arrangements as there are separate electrodes for the SVC/RV coil and pacing. While the SVC coil was damaged, the pacing electrodes remained unaffected. Since the patient has no episode of true VT/NSVT and the echocardiography was normal, she was managed temporarily by changing the pacemaker to asynchronous (DOO) mode.     

Real-time measurement of ICD lead motion during stereotactic body radiotherapy of ventricular tachycardia

BackgroundHere we aimed to evaluate the respiratory and cardiac-induced motion of a ICD lead used as surrogate in the heart during stereotactic body radiotherapy (SBRT) of ventricular tachycardia (VT). Data provides insight regarding motion and motion variations during treatment.Materials and methodsWe analyzed the log files of surrogate motion during SBRT of ventricular tachycardia performed in 20 patients. Evaluated parameters included the ICD lead motion amplitudes; intrafraction amplitude variability; correlation error between the ICD lead and external markers; and margin expansion in the superior-inferior (SI), latero-lateral (LL), and anterior-posterior (AP) directions to cover 90% or 95% of all amplitudes.ResultsIn the SI, LL, and AP directions, respectively, the mean motion amplitudes were 5.0 ± 2.6, 3.4. ± 1.9, and 3.1 ± 1.6 mm. The mean intrafraction amplitude variability was 2.6 ± 0.9, 1.9 ± 1.3, and 1.6 ± 0.8 mm in the SI, LL, and AP directions, respectively. The margins required to cover 95% of ICD lead motion amplitudes were 9.5, 6.7, and 5.5 mm in the SI, LL, and AP directions, respectively. The mean correlation error was 2.2 ± 0.9 mm.ConclusionsData from online tracking indicated motion irregularities and correlation errors, necessitating an increased CTV-PTV margin of 3 mm. In 35% of cases, the motion variability exceeded 3 mm in one or more directions. We recommend verifying the correlation between CTV and surrogate individually for every patient, especially for targets with posterobasal localization where we observed the highest difference between the lead and CTV motion.     

Under-Utilization of Implantable Cardioverter Defibrillators in Patients with Heart Failure - The Current State of Sudden Cardiac Death Prophylaxis

BackgroundDespite ACC/AHA guidelines indicating implantable cardioverter defibrillator (ICD) as class I therapy for primary prevention of sudden cardiac death in patients with EF≤35%, ICD utilization rates in real world practice have been low.ObjectiveTo determine the rate of ICD implantation at a tertiary care academic center and to assess the reasons for under-utilization of the same.MethodsReview of a prospectively collected database which included all patients diagnosed with an EF≤35% was performed to assess the rate of ICD implantation and mortality. Reasons for non-implantation of ICD were then assessed from detailed chart review.ResultsA total of 707 patients (age 69.4 ± 14.1 years) with mean EF of 26±7% were analyzed. Only 28% (200/707) of patients had ICDs implanted. Mortality was lower in the group with ICD (25% vs 37%, p=0.004). When patients who either died or were lost to follow-up prior to 2005 were excluded, ICD utilization rate was still low at 37.6%. The most common reason for non-implantation of ICD was physicians not discussing this option with their patients. Patient refusal was the second most common reason.ConclusionsICD Implantation rates for primary prevention of SCD in patients with EF≤35% is low. Physician and patient education should be addressed to improve the utilization rates.Key words: Implantable cardioverter-defibrillator, Outcomes, sudden cardiac death     

Defibrillation testing of the implantable cardioverter defibrillator: when, how, and by whom?

The implantable cardioverter-defibrillator (ICD) has become an integral part of treatment for a variety of patients with symptomatic, or at risk for, ventricular tachyarrhythmias. The ICD's effectiveness is attributed to its ability to promptly detect and terminate ventricular tachycardia (VT) and fibrillation (VF). The clinical trials that established the positive role of ICD therapy were based on patients who underwent some form of defibrillation testing at the time of implantation. Therefore, since its advent, intraoperative defibrillation testing of the ICD to assure reliable detection and termination of VT/VF has been a standard practice. But because of advances in defibrillator and lead technology, which now facilitates successful device implantation (i.e., low defibrillation energy requirement to allow for an adequate programmed safety margin) in the majority of patients, the necessity of defibrillation testing has been called into attention. Despite substantial progress, it is not altogether clear whether a wholesale abandonment of intraoperative ICD testing is appropriate at this point. We review pertinent data regarding pros and cons of ICD testing and offer a suggestion as to when, how, and who should test ICDs.     

Ultrasound-guided axillary vein puncture for cardiac devices implantation in patients under antithrombotic therapy

BackgroundUltrasound-guided axillary venous puncture (UGAVP) for cardiac devices implantation has been developed because of its rapidity, safety and potential long-term lead protection. Early work excluded defibrillators (ICD), cardiac resynchronization therapy (CRT) and upgrade procedures. Compared to the cephalic approach, in previous studies, there was a greater use of pressure dressings with this technique, suggesting a higher risk of bleeding.AimsTo assess UGAVP in patients under antithrombotic therapy (ATT) undergoing cardiac devices implantation including CRT/ICD.MethodsProspectively, consecutive patients eligible for a pacemaker or ICD implantation were included. All procedures were performed by a single operator, experienced with UGAVP for femoral access, and fluoroscopy-guided axillary vein access. Guidewires insertion time (from lidocaïne administration), and complications were systematically studied.ResultsFrom 457 cardiac device implantations, 200 patients (77.8 ± 10 y, male 58%) 360 leads were implanted by UGAVP including 36 ICD, 54 CRT and 14 upgrade procedures. A majority (90%) was under ATT: Vitamin K Antagonist or Heparin (n = 58, 29%), direct oral anticoagulant (n = 46, 23%), dual antithrombotic therapy (n = 18, 9%) and single antiplatelet drug (n = 82, 41%). UGAVP was successful in 95.78%. Mean insertion time for 1.8 guidewires per patient was 4.68 ± 3.6 min. No complication (no hematoma) was observed during the follow-up (mean of 45 ± 10 months). Guidewires insertion time reached its plateau after 15 patients.ConclusionUGAVP is fast, feasible and safe for patients under ATT undergoing device implantation including CRT/ICD and upgrade procedures, with a short learning curve.     

Preventing sudden death and the use of prophylactic implanted defibrillators

Implanted defibrillators have become mainstream therapy for the prevention of sudden cardiac death from ventricular tachyarrhythmias. A decade of studies has confirmed the superiority of ICDs over antiarrhythmic drug therapy in prolonging the life of patients with a prior history of sustained VT or VF. More recent studies have compared ICD therapy to drugs or no antiarrhythmic therapy as 'primary prophylaxis' in patients considered at high risk for sudden death or with prior MIs. In selected patients, ICDs lead to important relative and absolute reductions in mortality in patients with no prior history of sustained VT or VF. Clinicians need to carefully consider these studies in their management of patients with CAD and severe LV dysfunction.     

Unexpected inhibition of bradycardia pacing due to oversensing in ICD lead fracture associated with spurious tachyarrhythmia detection and discharges

Ιn a 76-year old man with a dual-chamber ICD implanted five years ago, dizzy spells and significant bradycardia on Holter were not initially recognized as inhibition of bradycardia pacing, due to oversensing. Hospital admission was deemed necessary only after repetitive ICD shocks attributed to right ventricular pace-sense lead fracture. The need to ensure adequate ICD antibradycardia backup pacing in pacing-dependent patients when deleterious sensing errors occur, cannot be overemphasized.