Robert A. Sorrentino

Chronic performance of an active fixation coronary sinus lead

BACKGROUND Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in appropriately selected patients with heart failure. Optimal left ventricular (LV) lead placement is useful in enhancing response from CRT. Three significant obstacles to LV lead placement are patient-specific variations in coronary venous anatomy, phrenic nerve stimulation, and a significant rate of LV lead dislodgement or microdislodgement. OBJECTIVE The primary objective of this study was to determine the safety and effectiveness of the Medtronic StarFix active fixation LV lead. Secondary objectives evaluated implant success, lead placement and procedure time, lead handling and lobe deployment, additional electrical performance, and all adverse events reported in the study. METHODS There were 441 patients enrolled in this multicenter study. Standard cardiac resynchronization therapy (CRT) inclusion criteria were used. Patients were followed up for a mean of 23 months. Implant data, success with CRT, LV lead performance, clinical outcomes, and experience with LV lead revisions were prospectively evaluated. RESULTS The mean LV stimulation threshold at implant was 1.3 +/- 1 volts and was stable over time. Sensing was also excellent. In 96.3% of the implantations in this study, the physician was able to place the lead in a nonanterior position. Extracardiac (phrenic nerve) stimulation required invasive intervention in 11 subjects (2.5%). Only 3 dislodgements (0.7%) were observed. Two occurred in the first 5 implants and were attributed to inadequate engagement of the venous subbranch. CONCLUSION The Medtronic 4195 is safe and highly efficacious. It affords the physician more choices in lead placement location and has a remarkably low dislodgement rate.

Cardiac implantable electronic device infection in patients with end-stage renal disease

INTRODUCTION Cardiac implantable electronic devices (CIED) are increasingly being used in end-stage renal disease (ESRD) patients. These patients have a high risk of device infection. OBJECTIVES To study the optimal management of device infections in patients with ESRD. METHOD We used the United States Renal Data System (USRDS) to assess the presence of a CIED and associated comorbidities, risk factors for infection, and mortality following device extraction or medical management in ESRD patients with CIED infection. Univariable, multivariable, and survival analyses were performed using USRDS data from 2005 to 2009. RESULTS Of 546,769 patients, 6.4% had CIED and 8.0% of those developed CIED infection. The major risk factors for device infection were black race, temporary dialysis catheter, and body mass index >25. Patients with artificial valves were excluded from the analysis. Only 28.4% of infected CIED were removed. CIED removal was more common in those with congestive heart failure. The median time to death following diagnosis of a CIED infection was 15.7 months versus 9.2 months for those treated via device extraction versus medical-only therapy (hazard ratio: 0.75; 95% confidence interval: 0.68-0.82). CONCLUSION Patients with ESRD and infected CIEDs have a poor prognosis. Rates of device extraction are low, but this strategy appears to be associated with modest improvement in survival.

A novel MRI-safe dual-chamber pacemaker system: Its time has come.

The electromagnetic interference of magnetic resonance imaging (MRI) has prevented many cardiac rhythm device patients and their doctors from using this imaging technology. The very powerful magnetic field generated by MRI can have several effects on an implanted pacemaker system, 1,2 The magnetic field’s attractive effect is minimal on pacemakers because they contain very little ferrous metal. Some studies have noted induced temperature elevations at the distal lead tip that could damage myocardium, causing a rise in pacing thresholds. The pulsed magnetic field during the imaging process has been theorized to cause rapid pacing beyond upper rate programming. Temporary or even permanent pacing inhibition or programming modifications have been postulated. Any of these effects might be life threatening. At least 10 deaths have been attributed to use of MRI in pacemaker patients. 3

Extraction of chronically implanted coronary sinus leads active fixation vs passive fixation leads

BACKGROUND The Medtronic model 4195 (StarFix) left ventricular lead is an active fixation lead that provides additional support within the coronary sinus (CS) via deployable lobes. While this lead has been shown to have excellent stability within the CS, concerns about its extractability have been raised. OBJECTIVE The aim of this study was to compare the safety and efficacy of the extraction of the model 4195 lead vs other Medtronic CS leads in a prospective cohort study. METHODS Patients undergoing extraction of this and other CS leads for standard indications were prospectively enrolled and studied. The primary outcomes of interest were the removal success rates and associated complication rates. Patients were followed for a month postprocedure. RESULTS The overall left ventricular lead extraction success rate was 97.6% (n = 205). Among 40 patients with chronic model 4195 leads, there were 37 successful extractions (92.5%) as compared to 98.8% for the 165 non-4195 leads. However, in 2 of the 3 StarFix lead extraction failures, standard extraction techniques were not used. All 10 of the model 4195 leads that had been implanted for less than 6 months were extracted without incident. CONCLUSION In this largest study of CS lead extractions published to date, the overall success rate of the extraction of chronically implanted CS leads is high and the complication rate is similar in these lead models. The extraction of the model 4195 lead is clearly more challenging, but it can be accomplished in high-volume extraction centers with experienced operators. It is recommended that the model 4195 lead be extracted by experienced operators.

Genomic-based diagnosis of arrhythmia disease in a personalized medicine era

ABSTRACT Introduction: Although thousands of potentially disease-causing mutations have been identified in a handful of genes, the genetic heterogeneity has led to diagnostic confusions, stemming directly from the limitations in our arsenal of genetic tools. Areas covered: We discuss the genetic basis of cardiac ion channelopathies, the gaps in our knowledge and how Next-generation sequencing technology (NGS) and can be used to bridge them, and how induced pluripotent stem cell (iPSC) derived-cardiomyocytes can be used for drug discovery. Expert commentary: Univariate, arrhythmogenic arrhythmias can explain some congenital arrhythmias, however, it is far from a comprehensive understanding of the complexity of many arrhythmias. Mutational screening is a critical step in personalized medicine and is critical to the management of patients with arrhythmias. The success of personalized medicine requires a more efficient way to identify a high number of genetic variants potentially implicated in cardiac arrhythmogenic diseases than traditional sequencing methods (eg, Sanger sequencing). Next-generation sequencing technology provides us with unprecedented opportunities to achieve high-throughput, rapid, and cost-effective detection of congenital arrhythmias in patients. Moreover, in personalized medicine era, IPSC derived-cardiomyocytes can be used as ‘cardiac arrhythmia in a dish’ model for drug discovery, and help us improve management of arrhythmias in patients by developing patient-specific drug therapies with target specificity.

CARDIAC SARCOIDOSIS: AN UNUSUAL CAUSE OF RECURRENT LARGE PERICARDIAL EFFUSION

Recurrent pericardial effusions are commonly idiopathic; however collagen vascular diseases and malignancies are important causes to exclude. Pericardial window is often required in patients with recurrent pericardial effusions. Diagnosis of the underlying condition may be challenging as pericardial

Catheter ablation within the sinuses of Valsalva

i s m b t c c a Cardiac electrophysiologists are continually challenged y arrhythmias originating from locations that may not eem to be amenable to a catheter ablative cure. In search of hese foci or reentrant circuits to ablate, we have even entured onto the epicardial surface either by percutaneusly entering the pericardial space or by surgical thoracotmy. We are more frequently using alternative approaches o ablation when the usual endocardial methods are not uccessful. The efficacy and long-term safety for the more ommon approaches to these foci or circuits is well-known. et more “remote” foci of electrically active myocardium ontinue to challenge us, either because of technical diffiulties in the delivery of an ablation catheter to the target rea or because of surrounding critical anatomic areas that ay be damaged by the ablative energy or subject to mehanical trauma, for example, the atrioventricular (AV) ode, coronary arteries, or valve apparatus. Sometimes the rea of concern is not in the vicinity of the arrhythmia focus ut downstream from the primary ablation target, as with an mbolic stroke. Ablative techniques are continually being valuated and refined to investigate the safety and efficacy f these techniques. The aortic valve with its three cusps and sinuses was rawn and studied in detail by da Vinci in 1513, predating he well-known anatomic works of Vesalius. Da Vinci used n excised aortic valve and glass model to study the eddy urrents within the sinuses, but his anatomic studies were ost until discovered by William Hunter in the 1780s. The inus of the aortic valve was named for Antonio Maria alsalva in his posthumous work from 1740, Opera, that as finally edited and published by Morgagni, a student f Valsalva. The sinuses of Valsalva (SOV) are imporant to a cardiac electrophysiologist not for their hydroynamic properties but for their relationship to small egions of myocardium that may be the uncommon ource of some atrial and ventricular arrhythmias. The natomic relationships of the aortic valve cusps and sinuses re more commonly referenced to the coronary ostia or ortic root and less so to the adjacent atrial or ventricular issue, which are at the base of each cusp or adjacent to the ortic wall portion of the valve apparatus. The noncoro-