Early repolarization pattern in an ethnically diverse population: Increased risk in Hispanics.

BACKGROUND: Early repolarization (ER) pattern on ECG is associated with an increased mortality in Caucasians. This study analyzed the association between ER pattern and all-cause mortality in a population of multiple ethnicities. METHODS: A total of 20 000 individuals were randomly selected and their ECGs were analyzed for ER pattern using the 2015 consensus: end-QRS notching or slurring with a J-point (Jp) ≥0.1 mV in contiguous inferior or lateral leads. Exclusion criteria were age <18, QRS duration of ≥120 ms, and acute myocardial infarction. Kaplan-Meier survival curves were used to assess crude survival, and multivariable logistic regression models were used to determine predictors of all-cause mortality. RESULTS: A total of 17 901 patients with a mean age of 53 met inclusion criteria. Individuals were 62% female, 14% White, 37% Black, 40% Hispanic, and 9% other. Median follow-up time was 6.4 years. ER pattern was noted in 995 (5.6%) patients. Jp ≥2 mm was noted in 282 (1.6%) patients. In those with ER pattern and Jp ≥1 mm, there was no difference in mortality when compared to individuals without Jp elevation (odds ratio [OR]: 0.962, 95% confidence of interval [CI]: 0.819-1.131). Patients with Jp ≥2 mm had a significantly increased all-cause mortality (OR: 1.333, 95% CI: 1.009-1.742). This increased mortality was also significant in Hispanic patients with Jp ≥2 mm (OR: 1.584, 95% CI: 1.003-2.502). CONCLUSION: ER pattern with Jp ≥2 mm is associated with increased mortality in a multiethnic population, apparently driven by an increased risk in Hispanics.

Use of antimicrobial agent pocket irrigation for cardiovascular implantable electronic device infection prophylaxis: Results from an international survey.

PURPOSE: Survey the usage and application protocol of antimicrobial agent pocket irrigation for cardiovascular implantable electronic device (CIED) infection prophylaxis. BACKGROUND: Local antibiotic usage for CIED infection prophylaxis, in particular pocket irrigation, is a well-known strategy but with little data on its clinical effectiveness. METHODS: An anonymous voluntary online survey was sent to a total of 2,092 arrhythmia-oriented cardiologists in 51 countries (1,490 from the United States). RESULTS: There were 487 responses (response rate 23.3%: U.S. 28.2%, outside of the U.S. 11.1%). Eighty-seven percent of respondents use intraoperative antimicrobial agent pocket irrigation and/or an antimicrobial eluting pouch to reduce CIED infection. Fifty-four percent of respondents believe that it is effective to use an antimicrobial agent pocket irrigation to reduce CIED infection; 33% of respondents are uncertain; a few consider this strategy ineffective (13%) or offered no opinion. Significant differences exist in the practice patterns and beliefs between the U.S. and non-U.S. countries (P < 0.05). Ninety-eight percent of respondents report using the same pocket irrigation protocol for permanent pacemaker versus implantable cardioverter defibrillator. Bacitracin (48%), vancomycin (39%), and a cephalosporin (29%) are the most commonly chosen antibiotics. A majority of the respondents are unaware of the cost of using antimicrobial agent pocket irrigation (69%) and neither are they concerned (67%). CONCLUSION: This international survey suggests that, while there are little clinical data to support or discourage such practice, the usage of antimicrobial agent pocket irrigation for CIED infection prophylaxis is widely used in current practice.

Efficacy and Safety Outcomes of Direct Oral Anticoagulants and Amiodarone in Patients with Atrial Fibrillation.

BACKGROUND: Direct oral anticoagulants (DOACs) and amiodarone are widely used in the treatment of nonvalvular atrial fibrillation. The DOACs are P-glycoprotein (P-gp) and cytochrome p-450 (CYP3A4) substrates. Direct oral anticoagulant levels may be increased by the concomitant use of potent dual P-gp/CYP3A4 inhibitors, such as amiodarone, which can potentially translate into adverse clinical outcomes. We aimed to assess the efficacy and safety of drug-drug interaction by the concomitant use of DOACs and amiodarone. METHODS: We performed a systematic review of MEDLINE, the Cochrane Central Register of Clinical Trials, and Embase, limiting our search to randomized controlled trials of patients with atrial fibrillation that have compared DOACs versus warfarin for prophylaxis of stroke or systemic embolism, to analyze the impact on stroke or systemic embolism, major bleeding, and intracranial bleeding risk in patients with concomitant use of amiodarone. Risk ratio (RR) 95% confidence intervals were measured using the Mantel-Haenszel method. The fixed effects model was used owing to heterogeneity (I2) < 25%. RESULTS: Four trials with a total of 71,683 patients were analyzed, from which 5% of patients (n = 3212) were concomitantly taking DOAC and amiodarone. We found no statistically significant difference for any of the clinical outcomes (stroke or systemic embolism [RR 0.85; 95% CI, 0.67-1.06], major bleeding [RR 0.91; 95% CI, 0.77-1.07], or intracranial bleeding [RR 1.10; 95% CI, 0.68-1.78]) among patients taking DOAC and amiodarone versus DOAC without amiodarone. CONCLUSION: On the basis of the results of this meta-analysis, co-administration of DOACs and amiodarone, a dual P-gp/CYP3A4 inhibitor, does not seem to affect efficacy or safety outcomes in patients with atrial fibrillation.

Referral Patterns for Primary Prophylaxis Implantable Cardioverter Defibrillator Therapy for an Urban US Population.

Implantable cardioverter defibrillators (ICDs) have been demonstrated to improve survival for both primary and secondary prevention of sudden cardiac arrest. However, studies suggest that ICD therapy is underused in appropriate candidates. Sex and racial disparities in ICD use have been suggested. We sought to characterize the referral patterns of high-risk patients for the primary prophylaxis of sudden cardiac arrest at a tertiary academic medical center serving a diverse population in an urban US setting. Electronic hospital databases were retrospective reviewed for patients meeting criteria for prophylactic ICD implantation. We evaluated the association of gender, age, race, and primary language with the referral and subsequent implantation of an ICD. We identified 1,055 patients satisfying prophylactic ICD criteria: 600 men, mean age 62.6 years, 27.6% black, 19.3% white, 23.3% Hispanic, and 49.8% primary language of English. Of the 673 patients (63.7%) referred for ICD evaluation, 345 underwent implantation, 125 declined, and 203 had significant co-morbidities that precluded implantation. Gender, race, and primary language were not associated with referral for ICD or with decision to proceed with implantation. Patients of increased age were less likely to be referred for ICD and were more likely to refuse implantation. ICD therapy was not considered in 146 patients eligible for prophylactic implantation. In conclusion, referral rates for ICD consideration were higher at our institution than in previous reports. Nonetheless, 14% of appropriate patients were not considered. This argues for the importance of increased education for patients and referring physicians.

Prognostic value of automatically detected early repolarization.

Early repolarization associated with sudden cardiac death is based on the presence of >1-mm J-point elevations in inferior and/or lateral leads with horizontal and/or downsloping ST segments. Automated electrocardiographic readings of early repolarization (AER) obtained in clinical practice, in contrast, are defined by ST-segment elevation in addition to J-point elevation. Nonetheless, such automated readings may cause alarm. We therefore assessed the prevalence and prognostic significance of AER in 211,920 patients aged 18 to 75 years. The study was performed at a tertiary medical center serving a racially diverse urban population with a large proportion of Hispanics (43%). The first recorded electrocardiogram of each individual from 2000 to 2012 was included. Patients with ventricular paced rhythm or acute coronary syndrome at the time of acquisition were excluded from the analysis. All automated electrocardiographic interpretations were reviewed for accuracy by a board-certified cardiologist. The primary end point was death during a median follow-up of 8.0 ± 2.6 years. AER was present in 3,450 subjects (1.6%). The prevalence varied significantly with race (African-Americans 2.2%, Hispanics 1.5%, and non-Hispanic whites 0.9%, p <0.01) and gender (male 2.4% vs female 0.6%, p <0.001). In a Cox proportional hazards model controlling for age, smoking status, heart rate, QTc, systolic blood pressure, low-density lipoprotein cholesterol, body mass index, and coronary artery disease, there was no significant difference in mortality regardless of race or gender (relative risk 0.98, 95% confidence interval 0.89 to 1.07). This was true even if J waves were present. In conclusion, AER was not associated with an increased risk of death, regardless of race or gender, and should not trigger additional diagnostic testing.

Rate of cardiovascular implantable electronic device (CIED) re-extraction after recurrent infection.

BACKGROUND: Patients who develop a cardiovascular implantable electronic device (CIED) infection requiring extraction may have risk factors that make them prone to developing another infection of the reimplanted CIED. However, the rate of a second infection requiring repeat extraction in such patients is unknown and may have important clinical implications. METHODS: We retrospectively reviewed all patients at our institution from January 2001 to October 2012 who underwent a CIED extraction for an infection and then required reimplantation. We then reviewed the incidence of a repeat extraction due to a second infection. Clinical and device parameters at the time of the second infection were retrieved. RESULTS: There were 168 patients who underwent a CIED extraction because of infection and were subsequently reimplanted. The median time to reimplantation was 3 [1(st) quartile: 1, 3(rd) quartile: 10] days. After a mean follow-up of 4.4 ± 2.7 years, nine (5.4%) patients underwent a repeat CIED extraction due to a second infection. Six repeat extractions (67%) occurred in the first year, leading to an event rate of 3.9% within 1 year of reimplantation. Patients with a second infection requiring a repeat CIED extraction were younger (57 ± 20 vs 68 ± 16, P = 0.046). Pocket infection was the most common presentation of a second infection, occurring in eight of the nine patients. CONCLUSION: The rate of a second infection leading to a CIED repeat extraction is elevated within the first year after reimplantation. To determine predictors of recurring infection, analysis of a larger multicenter series is warranted.

Chest radiographs are valuable in demonstrating clinically significant pacemaker complications that require reoperation.

PURPOSE: To evaluate the utility of chest radiography in demonstrating clinically significant pacemaker complications that required reoperation. METHODS: In this retrospective case-controlled series, we identified 14 consecutive adults who required pacemaker reoperation and who had chest radiographs available for review (6 men, 8 women; mean age, 71 years [range, 43-95 years]). Ten patients had pacemakers implanted at our institution, and 4 were referred for reoperation. Forty-two controls, 3 for each patient, had postoperative chest radiographs and normal device function (25 men, 17 women; mean age 76 years [range, 37-96 years]). All postoperative chest radiographs, including 1-year follow-ups, were blindly reviewed by at least 2 of 4 radiologists for lead perforation and position of right atrial and right ventricular leads. Follow-up radiographs were assessed for lead perforation, lead displacement, and lead fracture. Data were analysed by using the Fisher exact test. RESULTS: Of the patients, 1.7% (10/581) required reoperation for pacemaker dysfunction (noncapture, oversensing, abnormal atrial and ventricular thresholds, failing impedance), extracardiac stimulation, and lead perforation and/or displacement. There were no lead fractures. Chest radiographs demonstrated pacemaker complications in 57% of patients (8/14) at a median of 2 days (<1-32 days) after implantation and in 5% of the controls (2/42) (P < .0001). None of the abnormalities were noted on the official reports. Among subgroups, chest radiographs were abnormal for the following indications: pacemaker dysfunction in 4 of 7 patients versus 0 of 21 controls (P = .0017), extracardiac stimulation in 1 of 3 patients vs 0 of 9 controls (P = .25), and lead perforation and/or displacement in 3 of 4 patients vs 2 of 12 controls (P = .06). CONCLUSIONS: Chest radiographs are useful after pacemaker placement and demonstrate the majority of complications that require reoperation. Familiarity with the expected normal position of the leads, appearances of pacemaker complications, and comparison with prior radiographs is crucial in rendering a correct diagnosis that guides patient management.

The psychological impact of implantable cardioverter-defibrillator recalls and the durable positive effects of counseling.

BACKGROUND: It is known that patients with lifesaving devices such as implantable cardioverter-defibrillators (ICDs) may be alarmed and worried by recalls or alerts related to their ICDs. OBJECTIVES: This study aimed to determine whether counseling has any short- or long-term benefits, and to look for characteristics that identify those most worried and those most in need of counseling. METHODS: Among 100 patients with recall or alert ICDs, 14 were pacer dependent; 50 had ICDs for 1 degrees prevention and 22 were women. Patients completed a survey indicating how worried they were on learning of the recall or alert (0-10 scale). After counseling and advice in accordance with manufacturer guidelines, patients were asked to indicate their level of worry, and were again asked after 6 months. RESULTS: For all patients, the "worry level" at the initial interview was 5.0+/-3.7, falling to 2.2+/-3.0 after counseling (P < 0.001) and 1.4+/-2.3 after 6 months (P < 0.001 vs both earlier levels). There were no significant differences between those implanted for 1 degrees versus 2 degrees prevention or for pacer dependency. Women were initially more worried than men, but not for the long term. The 49 patients whose ICDs could be managed by reprogramming or software fix had significant reduction in worry after counseling and at 6 months compared to others. The 18 patients recommended for operative intervention remained more concerned after counseling (3.5+/-3.3 vs 1.9+/-2.9, P = 0.043). CONCLUSIONS: Patients' concerns resulting from ICD recalls or alerts can be reduced by appropriate counseling. Those patients whose ICDs could be reprogrammed to safer parameters had the most reduction in worry levels.

Clinical utility of intraprocedural transesophageal echocardiography during transvenous lead extraction.

BACKGROUND: Transvenous lead extraction carries a risk of significant complications. Although intraoperative transesophageal echocardiography (TEE) is widely used to monitor cardiac performance and structures, its utility during transvenous lead extraction has not been well described. OBJECTIVE: This study evaluates the utility of TEE during transvenous lead extraction. METHODS: The records of 108 consecutive patients who underwent transvenous lead extraction with TEE guidance were reviewed. RESULTS: Transvenous extraction of 202 leads was attempted; complete extraction was achieved for 174 leads (86%) and partial extraction for 13 leads with clinically acceptable outcomes in 187 leads (93%). Mean age of the patients was 63 +/- 21 (14-99) years and 37% were female. The average number of leads per patient was 1.9 (1-6). Mean implant duration was 71 +/- 57 (1-360) months. Indications for extraction were pocket infection (53 patients), bacteremia (33), atrial J-lead fracture or recall (13), lead malfunction (8), and venous thrombosis (1). TEE identified critical findings that prompted emergency surgical intervention or converted transvenous lead extraction to surgical explantation in 6 patients (two cases with cardiac laceration, 3 cases of cardiac tamponade, and one case with a large vegetation and a patent foramen ovale). TEE eliminated the need for the premature termination of the procedure in 11 patients by excluding significant structural cardiac damage. Overall, TEE provided clinically useful information during transvenous lead extraction in 17 cases (16%). CONCLUSIONS: TEE during transvenous lead extraction provides valuable real-time information that improves efficacy and safety.

Intravenous sedation for cardiac procedures can be administered safely and cost-effectively by non-anesthesia personnel.

AIMS: Primary: to determine the safety and efficacy of intravenous sedation for cardiac procedures administered by non-anesthesia personnel. Secondary: to assess cost effectiveness of such sedation. METHODS: Anesthesiologists trained non-anesthesia personnel, and established our sedation protocol, which was then used in 9,558 patients who had cardiac procedures with sedation by non-anesthesia personnel, recorded on a computerized database. Most sedation used was midazolam (MID) and morphine (MOR). Complications and problems were derived from the database and quality assurance committee records. Doses were based on desired level of sedation and procedure duration; highest dose used: MID 78 mg, MOR 84 mg. RESULTS: Data included catheterization (n = 3,819) and transesophageal echo procedures (n = 260); and overall electrophysiology (n = 5,479) and selected subsets. There were complications or problems in only 9 patients (0.1%), a strong safety statement. There were 3 deaths in electrophysiology related procedures, 2 deaths in catheterization related procedures, all in very sick patients and not definitely related to sedation; 4 others developed clinical instability (hives, hypotension and heart failure-all with no sequellae), 2 of which needed reversal medications. Three patients (<0.03%) proved difficult to sedate, and their procedures were completed with help from the anesthesia department; by protocol this was not a complication. A total of $5,365,691 was saved during the last decade on cardiac procedures performed with conscious sedation. CONCLUSION: Non-anesthesia personnel can administer intravenous sedation for cardiac procedures in cardiac settings, with safety and cost-effectiveness demonstrated over many years. Anesthesia services are still appropriate for selected cases.

Rate responsive pacemakers: a rapid assessment protocol.

BACKGROUND: Rate responsive (RR) pacemakers are commonly implanted with nominal conservative factory-set responsiveness, which is usually accepted because established exercise protocols are time-consuming. We aimed for efficient assessment of RR pacemaker settings. METHODS: We tested exercise heart rates in controls and paced patients using a brief exercise test that approximates real-life levels of exertion. The test used a nonmotorized treadmill: 30 seconds walking at patient-determined speed followed by 15 seconds brisk exertion. Subjects totaled 110: 26 with RR pacemakers; 22 with non-RR pacers; 27 "sick" nonpaced control patients; and 35 healthy controls. Heart rate (HR) was measured prior to exercise, after 30 seconds of casual walk, after 15 seconds of brisk walk, and 1 minute into recovery. Testing required <5 minutes from set-up to recovery. RESULTS: The 26 RR pacer patients had a mean HR at rest = 74 +/- 10 beats per minute (bpm), walk = 87 +/- 14, and brisk = 94 +/- 18 (increase 27%). Non-RR pacer patients (n = 22): rest = 73 +/- 12 bpm, walk = 88 +/- 14, and brisk = 94 +/- 17 (increase 24.3%, P = 0.60 vs RR patients). "Sick" controls (n = 27): rest = 78 +/- 14 bpm, walk = 102 +/- 17, and brisk = 117 +/- 18 (increase 51.9%, P< 0.001 vs RR pts). For the healthy controls, HRs were at rest 83+/11 bpm, walk = 104 +/- 12, and brisk = 117 +/- 13 (P< 0.001 compared to both paced groups; P = NS vs sick controls). CONCLUSIONS: Nominal RR settings may be suboptimal for many patients. The nonmotorized treadmill test allows quick and inexpensive assessment of RR programming, with the potential for efficient RR optimization.

Prevalence and characterization of asymptomatic pacemaker and ICD lead perforation on CT.

BACKGROUND: Pacemakers and implantable cardiac defibrillators (ICDs) are widely used for the management of cardiac arrhythmias and congestive heart failure (CHF). Acute implantation complication rates range from 3% to 7%. The aim of this study is to describe the incidence of lead perforation on computed tomography (CT), and correlate these findings with electrophysiologic data. METHODS: Images of 100 consecutive patients with permanent pacemakers (n = 72) or ICDs (n = 28) who underwent multidetector CTs of the chest were identified. Cases were reviewed by 2 cardiothoracic radiologists, and a third if there was disagreement. Each CT was reviewed for device and fixation type, tip position, and presence of pericardial effusion. Results were correlated with lead impedance and pacing threshold, when available [79% (79/100)]. A cardiac electrophysiologist interpreted device data. RESULTS: All 100 patients had right ventricular leads (58 passive, 42 active) and 61 had right atrial leads (12 passive, 49 active). 15% (15/100) of patients had a lead perforation. Perforation rates were 15% (9/61) for atrial and 6% (6/100) for ventricular leads (P < 0.05, chi square). Four of 28 (14%) right ventricular ICD leads and 2 of 72 (3%)right ventricular pacemaker leads were perforated (P < 0.05, chi square). 12% (6/49) of active right atrial leads, and 25% (3/12) of passive right atrial leads perforated (P = NS, chi square). 7% (3/42) of active right ventricular leads, and 5% (3/58) of passive ventricular leads perforated (P = NS, chi square). Electrophysiologic parameters did not differ significantly between perforated and nonperforated leads. CONCLUSION: Asymptomatic perforation is a common phenomenon and rarely resulting in electrophysiologic consequences. Atrial leads perforated more frequently than ventricular leads, and ventricular ICD leads perforated more frequently than ventricular pacemaker leads.

Effects of cardioactive medications on retrograde conduction: continuing relevance for current devices.

INTRODUCTION: Retroconduction (ventriculo-atrial conduction) remains a problem for patients with implanted cardiac rhythm devices. Pacemaker algorithms can detect and terminate endless loop tachycardia (ELT), but actual prevention of ELT may require anti-arrhythmic drugs (AADs). Similarly, AADs can affect ICD rhythm discrimination algorithms that depend on atrio-ventricular ratios. There is concern whether these drugs remain effective during stress situations. METHODS: Electrophysiologic studies that included retroconduction testing using slow ramp pacing were done in 1332 patients. The presence or absence of retroconduction at baseline and with drug was recorded, as was the rate at block. As a stress surrogate, isoproterenol was used to test retroconduction and reversal of drug-induced block. RESULTS: Procainamide, mexiletine, phenytoin, disopyramide, quinidine, beta-blockers, encainide, and amiodarone caused complete retrograde block or decreased the rate at which block occurred (mean 76% of patients, p < 0.008), whereas digoxin, lidocaine, diltiazem, and verapamil did not. Isoproterenol (in the absence of AADs) increased the rate at block in 82% of 404 patients with retroconduction at baseline (p < 0.005). Of 319 patients without retroconduction at baseline, 134 (42%) developed retroconduction after isoproterenol. Isoproterenol reversed retrograde block in 39% of patients with block on an AAD. Amiodarone, digoxin, and the combination of digoxin plus a beta-blocker were most effective at resisting this reversal of ventriculo-atrial block (80%, 68%, and 75% respectively). CONCLUSION: Most of the AADs reviewed increase the cycle length at block or abolish retroconduction, while isoproterenol has the opposite effect. Anti-arrhythmic medications, particularly amiodarone, digoxin, and the combination of digoxin plus a beta-blocker may be considered for a patient with multiple ELT episodes or certain ICD detection problems.

Value of pre-hospital discharge defibrillation testing in recipients of implanted cardioverter defibrillators.

Opinions vary regarding the need to perform defibrillation testing prior to hospital discharge in recipients of state-of-the-art cardioverter defibrillators (ICDs). Our protocol is to perform predischarge ICD testing 1 day after implant. This report includes 682 consecutive implants. Adverse observations at testing were grouped into (1) risk of defibrillation failure, (2) surgical complications, (3) sensing/pacing issues or narrow defibrillation margin warranting closer follow-up, or (4) findings correctable by device reprogramming. Among the 682 patients, 63% had single-chamber and 37% dual-chamber or biventricular ICDs. In 48 patients (7%) there were 69 concerns and/or interventions, with overlaps among the four categories, including one failure to defibrillate (0.15%), and six other patients at risk. Surgical complications included 11 hematomas (1.6%), and six lead dysfunctions. Closer follow-up was indicated in 19 patients (2.7%), for high pacing thresholds in seven, sensing issues in seven, and <10 J defibrillation margin in five. Device reprogramming was needed in 31 patients (4.5%), for tachycardia detection and therapy settings in 12, and for pacing/sensing functions in 22 patients. In eight patients ventricular fibrillation could not be induced. There was no morbidity or mortality due to testing. The state-of-the-art ICDs delivering biphasic shocks are remarkably reliable. The routine pre-hospital discharge defibrillation testing of such ICDs may be optional and left to the physicians' discretion.