Differences Between Access to Follow-Up Care and Inappropriate Shocks Based on Insurance Status of Implantable Cardioverter Defibrillator Recipients.

Differences in implantable cardioverter defibrillator (ICD) utilization based on insurance status have been described, but little is known about postimplant follow-up patterns associated with insurance status and outcomes. We collected demographic, clinical, and device data from 119 consecutive patients presenting with ICD shocks. Insurance status was classified as uninsured/Medicaid (uninsured) or private/Health Maintenance Organization /Medicare (insured). Shock frequencies were analyzed before and after a uniform follow-up pattern was implemented regardless of insurance profile. Uninsured patients were more likely to present with an inappropriate shock (63% vs 40%, p = 0.01), and they were more likely to present with atrial fibrillation (AF) as the shock trigger (37% vs 19%, p = 0.04). Uninsured patients had a longer interval between previous physician contact and index ICD shock (147 ± 167 vs 83 ± 124 days, p = 0.04). Patients were followed for a mean of 521 ± 458 days after being enrolled in a uniform follow-up protocol, and there were no differences in the rate of recurrent shocks based on insurance status. In conclusion, among patients presenting with an ICD shock, underinsured/uninsured patients had significantly longer intervals since previous physician contact and were more likely to present with inappropriate shocks and AF, compared to those with private/Medicare coverage. After the index shock, both groups were followed uniformly, and the differences in rates of inappropriate shocks were mitigated. This observation confirms the importance of regular postimplant follow-up as part of the overall ICD management standard.

Transient and persistent conduction abnormalities following transcatheter aortic valve replacement with the Edwards-Sapien prosthesis: a comparison between antegrade vs. retrograde approaches.

BACKGROUND: Electrocardiographic conduction abnormalities following transcatheter aortic valve replacement (TAVR) with the Edwards-Sapien valve (ESV) are not uncommon and may be transient. We sought to examine the clinical time-course of conduction abnormalities after TAVR with ESV and determine risk factors for persistent abnormalities. METHODS: In this single-center prospective study, 116 consecutive patients underwent implantation of the ESV after approval by the Food and Drug Administration (FDA). Demographic, clinical, and intra-procedural variables were collected in a registry, including ECGs before, immediately after, and at discharge from hospital. Conduction abnormalities were analyzed including PR interval lengthening, QRS widening, left bundle branch block (LBBB), and high-grade AV block. RESULTS: There were 92 patients included in the analysis. A total of 41 new conduction abnormalities were observed in 31 (34 %) patients: 7 new PR prolongation, 14 QRS widening, 14 new LBBB, and 5 high-grade AV block requiring permanent pacemaker. Of the 41 new CAs, 11 (27 %) were transient; of the transient abnormalities, 9 (82 %) resolved within 24 h of the index procedure. Chronic kidney disease was a risk factor for the development of a persistent abnormality and for need for PPM. Antegrade approach was associated with the development of persistent LBBB and persistent QRS widening. CONCLUSIONS: A significant proportion of conduction abnormalities after ESV implantation improved prior to discharge from the hospital, usually within 24 h. CKD is associated with persistence of abnormalities and with need for PPM. Antegrade approach increases risk for new intraventricular conduction delays, including LBBB.

Transient variations of transthoracic impedance as a predictor of heart failure and death in patients with implanted defibrillators.

BACKGROUND: Transient variations in physiological parameters may forewarn of life-threatening cardiac events, but are difficult to identify clinically. Implantable cardioverter defibrillators (ICD) designed to measure transthoracic impedance provide a surrogate marker for pulmonary congestion. OBJECTIVE: The aim of this study is to determine if the frequency of changes in transthoracic impedance (TTI) is associated with congestive heart failure (CHF) exacerbation and predicts mortality. METHODS: We followed 109 consecutive patients (pts) with ICDs (n=58) or CRT-ICDs (n=51) for a mean of 21.3 (+10.2) months. Using 80 ohm-days as a reference, we correlated the frequency of TTI changes above this index to CHF hospitalizations or death. RESULTS: There was at least one TTI threshold crossing in 79 (72%) pts over 23.3 months follow-up, with a mean of 1.8 ± 3.4 per year. There were 18 pts with CHF hospitalizations who had a mean of 4.3 TTI threshold crossings/year (S.D.=±7.3; median=2.8), compared to 1.3 (S.D.=±1.5; median=0.8) among pts without CHF hospitalizations (p=0.0006). Among 20 patients who died during follow-up, there were 4.2 (S.D.=±7.0; median=2.9) TTI threshold crossings/year, compared with 1.3 (S.D.=±1.3; median=0.9) threshold crossings/year among survivors (p=0.0004). Using Cox Proportional Hazard modeling, after adjusting for age, baseline EF, and number of shocks, TTI threshold crossing was an independent predictor of death (HR 1.72, 95% CI 1.26-2.36, p=0.001). CONCLUSIONS: Increased frequency of TTI threshold crossings may be a useful predictor of transient risk for identifying a subgroup of ICD recipients at greater individual risk for death or CHF hospitalizations.

The impact of transvenous lead extraction on tricuspid valve function.

BACKGROUND: Few data exist regarding the effect of transvenous lead extraction (TLE) on tricuspid valve function. The objective of this study was to examine the effect of TLE on the development of postprocedure tricuspid regurgitation (TR). OBJECTIVE: To assess the impact of TLE on tricuspid valve function. METHODS: A single center retrospective analysis of consecutive patients referred for TLE between June 2006 and November 2011. Patients were included only if they underwent transthoracic echocardiography (TTE) before and after lead extraction (N = 124). Patients were assigned a preprocedure and postprocedure TR score on a continuous scale from 0 to 6 (0 = none, 1 = trace, 2 = mild, 3 = mild/moderate, 4 = moderate, 5 = moderate/severe, and 6 = severe). A clinically significant increase in TR was defined as both (1) an increase in TR score of at least two points, and (2) a postprocedure TR score ≥4 (moderate). RESULTS: A total of 124 patients referred for TLE underwent a TTE both before (9 ±16 months) and after lead extraction (4 ± 8 months). A total of 200 leads (1.6 ± 0.8 per patient) were extracted. The mean change in TR score after lead extraction was +0.18 (95% confidence interval [CI] -0.03 to 0.39, P = 0.11). A clinically significant increase in TR occurred in 7/124 (5.6% [CI 2.3-11.3%]) patients. Age ≥75 (+0.45, [CI 0.07-0.84, P = 0.02]), removal of ≥2 leads (+0.40 [CI 0-0.81, P = 0.05]), and powered sheath-assisted extraction (+0.34 [CI 0.05-0.62, P = 0.02]) were significantly associated with an increase in TR score. CONCLUSION: TLE is rarely associated with the development of clinically significant TR. In our cohort, patient age ≥75 years, pacemaker as opposed to ICD, and removal of ≥2 leads predicted worsening TR.

Comparison of inferolateral early repolarization and its electrocardiographic phenotypes in pre- and postadolescent populations.

Inferolateral early repolarization (ER) patterns on standard electrocardiogram (ECG) are associated with increased risk for cardiac and arrhythmic death in general adult population cohorts. We sought to determine the prevalence of inferolateral ER on surface ECG in multiracial pre- and postadolescent populations and to analyze its association with age, race, gender, and ST-segment patterns. A retrospective review was conducted of all ECGs recorded from preadolescent (aged 8-12 years, n = 719) and postadolescent (aged 21-25 years, n = 755) patients seen at a large academic medical center between January 1, 2009, and December 31, 2010. The overall prevalence of inferolateral ER was similar in the preadolescent and postadolescent populations (17% vs 16%, NS). The prevalence of ER increased after puberty in male patients (16% to 25%, p <0.001) and decreased in female patients (18% to 9%, p <0.001). Prevalence of ascending early repolarization (benign variant) also increased in males after puberty (15% to 23%, p <0.004) and decreased in females (11% to 4%, p <0.001). There were no differences in the prevalence of the risk-associated horizontal/descending pattern (3% in both groups). Subgroup analysis was performed on ECGs from the cohort of outpatients without cardiac disease, and the statistical trends remained the same. In conclusion, the overall prevalence of inferolateral ER was higher in pre- and postadolescent populations than in adult populations. However, the prevalence of the risk-associated horizontal/descending ST-segment pattern was only 3%, comparable to prevalence rates in the adult population. The variations in prevalence by gender and age suggest a possible influence of reproductive hormones.

Catheter ablation of scar-related atypical atrial flutter.

AIMS: The aim of the study was to assess the impact of isthmus location of atypical atrial flutters/atrial tachycardias (ATs) on outcomes of catheter ablation. Atrial tachycardias are clinically challenging arrhythmias that can occur in the presence of atrial scar--often due to either cardiac surgery or prior ablation for atrial fibrillation. We previously demonstrated a catheter ablation approach employing rapid multielectrode activation mapping with targeted entrainment manoeuvrs. However, the role that AT isthmus location plays in acute and long-term success of ablation remains uncertain. METHODS AND RESULTS: Retrospective multicenter analysis of 91 consecutive AT patients undergoing ablation using a systematic four-step approach: (i) high-density activation mapping; (ii) analysis of atrial activation to identify wavefronts of electrical propagation; (iii) targeted entrainment of putative channels; and (iv) irrigated radiofrequency ablation of constrained regions of the circuit. Clinical outcomes, procedural details, and clinical profiles were determined. A total of 171 ATs (1.9 ± 1.0 per patient, 26% septal ATs) were targeted for ablation. The acute success rates were 97 and 77% for patients with either non-septal ATs or septal ATs, respectively (P = 0.0023). Similarly, the long-term success rates were 82 and 67% for patients with either no septal ATs or at least one septal AT, respectively (P = 0.1057). The long-term success rates were 75, 88, and 57% for patients with ATs associated with prior catheter ablation, cardiac surgery or MAZE, and idiopathic atrial scar, respectively. CONCLUSION: Catheter ablation of AT can be successfully performed employing a strategy of combined high-density activation and entrainment mapping. Septal ATs are associated with higher rates of acute and long-term recurrences.

Clinical significance of variants of J-points and J-waves: early repolarization patterns and risk.

The variations in the electrocardiographic patterns of J-point elevations, and the complex of J-points and J-waves in early repolarization (ER), in conjunction with disparities in associated sudden cardiac death (SCD) risk, have lead to a recognition of the need to carefully classify the spectrum of these observations. Many questions about the pathogenesis of J-wave patterns, and the associated magnitudes of risk, remain unanswered, especially in regard to the risk implications in certain high-prevalence subpopulations such as athletes, children, and adolescents. Interest in these electrocardiography (ECG) patterns has grown dramatically in recent years, in large part because of the frequency with which these patterns are observed on routine ECGs. In this review, we discuss the current knowledge on the prevalence of different J-point/J-wave patterns and estimates of the magnitude of mortality and SCD risk associated with J-point elevations and J-waves, in what has become known as ER patterns.

Appropriate use of radionuclide imaging.

The growth of radionuclide imaging has raised well-founded concerns about potential overutilization. In response to the need for guidance, appropriate use criteria have been developed, which categorize specific clinical scenarios such as whether radionuclide imaging would be reasonable (appropriate) to perform, or whether the test would be performed for uncertain or inappropriate indications. Using these criteria, practice patterns may be evaluated and information provided to practitioners regarding test ordering. This information, along with clinical decision support, may provide a foundation to improve the utilization of cardiac imaging, preserving patient access to these procedures, but with an emphasis on cost-effectiveness and safety.

Early repolarization: electrocardiographic phenotypes associated with favorable long-term outcome.

BACKGROUND: Early repolarization (ER) in inferior/lateral leads of standard ECGs increases the risk of arrhythmic death. We tested the hypothesis that variations in the ST-segment characteristics after the ER waveforms may have prognostic importance. METHODS AND RESULTS: ST segments after ER were classified as horizontal/descending or rapidly ascending/upsloping on the basis of observations from 2 independent samples of young healthy athletes from Finland (n=62) and the United States (n=503), where ascending type was the dominant and common form of ER. Early repolarization was present in 27/62 (44%) of the Finnish athletes and 151/503 (30%) of the US athletes, and all but 1 of the Finnish (96%) and 91/107 (85%) of US athletes had an ascending/upsloping ST variant after ER. Subsequently, ECGs from a general population of 10 864 middle-aged subjects were analyzed to assess the prognostic modulation of ER-associated risk by ST-segment variations. Subjects with ER ≥0.1 mV and horizontal/descending ST variant (n=412) had an increased hazard ratio of arrhythmic death (relative risk 1.43; 95% confidence interval 1.05 to 1.94). When modeled for higher amplitude ER (>0.2 mV) in inferior leads and horizontal/descending ST-segment variant, the hazard ratio of arrhythmic death increased to 3.14 (95% confidence interval 1.56 to 6.30). However, in subjects with ascending ST variant, the relative risk for arrhythmic death was not increased (0.89; 95% confidence interval 0.52 to 1.55). CONCLUSIONS: ST-segment morphology variants associated with ER separates subjects with and without an increased risk of arrhythmic death in middle-aged subjects. Rapidly ascending ST segments after the J-point, the dominant ST pattern in healthy athletes, seems to be a benign variant of ER.

Inferolateral early repolarization in athletes.

PURPOSE: Early repolarization (ER) has been considered a common benign ECG pattern among young athletes. In contrast, an inferolateral early repolarization pattern has been associated with an increased risk for sudden cardiac death (SCD). The aim of the study was to assess the prevalence of inferolateral ER among young collegiate athletes and to describe the characteristics associated to the pattern. METHODS: We analyzed ECGs from 503 athletes (51% males; age range, 17-24). Information on gender, body weight, race, sport, and family history of SCD was collected. ER was defined as a slow deflection of the down slope of the R wave (≥0.1 mV) or positive wave at J point (≥0.1 mV) in two consecutive inferior or in lateral leads. Additionally, we included voltage measurements according to the Sokolow-Lyon criteria and RR interval measurement. RESULTS: The prevalence of ER was 30% (inferior, 20%; lateral, 21%; both, 11%). Male gender (59% vs. 48%, p = 0.019), left ventricular hypertrophy (LVH) voltage (39% vs. 12%, p < 0.001) was significantly associated with the ER pattern. In addition, there was a trend towards longer RR interval in the inferior ER group (p = 0.06) and there were slightly more African-Americans with ER compared to non-African-American (34% vs. 28%, p = 0.22). Among females (p = 0.039) and African-Americans (p = NS), the association of LVH to ER was not as strong. CONCLUSION: ER is a common finding among young athletes. The ECG marker of LVH is the dominant shared characteristic among the athletes with ER, along with male gender and a trend to greater prevalence among African-American athletes.