ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices--summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines)

Physiological Pacing for the Prevention and Treatment of Heart Failure: a State-of-the-Art Review

Permanent pacing from the right ventricular apex can reduce quality of life and increase the risk of heart failure and death. This review summarizes the milestones in the evolution of pacemakers toward physiological pacing with biventricular pacing systems and lead implantation into the cardiac conduction system to synchronize cardiac contraction and relaxation. Both approaches aim to reproduce normal cardiac activation and help to prevent and treat heart failure. This review introduces the basic concepts and clinical evidence and discusses the practical uses of physiological pacing.

Perioperative cardiac risk reduction in non cardiac surgery

For patients undergoing nonemergent noncardiac surgery, care must be taken to identify patients at increased risk of major adverse cardiovascular events, as these remain a significant source of perioperative morbidity and mortality. Identification of at-risk patients requires careful attention to risk factors including assessment of functional status, medical comorbidities, and a medication assessment. After identification, to minimize perioperative cardiac risk, care should be taken through a combination of appropriate medication management, close monitoring for cardiovascular ischemic events, and optimization of pre-existing medical conditions. There are multiple society guidelines that aim to mitigate risk of cardiovascular morbidity and mortality in patients undergoing nonemergent noncardiac surgery. However, the rapid evolution of medical literature often creates gaps between the existing evidence and best practice recommendations. In this review, we aim to reconcile the recommendations made in the guidelines from the major cardiovascular and anesthesiology societies from the USA, Canada, and Europe, and to provide updated recommendations based on new evidence.

Cost of Pacing in Pediatric Patients With Postoperative Heart Block After Congenital Heart Surgery

Importance

Surgical correction of congenital heart defects (CHDs) has improved the lifespan and quality of life of pediatric patients. The number of congenital heart surgeries (CHSs) in children has grown continuously since the 1960s. This growth has been accompanied by a rise in the incidence of postoperative heart block requiring permanent pacemaker (PPM) implantation.

Objective

To assess the trends in permanent pacing after CHS and estimate the economic burden to patients and their families after PPM implantation.

Design, Setting, and Participants

In this economic evaluation study, procedure- and diagnosis-specific codes within a single-institution database were used to identify patients with postoperative heart block after CHS between January 1, 1960, and December 31, 2018. Patients younger than 4 years with postoperative PPM implantation were selected, and up to 20-year follow-up data were used for cost analysis based on mean hospital event charges and length of stay (LOS) data. Data were analyzed from January 1, 2020, to November 30, 2022.

Exposure

Implantation of PPM after CHS in pediatric patients.

Main Outcomes and Measures

Annual trends in CHS and postoperative PPM implantations were assessed. Direct and indirect costs associated with managing conduction health for the 20 years after PPM implantation were estimated using Markov model simulation and patient follow-up data.

Results

Of the 28 225 patients who underwent CHS, 968 (437 female [45.1%] and 531 male [54.9%]; 468 patients aged <4 years) received a PPM due to postoperative heart block. The rate of CHS and postoperative PPM implantations increased by 2.2% and 7.2% per year between 1960 and 2018, respectively. In pediatric patients younger than 4 years with PPM implantation, the mean (SD) 20-year estimated direct and indirect costs from Markov model simulations were $180 664 ($32 662) and $15 939 ($1916), respectively. Using follow-up data of selected patients with clinical courses involving 1 or more complication events, the mean (SD) direct and indirect costs were $472 774 ($212 095) and $36 429 ($16 706), respectively.

Conclusions and Relevance

In this economic evaluation study, the cost of PPM implantation in pediatric patients was found to accumulate over the lifespan. This cost may represent not only a substantial financial burden but also a health care burden to patient families. Reducing the incidence of PPM implantation should be a focused goal of CHS.

Association of left ventricular remodeling with cardiac resynchronization therapy outcomes

BACKGROUND

Cardiac resynchronization therapy (CRT) response stratified by left ventricular (LV) remodeling revealed differing mortality profiles for distinct patient cohorts. Measuring functional end points, as well as mortality, may better assess CRT efficacy and inform patient management. However, the association between LV remodeling and functional outcomes after CRT is not well understood.

OBJECTIVE

The purpose of this study was to evaluate long-term CRT outcomes by extent of LV remodeling.

METHODS

REsynchronization reVErses Remodeling in Systolic Left vEntricular dysfunction (ClinicalTrials.gov identifier NCT00271154) was a prospective, double-blind, randomized trial of CRT. Subjects were classified on the basis of LV end-systolic volume (LVESV) change from baseline to 6 months post-CRT: worsened (increase), stabilized (0%-≤15% reduction), responder (>15%-<30% reduction), and super-responder (≥30% reduction). Subjects were evaluated annually for 5 years.

RESULTS

The analyses included 353 subjects randomized to CRT-ON arm. All-cause mortality was higher in the worsened group than in the other 3 response groups (29.8% vs 8.0%; P < .0001), with no difference in survival among those groups (P = .87). A significant interaction between the LVESV group and time was observed for health status and quality of life (P = .02 for both). The interaction was not significant for 6-minute hall walk (P = .79); however, super-responders had increased walk distance compared with the other 3 response groups (P = .03).

CONCLUSION

Preventing further increase in LVESV with CRT was associated with reduced mortality, whereas functional measure improvement was associated with LV remodeling magnitude. These results support the consideration of functional and mortality end points to assess CRT efficacy and provide further evidence that the dichotomous "responder and nonresponder" classification should be modified.

Social determinants of pacemaker reuse among patients and family members in Pakistan

OBJECTIVES

This survey aimed to quantify the opinions of CIED reuse among patients and family members in Pakistan and to identify the social determinants which may predict these views.

METHODS

A questionnaire formulating attitudes toward PPM reuse was administered to patients and family members at cardiology institutes in Pakistan from 1 July 2022 to 30 September 2022. The eligibility criteria (age > 18 years; inline for PPM placement) were taken into account and incomplete responses were excluded from the final analysis.

RESULTS

A total of 9,246 participants recorded their responses, of which 7,152 (78.16%) accepted pre-used PPMs. The lower social class had more PPM reuse acceptance rate than the middle and upper class (92.72% vs. 60.52% vs. 35.38%), respectively. Age ≥ 65 (OR(95%CI): 0.68 (0.41-0.99); P-value = 0.023), male gender (OR(95%CI): 0.55 (0.35-0.72), P-value = 0.016), unemployment (OR(95%CI): 0.47 (0.25-0.64); P-value = 0.007), poor health status (OR(95%CI): 0.72 (0.53-0.92); P-value = 0.041), and lower social class (OR(95%CI): 0.36 (0.28-0.53); P-value = 0.003) were social determinants of PPM reuse acceptance.

CONCLUSION

Patients and their family members endorse the concept of PPM reuse in Pakistan who cannot afford new devices.

Physical function, psychological adjustment, and self-efficacy following sudden cardiac arrest and an initial implantable cardioverter defibrillator (ICD) in a social cognitive theory intervention: secondary analysis of a randomized control trial

BACKGROUND

Sudden cardiac arrest (SCA) survivorship results in unique issues in return to physical and psychological function. The purpose of the study was to compare recovery across the first year between SCA survivors and other arrhythmia patients who received a first-time implantable cardioverter defibrillator (ICD) for secondary prevention, participating in a social cognitive theory (SCT) intervention.

METHODS

168 (129 males, 39 females) who received an ICD for secondary prevention (SCA N = 65; other arrhythmia N = 103) were randomized to one of two study conditions: SCT intervention (N = 85) or usual care (N = 83). Outcomes were measured at baseline hospital discharge, 1, 3, 6, & 12 months: (1) Physical Function: Patient Concerns Assessment (PCA), SF-36 (PCS); (2) Psychological Adjustment: State Trait Anxiety (STAI), CES-D depression, SF-36 (MCS); (3) Self-Efficacy: Self-Efficacy (SCA-SE), Self-management Behaviors (SMB), Outcome Expectations (OE). Outcomes were compared over 12 months for intervention condition x ICD indication using general estimating equations.

RESULTS

Participants were Caucasian (89%), mean age 63.95 ± 12.3 years, EF% 33.95 ± 13.9, BMI 28.19 ± 6.2, and Charlson Index 4.27 ± 2.3. Physical symptoms (PCA) were higher over time for SCA survivors compared to the other arrhythmia group (p = 0.04), ICD shocks were lower in SCA survivors in the SCT intervention (p = 0.01); psychological adjustment (MCS) was significantly lower in SCA survivors in the SCT intervention over 6 months, which improved at 12 months (p = 0.05); outcome expectations (OE) were significantly lower for SCA survivors in the SCT intervention (p = 0.008).

CONCLUSIONS

SCA survivors had greater number of physical symptoms, lower levels of mental health and outcome expectations over 12 months despite participation in a SCT intervention. Trial registration Clinicaltrials.gov: NCT04462887.

Epicardial pacemaker insertion in a preterm very low birth weight neonate – An anaesthetic challenge

Congenital complete heart block (CCHB) has an incidence of one in 20,000 live births and carries a 20% risk of mortality. The hemodynamic instability due to bradycardia and asystole due to the increasing metabolic demands can be avoided by appropriate antenatal planning, timely delivery and initiation of medical treatment and early pacemaker insertion. In this report, we discuss the anaesthetic challenges of permanent epicardial pacemaker insertion with good outcomes in a 32-week gestational age 1380 grams neonate within a few hours of birth.

The Diagnostic Challenges Associated with Type 2 Myocardial Infarction

The diagnostic challenges associated with type 2 myocardial infarction (T2MI) evolve around an extensive evidence base. T2MI is a type of MI that occurs secondary to ischemia due to increased demand or decreased oxygen supply. This classification has been used for the last 5 years, yet there is little understanding of the characteristics and clinical outcomes. According to a survey, T2M1 can be caused mainly by different factors such as anemia (31%), sepsis (24%), and arrhythmia (17%). Other associated factors, such as age and gender, also play a part in the disease. The pathology behind T2MI is the rise and fall of cardiac troponin values with at least one value above the 99 percentile and evidence of an imbalance unrelated to coronary thrombosis. The diagnosis of the condition is evidence-based backed up with imaging techniques. The treatment of T2MI may involve blood pressure management, administration of blood products, heart rate control, and respiratory support. Depending on the clinical presentation, coronary evaluations can be used to assess the likelihood of coronary artery disease (CAD). If indicated, the MI guidelines may apply to CAD. If it shows, the MI guidelines may use electrocardiography findings of ST-segment elevation myocardial infarction (STEMI) or non-STEMI. However, the absence of CAD indicates that the benefits of cardiovascular risk reduction strategies with T2MI remain uncertain.

Bradyarrhythmias and Physiologic Pacing in the ICU

Bradyarrhythmias represent a common pathology in the intensive care unit (ICU) with etiologies of varying severity. Treatment has often been focused on correcting underlying causes and may require pacing for urgent hemodynamic support. In recent years, there has been interest in physiologic pacing modalities which avoid the dyssynchrony from right ventricular (RV) only pacing. Cardiac resynchronization therapy (CRT) through biventricular pacing is a well-established device-based electrical therapy in patients with wide QRS and heart failure. Recently, it has been shown that biventricular pacing may also be pursued for hemodynamic rescue in the ICU setting. Efforts to re-engage the conduction system with His bundle pacing or further downstream have also emerged as alternative means to deliver resynchronization, with early applications in the ICU now being reported. The goal of the review is to examine bradyarrhythmia causes and management in the ICU as well as investigate new approaches in physiologic pacing and their potential roles in critically ill patients.

Cardiac Resynchronization Therapy Response Assessment with Electromechanical Activation Mapping within 24 Hours of Device Implantation: A Pilot Study

BACKGROUND

Cardiac resynchronization therapy (CRT) response assessment relies on the QRS complex narrowing criterion. Yet one third of patients do not improve despite narrowed QRS after implantation. Electromechanical wave imaging (EWI) is a quantitative echocardiography-based technique capable of noninvasively mapping cardiac electromechanical activation in three dimensions. The aim of this exploratory study was to investigate the EWI technique, sensitive to ventricular dyssynchrony, for informing CRT response on the day of implantation.

METHODS

Forty-four patients with heart failure with left bundle branch block or right ventricular (RV) paced rhythm and decreased left ventricular ejection fraction (LVEF; mean, 25.3 ± 9.6%) underwent EWI without and with CRT within 24 hours of device implantation. Of those, 16 were also scanned while in left ventricular (LV) pacing. Improvement in LVEF at 3-, 6-, or 9-month follow-up defined (1) super-responders (ΔLVEF ≥ 20%), (2) responders (10% ≤ ΔLVEF < 20%), and (3) nonresponders (ΔLVEF ≤ 5%). Three-dimensionally rendered electromechanical maps were obtained under RV, LV, and biventricular CRT pacing conditions. Mean RV free wall and LV lateral wall activation times were computed. The percentage of resynchronized myocardium was measured by quantifying the percentage of the left ventricle activated within 120 msec of QRS onset. Correlations between percentage of resynchronized myocardium and type of CRT response were assessed.

RESULTS

LV lateral wall activation time was significantly different (P ≤ .05) among all three pacing conditions in the 16 patients: LV lateral wall activation time with CRT in biventricular pacing (73.1 ± 17.6 msec) was lower compared with LV pacing (89.5 ± 21.5 msec) and RV pacing (120.3 ± 17.8 msec). Retrospective analysis showed that the percentage of resynchronized myocardium with CRT was a reliable response predictor within 24 hours of implantation for significantly (P ≤ .05) identifying super-responders (n = 7; 97.7 ± 1.9%) from nonresponders (n = 17; 89.9 ± 9.9%).

CONCLUSION

Electromechanical activation mapping constitutes a valuable three-dimensional visualization tool within 24 hours of implantation and could potentially aid in the timely assessment of CRT response rates, including during implantation for adjustment of lead placement and pacing outcomes.

Redefining the Classifications of Response to Cardiac Resynchronization Therapy: Results From the REVERSE Study

OBJECTIVES

This study sought to assess the impact of a more detailed classification of response on survival.

BACKGROUND

Cardiac resynchronization therapy (CRT) improves functional status and outcomes in selected populations with heart failure (HF). However, approximately 30% of patients do not improve with CRT by various metrics, and they are traditionally classified as nonresponders.

METHODS

REVERSE (Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction) was a randomized trial of CRT among patients with mild HF. Patients were classified as Improved, Stabilized, or Worsened using prespecified criteria based on the clinical composite score (CCS) and change in left ventricular end-systolic volume index (LVESVi). All-cause mortality across CRT ON subgroups at 5 years was compared.

RESULTS

Of the 406 subjects surviving 1 year, 5-year survival differed between CCS subgroups (p = 0.03), with increased mortality in the Worsened response group. Of the 353 subjects with adequate echocardiograms, survival differed significantly between response groups (p < 0.001), also due to increased mortality in the Worsened group. When combining CCS and LVESVi results, the lowest survival was observed among subjects who worsened for both measures, whereas the highest survival occurred in subjects who did not worsen by either endpoint. Multivariate analysis showed that LVESVi worsening with CRT at 6 months, baseline LVESVi, and gender were independent predictors of survival.

CONCLUSIONS

For both CCS and reverse remodeling, patients who worsen with CRT have a high mortality, although remodeling was the more important endpoint. Patients who stabilize early with CRT have a much better prognosis than previously recognized, suggesting that the current convention of nonresponder classification should be modified. (REVERSE [Resynchronization Reverses Remodeling in Systolic Left Ventricular Dysfunction]; NCT00271154).

Relationship of LVEF and Myocardial Scar to Long-Term Mortality Risk and Mode of Death in Patients With Nonischemic Cardiomyopathy

BACKGROUND

Nonischemic cardiomyopathy is a leading cause of reduced left ventricular ejection fraction (LVEF) and is associated with high mortality risk from progressive heart failure and arrhythmias. Myocardial scar on cardiovascular magnetic resonance imaging is increasingly recognized as a risk marker for adverse outcomes; however, left ventricular dysfunction remains the basis for determining a patient's eligibility for primary prophylaxis with implantable cardioverter-defibrillator. We investigated the relationship of LVEF and scar with long-term mortality and mode of death in a large cohort of patients with nonischemic cardiomyopathy.

METHODS

This study is a prospective, longitudinal outcomes registry of 1020 consecutive patients with nonischemic cardiomyopathy who underwent clinical cardiovascular magnetic resonance imaging for the assessment of LVEF and scar at 3 centers.

RESULTS

During a median follow-up of 5.2 (interquartile range, 3.8, 6.6) years, 277 (27%) patients died. On survival analysis, LVEF ≤35% and scar were strongly associated with all-cause (log-rank test P=0.002 and P<0.001, respectively) and cardiac death (P=0.001 and P<0.001, respectively). Whereas scar was strongly related to sudden cardiac death (SCD; P=0.001), there was no significant association between LVEF ≤35% and SCD risk (P=0.57). On multivariable analysis including established clinical factors, LVEF and scar are independent risk markers of all-cause and cardiac death. The addition of LVEF provided incremental prognostic value but insignificant discrimination improvement by C-statistic for all-cause and cardiac death, but no incremental prognostic value for SCD. Conversely, scar extent demonstrated significant incremental prognostic value and discrimination improvement for all 3 end points. On net reclassification analysis, the addition of LVEF resulted in no significant improvement for all-cause death (11.0%; 95% CI, -6.2% to 25.9%), cardiac death (9.8%; 95% CI, -5.7% to 29.3%), or SCD (7.5%; 95% CI, -41.2% to 42.9%). Conversely, the addition of scar extent resulted in significant reclassification improvement of 25.5% (95% CI, 11.7% to 41.0%) for all-cause death, 27.0% (95% CI, 11.6% to 45.2%) for cardiac death, and 40.6% (95% CI, 10.5% to 71.8%) for SCD.

CONCLUSIONS

Myocardial scar and LVEF are both risk markers for all-cause and cardiac death in patients with nonischemic cardiomyopathy. However, whereas myocardial scar has strong and incremental prognostic value for SCD risk stratification, LVEF has no incremental prognostic value over clinical measures. Scar assessment should be incorporated into patient selection criteria for primary prevention implantable cardioverter-defibrillator placement.

Trends of Acute Kidney Injury Requiring Dialysis Among Hospitalized Patients Undergoing Invasive Electrophysiology Procedures

Electrophysiology (EP) procedures carry the risk of kidney injury due to contrast/hemodynamic fluctuations. We aim to evaluate the national epidemiology of acute kidney injury requiring dialysis (AKI-D) in patients undergoing EP procedures. Using the National Inpatient Sample, we included 2,747,605 adult hospitalizations undergoing invasive diagnostic EP procedures, ablation and implantable device placement from 2006 to 2014. We examined the temporal trend of AKI-D and outcomes associated with AKI-D. The rate of AKI-D increased significantly in both diagnostic/ablation group (8-21/10,000 hospitalizations from 2006 to 2014, P = 0.02) and implanted device group (19-44/10,000 hospitalizations from 2006 to 2014, P < 0.01), but it was explained by temporal changes in demographics and comorbidities. Cardiac resynchronization therapy and pacemaker placement had higher risk of AKI-D compared to implantable cardioverter-defibrillator placement (23 vs. 31 vs. 14/10,000 hospitalizations in cardiac resynchronization therapy, pacemaker placement, and implantable cardioverter-defibrillator group, respectively). Development of AKI-D was associated with significant increase in in-hospital mortality (adjusted odds ratio, 9.6 in diagnostic/ablation group, P < 0.01; adjusted odds ratio, 5.1 in device implantation group, P < 0.01) and with longer length of stay (22.5 vs. 4.5 days in diagnostic/ablation group, 21.1 vs. 5.7 days in implanted device group) and higher cost (282,775 vs. 94,076 USD in diagnostic/ablation group, 295,660 vs. 102,007 USD in implanted device group). The incidence of AKI-D after EP procedures increased over time but largely explained by the change of demographics and comorbidities. This increasing trend, however, was associated with significant increase in resource utilization and in-hospital mortality in these patients.

Cardiac arrhythmias in low- and middle-income countries

Many low- and middle-income countries (LMICs) are undergoing an epidemiological transition. With an improvement in socioeconomic conditions and an aging population, cardiovascular diseases (CVDs), like cardiac arrhythmias, are expected to increase in these countries. However, there are limited studies on the epidemiology and management of cardiac arrhythmias in LMICs. This review will highlight the unique challenges and opportunities that these countries face when managing cardiac arrhythmias.

Updated Clinical Evidence for Effective Cardiac Resynchronization Therapy in Congestive Heart Failure and Timing of Implant

Investigative works of the past 20 years have compiled extensive data on the effectiveness and implications of cardiac resynchronization therapy (CRT) in patients with heart failure. Since then, CRT has become a well-accepted and widely adapted adjunctive therapy for patients with heart failure with ventricular dyssynchrony. This overview discusses the updated knowledge on the benefits afforded with CRT and reviews the major clinical trials that have established CRT at its current practice. Based on the data, the indications of CRT and the timing of appropriate implant of CRT devices with respect to heart failure status will be presented.

Levels of Evidence Supporting American College of Cardiology/American Heart Association and European Society of Cardiology Guidelines, 2008-2018

Importance

Clinical decisions are ideally based on evidence generated from multiple randomized controlled trials (RCTs) evaluating clinical outcomes, but historically, few clinical guideline recommendations have been based entirely on this type of evidence.

Objective

To determine the class and level of evidence (LOE) supporting current major cardiovascular society guideline recommendations, and changes in LOE over time.

Data Sources

Current American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) clinical guideline documents (2008-2018), as identified on cardiovascular society websites, and immediate predecessors to these guideline documents (1999-2014), as referenced in current guideline documents.

Study Selection

Comprehensive guideline documents including recommendations organized by class and LOE.

Data Extraction and Synthesis

The number of recommendations and the distribution of LOE (A [supported by data from multiple RCTs or a single, large RCT], B [supported by data from observational studies or a single RCT], and C [supported by expert opinion only]) were determined for each guideline document.

Main Outcomes and Measures

The proportion of guideline recommendations supported by evidence from multiple RCTs (LOE A).

Results

Across 26 current ACC/AHA guidelines (2930 recommendations; median, 121 recommendations per guideline [25th-75th percentiles, 76-155]), 248 recommendations (8.5%) were classified as LOE A, 1465 (50.0%) as LOE B, and 1217 (41.5%) as LOE C. The median proportion of LOE A recommendations was 7.9% (25th-75th percentiles, 0.9%-15.2%). Across 25 current ESC guideline documents (3399 recommendations; median, 130 recommendations per guideline [25th-75th percentiles, 111-154]), 484 recommendations (14.2%) were classified as LOE A, 1053 (31.0%) as LOE B, and 1862 (54.8%) as LOE C. When comparing current guidelines with prior versions, the proportion of recommendations that were LOE A did not increase in either ACC/AHA (median, 9.0% [current] vs 11.7% [prior]) or ESC guidelines (median, 15.1% [current] vs 17.6% [prior]).

Conclusions and Relevance

Among recommendations in major cardiovascular society guidelines, only a small percentage were supported by evidence from multiple RCTs or a single, large RCT. This pattern does not appear to have meaningfully improved from 2008 to 2018.

Left bundle branch block and the evolving role of QRS morphology in selection of patients for cardiac resynchronization

BACKGROUND

The clinical significance of left bundle branch block (LBBB) has recently expanded with the discovery of a strong association with better outcomes in patients receiving cardiac resynchronization therapy.

METHODS

Several milestones have contributed to the current understanding on the role of LBBB in clinical practice.

RESULT

Sunao Tawara described the arrangement of components of what he called the cardiac conduction system from the atrioventricular node to the terminal Purkinje fibers that connect to the working myocardium, and his hypotheses on how it functions remain current. Mauricio Rosenbaum and colleagues developed the bifascicular model of the left-sided conduction system that explains the characteristic electrocardiographic changes associated with propagation disturbances in its components. Andrés Ricardo Pérez-Riera and others have disputed the bifascicular model as oversimplified and have emphasized the role of the left septal fascicle. Marcelo Elizari and colleagues have explained the importance of masquerading bundle branch block. Elena Sgarbossa and colleagues developed a scheme to recognize ST elevation myocardial infarction in patients with left bundle branch block which remains current after more than 20 years. Enrique Cabrera and others identified electrocardiographic signs of remote myocardial infarction.

CONCLUSION

Substantial progress has been made in the understanding of LBBB, yet its role in clinical practice continues to evolve and important gaps remain to which research should be directed.

What factors lead to the acceleration of ventricular tachycardia during antitachycardia pacing?-Results from over 1000 episodes

Introduction

Ventricular tachycardia (VT) acceleration due to antitachycardia pacing (ATP) therapy could be often observed in patients with implantable cardioverter defibrillator (ICD), which usually results in additional shock. However, few studies focused on the risk factors for VT acceleration caused by ATP therapy. The purpose of this study was to investigate risk factors for VT acceleration due to ATP delivery.

Methods

We retrospectively reviewed 1056 ATP episodes in 33 patients with structural heart diseases, of whom clinical characteristics and episodes details were evaluated.

Results

At individual patient level, number of VT morphologies recorded in electrograms during follow‐up was a risk factor with cutoff point of 1 (AUC 0.79, sensitivity 72.7%, specificity 77.3%, P < .001) to predict ATP acceleration (OR 3.50, P = .008). From episode‐based analysis, VT cycle length (VTCL) and mean variation in VTCL were risk factors to predict ATP acceleration (OR 0.98, P < 0.001 vs OR 1.06, P < .001, respectively), with cutoff points of 347 ms (AUC 0.67, sensitivity 82.5%, specificity 47.6%, P < .001) and 7.3 ms (AUC 0.66, sensitivity 77.5%, specificity 56.7%, P < .001), respectively. In addition, VTs with cycle length less than 347 ms were more likely to be accelerated by burst stimulation with more pulse numbers (OR 3.31, P < .001).

Conclusions

Number of VT morphologies, VTCL, and mean variation in VTCL are risk factors predicting ATP acceleration. Burst stimulation with less pulse numbers should be performed in VTs with cycle length less than 347 ms.

Utilization of cardiac resynchronization therapy in eligible patients hospitalized for heart failure and its association with patient outcomes

OBJECTIVES

We examined trends in CRT utilization overall and by sex and race and to assess whether CRT use is associated with a reduction in HF hospitalization and mortality.

BACKGROUND

It is unknown whether underutilization and race/sex-based differences in cardiac resynchronization therapy (CRT) use have persisted. The association between CRT and heart failure (HF) hospitalization and mortality in real-world practice remains unclear.

METHODS

We linked 72,008 HF patients from 388 hospitals participating in Get With The Guidelines HF eligible for CRT with Centers for Medicare & Medicaid Services data to assess CRT utilization trends, HF hospitalization rates, and all-cause mortality.

RESULTS

From 2005-2014, 18,935 (26.3%) eligible patients had CRT in place, implanted, or prescribed. The majority were male (60.0%) and white (61.9%). CRT utilization increased during the study period (P = .0002) especially in the early period. Women were less likely to receive CRT, and this difference increased over time (interaction P = .0037) despite greater mortality risk reduction (interaction P = .0043). Black patients were less likely than white patients to have CRT throughout the study period (adjusted hazard ratio (HR) 0.79; 95% CI 0.74-0.85). Patients with CRT implanted during the index hospitalization had lower mortality (adjusted HR 0.65; 95% CI 0.59-0.71) and were less likely to be readmitted for HF than patients without CRT (adjusted HR 0.64; 95% CI 0.58-0.71).

CONCLUSIONS/RELEVANCE

CRT use has increased in all populations, but it remains underutilized. CRT remains more common among white than black HF patients, and women were less likely than men to receive CRT despite deriving greater benefit.

ANMCO/SIT Consensus Document: telemedicine for cardiovascular emergency networks

Telemedicine has deeply innovated the field of emergency cardiology, particularly the treatment of acute myocardial infarction. The ability to record an ECG in the early prehospital phase, thus avoiding any delay in diagnosing myocardial infarction with direct transfer to the cath-lab for primary angioplasty, has proven to significantly reduce treatment times and mortality. This consensus document aims to analyse the available evidence and organizational models based on a support by telemedicine, focusing on technical requirements, education, and legal aspects.

Guidance on reuse of cardio-vascular catheters and devices in India: A consensus document

Reuse of medical device is accepted worldwide. Benefits of reuse include not only cost saving but a favorable impact on environment. However, certain requirements should be met for reuse to be safe and effective. The devices, which can be reused, should be clearly defined, a meticulous process for dis-infection and sterilization followed and its functionality ascertained before use. Further, an appropriate consent should be obtained where necessary and the cost saving entailed should be directly passed on to the patient.

Anesthesia for Noncardiac Surgery in Children with Congenital Heart Disease

This review covers the classification of congenital heart diseases, and the preoperative assessment, monitoring, anesthetic considerations, and management in the pediatric population with congenital heart disease. It does not present “recipes” for individual cardiac defects. The pathophysiology is presented as it relates to principles of management, patient assessment, selection, and application of an anesthetic regimen to specific cardiac lesions and procedures. Familiarity with the child's pathophysiology, preoperative preparation, choice of monitors, induction, maintenance, emergence from anesthesia, and plans for the postoperative period should avoid major problems in anesthetic management.

[ICD therapy in the primary prevention of sudden cardiac death: Risk stratification and patient selection]

Without the concept of primary prevention of sudden cardiac death, therapy with implantable defibrillators would not have reached the current distribution and clinical importance. Most of the scientific evidence of the concept is based on clinical studies from 1996-2005. More than 75 % of all defibrillator implantations are currently indicated as primary prevention. Implantable converter-defibrillator (ICD) therapy in the primary prevention of sudden cardiac death was incorporated into scientific guidelines starting in 1998. The historical development of the indications for ICD therapy in the primary prevention of sudden cardiac death is presented, reflecting major results of controlled, randomized clinical studies and guideline discussions.

The effect of reverse remodeling on long-term survival in mildly symptomatic patients with heart failure receiving cardiac resynchronization therapy: results of the REVERSE study

BACKGROUND

Cardiac resynchronization therapy (CRT) reduces mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure (HF). The magnitude of reverse remodeling predicts survival with many HF medical therapies. However, there are few studies assessing the effect of remodeling on long-term survival with CRT.

OBJECTIVE

The purpose of this study was to assess the effect of CRT-induced reverse remodeling on long-term survival in patients with mildly symptomatic heart failure.

METHODS

The REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction trial was a multicenter, double-blind, randomized trial of CRT in patients with mild HF. Long-term follow-up of 5 years was preplanned. The present analysis was restricted to the 353 patients who were randomized to the CRT ON group with paired echocardiographic studies at baseline and 6 months postimplantation. The left ventricular end-systolic volume index (LVESVi) was measured in the core laboratory and was an independently powered end point of the REsynchronization reVErses Remodeling in Systolic Left vEntricular Dysfunction trial.

RESULTS

A 68% reduction in mortality was observed in patients with ≥15% decrease in LVESVi compared to the rest of the patients (P = .0004). Multivariable analysis showed that the change in LVESVi was a strong independent predictor (P = .0002), with a 14% reduction in mortality for every 10% decrease in LVESVi. Other remodeling parameters such as left ventricular end-diastolic volume index and ejection fraction had a similar association with mortality.

CONCLUSION

The change in left ventricular end-systolic volume after 6 months of CRT is a strong independent predictor of long-term survival in mild HF.

Coronary sinus biomarker sampling compared to peripheral venous blood for predicting outcomes in patients with severe heart failure undergoing cardiac resynchronization therapy: the BIOCRT study

BACKGROUND

A significant minority of patients receiving cardiac resynchronization therapy (CRT) remain nonresponsive to this intervention.

OBJECTIVE

This study aimed to determine whether coronary sinus (CS) or baseline peripheral venous (PV) levels of established and emerging heart failure (HF) biomarkers are predictive of CRT outcomes.

METHODS

In 73 patients (aged 68 ± 12 years; 83% men; ejection fraction 27% ± 7%) with CS and PV blood samples drawn simultaneously at the time of CRT device implantation, we measured amino-terminal pro-B-type natriuretic peptide (NT-proBNP), galectin-3 (gal-3), and soluble ST2 (sST2) levels. NT-proBNP concentrations >2000 pg/mL, gal-3 concentrations >25.9 ng/mL, and sST2 concentrations >35 ng/mL were considered positive on the basis of established PV cut points for identifying "high-risk" individuals with HF. CRT response was adjudicated by the HF Clinical Composite Score. A major adverse cardiovascular event (MACE) was defined as the composite end point of death, cardiac transplant, left ventricular assist device, and HF hospitalization at 2 years.

RESULTS

NT-proBNP concentrations were 20% higher in the CS than in the periphery, while gal-3 and sST2 concentrations were 10% higher in the periphery than in the CS (all P < .001). There were 45% CRT nonresponders at 6 months and 16 (22%) patients with MACE. Triple-positive CS values yielded the highest specificity of 95% for predicting CRT nonresponse. Consistently, CS strategies identified patients at higher risk of developing MACE, with >11-fold adjusted increase for triple-positive CS patients compared to triple-negative patients (all P ≤ .04). PV strategies were not predictive of MACE.

CONCLUSION

Our findings suggest that CS sampling of HF biomarkers may be better than PV sampling for predicting CRT outcomes. Larger studies are needed to confirm our findings.

Annual atrial tachyarrhythmia burden determined by device interrogation in patients with cardiac implanted electronic devices is associated with a risk of ischaemic stroke independent of known risk factors

OBJECTIVES

This study evaluated the risk of non-fatal ischaemic stroke associated with increased long-term cumulative duration of atrial tachycardia (AT).

METHODS

We retrospectively reviewed the records of 260 patients with cardiovascular implantable electronic devices capable of monitoring AT. Patients were separated into zero, low and high AT burden groups. The cut-off point between low and high AT burden was defined by the median value of AT burden in the non-zero AT burden groups (5% in 1 year, about 18 days annually). The primary outcome was non-fatal ischaemic stroke.

RESULTS

The mean patient age was 63.3 ± 13.7 years, the average follow-up was 7.0 years and 10 patients had strokes. Multivariate analysis showed only hypertension and a diagnosis of atrial fibrillation (AF) were associated with stroke. The risk of stroke in patients with hypertension was 12.57-fold higher than in those without hypertension, and was 20.81-fold higher in patients with paroxysmal AF and 162.59-fold higher in patients with chronic AF than in those without AF. Kaplan-Meier analysis showed that stroke-free survival was significantly different in the three AT burden groups (P = 0.002, long-rank test); the rate was greatest in the zero AT burden group, followed by the low AT burden group and was lowest in the high AT burden group.

CONCLUSIONS

Patients who accumulated an AT duration exceeding 5% (18 days) of the total time in any of the 1-year periods are more likely to have an ischaemic stroke than those who have a low or zero AT burden.

Anesthetic management of a 2-day-old with complete congenital heart block

Maternal connective tissue disorders such as Systemic Lupus Erythematosus (most common), Sjogren's syndrome, mixed connective tissue disorders may lead to the rare condition of complete congenital heart block in the neonate. Rare fetal syndromes such as myocarditis, 18p syndrome, mucopolysaccharidoses and mitochondrial diseases are other causes. The mortality rate of this condition is inversely propotional to the age of presentation being 6 % in the neonatal age group. As the cardiac output in the neonate is heart rate dependent, it is crucial to maintain the heart rate in these patients. Pharamacological interventions with dopamine, isoprenaline, epinephrine and atropine are known for their variable response. Although permanent pacing is the most reliable mode of management, the access to it is often not readily available, especially in the developing countries. In such cases temporary pacing methods become lifesaving. Of all the modalities of temporary pacing (transcutaneous, transesophageal and transvenous) transcutaneous pacing is the most readily available and immediate mode. In this case report we present a two day old neonate with isolated complete congenital heart block and a resting heart rate of 50-55/min in immediate need of palliative surgery for trachea-esophageal fistula (TEF). With pharmacological intervention the heart rate could only be raised to 75-80/min. The surgery was successfully carried out using transcutaneous pacing to maintain a heart rate of 100/min.

Applications of Electrical Pacing in the Body

Gastric electrostimulation by a pulse generator is an area of intense interest for the treatment of obesity. The concept of a rhythmic electrical current applied to neural or myal tissues has been established for the treatment of major problems in many areas of the body or is being investigated.

Biventricular pacing in heart failure: a review

Biventricular pacing has been an exciting recent advance in the management of drug-refractory heart failure. This new therapy has evolved as much from necessity as scientific observation, since benefits derived from pharmacotherapy currently appear to have reached their peak. Clinical trials of biventricular pacing are establishing morbidity and mortality benefits in heart failure. New challenges in the use of these pacemakers are now arising. These include the accurate diagnosis of ventricular dyssynchrony and, hence, potential responders to the refinement of implantation of the left ventricular lead to the appropriate dyssynchronous ventricular area and optimization of pacemaker programming. This review gives a general overview of the principles and the current evidence for the use of biventricular pacemakers in the treatment of heart failure. In addition, a discussion of current research and future projects is included.

Implantable Defibrillators Improve Survival in Patients With Mildly Symptomatic Heart Failure Receiving Cardiac Resynchronization Therapy

Background—

Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. These benefits have been noted with both CRT-pacemakers as well as those devices with defibrillator backup (CRT-D). However, there are little data comparing mortality between these 2 device types.

Methods and Results—

REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) was a multicenter, randomized trial of CRT among patients with mild heart failure. Long-term annual follow-up for 5 years was preplanned. The present analysis was confined to the 419 patients who were randomized to active CRT group. CRT-pacemakers or CRT-D devices were implanted based on national guidelines at the time of enrollment, with 74 patients receiving CRT pacemaker devices and the remaining 345 patients receiving CRT-D devices. After 12 months of CRT, changes in the clinical composite score, left ventricular end systolic volume index, 6-minute walk time, and quality of life indices were similar between CRT pacemaker and CRT-D patients. However, long-term follow-up showed lower morality in the CRT-D group. Specifically, multivariable analysis showed that CRT-D (hazard ratio, 0.35; P =0.003) was a strong independent predictor of survival. Female sex, longer unpaced QRS duration, and smaller baseline left ventricular end systolic volume index also were also associated with better survival.

Conclusions—

REVERSE demonstrated that the addition of implantable cardioverter-defibrillator therapy to CRT is associated with improved long-term survival compared with CRT pacing alone in mild heart failure.

Clinical Trial Registration—

URL: http://clinicaltrials.gov . Unique Identifier: NCT00271154.

Appropriate therapies predict long-term mortality in primary and secondary prevention of sudden cardiac death

BACKGROUND

Less than 50% of patients implanted with an implantable cardioverter-defibrillator (ICD) receive device therapy during the follow-up. The aim of our study was to prospectively evaluate the predictive role of appropriate ICD therapy on long-term survival of patients implanted for primary or secondary sudden death prevention.

METHODS

From 2002 to 2003, 139 consecutive patients [mean age 66±9 years, male 77%, ischemic heart disease 56%, New York Heart Association functional class >II (74%), primary prevention 74%, mean left ventricular ejection fraction 30±9%, cardiac resynchronization ICD 65%] were enrolled. We collected and evaluated device therapies for at least 18 months and recorded survival status for more than 5 years.

RESULTS

Over a median follow-up of 18 months, 54 (39%) patients received at least one ICD intervention, with 28 patients receiving only appropriate ICD therapies, 13 only inappropriate therapies and 13 receiving both therapies. At a mean follow-up of 63±12 months, 30 deaths occurred in 130 patients (23%); for nine patients, we had no survival status information. Death was classified as cardiac in 22 (73%) patients, the most common cause was progressive heart failure. In a Cox proportional regression model, an appropriate ICD therapy was associated with a significant increase in the subsequent risk of death (hazard ratio 3.02, P=0.003).

CONCLUSION

In patients implanted with ICD or cardiac resynchronization therapy with ICD devices, for primary or secondary sudden cardiac death prevention, appropriate ICD therapy predicts a three-fold greater risk of death.

A case of riata® dual coil defibrillator lead failure in a patient with ventricular fibrillation

A 50-year-old man, who underwent a procedure for an implantable cardioverter defibrillator (ICD), visited the outpatient department of our clinic after suffering multiple ICD shocks. The ICD interrogation revealed recurrent shock due to a high frequency of noise that is sensed by the device as ventricular fibrillation. Chest radiography revealed a significant split in the insulation of the lead allowing the inner wire to protrude. We considered the removal of the failed lead, but the removal of ICD lead is potentially a high risk procedure, so we cut and capped a proximal part of the failed lead and inserted a new lead. This is the first report of a St. Jude Riata® dual coil defibrillator lead failure with clinical and radiologic evidence of a defect in lead insulation in Korea.

Improved survival after heart failure: a community-based perspective

BACKGROUND

Heart failure is a highly prevalent, morbid, and costly disease with a poor long-term prognosis. Evidence-based therapies utilized over the past 2 decades hold the promise of improved outcomes, yet few contemporary studies have examined survival trends in patients with acute heart failure. The primary objective of this population-based study was to describe trends in short- and long-term survival in patients hospitalized with acute decompensated heart failure (ADHF). A secondary objective was to examine patient characteristics associated with decreased long-term survival.

METHODS AND RESULTS

We reviewed the medical records of 9748 patients hospitalized with ADHF at all 11 medical centers in central Massachusetts during 1995, 2000, 2002, and 2004. Patients hospitalized with ADHF were more likely to be elderly and to have been diagnosed with multiple comorbidities in 2004 compared with 1995. Over this period, survival was significantly improved in-hospital, and at 1, 2, and 5 years postdischarge. Five-year survival rates increased from 20% in 1995 to 29% in 2004. Although survival improved substantially over time, older patients and patients with chronic kidney disease, chronic obstructive pulmonary disease, anemia, low body mass index, and low blood pressures had consistently lower postdischarge survival rates than patients without these comorbidities.

CONCLUSION

Between 1995 and 2004, patients hospitalized with ADHF have become older and increasingly comorbid. Although there has been a significant improvement in survival among these patients, their long-term prognosis remains poor, as fewer than 1 in 3 patients hospitalized with ADHF in 2004 survived more than 5 years.