Need For Pacemaker Research Articles

Conduction disorders in the setting of transcatheter aortic valve implantation: a clinical perspective

The presence of periprocedural conduction disorders (CDs) and the need for permanent pacemaker (PPM) after transcatheter aortic valve implantation (TAVI) are frequent findings in clinical practice. Notwithstanding, robust information on the prognostic and therapeutic implications of these complications are lacking. The newly occurrence of CD after TAVI seems related to the trauma of the conduction system during procedure. On the contrary, major predictors for PPM implantation after TAVI seem to be the use of CoreValve prosthesis (Medtronic, Minneapolis, MN) and the presence of CD before TAVI. An accurate pre-TAVI screening, careful valve implantation, as well as post-TAVI monitoring must be pursued to prevent avoidable PPM implantation. The aim of this report is to analyze the available data on this field and to propose some practical clinical tips to prevent or to manage these complications.

Predicting Functional Capacity in Patients with a Systemic Right Ventricle: Subjective Patient Self-assessment Is Better than B-type Natriuretic Peptide Levels and Right Ventricular Systolic Function

Many adults with transposition of the great arteries have an anatomic right ventricle functioning as the systemic ventricle and are known to develop congestive heart failure, premature cardiac death, and need for cardiac transplantation. Predictors of poor clinical outcome and functional status in patients with left ventricular failure do not always apply to these patients. We aimed to identify predictors of poor functional status in those patients with a systemic right ventricle. We performed a prospective study of 51 adults with transposition of the great arteries and systemic right ventricles. Demographic, clinical, laboratory, and imaging data were collected, and patients completed a Minnesota Living with Heart Failure Questionnaire (MLHFQ). Comparisons were made between those patients with d-type transposition of the great arteries (dTGA) who have undergone prior atrial switch and those with congenitally corrected transposition (ccTGA). A correlation analysis was performed to identify predictors of poor functional status, as determined by a 6-minute walk distance test. Median age was 30 years (range 19-65). Median B-type natriuretic peptide was 48 pg/mL (range 16-406). There were 27 patients (53%) with moderate-severe right ventricular dysfunction and 10 (20%) with moderate-severe tricuspid valve regurgitation. The median MLHFQ score was 9 (range 0-78) and 6-minute walk test was 510 m (range 231-703). Forty-one patients had a diagnosis of dTGA atrial switch and 11 patients had ccTGA. Patients with ccTGA were significantly older (40 vs. 28 years, P =.004) and had more tricuspid valve regurgitation (P =.02). Despite this, their MLHFQ scores were significantly lower (2.5 vs. 17, P =.04) and they walked further (635 vs. 504 m, P =.02). Predictors of a short 6-minute walk distance included short stature (P =.009) and dTGA (P =.002). The patient's self-assessment of poor health, as measured by an increased New York Heart Association class (P =.003) and a decreased MLHFQ score (P >.0001) also correlated. B-type natriuretic peptide levels, right ventricular dysfunction, severity of tricuspid valve regurgitation, need for pacemaker, and clinical signs of heart failure did not correlate with exercise tolerance. Traditional parameters used to predict outcomes in patients with left ventricular failure are not predictive in patients with a systemic right ventricle. Instead, patient's self-assessment of functional status did correlate with objective functional status.

Sinus Bradycardia and Sinus Pauses Immediately after Electrical Cardioversion of Persistent Atrial Fibrillation—What Do They Mean?

To determine the role of sinus bradyarrhythmia (SB) immediately after electrical cardioversion of persistent atrial fibrillation (AF) on the short-term recurrence rate and long-term pacemaker need and all-cause mortality. SB defined as sinus bradycardia (sinus rate <40 bpm for ≥2 consecutive cycles) and/or sinus pauses (>2 s), were recorded during 5 minutes immediately after successful DC cardioversion in 140 consecutive patients with persistent AF. SB was observed during the first minute of SR in 31 patients (22%). Sinus bradycardia was present in 27 patients, sinus pauses in 16 (>3 s in 10) patients, and both in 12 patients. Compared to patients without SB, the mean heart rate during the first minute after cardioversion was lower, 57 ± 13 versus 63 ± 11 bpm; P < 0.05, while the mean heart rates during the subsequent 4 minutes were not statistically significantly different. The AF recurrence rates were not significantly different at 1 week (45% vs. 40%), or at 3 months (68% vs. 53%) in patients with or without SB. After a mean follow-up of 86 ± 6 months the pacemaker implantation rate was 10% versus 11% (NS) and an all-cause mortality of 26 versus 18% (NS). SB immediately after electrical cardioversion of persistent AF had no significant impact on the 3-month AF recurrence rate, the long-term need for pacemaker or all-cause mortality.

Transcatheter Aortic Valve Implantation With the Edwards SAPIEN Versus the Medtronic CoreValve Revalving System Devices

The aim of this study was to compare outcomes after transfemoral transcatheter aortic valve implantation with the Medtronic CoreValve (MCV) versus the Edwards SAPIEN/SAPIEN XT transcatheter heart valve (ESV) for severe aortic stenosis. No large matched comparison study has been conducted so far evaluating both commercially available devices. The data from databases of 4 experienced European centers were pooled and analyzed. Due to differences in baseline clinical characteristics, propensity score matching was performed. Study objectives were Valve Academic Research Consortium outcomes at 30 days and 1 year. In total, 793 patients were included: 453 (57.1%) treated with the MCV and 340 (42.9%) with the ESV. After propensity matching, 204 patients were identified in each group. At 30 days, there were no differences in all-cause mortality (MCV, 8.8% vs. ESV, 6.4%; hazard ratio [HR]: 1.422; 95% confidence interval [CI]: 0.677 to 2.984; p = 0.352), cardiovascular mortality (MCV, 6.9% vs. ESV, 6.4%; HR: 1.083; 95% CI: 0.496 to 2.364; p = 0.842), myocardial infarction (MCV, 0.5% vs. ESV, 1.5%; HR: 0.330; 95% CI: 0.034 to 3.200; p = 0.339), stroke (MCV, 2.9% vs. ESV, 1.0%; HR: 3.061; 95% CI: 0.610 to 15.346; p = 0.174), or device success (MCV, 95.6% vs. ESV, 96.6%; HR: 0.770; 95% CI: 0.281 to 2.108; p = 0.611). Additionally, there were no differences in major vascular complications (MCV, 9.3% vs. ESV, 12.3%; HR: 0.735; 95% CI: 0.391 to 1.382; p = 0.340) or life-threatening bleeding (MCV, 13.7% vs. ESV, 8.8%; HR: 1.644; 95% CI: 0.878 to 3.077; p = 0.120). MCV was associated with more permanent pacemakers (22.5% vs. 5.9%; HR: 4.634; 95% CI: 2.373 to 9.050; p < 0.001). At 1 year, there were no differences in all-cause (MCV, 16.2% vs. ESV, 12.3%; HR: 1.374; 95% CI: 0.785 to 2.407; p = 0.266) or cardiovascular (MCV, 8.3% vs. ESV, 7.4%; HR: 1.145; 95% CI: 0.556 to 12.361; p = 0.713) mortality. No differences between the 2 commercially available transfemoral transcatheter aortic valve implantation devices were observed at the adjusted analysis in Valve Academic Research Consortium outcomes except for the need for permanent pacemakers with the MCV.

A comparison of the results of the bicaval and biatrial surgical technique in orthotopic heart transplantation: A review and meta-analysis

Background: This study aims to evaluate the outcomes of bicaval and biatrial techniques in orthotopic heart transplantation. Methods: Between May 1966 and May 2011, a literature survey was conducted using electronic search engines including PubMed, Medline and Google and manually surveying the magazines on heart and vascular surgery. A total of 36 prospective and retrospective controlled studies which met the inclusion criteria were included in the metaanalysis. The outcomes of both techniques were evaluated using random and fixed-effect method, based on their significant heterogeneous nature. Statistical analysis was performed using Comprehensive Meta Analysis version 2 software. Results: It was found that the results of eight meta-analyses obtained (tricuspid and mitral insufficiency, the need for permanent or temporary pacemaker, sinus rhythm, survival at 1 and 10 year, the right atrial pressure) were significantly improved in bicaval group, compared to the biatrial group. Conclusion: Our study results showed that the outcomes of the bicaval technique were better, compared to biatrial technique. We believe that the bicaval anastomosis technique may have a positive effect on morbidity, due to its clinical and hemodynamical benefits.

Outcomes of cardiac transplantation in septuagenarians

Cardiac transplantation in many centers is programmatically limited to patients aged younger than 70 years. We investigated the trends and outcomes for cardiac transplantation in recipients aged 70 years and older in the United States. De-identified data were provided by United Network of Organ Sharing. Transplant recipients were grouped by age 60-69 years and 70 years and older. Univariate comparisons were performed using Student's t-test or the Pearson chi-square test. Survival was estimated using the Kaplan-Meier technique and compared with the log-rank test. Cox regression was used to determine predictors of death after transplant. Statistical significance was assigned to p < 0.05. Between January 1, 1998, and June 15, 2010, 5,807 sexagenarians and 332 septuagenarians received allografts. The septuagenarian cohort had more men, less diabetes, was less likely to have a ventricular assist device, and more likely to be status II. Donors for septuagenarians were older and died more frequently from intracranial hemorrhage. Median unadjusted survival was 9.8 years for sexagenarians vs 8.5 years for septuagenarians (p = 0.003). There was no difference in the incidence of cerebrovascular accident, length of stay, or pacemaker need between groups. Septuagenarians were less likely to be treated for rejection the first year (p = 0.001). Age was a multivariate predictor of death (hazard ratio, 1.289; 95% confidence interval, 1.039-1.6; p = 0.021). Selected septuagenarians with advanced heart failure can derive great benefit from cardiac transplantation, although survival is inferior to that of an immediately younger sexagenarian cohort. Most of the mortality risk is seen in the first year after transplantation. A reduced incidence of rejection was observed and warrants further study.

Factors Predicting and Having an Impact on the Need for a Permanent Pacemaker After CoreValve Prosthesis Implantation Using the New Accutrak Delivery Catheter System

The purpose of this study was to evaluate the need for a permanent pacemaker after transcatheter aortic valve implantation with the CoreValve prosthesis (Medtronic, Inc., Minneapolis, Minnesota) using the new Accutrak delivery system (Medtronic, Inc.). The need for a permanent pacemaker is a recognized complication after transcatheter aortic valve implantation with the CoreValve prosthesis. Between April 23, 2008 and May 31, 2011, 195 consecutive patients with symptomatic aortic valve stenosis underwent transcatheter aortic valve implantation using the self-expanding CoreValve prosthesis. In 124 patients, the traditional delivery system was used, and in 71 patients, the Accutrak delivery system was used. There were no significant differences in baseline electrocardiographic characteristics between the traditional system and the Accutrak patients: PR interval: 153 ± 46 mm versus 165 ± 30 mm, p = 0.12; left bundle branch block: 22 (20.2%) versus 8 (12.7%), p = 0.21; right bundle branch block: 21 (19.3%) versus 8 (12.7%), p = 0.26. The depth of the prosthesis in the left ventricular outflow tract was greater with the traditional system than with the Accutrak system (9.6 ± 3.2 mm vs. 6.4 ± 3 mm, p < 0.001) and the need for a permanent pacemaker was higher with traditional system than with Accutrak (35.1% vs. 14.3%, p = 0.003). The predictors of the need for a pacemaker were the depth of the prosthesis in the left ventricular outflow tract (hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 1.08 to 1.34, p < 0.001), pre-existing right bundle branch block (HR: 3.5, 95% CI: 1.68 to 7.29, p = 0.001), and use of the traditional system (HR: 27, 95% CI: 2.81 to 257, p = 0.004). The new Accutrak delivery system was associated with less deep prosthesis implantation in the left ventricular outflow tract, which could be related to the lower rate of permanent pacemaker requirement.

Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST)

Background— Catheter ablation (CA) and minimally invasive surgical ablation (SA) have become accepted therapy for antiarrhythmic drug–refractory atrial fibrillation. This study describes the first randomized clinical trial comparing their efficacy and safety during a 12-month follow-up. Methods and Results— One hundred twenty-four patients with antiarrhythmic drug–refractory atrial fibrillation with left atrial dilatation and hypertension (42 patients, 33%) or failed prior CA (82 patients, 67%) were randomized to CA (63 patients) or SA (61 patients). CA consisted of linear antral pulmonary vein isolation and optional additional lines. SA consisted of bipolar radiofrequency isolation of the bilateral pulmonary vein, ganglionated plexi ablation, and left atrial appendage excision with optional additional lines. Follow-up at 6 and 12 months was performed by ECG and 7-day Holter recording. The primary end point, freedom from left atrial arrhythmia &gt;30 seconds without antiarrhythmic drugs after 12 months, was 36.5% for CA and 65.6% for SA ( P =0.0022). There was no difference in effect for subgroups, which was consistent at both sites. The primary safety end point of significant adverse events during the 12-month follow-up was significantly higher for SA than for CA (n=21 [34.4%] versus n=10 [15.9%]; P =0.027), driven mainly by procedural complications such as pneumothorax, major bleeding, and the need for pacemaker. In the CA group, 1 patient died at 1 month of subarachnoid hemorrhage. Conclusion— In atrial fibrillation patients with dilated left atrium and hypertension or failed prior atrial fibrillation CA, SA is superior to CA in achieving freedom from left atrial arrhythmias after 12 months of follow-up, although the procedural adverse event rate is significantly higher for SA than for CA. Clinical Trial Registration— URL: http://clinicaltrials.gov . Unique identifier: NCT00662701.

Procedural Risk and Long Term Outcome of Pacemaker System Removal by Using Cardio-Pulmonary Bypass

Objective: Some patients with pervenous pacemaker need to remove whole pacing system via median sternotomy by using cardio-pulmonary bypass (CPB) because of infection or system failure. We examined the procedural risk and long term outcome of removal of pacing system by using CPB. Methods: From August 1998 to April 2011, the removal of leads was performed in 8 patients (mean age 59 years, including 7 male and 1 female) via median sternotomy by using CPB under general anesthesia. The original diseases were 4 A-V block, 2 SSS, 1 AF and 1 Brugada syndrome. The reason for removal were eradicating infection in 6 cases and allergy in 1 case, lead functional failure in 1 case. Positive culture results were observed in 5 cases of 6 infections cases, including 2 MSSA, 1 MRSA, 1 CNS, and 1 MRSE. Results: The Mode of concomitant operation includes 2 mitral valvuloplasty, 1 CABG, and 2 tricuspid annulo-plasty and 7 putting of myocardial pacing lead. For the long term follow up, one case of infection recurrence was observed, then received exchanging of the infected system. We identified all of the 7 cases that were followed up are alive. Conclusions: Complete removals of pacing system by using CPB were safe and have been successful with favorable long term results.

Findings of a Mixed Transfemoral Aortic Valve Implantation Program Using Edwards and CoreValve Devices

Introduction and objectives Transfemoral implantation of an Edwards-SAPIEN (ES) or Medtronic CoreValve (MCV) aortic valve prosthesis is an alternative to surgical replacement for patients with severe aortic stenosis and a high surgical risk. The study's aim was to compare results obtained with these two devices. Methods Prospective observational study of transfemoral prosthesis implantation performed at our center. Results Of the 76 patients (age 83 ± 6 years, 63% female, logistic EuroSCORE 18 ± 9) included, 50 were assigned the ES and 26 the MCV device. There was no difference between the groups in age, sex, functional class, valve area, associated conditions, or EuroSCORE. Implantation was successful in 84% of the ES group and 100% of the MCV group ( P = .04). There were three cases of tamponade, two aortic dissections and one valve malposition in the ES group. The two groups had similar vascular access complication rates (26% vs. 23%; P = NS), but pacemaker need was greater with the MCV (10% vs. 39%; P = .003). Mortality rates at 30 days were 12% and 20% ( P = NS) in the ES and MCV groups, respectively, and at 1 year, 24% and 20% ( P = NS), respectively. After a follow-up of 367 ± 266 days in the ES group and 172 ± 159 days in the MCV group, three patients died. Clinical improvement was maintained in other patients and no echocardiographic changes were observed. Conclusions In-hospital mortality, the complication rate and medium-term outcomes were similar with the two devices. The only difference observed was a higher implantation success rate with the MCV, although at the expense of a greater frequency of atrioventricular block.

Resultados de un programa mixto de implantación de prótesis aórtica por vía transfemoral con los dispositivos de Edwards y CoreValve

Introduction and objectives Transfemoral implantation of an Edwards SAPIEN (ES) or Medtronic CoreValve (MCV) aortic valve prosthesis is an alternative to surgical replacement for patients with severe aortic stenosis and a high surgical risk. The study's aim was to compare results obtained with these two devices. Methods Prospective observational study of transfemoral prosthesis implantation performed at our center. Results Of the 76 patients (age 83 ± 6 years, 63% female, logistic EuroSCORE 18 ± 9) included, 50 were assigned the ES and 26 the MCV device. There was no difference between the groups in age, sex, functional class, valve area, associated conditions, or EuroSCORE. Implantation was successful in 84% of the ES group and 100% of the MCV group ( P = .04). There were three cases of tamponade, two aortic dissections and one valve malposition in the ES group. The two groups had similar vascular access complication rates (26% vs. 23%; P = NS), but pacemaker need was greater with the MCV (10% vs. 39%; P = .003). Mortality rates at 30 days were 12% and 20% ( P = NS) in the ES and MCV groups, respectively, and at 1 year, 24% and 20% ( P = NS), respectively. After a follow-up of 367 ± 266 days in the ES group and 172 ± 159 days in the MCV group, three patients died. Clinical improvement was maintained in other patients and no echocardiographic changes were observed. Conclusions In-hospital mortality, the complication rate and medium-term outcomes were similar with the two devices. The only difference observed was a higher implantation success rate with the MCV, although at the expense of a greater frequency of atrioventricular block. Full English text available from: www.revespcardiol.org

“Device landing zone” calcification, assessed by MSCT, as a predictive factor for pacemaker implantation after TAVI

After trans-catheter aortic valve implantation (TAVI), the need for postinterventional pacemaker (PM) implantation can occur in as many as 10-50% of cases, but it is not yet clear, how this need can be predicted. The aim of this study was to assess the possible predictive factors of post TAVI PM implantation based on Computed Tomography (CT) measured aortic valve calcification and its distribution. We prospectively analyzed 81 consecutive symptomatic patients with severe AS scheduled for TAVI using the CoreValve prosthesis (Medtronic, Minneapolis, USA). In all patients, a native and contrast-enhanced multislice cardiac CT was performed preinterventionally, estimating calcification load of the native valve cusps and of the adjacent outflow tract (so called "device landing zone", DLZ) by the Agatston Score (AgS). Objective, computer-evaluated, preprocedural ECG-analysis was performed with regards to pre-existing conduction abnormalities. Transthoracic echocardiography was performed pre and post TAVI. TAVI was successful in all cases. PM implantation was deemed necessary in altogether 32 patients, out of 67 without a PM pre-TAVI (32/67, 47%). Various parameters were tested as predictors of post TAVI PM in a multivariate logistic regression analysis model. Female sex (P = 0,005) and depressed EF (P = 0,023) showed a significant correlation. PM implantation correlated also to the DLZ calcification, as assessed by CT (P = 0,004). This model leads to an AUC (area under the ROC-receiver operator characteristics-curve) of 0.83. Calcium amount in the CoreValve DLZ in combination with clinical data could predict the need for post TAVI PM implantation.

Relation of QRS Width in Healthy Persons to Risk of Future Permanent Pacemaker Implantation

In the setting of acute myocardial infarction, prolongation of the QRS interval on electrocardiography identifies patients at risk for needing permanent pacemaker implantation. However, the implications of prolonged QRS intervals in healthy subjects are unclear, especially given that the QRS prolongation encountered in this setting is typically mild. The aim of this study was to assess the relation between QRS duration and incident pacemaker implantation in a community-based cohort of 8,311 subjects (mean age 54 years, 55% women) who attended 17,731 routine examinations with resting 12-lead electrocardiography. QRS duration was analyzed as a continuous and a categorical variable (<100, 100 to <120, and > or =120 ms). During up to 35 years of follow-up, 157 participants (56 women) developed need for permanent pacemakers. In multivariable Cox regression models adjusting for cardiovascular risk factors and previous myocardial infarction or heart failure, mild QRS prolongation was associated with a threefold risk for pacemaker implantation (adjusted hazard ratio 2.90, 95% confidence interval 1.81 to 4.66, p <0.0001), and bundle branch block was associated with a fourfold risk for pacemaker implantation (hazard ratio 4.43, 95% confidence interval 2.94 to 6.68, p <0.0001). Each standard deviation increment in QRS duration (11 ms) was associated with an adjusted hazard ratio of 1.14 (95% confidence interval 1.11 to 1.18, p <0.0001) for pacemaker placement. This association remained significant after excluding subjects with QRS durations > or =120 ms. In conclusion, subjects with prolonged QRS durations, even without bundle branch block, are at increased risk for future pacemaker implantation. Such individuals may warrant monitoring for progressive conduction disease.

Continuous suture technique and impairment of the atrioventricular conduction after aortic valve replacement.

Atrioventricular (AV) conduction impairment represents an infrequent complication following aortic valve replacement (AVR). Although several conditions have been considered as potential risk factors for such a postoperative event, the role of the surgical technique has not been evaluated. The aim of this study was to investigate if the suture technique for implantation of the prosthetic valve is a potential risk factor need of pacemaker (PM) implantation after AVR. One hundred twenty-four patients undergoing AVR were enrolled in this study. A "continuous" suture technique was performed in 72 patients (58%; Group A), whereas an "interrupted" suture technique was used in 52 patients (42%; Group B). The incidence of "major," requiring PM implantation, as well as "minor," without PM implantation, impairment of the AV conduction was evaluated and compared in the two groups by means of univariate and multivariate analyses. The patients of the two groups were homogenous for all preoperative parameters except patient age. A longer clamp time was present in the patients of group B than those of group A (73 +/- 24 minutes and 60 +/- 24 minutes, respectively; p < 0.01). Postoperatively, hospital mortality consisted of four patients (3.2%) with no statistical importance between the two groups. Eleven patients of group A (17.5%) and one patient of group B1 (2.2%) required PM implantation (p < 0.05). Prolonged P-R interval was recorded in 15 patients of group A and in 5 patients of group B (p < 0.05). We showed that the continuous suture technique increases the need for postoperative PM implantation after AVR. No major differences have been observed, however, regarding in-hospital mortality and length of hospital stay, regardless of the type of prosthetic suture technique.

Safety and Efficacy of the Subclavian Approach for Transcatheter Aortic Valve Implantation With the CoreValve Revalving System

Transcatheter aortic valve implantation (TAVI) is a new option for patients with severe aortic stenosis at high surgical risk. The standard retrograde approach through the femoral artery is contraindicated in case of unfavorable iliofemoral anatomy or extensive disease. In these patients, a trans-subclavian approach may be feasible. Between June 2007 and July 2009, TAVI with the CoreValve bioprosthesis (Medtronic, Minneapolis, Minn) was performed in 514 consecutive patients at 13 Italian hospitals, using the subclavian approach in 54 cases. The median logistic EuroSCORE was significantly higher in the subclavian (19.4; interquartile range, 12.5 to 29.8) versus femoral group (25.3; interquartile range, 15.1 to 36.6) (P=0.03), as well as the rate of comorbidities. Procedural success was obtained in 100% versus 98.4% of the subclavian versus femoral groups, respectively (P=0.62), with intraprocedural mortality of 0% versus 0.9% (P=1.00). The most common in-hospital complications were a new left bundle-branch block (22.4%) and the need for pacemaker (16.3%). No specific complications for the subclavian access (vessel rupture, vertebral or internal mammary ischemia) were reported. The learning curve for the subclavian approach led to a wider use of local anesthesia. Thirty-day mortality was 0% versus 6.1% in the subclavian versus femoral groups, respectively (P=0.13). Six-month mortality rate was 9.4% versus 15.8% (P=0.44), whereas valve-related adverse events were 13.6% versus 13.9% (P=0.79). TAVI through the subclavian approach appeared feasible and safe, with excellent procedural success and low in-hospital complication rates. This new technique allows patients with contraindications to the femoral approach to be treated with TAVI.

The ROSE (Risk Stratification of Syncope in the Emergency Department) Study

This single-center prospective observational study was designed to develop a clinical decision rule to predict serious outcomes and all-cause mortality within 1 month of emergency department (ED) presentation with a syncopal episode. Serious outcomes were defined as acute myocardial infarction, life-threatening cardiac dysrhythmia, need for pacemaker or implantable defibrillator placement, pulmonary embolism, acute stroke, acute intracranial hemorrhage, significant hemorrhage requiring blood transfusion, need for acute surgical intervention, or need for acute endoscopic procedure.

Pacemaker Laser Lead Extraction and Reimplantation of Dual-Chamber Implantable Cardioverter Defibrillator Via Mustard Baffle in Complete Transposition of Great Arteries

We present a case of a complicated lead extraction and reimplantation of an implantable cardioverter defibrillator (ICD) in a young woman with complete transposition of great arteries (CTGA), a cyanotic congenital heart defect in which the aorta and the pulmonary trunk are transposed. The malformation results in two parallel circulations, whereby the left ventricle is attached to the pulmonary trunk and the right ventricle is attached to the aorta. Survival depends on the mixing of these two circulations at the level of the atria or ventricles or great arteries. Balloon atrial septostomy and creation of an intraatrial baffle are procedures that increase atrial mixing, increase systemic oxygenation, and hence improve survival. With the improved survival of patients with CTGA, there is an increasing need for permanent pacemakers (PPMs) and ICDs for rhythm disturbances. These leads and/or devices are often inserted when the patients are very young and need to be replaced or explanted in adulthood due to device or lead malfunction, device associated infection, or generator replacement or upgrades. These procedures are often complicated by the patients' complex anatomy and/or shunts. We describe a patient with CTGA who had an intraatrial baffle and a nonfunctioning dual-chamber PPM. The lead was extracted via the baffle and the old PPM was upgraded to an ICD. Such descriptions are rare.

Does ABO-incompatible and ABO-compatible neonatal heart transplant have equivalent survival?

A best evidence topic (BET) in cardiac surgery was written according to a structured protocol. The question addressed was whether ABO-incompatible (ABO-I) heart transplant recipients have a similar survival rate as an ABO-compatible (ABO-C) transplant in the pediatric population <1 year of age. Altogether more than 112 papers were found using the reported search, of which 10 represented the best evidence to answer the clinical question. Generally, ABO-I transplantation has been associated with the neonatal population because of the relative immaturity of the immune system for the first year of life. In the BET the search-term 'pediatric' was used as a method to ensure retrieval all relevant papers. However, the vast majority of the patients reviewed were <1 year of age with specific techniques undertaken to modulate preoperative, intraoperative and postoperative isohemagglutinin titer levels with rejection monitoring. Therefore, the BET conclusions should not be applied to the pediatric group as a broad age classification. Two large series are of particular interest. Patel et al. reviewed all primary heart transplantation recipients < or =1 year of age in the United Network for Organ Sharing/Organ Procurement and Transplantation Network (UNOS/OPTN) registry (ABO-I=35 vs. ABO-C=556). There was no difference in 30-day mortality (ABO-I=5.9% vs. ABO-C=8.8%; P=0.55); one-year mortality (ABO-I=16.6% vs. ABO-C=14.7%; P=0.77); graft rejection (ABO-I=1 vs. ABO-C=0); and graft failure (ABO-I=24% vs. ABO-C=24%; P>0.99). Three-year Kaplan-Meier survival was 70% (P=0.85). Propensity score adjusted analysis did not implicate ABO-I as a predictor of mortality [hazard ratio (HR)=3.6, confidence interval (CI): 0.2-49.0; P=0.33]. The ABO-I group demonstrated an increased need for pacemaker (ABO-I=3.1% vs. ABO-C=0.4%; P=0.03) and higher stroke rate (ABO-I=12.9% vs. ABO-C=1.3%; P<0.0001). Dipchand et al. published the results of the Toronto cohort from 1992 to 2006 (ABO-I=16 vs. ABO-C=38). The median age at transplantation (ABO-I=88 days vs. ABO-C=84 days; P=0.82) and the number of neonatal transplant recipients (ABO-I=17% vs. ABO-C=22%; P=0.59) was similar. The freedom from post-transplantation death or retransplantation was equivalent at one year (ABO-I=77% vs. ABO-C=84%) and seven years (ABO-I=74% vs. ABO-C=74%; P=0.87). No significant difference was observed for the five-year freedom from: rejection (ABO-I=60% vs. ABO-C=45%; P=0.41); renal dysfunction (ABO-I=67% vs. ABO-C=72%; P=0.70); allograft vasculopathy (ABO-I=87% vs. ABO-C=78%; P=0.45); and post-transplantation lymphoproliferative disorder (PTLD) (ABO-I=87% vs. ABO-C=86%; P=0.93). We conclude that ABO-I transplantation is comparable to ABO-C transplantation, with several retrospective papers concluding there is no difference in mortality, morbidity or graft failure in the pediatric population <1 year of age.

Electrocardiographic and further predictors for permanent pacemaker requirement after transcatheter aortic valve implantation

The objective of this study was to identify electrocardiographic (ECG) and further predictors for atrioventricular (AV) block with a need for pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI). Pre- and post-procedural ECGs of patients with severe aortic stenosis and ongoing TAVI were investigated in a prospective study. From 50 consecutive patients enrolled in the study (mean age 80 +/- 6 years, 46% men), 17 (34%) experienced an AV block with subsequent requirement of a permanent PM [16 of 36 (44.4%) with CoreValve System and 1 of 14 (7.1%) with Edwards Sapiens System]. In patients with right bundle branch block (RBBB), PM implantation had to be performed more frequently [6 of 6 (100%) with CoreValve System and none with Edwards Sapiens System], P = 0.005. An AV block (Mobitz II second degree and third degree) occurred mostly within the first 24 h (range: Days 0-13) after the index procedure. No recovery of AV conduction with a change in PM indication occurred in a mean follow-up time of 13 +/- 6 days. Our data demonstrate that patients with pre-operative RBBB and those receiving CoreValve prosthesis are at a significantly higher risk for PM implantation after TAVI. Therefore, patients with the presence of RBBB before TAVI may be at lower risk for PM implantation using the Edwards Sapiens System.

Changes in Atrioventricular Conduction and Predictors of Pacemaker Need After Percutaneous Implantation of the CoreValve ® Aortic Valve Prosthesis

Although changes in atrioventricular conduction frequently occur after percutaneous implantation of an aortic valve prosthesis, little is known about the mechanisms involved or how these changes progress. We investigated ECG abnormalities and predictors of pacemaker need after percutaneous implantation of the CoreValve® aortic valve prosthesis. Between April 2008 and October 2009, 65 patients with symptomatic severe aortic stenosis received a CoreValve® prosthesis. Clinical and ECG parameters were recorded and predictors of pacemaker need due to advanced atrioventricular block were investigated. The analysis excluded three patients because they had pacemakers and a fourth who died during the procedure. The patients' mean age was 79 ± 7.8 years and their logistic EuroSCORE was 20 ± 14%. Implantation was successful in 98.4%. After implantation, 47.5% had left bundle branch block and 21 patients (34.4%) required a permanent pacemaker. The need for a pacemaker was associated with a greater depth of prosthesis implantation in the left ventricular outflow tract (LVOT): 13 ± 2.5 mm vs. 8.8 ± 2.8 mm (P< .001). Moreover, depth was the only predictor: odds ratio 1.9, 95% confidence interval 1.19-3.05 (P< .007). A cutpoint of 11.1 mm for the prosthesis depth in the LVOT had a sensitivity of 81% and a specificity of 84.6% for predicting the need for a pacemaker. After CoreValve® aortic valve prosthesis implantation, a high percentage of patients needed a permanent pacemaker for advanced atrioventricular block. The only independent predictor was the depth of the prosthesis in the LVOT, which could serve as an early indicator of pacemaker need.