Elizabeth Sartori Crevelari

Incidência de choques e qualidade de vida em jovens com cardioversor-desfibrilador implantável

OBJECTIVES To analyze the incidence and causes of ICD therapies in children and young adults and verify their impact on the quality of life (QoL). METHODS From March/1977 to February/2006, 29 patients (15.7+/-5.4 years old) were submitted to ICD implants. Aborted cardiac arrest (41.5%), sustained ventricular tachycardia (27.6%) and primary prophylaxis of sudden cardiac death (30.9%) indicated device therapy. The number of therapies was evaluated by interviewing patients and by ICD diagnostic data. The SF-36 questionnaire was used to measure the QoL and the results were compared to healthy population. The expectative of freedom from ICD therapies were estimated by the Kaplan-Meier method. RESULTS After 2.6+/-1.8 years follow-up, 8 (27.6%) patients received 141 appropriate ICD shocks due to ventricular tachycardia (6) or ventricular fibrillation (2), and 11 (37.9%) patients received 152 inappropriate ICD shocks due to supraventricular tachyarrhythmias (8) or oversensing (3). Expectative of freedom from appropriate shocks was 74.2+/-9.0% and 66.7+/-10.7% after one and three years, respectively. Compared to healthy population, QoL decreased in physical function (61.7+/-28.7), vitality (64.7+/-19.1), mental health (65.9+/-22.7) and role-emotional domains (66.7+/-38.5). All patients referred fear and concern related to ICD use. CONCLUSION Despite the efficacy of ICD therapies, the high incidence of appropriate and inappropriate shocks interfered in patients QoL and adaptation to the device.

Laser assisted extraction of pacemaker and implantable defibrillator leads

OBJECTIVE To analyze the results of laser-assisted extraction of permanent pacemaker and defibrillator leads. METHODS We operated upon 36 patients, whose mean age was 54.2 years, and extracted 56 leads. The reasons for extracting the leads were as follows: infection in 19 patients, elective replacement in 13, and other causes in 4 patients. The mean time of catheter placement was 7.5+/-5.5 years. Forty-seven leads were from pacemakers, and 9 were from defibrillators. Thirty-eight leads were in use, 14 had been abandoned in the pacemaker pocket, and 4 had been abandoned inside the venous system. RESULTS We successfully extracted 54 catheters, obtaining a 96.4% rate of success and an 82.1% rate for complete extraction. The 2 unsuccessful cases were due to the presence of calcium in the trajectory of the lead. The mean duration of laser light application was 123.0+/-104.5 s, using 5,215.2+/-4,924.0 pulses, in a total of 24.4+/-24.2 cycles of application. Thirty-four leads were extracted from the myocardium with countertraction after complete progression of the laser sheath, 12 leads came loose during the progression of the laser sheath, and the remaining 10 were extracted with other maneuvers. One patient experienced cardiac tamponade after extraction of the defibrillator lead, requiring open emergency surgery. CONCLUSION The use of the excimer laser allowed extraction of the leads with a 96% rate of success; it was not effective in 2 patients who had calcification on the lead. One patient (2.8%) had a complication that required cardiac surgery on an emergency basis.

Glocal Clinical Registries: Pacemaker Registry Design and Implementation for Global and Local Integration - Methodology and Case Study

Background The ability to apply standard and interoperable solutions for implementing and managing medical registries as well as aggregate, reproduce, and access data sets from legacy formats and platforms to advanced standard formats and operating systems are crucial for both clinical healthcare and biomedical research settings. Purpose Our study describes a reproducible, highly scalable, standard framework for a device registry implementation addressing both local data quality components and global linking problems. Methods and Results We developed a device registry framework involving the following steps: (1) Data standards definition and representation of the research workflow, (2) Development of electronic case report forms using REDCap (Research Electronic Data Capture), (3) Data collection according to the clinical research workflow and, (4) Data augmentation by enriching the registry database with local electronic health records, governmental database and linked open data collections, (5) Data quality control and (6) Data dissemination through the registry Web site. Our registry adopted all applicable standardized data elements proposed by American College Cardiology / American Heart Association Clinical Data Standards, as well as variables derived from cardiac devices randomized trials and Clinical Data Interchange Standards Consortium. Local interoperability was performed between REDCap and data derived from Electronic Health Record system. The original data set was also augmented by incorporating the reimbursed values paid by the Brazilian government during a hospitalization for pacemaker implantation. By linking our registry to the open data collection repository Linked Clinical Trials (LinkedCT) we found 130 clinical trials which are potentially correlated with our pacemaker registry. Conclusion This study demonstrates how standard and reproducible solutions can be applied in the implementation of medical registries to constitute a re-usable framework. Such approach has the potential to facilitate data integration between healthcare and research settings, also being a useful framework to be used in other biomedical registries.

Comportamento funcional dos portadores de marcapasso convencional submetidos a ressincronização cardíaca

BACKGROUND Cardiac resynchronization therapy (CRT) is an efficient treatment for patients with heart failure (HF), severe ventricular dysfunction and intraventricular block. Conventional pacemakers (CPM) implanted in the right ventricular apical area cause alterations in the normal sequence of cardiac activation similar to those induced by LBBB (left bundle-branch block). Therefore, patients with CPM and advanced HF could be candidates to undergo CRT, but as only small numbers of patients have been evaluated so far, definitive conclusions are lacking. OBJECTIVE To assess the clinical and functional outcome of cardiac resynchronization therapy (CRT) in patients with conventional pacemakers. METHODS Patients with CPM, who were in NYHA HF functional class III/IV class refractory to drug therapy, and left ventricular ejection fraction (LVEF) ) <35% underwent CRT. Patients clinical-functional behavior was assessed prospectively six months after the procedure. The improvement of one HF-functional class was set as an effective response to the procedure. The following was assessed: QRS duration (ECG), diastolic diameter (LVDd), left ventricular systolic diameter (LVSd) and LVEF seen on the echocardiogram. For the statistical analysis, Students paired t test and Spearmans correlation were used. RESULTS Twenty-nine patients (mean age 61.5) were evaluated. Of these, six were females, and chagasic cardiomyopathy was predominant. During the clinical follow-up of 22.7+/-13 months, 86.2% of the patients benefited from CRT. Within this group, the mean LVEF increased by 18% (p=0.013), QRS duration dropped by 11.8% (p=0.002) and no significant reduction in left ventricular intracavitary diameters was observed. CONCLUSION CRT is effective for patients with CPM and advanced HF as it yields a high rate of response (86.2%), significantly improves LVEF and reduces QRS duration.

Criteria for pacemaker explant in patients without a precise indication for pacemaker implantation.

MARTINELLI, M., et al.: Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker Implantation. Unnecessary pacemaker implantation may cause significant social and psychological consequences, the inconvenience of periodic office visits, and the expense of pulse generator replacement. Establishing adequate criteria for explanting pacemakers is crucial and has not yet been described. This study presents the results of a study protocol for explanting the pacemaker in patients without a clear indication for pacemaker implantation. Seventy pacemaker users without a clear reason for the implantation were included in the study conducted from August 1986 to November 1998 and were prospectively followed. The investigation consisted of clinical and neurological evaluations, echocardiogram, exercise testing, and tilt table testing. When these tests were negative, the pulse generator energy and stimulation rates were reprogrammed to the lowest values. Periodic Holter monitoring was conducted during follow‐up. When asymptomatic for 1 year, patients underwent an electrophysiological evaluation of sinus and atrioventricular junction function and ventricular vulnerability. When the electrophysiological study was negative, pacemaker explantation was performed. Of the 70 patients, 35 had their pacemaker explanted; 3 were excluded due to a positive tilt table test and electrophysiological study, and 3 are waiting for pacemaker explantation. Mean follow‐up after pacemaker explantation was 30.3 months, and all patients remained asymptomatic, except for one patient who died of a noncardiac cause. Critical analysis of pacemaker users without a well‐established indication is justified because it may allow pacemaker explant in a significant proportion of these patients, and it may bring considerable social, economic, and psychological benefits.

Quality of Life and Functional Capacity after Long-Term Right Ventricular Pacing in Pediatrics and Young Adults with Congenital Atrioventricular Block

Although several studies have demonstrated deleterious consequences of chronic right ventricular (RV) pacing on ventricular function and synchronicity, its effects on health‐related quality of life (HRQoL) and functional exercise capacity remain uncertain. We aimed to evaluate the effect of RV pacing on HRQoL and functional capacity of children and young adults with congenital complete atrioventricular block (CCAVB).

Functional Capacity of Patients with Pacemaker Due to Isolated Congenital Atrioventricular Block

Background Isolated congenital atrioventricular block (CAVB) is a rare condition with multiple clinical outcomes. Ventricular remodeling can occur in approximately 10% of the patients after pacemaker (PM) implantation. Objectives To assess the functional capacity of children and young adults with isolated CAVB and chronic pacing of the right ventricle (RV) and evaluate its correlation with predictors of ventricular remodeling. Methods This cross-sectional study used a cohort of patients with isolated CAVB and RV pacing for over a year. The subjects underwent clinical and echocardiographic evaluation. Functional capacity was assessed using the six-minute walk test. Chi-square test, Fishers exact test, and Pearson correlation coefficient were used, considering a significance level of 5%. Results A total of 61 individuals were evaluated between March 2010 and December 2013, of which 67.2% were women, aged between 7 and 41 years, who were using PMs for 13.5 ± 6.3 years. The percentage of ventricular pacing was 97.9 ± 4.1%, and the duration of the paced QRS complex was 153.7 ± 19.1 ms. Majority of the subjects (95.1%) were asymptomatic and did not use any medication. The mean distance walked was 546.9 ± 76.2 meters and was strongly correlated with the predicted distance (r = 0.907, p = 0.001) but not with risk factors for ventricular remodeling. Conclusions The functional capacity of isolated CAVB patients with chronic RV pacing was satisfactory but did not correlate with risk factors for ventricular remodeling.

Marca-passo cardíaco definitivo em crianças com bradicardia pós-operatória: resultados tardios

Objective: To evaluate the long-term outcomes of children submitted to permanent cardiac pacing due to postoperative bradycardia and to identify risk factors for mortality. Methods: From 1980 to 2004, 120 children were submitted to permanent pacemaker implantation. Interval between the defect correction and pacemaker implantation was 1.2 ± 2.8 years on average (median = 21 days). Atrioventricular blocks were present in 94.2% of patients. Transvenous leads (78.3%) and ventricular pacemaker systems (79.2%) were used in most cases. Risk factors were studied using the Cox proportional model. The Kaplan-Meier method and the LogRank test were used to analyze survival. Results: After a mean of 5.7 ± 5.9 years (maximum = 22.5 years) of follow-up, 97 patients were alive and 23 were lost from the follow-up study. The main causes of death were terminal heart failure (10), infection not related to implantation (six), and sudden death (three). The 5-, 10-, and 15-year survival rates were 80.9 ± 4.1%, 75.4 ± 5.5% and 67.2 ± 7.4%, respectively. The persistence of hemodynamic problems (palliative procedures, the use of valve prostheses or the presence of residual defects) was identified as the only independent risk predictors for mortality, with significant alterations in the survival curves (p=0.0123). Conclusion: The implant of permanent pacemakers in children provided good survival expectancy, mainly depending on the underlying disease and the type of the correction made. Palliative corrections, such as the presence of residual defects or the use of valve prostheses were the only predictors of poor results in these children.

Usefulness of preoperative venography in patients with cardiac implantable electronic devices submitted to lead replacement or device upgrade procedures

Background Venous obstructions are common in patients with transvenous cardiac implantable electronic devices, but they rarely cause immediate clinical problems. The main consequence of these lesions is the difficulty in obtaining venous access for additional leads implantation. Objectives We aimed to assess the prevalence and predictor factors of venous lesions in patients referred to lead reoperations, and to define the role of preoperative venography in the planning of these procedures. Methods From April 2013 to July 2016, contrast venography was performed in 100 patients referred to device upgrade, revision and lead extraction. Venous lesions were classified as non-significant (< 50%), moderate stenosis (51-70%), severe stenosis (71-99%) or occlusion (100%). Collateral circulation was classified as absent, discrete, moderate or accentuated. The surgical strategy was defined according to the result of the preoperative venography. Univariate analysis was used to investigate predictor factors related to the occurrence of these lesions, with 5% of significance level. Results Moderate venous stenosis was observed in 23%, severe in 13% and occlusions in 11%. There were no significant differences in relation to the device side or the venous segment. The usefulness of the preoperative venography to define the operative tactic was proven, and in 99% of the cases, the established surgical strategy could be performed according to plan. Conclusions The prevalence of venous obstruction is high in CIED recipients referred to reoperations. Venography is highly indicated as a preoperative examination for allowing the adequate surgical planning of procedures involving previous transvenous leads.

Complications after Surgical Procedures in Patients with Cardiac Implantable Electronic Devices: Results of a Prospective Registry

Background: Complications after surgical procedures in patients with cardiac implantable electronic devices (CIED) are an emerging problem due to an increasing number of such procedures and aging of the population, which consequently increases the frequency of comorbidities. Objective: To identify the rates of postoperative complications, mortality, and hospital readmissions, and evaluate the risk factors for the occurrence of these events. Methods: Prospective and unicentric study that included all individuals undergoing CIED surgical procedures from February to August 2011. The patients were distributed by type of procedure into the following groups: initial implantations (cohort 1), generator exchange (cohort 2), and lead-related procedures (cohort 3). The outcomes were evaluated by an independent committee. Univariate and multivariate analyses assessed the risk factors, and the Kaplan-Meier method was used for survival analysis. Results: A total of 713 patients were included in the study and distributed as follows: 333 in cohort 1, 304 in cohort 2, and 76 in cohort 3. Postoperative complications were detected in 7.5%, 1.6%, and 11.8% of the patients in cohorts 1, 2, and 3, respectively (p = 0.014). During a 6-month follow-up, there were 58 (8.1%) deaths and 75 (10.5%) hospital readmissions. Predictors of hospital readmission included the use of implantable cardioverter-defibrillators (odds ratio [OR] = 4.2), functional class III-IV (OR = 1.8), and warfarin administration (OR = 1.9). Predictors of mortality included age over 80 years (OR = 2.4), ventricular dysfunction (OR = 2.2), functional class III-IV (OR = 3.3), and warfarin administration (OR = 2.3). Conclusions: Postoperative complications, hospital readmissions, and deaths occurred frequently and were strongly related to the type of procedure performed, type of CIED, and severity of the patients underlying heart disease.