Biomolecule-Interactive Flexible Light Emitting Capacitor Display.

Ultrathin, lightweight, flexible, and conformable interactive displays that transduce external stimuli into human-readable signals are essential for emerging applications, such as wearable electronics, human-machine interfaces, and soft robots. Herein, a biomolecule-interactive flexible light emitting capacitor (LEC) display (BIO-LEC) capable of dynamic and quantitative visualization of biomolecules through naked-eye detectable electroluminescence (EL) emission is reported. BIO-LEC comprises a coplanar LEC light source at the bottom, and a designed microfluidic chip as sampling compartment at the top. The quantitative measurement feature of BIO-LEC is achieved by introducing the top liquid electrode, which possesses a unique long dielectric realization time, in the microfluidic chip. BIO-LEC is novel for the following reasons, 1) simple stimuli response principle based on correlating EL intensity to dielectric properties of the top liquid electrode; 2) simple test conditions whereby no labeling is required in the analyte solution to optically detect biomolecules; 3) effective sampling method through the design of an integrated microfluidic chip for hosting the top liquid electrode, ensuring good reproducibility and preventing contamination; 4) sensitive detection limit for heparin concentrations at clinically relevant levels, and 5) high compliance with industrial manufacturing standards.

How, when, and why individuals with stage IV cancer seen in an outpatient setting are referred to palliative care: a mixed methods study.

PURPOSE: Early palliative care (PC) for individuals with advanced cancer improves patient and family outcomes and experience. However, it is unknown when, why, and how in an outpatient setting individuals with stage IV cancer are referred to PC. METHODS: At a large multi-specialty group in the USA with outpatient PC implemented beginning in 2011, clinical records were used to identify adults diagnosed with stage IV cancer after January 1, 2012 and deceased by December 31, 2017 and their PC referrals and hospice use. In-depth interviews were also conducted with 25 members of medical oncology, gynecological oncology, and PC teams and thematically analyzed. RESULTS: A total of 705 individuals were diagnosed and died between 2012 and 2017: of these, 332 (47%) were referred to PC, with 48.5% referred early (within 60 days of diagnosis). Among referred patients, 79% received hospice care, versus 55% among patients not referred. Oncologists varied dramatically in their rates of referral to PC. Interviews revealed four referral pathways: early referrals, referrals without active anti-cancer treatment, problem-based referrals, and late referrals (when stopping treatment). Participants described PC's benefits as enhancing pain/symptom management, advance care planning, transitions to hospice, end-of-life experiences, a larger team, and more flexible patient care. Challenges reported included variation in oncologist practices, patient fears and misconceptions, and access to PC teams. CONCLUSION: We found high rates of use and appreciation of PC. However, interviews revealed that exclusively focusing on rates of referrals may obscure how referrals vary in timing, reason for referral, and usefulness to patients, families, and clinical teams.

Evolving Goals of Care Discussions as Described in Interviews With Individuals With Advanced Cancer and Oncology and Palliative Care Teams.

BACKGROUND: Individuals with advanced cancer and their families have negative end-of-life experiences when the care they receive is not aligned with their values and preferences. OBJECTIVE: To obtain in-depth information on how patients with advanced cancer and the oncology and palliative care (PC) clinicians who care for them discuss goals of care (GoC). DESIGN: The research team conducted in-depth interviews and qualitative data analysis using open coding to identify how perspectives on GoC discussions vary by stage of illness, and experience with PC teams. SETTING/SUBJECTS: Twenty-five patients and 25 oncology and PC team members in a large multi-specialty group in Northern California. RESULTS: At the time of diagnosis participants described having establishing GoC conversations about understanding the goal of treatment (e.g. to extend life), and prognosis ("How much time do I have?"). Patients whose disease progressed or pain/symptoms increased reported changing GoC conversations about stopping treatment, introducing hospice care, prognostic awareness, quality of life, advance care planning, and end-of-life planning. Participants believed in the fluidity of prognosis and preferences for prognostic communication varied. Patients appreciated how PC teams facilitated changing GoC conversations. Timing was challenging; some patients desired earlier conversations and PC involvement, others wanted to wait until things were "going downhill." CONCLUSION: Patients and clinical teams acknowledged the complexity and importance of GoC conversations, and that PC teams enhanced conversations. The frequency, quality, and content of GoC conversations were shaped by patient receptivity, stage of illness, clinician attitudes and predispositions toward PC, and early integration of PC.

Rapid De-Escalation and Triaging Patients in Community-Based Palliative Care.

CONTEXT: The coronavirus disease 2019 (COVID-19) pandemic created a rapid and unprecedented shift in our medical system. Medical providers, teams, and organizations have needed to shift their visits away from face-to-face visits and toward telehealth (both by phone and through video). Palliative care teams who practice in the community setting are faced with a difficult task: How do we actively triage the most urgent visits while keeping our vulnerable patients safe from the pandemic? MEASURES: The following are recommendations created by the Palo Alto Medical Foundation Palliative Care and Support Services team to help triage and coordinate for timely, safe, and effective palliative care in the community and outpatient setting during the ongoing COVID-19 pandemic. Patients are initially triaged based on location followed by acuity. Interdisciplinary care is implemented using strict infection control guidelines in the setting of limited personal protective equipment resources. We implement thorough screening for COVID-19 symptoms at multiple levels before a patient is seen by a designated provider. CONCLUSIONS/LESSONS LEARNED: We recommend active triaging, communication, and frequent screening for COVID-19 symptoms for palliative care patients been evaluated in the community setting. An understanding of infection risk, mutual consent between designated providers, patients, and their families are crucial to maintaining safety while delivering community-based palliative care during the COVID-19 pandemic.

Extended dual antiplatelet therapy for Asian patients with acute coronary syndrome: expert recommendations.

BACKGROUND: Recently, new evidence from large scale trials and updated guidelines have emerged on the risks and benefits of extended dual antiplatelet therapy (DAPT) for patients with acute coronary syndrome (ACS). AIMS: To discuss, clarify and advise on the application of the evidences and guidelines on individual patient selection for extended DAPT, with regard to balancing risk factors, particularly in Asian populations. METHODS: A total of 14 local cardiologists from Hong Kong with extensive experience in cardiology and cardiac interventions convened in a series of 3 advisory board meetings from October 2016 to September 2017, which included reviews of new evidence in the literature and discussions of the latest clinical trends, using an anonymous, electronic voting system for arriving at consensuses. RESULTS: Recommendations were produced for the following nine risk factors: old age (>65), chronic kidney disease (CKD), diabetes mellitus (DM), recurrent myocardial infarction (MI), multi-vessel disease (MVD), multiple stents, bioresorbable vascular scaffold (BVS) stent, left main stenting and peripheral artery disease (PAD). Strong ischaemic risk factors include DM, recurrent MI, MVD and/or >3 stents; less-strong ischaemic factors include CKD, left main stenting, BVS stent and PAD. Old age can be an unclear risk factor due to variations in physical fitness even among patients of identical age. DISCUSSION: The strengths and limitations of the results were acknowledged. CONCLUSION: ACS patients with ischaemic risk factors could be considered for extended DAPT beyond 12 months, while balancing the risk of bleeding.

Community-Based Palliative Care and Advance Care Planning Documentation: Evidence from a Multispecialty Group.

BACKGROUND/OBJECTIVES: With the growing public demand for access to critical health data across care settings, it is essential that advance care planning (ACP) information be included in the electronic health record (EHR) so that multiple clinicians can access it and understand individuals' preferences for end-of-life care. Community-based palliative care programs often incorporate ACP services. This study examined whether a community-based palliative care program is associated with digitally extractable ACP documentation in the EHR. DESIGN: Observational study using propensity score-weighted generalized estimation equations to examine patterns of digitally extractable ACP documentation. SETTING: Palo Alto Medical Foundation (PAMF), a multispecialty ambulatory healthcare system in northern California. PARTICIPANTS: Individuals aged 65 and older with serious illnesses between January 1, 2013, and December 31, 2014 (N = 3,444). INTERVENTION: Community-based palliative care program in PAMF. MEASUREMENTS: Digitally extractable ACP in EHR. RESULTS: We found that only 14% (n = 483) of individuals with serious illnesses had digitally extractable ACP in electronic health records. Of the 6% of individuals receiving palliative care, 65% had ACP, versus 11% of those not receiving palliative care. Study results showed a strong positive association between palliative care and ACP. CONCLUSION: Only a small percentage of individuals with serious illnesses had ACP documentation in the EHR. Individuals with serious illnesses infrequently used palliative care delivered by board-certified palliative care specialists. Palliative care service use was associated with higher rates of ACP after controlling for organizational and individual characteristics using a propensity score weighting method. Scalable interventions targeted at non-palliative care clinicians for universal access to ACP are needed.

Provider Perspectives on Advance Care Planning Documentation in the Electronic Health Record: The Experience of Primary Care Providers and Specialists Using Advance Health-Care Directives and Physician Orders for Life-Sustaining Treatment.

CONTEXT: Advance care planning (ACP) is valued by patients and clinicians, yet documenting ACP in an accessible manner is problematic. OBJECTIVES: In order to understand how providers incorporate electronic health record (EHR) ACP documentation into clinical practice, we interviewed providers in primary care and specialty departments about ACP practices (n = 13) and analyzed EHR data on 358 primary care providers (PCPs) and 79 specialists at a large multispecialty group practice. METHODS: Structured interviews were conducted with 13 providers with high and low rates of ACP documentation in primary care, oncology, pulmonology, and cardiology departments. The EHR problem list data on Advance Health Care Directives (AHCDs) and Physician Orders for Life-Sustaining Treatment (POLST) were used to calculate ACP documentation rates. RESULTS: Examining seriously ill patients ≥65 years with no preexisting ACP documentation seen by providers during 2013 to 2014, 88.6% (AHCD) and 91.1% (POLST) of 79 specialists had zero ACP documentations. Of 358 PCPs, 29.1% (AHCD) and 62.3% (POLST) had zero ACP documentations. Interviewed PCPs often believed ACP documentation was beneficial and accessible, while specialists more often did not. Specialists expressed more confusion about documenting ACP, whereas PCPs reported standard clinic workflows. Problems with interoperability between outpatient and inpatient EHR systems and lack of consensus about who should document ACP were sources of variations in practices. CONCLUSION: Results suggest that providers desire standardized workflows for ACP discussion and documentation. New Medicare reimbursement for ACP and an increasing number of quality metrics for ACP are incentives for health-care systems to address barriers to ACP documentation.

Multiple locations of advance care planning documentation in an electronic health record: are they easy to find?

BACKGROUND: The ambulatory care setting is a new frontier for advance care planning (ACP). While electronic health records (EHR) have been expected to make ACP documentation more retrievable, the literature is silent on the locations of ACP documentation in EHRs and how readily they can be found. OBJECTIVE: The study's objective is to identify the locations of ACP documentation in EpicCare EHR and to determine which patient and primary care provider (PCP) characteristics are associated with having a scanned ACP document. A scanned document (SD) is the only documentation containing signatures (unsigned documents are not legally valid). DESIGN: The study design is a retrospective review of EpicCare EHR records. The search of terms included advance directives, living will, Physician Orders for Life-Sustaining Treatments (POLST), power of attorney, and do-not-resuscitate. SETTING/SUBJECTS: Subjects were patients in a multispecialty practice in California age 65 or older who had at least one ACP documentation in the EHR. MEASUREMENTS: Measurements were types and locations of documentation, and characteristics of patients and physicians. RESULTS: About 50.9% of patients age 65 or older had at least one ACP documentation in the EHR (n=60,105). About 33.5% of patients with ACP documentation (n=30,566) had an SD. Patients' age, gender, race, illnesses, and when their physician started at the medical group were statistically significantly associated with the probability of having a scanned ACP document. CONCLUSIONS: Only 33.5% of patients with ACP documentation somewhere in the EHR had an SD. Standardizing the location of these documents should become a priority to improve care. Actions are needed to eliminate disparities.

Treadmill scores in elderly men.

OBJECTIVES: This study seeks to further characterize the role of exercise testing in the elderly for prognosis and diagnosis of coronary artery disease. BACKGROUND: Recent exercise testing guidelines have recognized that statements regarding the elderly do not have an adequate evidence-based quality because the studies they are based on have limitations in sample size and design. The Duke Treadmill Score has been recommended for risk stratification, but recent evidence has suggested that it does not function in the elderly. METHODS: The study population consisted of male veterans (1872 patients >or=65 years; 3798 patients <65 years) who underwent routine clinical exercise testing with a mean follow-up of six years. A subset who underwent coronary angiography as clinically indicated (elderly, n = 405; younger, n= 809) were included. The primary outcome for all subjects was cardiovascular mortality with coronary angiographic findings as the outcome in those selected for angiography. RESULTS: In survival analysis, exercise-induced ST depression was prognostic in both age groups only when cardiovascular death was considered as the end point. Peak metabolic equivalents were the most significant predictor for both age groups only when all-cause death was considered as the end point. New age-specific prognostic scores were developed and found to be predictive for cardiovascular mortality in the elderly. Moreover, in the angiographic subset of the elderly, a specific diagnostic score provided significantly better discrimination than exercise ST measurements alone. For any new score, there is a need for validation in another elderly population. CONCLUSIONS: The mortality end point affected the choice of prognostic variables. This study demonstrates that exercise test scores can be helpful for the diagnosis and prognosis of coronary disease in the elderly.

Mechanism of immediate recurrences of atrial fibrillation after restoration of sinus rhythm.

An immediate recurrence of AF may occur after restoration of sinus rhythm. Although pulmonary vein (PV) isolation has been shown to prevent immediate recurrence of AF, the specific trigger for immediate recurrence of AF has not been described. In 89 consecutive patients (mean age 53 +/- 11 years) who had sinus rhythm restored by spontaneous or transthoracic cardioversion in the course of a PV isolation procedure, electrograms recorded within a PV and in the adjacent left atrium were analyzed to determine the mechanism of initiation of immediate recurrence of AF. Immediate recurrence of AF was defined as a recurrence of AF within 90 seconds after restoration of sinus rhythm. There were 124 episodes of immediate recurrence of AF at a mean of 18 +/- 23 seconds after cardioversion. Recordings within the PV that triggered the immediate recurrence of AF were available in 23 (19%) of the 124 immediate recurrence of AF episodes. Among these 23 episodes of immediate recurrence of AF, all (100%) were triggered by a burst of PV tachycardia (P < 0.001). The coupling interval and prematurity index (coupling interval/preceding sinus cycle length) of the premature depolarizations that did and did not trigger immediate recurrence of AF were 246 +/- 67 ms and 0.30 +/- 0.11 vs 378 +/- 117 ms and 0.49 +/- 0.16, respectively (P < 0.01). Immediate recurrence of AF was abolished by PV isolation. The mechanism of immediate recurrence of AF is a burst of PV tachycardia, not a single premature depolarization. Immediate recurrence of AF identifies patients with AF in whom the PVs may play a major role in the initiation of AF.

Atrial electrogram amplitude and efficacy of cavotricuspid isthmus ablation for atrial flutter.

Large atrial electrogram amplitudes recorded in the cavotricuspid isthmus (CTI) may reflect thick atrial musculature. For this reason, in patients with atrial flutter, the efficacy of an application of conventional radiofrequency energy may be related to the amplitude of the local atrial electrogram. In 100 consecutive patients (mean age 59 +/- 13 years) with atrial flutter, contiguous applications of radiofrequency energy were delivered in the CTI. The criterion for complete CTI block was the presence of widely split double potentials (>110 ms) along the entire ablation line during pacing from the coronary sinus and posterolateral right atrium. The atrial electrogram amplitude was measured before and after applications of radiofrequency energy at sites of gaps in the ablation line. Complete CTI block was achieved in 90 (90%) of the 100 patients. The mean atrial electrogram amplitudes at gap sites where an application of radiofrequency energy did and did not result in complete block were 0.36 +/- 0.42 and 0.67 +/- 0.62 mV, respectively (P < 0.01). The positive and negative predictive values (for complete block) of a >/=50% decrease in electrogram amplitude after an application of radiofrequency energy were 100% and 35%, respectively. The mean atrial electrogram amplitude is larger at CTI sites where complete isthmus block cannot be achieved with conventional radiofrequency energy. The efficacy of conventional radiofrequency ablation may be improved by identifying areas in the CTI where the voltage is relatively low.

Anatomy of the pulmonary veins in patients with atrial fibrillation and effects of segmental ostial ablation analyzed by computed tomography.

INTRODUCTION: The anatomic arrangement of pulmonary veins (PVs) is variable. No prior studies have quantitatively analyzed the effects of segmental ostial ablation on the PVs. The aim of this study was to determine the effect of segmental ostial radiofrequency ablation on PV anatomy in patients with atrial fibrillation (AF). METHODS AND RESULTS: Three-dimensional models of the PVs were constructed from computed tomographic (CT) scans in 58 patients with AF undergoing segmental ostial ablation to isolate the PVs and in 10 control subjects without a history of AF. CT scans were repeated approximately 4 months later. PV and left atrial dimensions were measured with digital calipers. Four separate PV ostia were present in 47 subjects; 3 ostia were present in 2 subjects; and 5 ostia were present in 9 subjects. The superior PVs had a larger ostium than the inferior PVs. Patients with AF had a larger left atrial area between the PV ostia and larger ostial diameters than the controls. Segmental ostial ablation resulted in a 1.5 +/- 3.2 mm narrowing of the ostial diameter. A 28% to 61% focal stenosis was present 7.6 +/- 2.2 mm from the ostium in 3% of 128 isolated PVs. There were no instances of symptomatic PV stenosis during a mean follow-up of 245 +/- 105 days. CONCLUSION: CT of the PVs allows identification of anatomic variants prior to catheter ablation procedures. Segmental ostial ablation results in a significant but small reduction in ostial diameter. Focal stenosis occurs infrequently and is attributable to delivery of radiofrequency energy within the PV.

Effect of atrial fibrillation duration on probability of immediate recurrence after transthoracic cardioversion.

INTRODUCTION: An immediate recurrence of atrial fibrillation (IRAF) appears to be more common after early restoration of sinus rhythm with an implantable atrial defibrillator than after elective transthoracic cardioversion, which suggests that the probability of IRAF may be related to the duration of AF. METHODS AND RESULTS: Transthoracic cardioversion was performed 85 +/- 187 days (range 7 minutes to 8 years) after the onset of atrial fibrillation in 315 patients (mean age 61 +/- 13 years). IRAF was defined as a recurrence of AF within 60 seconds after restoration of sinus rhythm. IRAF occurred in 56% of patients when cardioversion was performed within 1 hour of the onset of AF compared with 12% of patients when cardioversion was performed after 24 hours of AF (P < 0.001). The duration of AF was the only independent predictor of IRAF among the clinical variables of age, gender, structural heart disease, antiarrhythmic drug therapy, and cardioversion energy (P < 0.01). CONCLUSION: IRAF is more likely to occur when the duration of AF is <1 hour than when the duration is >24 hours. This observation has clinical implications for the most appropriate timing of cardioversion, particularly in patients who receive device therapy for AF.

Effects of operator experience on the outcome and duration of pulmonary vein isolation procedures for atrial fibrillation.

Segmental, ostial ablation to isolate the pulmonary veins has been shown to be effective for the treatment of atrial fibrillation (AF). The purpose of this study was to determine the effects of operator experience on the outcome and duration of pulmonary vein isolation procedures for AF. One hundred three consecutive patients with AF underwent segmental, ostial ablation to isolate pulmonary veins. The effect of operator experience on the outcome and duration of the procedure was measured. The mean procedure duration was 232 +/- 70 minutes (range 50 to 460). There was an indirect linear relation between the total procedure time and the number of procedures performed (r = -0.68; p <0.001), and between the total fluoroscopic time and the number of procedures performed (r = -0.71; p <0.001). The percentage of patients in whom complete isolation of the pulmonary veins was achieved and the total duration of radiofrequency energy delivered during the procedures remained stable as operator experience increased. Operator experience was not an independent predictor of recurrent AF. The primary effect of operator experience on pulmonary vein isolation procedures for AF was a marked reduction in the duration of the procedure and fluoroscopic time. Long procedure durations and large amounts of radiation exposure may currently limit the widespread application of this therapy. The results of this study suggest that after >75 cases, segmental ablation to isolate the pulmonary veins using fluoroscopy and conventional radiofrequency ablation usually is feasible in <3 hours.

Segmental ostial ablation to isolate the pulmonary veins during atrial fibrillation: feasibility and mechanistic insights.

BACKGROUND: The purpose of this study was to determine the feasibility and mechanistic implications of segmental pulmonary vein (PV) ostial ablation during atrial fibrillation (AF). METHODS AND RESULTS: Forty consecutive patients underwent PV isolation for AF. Among 125 PVs targeted for isolation, ablation was performed during AF in 70 veins and during sinus rhythm in 55 veins. A decapolar Lasso catheter was positioned near the ostium. During AF, ostial ablation was performed near the Lasso catheter electrodes that recorded a tachycardia with a cycle length shorter than in the adjacent left atrium. During sinus rhythm, ostial ablation was guided by PV potentials. Complete PV isolation was achieved in 70 PVs (100%) ablated during AF and in 53 PVs (96%) ablated during sinus rhythm (P=0.4). The mean durations of radiofrequency energy needed for isolation were 7.4+/-4.4 and 5.2+/-3.9 minutes during AF and sinus rhythm, respectively (P<0.01). Before ablation, an immediate recurrence of AF (IRAF), occurred after cardioversion in 18 of 40 patients, and IRAF was consistently abolished by PV isolation. The probability of AF termination during isolation of a PV was directly related to the extent of tachycardia in that vein. As more PVs were isolated, induction of persistent AF by rapid pacing became less likely. CONCLUSIONS: Segmental ostial ablation guided by PV tachycardia during AF is feasible and as efficacious as during sinus rhythm. The responses to cardioversion, ablation, and rapid pacing observed in this study imply that IRAF is triggered by the PVs and that PV tachycardias may play an important role in the perpetuation of AF.

Comparison of amiodarone versus ibutilide for the prevention of immediate recurrences of atrial fibrillation during pulmonary vein isolation.

During segmental ostial ablation for pulmonary vein isolation, pulmonary vein potentials are easily identified during sinus rhythm or left atrial pacing. Therefore, maintenance of atrial fibrillation (AF) during the procedure is desirable. However, cardioversion is occasionally followed by an immediate recurrence of AF. This study compared the efficacy of ibutilide and amiodarone in preventing immediate recurrences of AF in patients who underwent pulmonary vein isolation. The subjects of this study were 25 patients (mean age 56 +/- 10 years) who underwent pulmonary vein isolation for AF who had an immediate recurrence of AF within 60 seconds after 2 transthoracic cardioversions. The patients were randomized to receive an infusion of either 300 mg of amiodarone over 10 minutes or 1 mg of ibutilide over 5 minutes. Cardioversion was repeated 15 minutes after the drug infusion. If immediate recurrences of AF occurred 2 more times, the alternative study drug was administered, and cardioversion was repeated. Immediate recurrences of AF were suppressed by amiodarone in 8 of 10 patients (80%), and by ibutilide in 9 of 15 patients (60%, p = 0.4). After crossover, immediate recurrence of AF was suppressed in 2 of 6 patients (33%) by amiodarone, and in 1 of 2 patients (50%) by ibutilide (p = 0.6). Ibutilide and amiodarone, when used alone or in combination, prevented immediate recurrences of AF in 20 of 25 patients (80%). There were no adverse drug effects. Ibutilide and amiodarone were equally effective in suppressing immediate recurrences of AF. Overall, immediate recurrences of AF can be prevented by amiodarone and/or ibutilide in 80% of patients.

Mechanistic significance of intermittent pulmonary vein tachycardia in patients with atrial fibrillation.

INTRODUCTION: The significance of intermittent tachycardia within a pulmonary vein (PV) during an episode of atrial fibrillation (AF) is unclear. The aim of this study was to determine the role that intermittent PV tachycardias play in AF. METHODS AND RESULTS: In 56 patients with AF, segmental ostial ablation guided by PV potentials was performed to isolate the PVs. The characteristics of intermittent PV tachycardias and the inducibility of AF before and after PV isolation were analyzed prospectively. During AF, a PV tachycardia (mean cycle length 130 +/- 30 msec) with exit block to the left atrium was present in 93% of left superior, 80% of left inferior, 73% of right superior, and 7% of right inferior PVs. The site of shortest cycle length during AF alternated between the PVs and left atrium 1 to 13 times per minute. Complete isolation was achieved in 168 (94%) of 178 targeted PVs. In 99% of PVs, tachycardia resolved upon isolation. AF was persistent before and after PV isolation in 100% and 27% of patients, respectively (P < 0.001). CONCLUSION: Intermittent bursts of tachycardia are observed within multiple PVs during persistent AF in a majority of patients. After PV isolation, PV tachycardias almost always resolve, and AF is less likely to be inducible or persistent. These observations suggest a dynamic interplay between the atria and PVs, with intermittent bursts of PV tachycardia being dependent on left atrial input and with the probability of persistent AF diminishing when PV tachycardias are eliminated by PV isolation.

Clinical significance of early recurrences of atrial fibrillation after pulmonary vein isolation.

OBJECTIVES: The purposes of this study were to describe the prevalence of early recurrences of atrial fibrillation (ERAF) that occur within two weeks after pulmonary vein (PV) isolation, and to determine whether ERAF is predictive of long-term outcome after PV isolation. BACKGROUND: Atrial fibrillation (AF) sometimes recurs within days after PV isolation and may prompt an early repeat intervention. METHODS: Segmental PV isolation was performed using radiofrequency energy in 110 consecutive patients (mean age 53 +/- 11 years) with paroxysmal (93 patients) or persistent (17 patients) AF. Three to four PVs were targeted for isolation in all patients. Pulmonary vein isolation was complete in 338 of the 358 PVs that were targeted (94%). RESULTS: Early recurrences of AF occurred in 39 of 110 patients (35%) at a mean of 3.7 +/- 3.5 days after the procedure. The prevalence of ERAF was similar in patients with paroxysmal and persistent AF (33% and 47%, respectively, p = 0.4). Beyond the first two weeks, at 208 +/- 125 days of follow-up, 60 of the 71 patients without ERAF (85%) and 12 of the 39 patients with ERAF (31%) were free of recurrent AF in the absence of antiarrhythmic drug therapy (p < 0.001). CONCLUSIONS: Early recurrences of AF occur in approximately 35% of patients within two weeks after isolation of three to four PVs, and are associated with a lower long-term success rate than in patients without ERAF. However, approximately 30% of patients with ERAF have no further symptomatic AF during long-term follow-up. Therefore, temporary antiarrhythmic drug therapy may be more appropriate than early repeat ablation in patients with ERAF.

Pulmonary vein isolation for paroxysmal and persistent atrial fibrillation.

BACKGROUND: The pulmonary veins (PVs) have been demonstrated to often play an important role in generating atrial fibrillation (AF). The purpose of this study was to determine the safety and efficacy of segmental PV isolation in patients with paroxysmal or persistent AF. METHODS AND RESULTS: In 70 consecutive patients (mean age, 53 +/- 11 years) with paroxysmal (58) or persistent (12) AF, segmental PV isolation guided by ostial PV potentials was performed. The left superior, left inferior, and right superior PVs were targeted for isolation in all patients, and the right inferior PV was isolated in 20 patients. Among the 230 targeted PVs, 217 (94%) were completely isolated, with a mean of 6.5 +/- 4.2 minutes of radiofrequency energy applied at a maximum power setting of 35 W. A second PV isolation procedure was performed in 6 patients (9%). At 5 months of follow-up, 70% of patients with paroxysmal and 22% of patients with persistent AF were free from recurrent AF (P<0.001), and 83% of patients with paroxysmal AF were either free of symptomatic AF or had significant improvement. Among various clinical characteristics, only paroxysmal AF was an independent predictor of freedom from recurrence of AF (P<0.05). One patient developed unilateral quadrantopsia after the procedure. There were no other complications. CONCLUSIONS: With a segmental isolation approach that targets at least 3 PVs, a clinically satisfactory result can be achieved in >80% of patients with paroxysmal AF. The clinical efficacy of pulmonary vein isolation is much lower when AF is persistent than when it is paroxysmal.