Cardiac electrophysiology review最新文献

{"title":"Second Vasovagal Pacemaker Study (VPS II): rationale, design, results, and implications for practice and future clinical trials.","authors":"Robert Sheldon,&nbsp;Stuart Connolly","doi":"10.1023/B:CEPR.0000023157.37745.76","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023157.37745.76","url":null,"abstract":"<p><p>Vasovagal syncope causes substantial morbidity. Various medications have been studied with goals of reducing event-rates and improving quality of life. Results have been mixed, with few drugs demonstrating benefit. Bradycardia usually accompanies vasovagal syncope during positive tilt table tests, and is recorded in up to 50% of clinical syncopal spells documented on electrocardiographic loop recorders. These findings form the rationale for studies of the effectiveness of pacing in preventing vasovagal syncope. Three historically controlled trials of permanent pacing showed that 80-90% of patients had a marked symptomatic improvement, with 90-95% reductions in the number of expected syncopal spells. Subsequently three open-label trials randomized a total of 189 patients evenly to medical therapy or pacemakers in trials that used the proportion of patients with recurrent syncope as the primary outcome. They showed relative risk reductions of 80-87% in the paced patients. However these early studies were not blinded, raising concern about the possible role of a significant placebo effect. This issue was addressed in the recent Second Vasovagal Pacemaker Study (VPS II), in which 100 patients received pacemakers. They then were randomized to pacing with rate drop sensing, or sensing without pacing. The cumulative risk of syncope at 6 months was 40% for the control group and 31% for the actively paced group. The relative risk reduction in time to syncope with pacing was 30% (1 p = 0.14). The AHA/ACC guidelines about pacing and vasovagal syncope should be reassessed. Future clinical trials of therapies for vasovagal syncope should be randomized and placebo-controlled.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"411-5"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023157.37745.76","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pacing for vasovagal syncope after the second Vasovagal Pacemaker Study (VPS II): a matter of judgement.","authors":"Geoffrey M Trim,&nbsp;Andrew D Krahn,&nbsp;George J Klein,&nbsp;Allan C Skanes,&nbsp;Raymond Yee","doi":"10.1023/B:CEPR.0000023168.26698.1e","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023168.26698.1e","url":null,"abstract":"<p><p>Vasovagal or neurocardiogenic syncope is a common benign condition. In the majority of patients it regresses naturally, or can be controlled by conservative therapy. However there is a group of patients who remain severely affected despite lifestyle measures, counselling and medication. Pacing has been considered in these patients as a result of logic, observational studies, and three randomised but unblinded studies, VPS, VASIS and SYDIT. A randomised and blinded study, VPS II, was recently published, the results of which undermined the results of these preceding studies: despite a 30% trend towards reduced syncope in patients with active pacing, the result was not statistically significant. This left clinicians with a dilemma, whether or not to pace in patients with disabling syncope despite conservative therapy. We believe, based on a review of all currently available evidence, that there remains a role for pacing in the patient with evidence of significant cardioinhibition, particularly severe bradycardia or asystole, and ongoing disabling syncope in spite of conservative measures. When to pace in these patients is a matter of clinical judgement. The threshold for pacing should remain high, however, with extensive attempts of conservative and pharmacological measures and with appropriate discussions with patients prior to instituting pacing, regarding the risks and long-term implications of a pacemaker. More needs to be learned about optimal pacing modalities.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"416-20"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023168.26698.1e","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does sinus rhythm beget sinus rhythm? Effects of prompt cardioversion on the frequency and persistence of recurrent atrial fibrillation.","authors":"Hung-Fat Tse,&nbsp;Chu-Pak Lau","doi":"10.1023/B:CEPR.0000023139.45437.93","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023139.45437.93","url":null,"abstract":"<p><p>Recent clinical and experimental studies have demonstrated that atrial fibrillation (AF) alters the electrical and mechanical remodeling of the atrium, which subsequently promote the maintenance and recurrence of AF. If atrial remodeling can be prevented with prompt and repeated cardioversion, the likelihood of AF recurrence may be reduced. Recent clinical studies have demonstrated that the strategies of transesophageal echocardiography facilitated early cardioversion and early repeated cardioversion may be clinically valuable in some patients who have persistent AF and recurrence of arrhythmia after the initial cardioversion. Furthermore, the use an implantable atrial defibrillator (IAD) for early repeated device-based cardioversion to maintain sinus rhythm appears to be safe and clinically feasible. Early cardioversion by IAD reduces AF burden, reverses atrial remodeling and prevents subsequent AF recurrence in selected patients without structural heart disease implanted with this device, indicating possible \"sinus rhythm begets sinus rhythm\". Despite encouraging initial observations, further long-term clinical studies in a larger patient population are needed to confirm this finding. Furthermore, whether the use of IAD in the fully automatic mode to provide immediate termination of AF episodes could intensify the potential beneficial effect and the clinical efficacy of this approach in patients with structural heart disease needs to be evaluated.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"359-65"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023139.45437.93","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: a prospective hemodynamic study.","authors":"Stephane Garrigue,&nbsp;Pierre Bordachar,&nbsp;Sylvain Reuter,&nbsp;Pierre Jaïs,&nbsp;Michel Haïssaguerre,&nbsp;Jacques Clementy","doi":"10.1023/B:CEPR.0000023167.11038.8f","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023167.11038.8f","url":null,"abstract":"<p><strong>Background: </strong>Left ventricular pacing (LVP) and biventricular pacing (BVP) have been proposed as treatments for patients with advanced heart failure complicated by discoordinate contraction due to intraventricular conduction delay. For patients in sinus rhythm, BVP works in part by modulating the electronic atrial-ventricular time delay and thus optimizing contractile synchrony, the contribution of atrial systole, and reducing mitral regurgitation. However, little is known of the mechanisms of BVP in heart failure patients with drug-resistant chronic atrial fibrillation. HYPOTHESIS AND METHODS: LVP differs from BVP because hemodynamic and clinical improvement occurs in association with prolongation rather than shortening of the QRS duration. We sought to determine if LVP or BVP improves mechanical synchronization in the presence of atrial fibrillation. Thirteen patients with chronic atrial fibrillation, severe heart failure and QRS >or=140 ms received (after His bundle ablation) a pacemaker providing both LVP and BVP. The mean age was 62 +/- 6 years and left ventricular ejection fraction was 24 +/- 8%. After a baseline phase of one month with right ventricular pacing, all patients underwent in random order 2 phases of 2 months (LVP and BVP). At the end of each phase, an echocardiogram, a hemodynamic analysis at rest and during a 6-minute walking test and a cardio-pulmonary exercise test were performed.</p><p><strong>Results: </strong>LVP and BVP provided similar performances at rest (p = ns). The 6-minute walking test revealed similar performances in both pacing modes but patients were significantly more symptomatic at the end of the test with LVP ( p = 0.035). The cardio-pulmonary exercise test showed higher performances with BVP (92 +/- 34 Watts) vs. LVP (77 +/- 23; p = 0.03). LVP was associated with significantly more premature ventricular complexes recorded during the 6 minute walking test (49 +/- 71) than BVP (10 +/- 23; p = 0.04).</p><p><strong>Conclusions: </strong>In this small series of patients with atrial fibrillation, congestive heart failure and a prolonged QRS duration, LVP and BVP provided similar hemodynamic effects at rest whereas BVP was associated with better hemodynamic effects during exercise and fewer premature ventricular complexes. Although the mechanisms for the observed differences are uncertain, it is possible that there is worsening of right ventricular function due to a rise in left-to-right electromechanical delay during exercise. Increased catecholamines release might contribute to the lower exercise tolerance and greater number of premature ventricular complexes recorded during exercise observed during LVP compared to BVP.</p><p><strong>Recommendations: </strong>Patients with atrial fibrillation, heart failure and QRS prolongation who are candidates for His-bundle ablation and cardiac resynchronization therapy may respond better to BVP rather than to LVP.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"315-24"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023167.11038.8f","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24458406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atrial fibrillation: should we target platelets or the coagulation pathway?","authors":"Kiat T Tan,&nbsp;Gregory Y H Lip","doi":"10.1023/B:CEPR.0000023141.17553.f1","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023141.17553.f1","url":null,"abstract":"<p><p>Based on the established fact that anticoagulation with warfarin is superior to antiplatelet agents in the prevention of thromboembolic events in atrial fibrillation (AF), we propose that, in contrast to atherothrombotic disorders, the risk of developing a stroke or thromboembolic event in AF is more likely to be affected by the coagulation pathway than by platelet activity. Indeed, platelet-rich thrombi may be the predominant underlying pathophysiological process in coronary artery disease patients, thus representing an entirely different prothrombotic profile to the patients with AF, where clotting factor abnormalities (and thus fibrin-rich thrombi) are more likely. Thus, we would hypothesise that warfarin is probably more likely to be more beneficial than aspirin-clopidogrel combination therapy when used in this setting. Indeed, this hypothesis would need to be tested in large randomised clinical trials.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"370-1"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023141.17553.f1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aspirin--anticoagulant combination in patients with non valvular atrial fibrillation commentary on the FFAACS study results.","authors":"Philippe P Lechat","doi":"10.1023/B:CEPR.0000023142.88884.d8","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023142.88884.d8","url":null,"abstract":"<p><p>The prevention of the thromboembolic complications of chronic atrial fibrillation remains a therapeutic challenge because they cannot be completely suppressed by vitamin K antagonists with a target international normalized ratio between 2 and 3. Evaluation of the combination at that international normalized ratio level with antiplatelet therapy was the aim of the placebo-controlled double-blind Fluindione Fibrillation Auriculaire, Aspirine et Contraste Spontané (FFAACS) study with fluindione (as anticoagulant) and aspirin (100 mg) in patients with chronic atrial fibrillation at high risk of thromboembolic complications. The study was prematurely stopped because of insufficient recruitment rate resulting in very low power. An increase of minor bleeding complications was observed in the combination arm. Given these preliminary results, this combination cannot be recommended in such patients. The question remains with respect to antithrombotic therapy in patients with atrial fibrillation if the risk of severe bleeding complications outweighs the benefit of avoiding ischemic stroke.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"372-3"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023142.88884.d8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationships between pacing mode and quality of life: evidence from randomized clinical trials.","authors":"David Newman","doi":"10.1023/B:CEPR.0000023164.83349.c5","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023164.83349.c5","url":null,"abstract":"<p><p>Although mode-dependent differences in mortality are for the moment unproven, establishing a health-related quality of life difference between assigned pacing modes would be useful. Such a difference, if one exists, should be >or=0.5 standard deviation units among scales using validated instruments to have significant clinical meaning. Two large data sets, the Canadian Trial of Physiological Pacing (CTOPP) and the Mode Selection Trial (MOST) both similar in design, largely failed to clearly establish such a significant difference. Another trial the Pacemaker Selection in the Elderly (PASE) did suggest that for sinus node disease, DDD-R pacing may lead to an improvement in quality of life mainly early post implant. Two other large trials, UK-PACE and DANPACE have yet to present quality of life related results. All published data have established that restoration of chronotropic competence by pacing leads to improvements in quality of life that are significant. In CTOPP an attempt to quantify a mode-dependent difference for a pacemaker syndrome suggested that the prevalence and clinical importance of pacemaker syndrome may be exaggerated. The relative ease of crossover from VVI-R to DDD, by device upgrade in CTOPP or by programming in MOST, may explain the 2.9% vs. 31% crossover rates seen in CTOPP vs. MOST respectively. Trials to date may have had a mode dependent difference undermined by possible adverse effects from right ventricular apical sites of pacing. Future trial data; DANPACE, sinus node disease AAI-R vs. DDD-R and PAVE, post AVJ ablation VVI-R vs. VVI-CRT, will asses in more detail the role of site of pacing as a factor in determining mode dependent outcomes in pacing.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"401-5"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023164.83349.c5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cardiac resynchronization therapy with or without an implantable defibrillator: only indicated when everything else has failed?","authors":"J Ghosh,&nbsp;Gerry Kaye,&nbsp;J G F Cleland","doi":"10.1023/B:CEPR.0000023160.76069.42","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023160.76069.42","url":null,"abstract":"<p><p>Cardiac resynchronization therapy (CRT) is potentially an important new treatment for patients with heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony. There is growing evidence that CRT can improve symptoms although it is possible that similar benefits could be obtained by skillful manipulation of pharmacological therapy. There is also preliminary but inconclusive evidence to suggest that CRT alone or in synergy with an implantable cardiac defibrillator (ICD) may reduce morbidity and mortality. However, fashion is in danger of overtaking facts and it is important to ensure that benefits are not only statistically proven but clinically meaningful and cost-effective. Optimal timing of intervention and patient selection will be essential to ensure that treatment is deployed efficiently. If CRT with or without ICD becomes part of mainstream therapy for heart failure this will have far-reaching consequences for heart failure management. Implantation is a skilled and often time-consuming procedure. Long-term management of both CRT and ICD is likely to provide challenges in terms of lead technology, pacing thresholds and device management. Heart failure physicians will have to learn new skills and collaborate more closely with electrophysiologists. Such developments, in addition to the need for complex pharmacological interventions will accelerate the move away from general practice and towards specialist care for this most common of malignant diseases. If CRT does reduce mortality, it will graduate from an adjunctive therapy which could be used to an essential one that should be used as part of routine therapy for appropriate patients. Currently, CRT is a symptomatic therapy for patients with severe heart failure resistant to intensive pharmacological therapy delivered by a heart failure specialist.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"421-9"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023160.76069.42","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Risk stratification for sudden death: do we need anything more than ejection fraction?","authors":"Alfred E Buxton","doi":"10.1023/B:CEPR.0000023159.96742.d2","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023159.96742.d2","url":null,"abstract":"<p><p>Recent studies have emphasized the prognostic significance of left ventricular ejection fraction in patients with coronary and other types of heart disease. Ejection fraction relates as a continuous variable to mortality risk. In patients with a variety of underlying heart diseases, the lower the ejection fraction, the higher observed mortality. However, while ejection fraction is statistically associated with mortality, it is only one of multiple factors that impact on mortality. In order to assess the clinical utility of ejection fraction, it is necessary to assess the sensitivity as well as the specificity of commonly used cut points in identification of patients at mortality risk. In this manuscript, it is shown that ejection fraction lacks sensitivity, and its specificity is suspect in patients with chronic coronary artery disease. The dangers of focusing on ejection fraction are that many patients whose ejection fractions exceed commonly used cut offs experience sudden death. Finally, because ejection fraction is not specific in predicting mode of death, utilization of expensive technology such as the implantable defibrillator based solely on ejection fraction will not be very cost-effective.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"434-7"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023159.96742.d2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does rapid atrial pacing terminate atrial fibrillation? A comparison of laboratory and device termination studies.","authors":"Andrew R J Mitchell,&nbsp;Neil Sulke","doi":"10.1023/B:CEPR.0000023137.24735.6b","DOIUrl":"https://doi.org/10.1023/B:CEPR.0000023137.24735.6b","url":null,"abstract":"<p><p>Atrial fibrillation is understood to be a re-entrant arrhythmia and for many years electrophysiologists have attempted to pace-terminate the rhythm. Several studies have demonstrated that an excitable gap is present during atrial fibrillation and that the capture of small amounts of atrial tissue is possible. Early attempts to terminate atrial fibrillation however were unsuccessful. The rapid development of pacemaker and defibrillator technology has provided an exciting new direction for the treatment of recurrent symptomatic atrial fibrillation. Results from studies of the effectiveness of atrial anti-tachycardia pacing algorithms have suggested that 50% of atrial arrhythmias (including atrial fibrillation) can be pace-terminated. These findings conflict with data from the electrophysiology laboratory where atrial fibrillation has yet to be convincingly terminated. In this review, the current literature is discussed and possible reasons for this discrepancy are proposed.</p>","PeriodicalId":80888,"journal":{"name":"Cardiac electrophysiology review","volume":"7 4","pages":"352-4"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1023/B:CEPR.0000023137.24735.6b","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24457689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}