I. C. Van Gelder

Gene expression of proteins influencing the calcium homeostasis in patients with persistent and paroxysmal atrial fibrillation

OBJECTIVEnPersistent atrial fibrillation (AF) results in an impairment of atrial function. In order to elucidate the mechanism behind this phenomenon, we investigated the gene expression of proteins influencing calcium handling.nnnMETHODSnRight atrial appendages were obtained from eight patients with paroxysmal AF, ten with persistent AF (> 8 months) and 18 matched controls in sinus rhythm. All controls underwent coronary artery bypass grafting, whereas most AF patients underwent Coxs MAZE surgery (n = 12). All patients had a normal left ventricular function. Total RNA was isolated and reversely transcribed into cDNA. In a semi-quantitative polymerase chain reaction the cDNA of interest and of glyceraldehyde-3-phosphate dehydrogenase were coamplified and separated by ethidium bromide-stained gel electrophoresis. Slot blot analysis was performed to study protein expression.nnnRESULTSnL-type calcium channel alpha 1 and sarcoplasmic reticulum Ca(2+)-ATPase mRNA (-57%, p = 0.01 and -28%, p = 0.04, respectively) and protein contents (-43%, p = 0.02 and -28%, p = 0.04, respectively) were reduced in patients with persistent AF compared to the controls. mRNA contents of phospholamban, ryanodine receptor type 2 and sodium/calcium exchanger were comparable. No changes were observed in patients with paroxysmal AF.nnnCONCLUSIONSnAlterations in gene expression of proteins involved in the calcium homeostasis occur only in patients with long-term persistent AF. In the absence of underlying heart disease, the changes are rather secondary than primary to AF.

Use of an implantable loop recorder to increase the diagnostic yield in unexplained syncope: results from the PICTURE registry

Aims To collect information on the use of the Reveal implantable loop recorder (ILR) in the patient care pathway and to investigate its effectiveness in the diagnosis of unexplained recurrent syncope in everyday clinical practice. Methods and results Prospective, multicentre, observational study conducted in 2006–2009 in 10 European countries and Israel. Eligible patients had recurrent unexplained syncope or pre-syncope. Subjects received a Reveal Plus, DX or XT. Follow up was until the first recurrence of a syncopal event leading to a diagnosis or for ≥1 year. In the course of the study, patients were evaluated by an average of three different specialists for management of their syncope and underwent a median of 13 tests (range 9–20). Significant physical trauma had been experienced in association with a syncopal episode by 36% of patients. Average follow-up time after ILR implant was 10 ± 6 months. Follow-up visit data were available for 570 subjects. The percentages of patients with recurrence of syncope were 19, 26, and 36% after 3, 6, and 12 months, respectively. Of 218 events within the study, ILR-guided diagnosis was obtained in 170 cases (78%), of which 128 (75%) were cardiac. Conclusion A large number of diagnostic tests were undertaken in patients with unexplained syncope without providing conclusive data. In contrast, the ILR revealed or contributed to establishing the mechanism of syncope in the vast majority of patients. The findings support the recommendation in current guidelines that an ILR should be implanted early rather than late in the evaluation of unexplained syncope.

VERDICT: The verapamil versus digoxin cardioversion trial: A randomized study on the role of calcium lowering for maintenance of sinus rhythm after cardioversion of persistent atrial fibrillation

Verapamil and Atrial Fibrillation. Introduction: Many relapses of atrial fibrillation (AF) occur, especially during the first week(s) after electrical cardioversion (ECV). The aim of the present study was to compare in a randomized design the efficacy of verapamil (intracellular calcium lowering) versus digoxin (calcium increasing) for maintenance of sinus rhythm after ECV.

Gene expression of the natriuretic peptide system in atrial tissue of patients with paroxysmal and persistent atrial fibrillation

Natriuretic Peptide System in AF. Introduction: Circulating cardiac natriuretic peptides play an important role in maintaining volume homeostasis, especially during conditions affecting hemodynamics. During atrial fibrillation (AF), levels of plasma atrial natriuretic peptide (ANP) becomes elevated. The aim of this study was to gather information about gene expression of the natriuretic peptide system on the atrial level in patients with AF.

Atrial Ultrastructural Changes During Experimental Atrial Tachycardia Depend on High Ventricular Rate

Introduction: Atrial structural and electrophysiologic changes occur during atrial tachycardia. The role of high ventricular rate in these processes remains to be established.

The Role of Atrial Electrical Remodeling in the Progression of Focal Atrial Ectopy to Persistent Atrial Fibrillation

Focal Atrial Fibrillation and Electrical Remodeling. Although atrial fibrillation‐ (AF) induced changes in atrial refractoriness (atrial electrical remodeling) have been demonstrated in a number of different animal models, the clinical significance of this process is unknown. We describe a patient in whom there has been documented progression of atrial ectopy to persistent AF accompanied by evidence of atrial electrical remodeling, with reversal of remodeling following successful ablation of the focal source of AF. A second patient with focal AF, but with a “nonfocal” appearance on the ECG, is also described. These cases illustrate: (1) the possibility that a significant proportion of younger patients with idiopathic persistent AF may well have a focal source as the underlying abnormality; and (2) atrial electrical remodeling reverses following ablation of the underlying source.

Cardiac resynchronisation therapy and the role of optimal device utilisation

Despite established selection criteria, 30 to 40% of patients do not respond to cardiac resynchronisation therapy. By optimising programming of the device response to cardiac resynchronisation, therapy can be improved. (Neth Heart J 2009;17:354–7.)

Planning and monitoring of patients for electrical cardioversion for atrial fibrillation

ObjectivesThis study evaluated the waiting list for elective electrical cardioversion (ECV) for persistent atrial fibrillation (AF), focusing on when and why procedures were postponed. We compared the effects of management of the waiting list conducted by physicians versus management by nurse practitioners (NPs) and we evaluated the safety of our anticoagulating policy by means of bleeding or thromboembolic complications during and after ECV.BackgroundNot all patients selected for ECV receive their treatment at the first planned instance due to a variety of reasons. These reasons are still undocumented.MethodsWe evaluated 250 consecutive patients with persistent AF admitted to our clinic for elective ECV.ResultsWithin 5 to 6xa0weeks, 186 of 242 patients (77%) received ECV. The main reason for postponing an ECV was an inadequate international normalised ratio (INR); other reasons included spontaneous sinus rhythm and switch to rate control. A total of 23 of the 147 patients (16%) managed by the research physician were postponed due to an inadequate INR at admission versus 4 out of 98 patients (4%) managed by NPs (pu2009=u20090.005)ConclusionAn inadequate INR is the main reason for postponing an ECV. Management of ECV by NPs is safe and leads to less postponing on admission.

Dronedarone in patients with atrial fibrillation

Dronedarone is a recently developed new class III antiarrhythmic drug which possesses electrophysiological properties of all four Vaughan-Williams classes. An important difference with amiodarone is that it does not contain an iodine component and therefore lacks the iodine-related adverse effects. Based on currently available data, dronedarone can not be recommended as first-line therapy for either rhythm or rate control. We recommend to initiate rhythm or rate control with drugs as indicated in the 2006 guidelines of the ESC and other organisations. As amiodarone, dronedarone can be given to patients for whom standard drug therapy is not effective, or limited by (severe) side effects, although it is less effective than amiodarone. Nevertheless, it may be considered to give dronedarone initially to patients who would otherwise have received amiodarone, since the latter has more severe side effects than the former drug. The daily dosage of dronedarone is oral administration, 400 mg twice daily. Dronedarone is contraindicated in patients with impaired left ventricular function (NYHA class III/IV) and haemodynamic instability. (Neth Heart J 2010;18:370-3.)

Drug Prevention of Atrial Fibrillation: Are Novel Agents More Effective Than the Old Ones?

This report concerns paroxysmal and persistent atrial fibrillation (AF). Paroxysmal AF usually occurs in short episodes which terminate spontaneously. By contrast, persistent AF does not self-terminate and needs electrical cardioversion for restoration of sinus rhythm [1]. Cardioversion for persistent AF is in general successful. However, the Achilles’ heel in the treatment of both paroxysmal and persistent AF is arrhythmia recurrence. It should be kept in mind that restoration of sinus rhythm, either chemically or electrically, should only be attempted after adequate treatment of the underlying disease. The present review will deal with prevention of AF, focusing on new antiarrhythmic (Vaughan-Williams class III) drugs, recently discovered beneficial effects of conventional antiarrhythmic drugs, and alternative medical treatment strategies.