Rg Tieleman

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.

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.

Alterations in Gene Expression of Proteins Involved in the Calcium Handling in Patients with Atrial Fibrillation

Gene Expression in Human Atrial Fibrillation. Introduction: Atrial fibrillation (AF) leads to a loss of atrial contraction within hours to days. During persistence of AF, cellular dedifferentiation and hypertrophy occur, eventually resulting in degenerative changes and cell death. Abnormalities in the calcium handling in response to tachycardia‐induced intracellular calcium overload play a pivotal role in these processes.

Long-term outcome of electrical cardioversion in patients with chronic atrial flutter

OBJECTIVE: To determine the long-term outcome of serial electrical cardioversion therapy in patients with chronic atrial flutter. DESIGN: Prospective study, case series. SETTING: University hospital. PATIENTS: 50 consecutive patients with chronic (> 24 hours) atrial flutter without a previous relapse on antiarrhythmic drugs. INTERVENTIONS: Elective electrical cardioversion therapy, if necessary repeated, to obtain and keep patients in sinus rhythm. If the first cardioversion resulted in sinus rhythm, patients were not given antiarrhythmic drugs. Relapses were managed by repeated cardioversions then anti-arrhythmic drugs were used serially in a set sequence. MAIN OUTCOME MEASURE: Maintenance of sinus rhythm. RESULTS: Mean (SD) follow up was 3.5 (1.7) years. The first cardioversion was successful in 48 patients (96%). After a single shock and without antiarrhythmic drugs being used, 42% of the patients maintained sinus rhythm in the long-term. Only left atrial size was inversely related to the efficacy of one shock (P = 0.025). With serial cardioversion 90% of the patients were kept in sinus rhythm for 5 years. Univariate analysis showed that a long duration of arrhythmia and impaired cardiac function were both related to poor outcome. During follow up 3 patients died of progression of heart failure and another 5 died suddenly. None of these 5 patients was on antiarrhythmic drugs. CONCLUSIONS: Electrical cardioversion was an effective and safe method of converting chronic atrial flutter to sinus rhythm. To maintain sinus rhythm, more than half of the patients required multiple shocks and prophylactic antiarrhythmic drugs. Sudden death was relatively frequent in the study population; the limited data available from this study suggest that such deaths were caused by the underlying disease and not drug related proarrhythmia.

Electrical remodeling and atrial dilation during atrial tachycardia are influenced by ventricular rate: role of developing tachycardiomyopathy.

Atrial Remodeling in Tachycardiomyopathy. Introduction: Atrial fibrillation (AF) and congestive heart failure (CHF) are two clinical entities that often coincide. Our aim was to establish the influence of concomitant high ventricular rate and consequent development of CHF on electrical remodeling and dilation during atrial tachycardia.