M Kuehne

Incidence of new-onset atrial fibrillation after cavotricuspid isthmus ablation for atrial flutter

AimsnIn patients with cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL), the decision to hold oral anticoagulation (OAC) often becomes an issue. The purpose of this study was to describe the incidence of the development of atrial fibrillation (AF) after CTI ablation in patients with documented AFL with and without a previous history of AF and to identify risk predictors for the occurrence of AF after CTI.nnnMethods and resultsnWe included 364 consecutive patients undergoing successful CTI ablation. Thereof, 230 patients (170 male; age 66u2009±u200911 years) had AFL only (AFL group) and 134 patients (94 male; age 65u2009±u200911 years) had AFL and previously documented AF (AFL and AF group). Over a mean follow-up of 22u2009±u200920 months, 163 (71%) patients in the AFL group and 67 (50%) patients in the AFL and AF groups had no documentation of a recurrent atrial arrhythmia (Pu2009<u20090.001). AF developed in 51 patients (22%) in the AFL group and in 57 (43%) patients in the AFL and AF groups (Pu2009<u20090.001). In patients without history of AF, left atrial diameter was the only predictor of development of AF (HR 1.058 [95%CI 1.011-1.108], Pu2009=u20090.016). Multivariate analysis of the total population identified history of AF (HR 1.918 [95%CI 1.301-2.830], Pu2009=u20090.001) and BMI as predictors for AF development (HR 1.052 [95%CI 1.012-1.093], Pu2009=u20090.011).nnnConclusionnOur results indicate that new-onset AF develops in a significant proportion of patients undergoing CTI for AFL. One should therefore be careful to withhold OAC. Furthermore, pulmonary vein isolation should be considered in conjunction with CTI, particularly in patients with previously documented AF.

Prohormones in the Early Diagnosis of Cardiac Syncope

Background The early detection of cardiac syncope is challenging. We aimed to evaluate the diagnostic value of 4 novel prohormones, quantifying different neurohumoral pathways, possibly involved in the pathophysiological features of cardiac syncope: midregional–pro‐A‐type natriuretic peptide (MRproANP), C‐terminal proendothelin 1, copeptin, and midregional‐proadrenomedullin. Methods and Results We prospectively enrolled unselected patients presenting with syncope to the emergency department (ED) in a diagnostic multicenter study. ED probability of cardiac syncope was quantified by the treating ED physician using a visual analogue scale. Prohormones were measured in a blinded manner. Two independent cardiologists adjudicated the final diagnosis on the basis of all clinical information, including 1‐year follow‐up. Among 689 patients, cardiac syncope was the adjudicated final diagnosis in 125 (18%). Plasma concentrations of MRproANP, C‐terminal proendothelin 1, copeptin, and midregional‐proadrenomedullin were all significantly higher in patients with cardiac syncope compared with patients with other causes (P<0.001). The diagnostic accuracies for cardiac syncope, as quantified by the area under the curve, were 0.80 (95% confidence interval [CI], 0.76–0.84), 0.69 (95% CI, 0.64–0.74), 0.58 (95% CI, 0.52–0.63), and 0.68 (95% CI, 0.63–0.73), respectively. In conjunction with the ED probability (0.86; 95% CI, 0.82–0.90), MRproANP, but not the other prohormone, improved the area under the curve to 0.90 (95% CI, 0.87–0.93), which was significantly higher than for the ED probability alone (P=0.003). An algorithm to rule out cardiac syncope combining an MRproANP level of <77 pmol/L and an ED probability of <20% had a sensitivity and a negative predictive value of 99%. Conclusions The use of MRproANP significantly improves the early detection of cardiac syncope among unselected patients presenting to the ED with syncope. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01548352.

Design of the Swiss Atrial Fibrillation Cohort Study (Swiss-AF): structural brain damage and cognitive decline among patients with atrial fibrillation

BACKGROUNDnSeveral studies found that patients with atrial fibrillation (AF) have an increased risk of cognitive decline and dementia over time. However, the magnitude of the problem, associated risk factors and underlying mechanisms remain unclear.nnnMETHODSnThis article describes the design and methodology of the Swiss Atrial Fibrillation (Swiss-AF) Cohort Study, a prospective multicentre national cohort study of 2400 patients across 13 sites in Switzerland. Eligible patients must have documented AF. Main exclusion criteria are the inability to provide informed consent and the presence of exclusively short episodes of reversible forms of AF. All patients undergo extensive phenotyping and genotyping, including repeated assessment of cognitive functions, quality of life, disability, electrocardiography and cerebral magnetic resonance imaging. We also collect information on health related costs, and we assemble a large biobank. Key clinical outcomes in Swiss-AF are death, stroke, systemic embolism, bleeding, hospitalisation for heart failure and myocardial infarction. Information on outcomes and updates on other characteristics are being collected during yearly follow-up visits.nnnRESULTSnUp to 7 April 2017, we have enrolled 2133 patients into Swiss-AF. With the current recruitment rate of 15 to 20 patients per week, we expect that the target sample size of 2400 patients will be reached by summer 2017.nnnCONCLUSIONnSwiss-AF is a large national prospective cohort of patients with AF in Switzerland. This study will provide important new information on structural and functional brain damage in patients with AF and on other AF related complications, using a large variety of genetic, phenotypic and health economic parameters.

Case report: electrical storm during induced hypothermia in a patient with early repolarization

BackgroundPopulation based studies showed an association of early repolarization in the electrocardiogram (ECG) and a higher rate of sudden cardiac death presumably due to ventricular fibrillation. The triggers for ventricular fibrillation in patients with early repolarization are not fully understood.Case presentationWe describe the case of a young patient with a survived ventricular fibrillation arrest while asleep followed by multiple episodes of recurrent ventricular fibrillation. The admission ECG showed an early repolarization pattern with substantial J-point elevation in most of the ECG-leads. After initiation of a hypothermia protocol, the patient developed an electrical storm with multiple ventricular fibrillation episodes requiring multiple cardioversions. Intravenous isoproterenol infusion successfully suppressed the malignant arrhythmia.ConclusionHypothermia appears proarrhythmic in patients with early repolarization and may trigger ventricular fibrillation. This knowledge is particularly important when initiating temperature management protocols in patients after a survived cardiac arrest. During the acute phase of an early repolarization associated electrical storm, isoproterenol is the most effective treatment suppressing the ventricular fibrillation-inducing premature ventricular complexes at higher heart rates.