In this population with symptomatic persistent AF and LA enlargement, septal E/e' ratio ≥11 and AF duration >90 days predicted AF recurrence at 3 months.

BACKGROUND Short QT syndrome (SQTS) is a congenital ion channel disease characterized by an increased risk of sudden cardiac death. Little is known about the possibility that accelerated repolarization alters mechanical function in SQTS.OBJECTIVES The study investigated the presence of left ventricular dysfunction and mechanical dispersion, assessed by tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE), and their correlation with QT interval duration and genetics.METHODS Fifteen SQTS patients (7 with HERG and 3 with KCNQ1 mutation) were studied. Electrocardiographic and echocardiographic parameters were compared with age-and sex-matched healthy controls.RESULTS When compared to the control group, SQTS patients showed reduced left ventricular contraction (global longitudinal strain: À16.0% Ϯ 3.4% vs À22.6% Ϯ 1.7%, P o .001; myocardial performance index 0.59 Ϯ 0.17 vs 0.34 Ϯ 0.08, P o .001) and a higher incidence of ejection fraction o55% (odds ratio 11, 95% confidence interval 1.045-374, P ¼ .04). Mechanical dispersion assessed by TDI (P o .01) and STE (P o .001) was higher in the SQTS group than in controls; each parameter showed a significant inverse correlation with QT interval but not with QT dispersion.CONCLUSION This study showed that in SQTS systolic function may also be affected. SQTS patients presented a significant dispersion of myocardial contraction. TDI and STE could become part of the evaluation of this rare disease.

Leukocyte telomere length (LTL) provides a potential marker of biological age, closely related to the endothelial dysfunction and consequently to the atherosclerotic process. To investigate the relationship between the LTL and the risk of premature acute myocardial infarction and to evaluate the predictive value of LTL on the onset of major cardiovascular events, 199 patients from 18 to 48 years old with first diagnosis of acute myocardial infarction were enrolled and were matched with 190 controls for sex and age (±1 year). Clinical data and coronary artery disease were evaluated at enrollment and at follow up. LTL was measured at enrollment using a quantitative PCR-based method. No significant differences were observed in LTL between cases and controls (p = 0.20) and with the presence of coronary artery disease in patients (p = 0.47). Hypercholesterolemic cases presented LTL significantly longer than cases without hypercholesterolemia (t/s: 0.82±0.16 p = 0.79 and t/s norm: 0.79±0.19 p = 0.01), as confirmed in multivariate regression analysis (p = 0.005, β = 0.09). Furthermore, multivariate regression analysis showed LTL significantly shorter in hypertensive cases than in normotensive cases (p = 0.04, β = −0.07). One hundred seventy-one cases (86%) ended the average follow up of 9±5 years, 92 (54%) presented a major cardiovascular event. At multivariate regression analysis the LTL detected at enrollment did not represent a predictive factor of major cardiovascular events nor it significantly impacted with cumulative events. Based on present cohort of young Italian patients, the LTL did not represent a marker of acute myocardial infarction nor had a predictive role at medium term follow up.

2576ANTOLINI M et al. Circulation JournalOfficial Journal of the Japanese Circulation Society http://www. j-circ.or.jp dent predictor of LA function improvement at follow-up, but previous studies have not identified a cut-off of LA function able to predict LA functional recovery. 8 The aim of this mono-center prospective study was therefore to clarify the effect of AF ablation on LA function according to baseline atrial performance. Methods Patient EnrollmentFrom March to December 2013, all consecutive patients who underwent catheter ablation for paroxysmal or persistent AF in the electrophysiology laboratory were considered for enrollment. Only those who presented in sinus rhythm at baseline adiofrequency catheter ablation (RFCA) is an effective treatment in rhythm-control therapy for atrial fibrillation (AF), with a reduction in AF recurrence ranging from 50 to 80%. 1-3 By promoting a reduction in arrhythmic burden, RFCA improves symptoms and quality of life. 4,5Despite both structural and functional changes after RFCA having been extensively studied, the effect of AF ablation on left atrial (LA) function has not yet been sufficiently determined and remains a pivotal topic also with regard to the consequences of decision on whether to discontinue anticoagulation after successful ablation. 6 In patients with impaired LA function, the risk of thrombus formation is potentially augmented, irrespective of the classical risk factors. 7Pre-ablation LA function has been identified as an indepen- Background: Data are lacking on the effect of radiofrequency catheter ablation (RFCA) on atrial function. The aim of this study was to determine a cut-off of pre-ablation left atrial (LA) function in order to predict atrial functional recovery after RFCA. R

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