Left atrial contractile strain predicts recurrence of atrial tachyarrhythmia after catheter ablation.

BACKGROUND: Despite improvement in treatment strategies of atrial fibrillation (AF), a considerable number of patients still experience recurrence of atrial tachyarrhythmia (ATA) following catheter ablation (CA). This study aimed to investigate the prognostic value of left atrial (LA) deformation analysis in a large group of patients undergoing CA for AF. METHODS: This study included 678 patients with AF. Echocardiography including two-dimensional speckle tracking echocardiography (2DSTE) was performed in all patients prior to CA. Logistic regression analysis was used to assess the association between ATA recurrence and LA strain during reservoir phase (LASr), LA strain during contraction phase (LASct), and LA strain during conduit phase (LAScd). RESULTS: During one-year follow-up, 274 (40%) experienced ATA recurrence. Median age of the included study population was 63.2 years (IQR: 55.5, 69.5) and 485 (72%) were male. Patients with recurrence had lower LASr (22.6% vs. 25.1%, p = 0.001) and LASct (10.7% vs. 12.4%, p < 0.001). No difference in LAScd was observed. After adjusting for potential clinical and echocardiographic confounders LASr (OR = 1.04, CI95% [1.01; 1.07], p = 0.015, per 1% decrease) and LASct (OR = 1.06, CI95% [1.02; 1.11], p = 0.007, per 1% decrease) remained independent predictors of recurrence. However, in patients with a normal-sized LA (LA volume index<34 mL/m2), only LASct remained an independent predictor of recurrence (OR = 1.07, CI95% [1.01; 1.12], p = 0.012, per 1% decrease). CONCLUSION: In patients undergoing CA for AF, LA deformation analysis by 2DSTE could be of use in risk stratification in clinical practice regarding ATA recurrence, even in patients with a normal-sized LA.

Volume and dimensions of angiographically normal coronary arteries assessed by multidetector computed tomography.

BACKGROUND: The objective of this study was to determine normal values for coronary artery volume (CAV) and individual vasculature and segment dimensions. METHODS: We examined 200 healthy volunteers with an Agatston score of 0 and a normal, high quality coronary CTA. Using 320 slice multidetector row CT and designated vessel tracing software with border detection algorithm, the main coronary arteries and branches were delineated and total and segmental dimensions calculated. RESULTS: 2931 segments (98.9%) could be adequately delineated. Of the 173 subjects with adequate coronary delineations, 140 subjects (81%) received nitroglycerin (NTG) prior to the scan. CAV was 4.33 ml (95% CI: 2.27-6.39) in subjects with NTG and 2.55 ml (95% CI: 0.34-4.76) in subjects without NTG (p < 0.0001). Left ventricular mass (LVM) was strongly correlated with CAV (p < 0.0001) independently of body surface area and gender, whereas gender was not independently correlated with CAV. From right, balanced to left coronary dominance, the left anterior descending artery vasculature mean contribution to CAV increased slightly (37%, 40% and 43%, p = 0.002), and the mean contributions of right coronary artery (RCA) and left circumflex artery (LCX) vasculature was inversely related - from right, balanced to left 46%, 32% and 16% for RCA (p < 0.0001); and 16%, 27% and 38% for LCX (p < 0.0001). CONCLUSION: Normal values for coronary artery volume as assessed by coronary CTA are reported. They strongly correlate with NTG administration and left ventricular mass. The respective contribution of the left and right coronary vascularture is influenced by coronary dominance.