Unipolar atrial electrogram morphology is affected by age: evidence from high-resolution epicardial mapping

Figures

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  Figure 1.. The upper left panel shows a schematic presentation of the 192-unipolar electrode array on the RA, LA and BB. The upper right panel demonstrates a typical color-coded activation map demonstrating lines of conduction block, defined as local activation time differences between adjacent electrodes of ≥12ms; corresponding long double potentials are shown outside the activation map. Isochronal lines (thin black lines) are drawn at 10-millisecond intervals, and the black arrow indicates the propagation direction of the SR wavefront. IVC: inferior vena cava; SVC: superior vena cava; RA: right atrium; BB: Bachmann’s bundle; LA: left atrium; PV(A) : pulmonary vein (area); SP: single potential; SDP: short double potential; LDP: long double potential; FP: fractionated potential.

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  Figure 2.. U-AEGM type maps demonstrating the proportions of the different U-AEGM morphologies, obtained from four representative patients of different ages ranging from 42 to 76 years. These maps clearly show that the proportion of SDPs, LDPs and FPs at BB is higher in the oldest patient. U-AEGM: unipolar, unipolar atrial electrogram; SP: single potential; SDP: short double potential; LDP: long double potential; FP: fractionated potential; BB: Bachmann’s bundle.

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  Figure 3.. Relationship between age and BB U-AEGMs. Age is negatively correlated with SPs, and positively correlated with LDPs and FPs in model I. After adjusting for all confounding factors in model II, age is negatively correlated with SPs and positively correlated with SDPs, LDPs and FPs. Variables related to U-AEGM morphology in univariable linear regression analysis were adjusted in model I; body mass index, gender, hypertension, dyslipidemia, diabetes mellitus, myocardial infarction, left ventricular function, left atrial dilatation, and medications were adjusted in model II. U-AEGM: unipolar atrial electrogram; SP: single potential; SDP: short double potential; LDP: long double potential; FP: fractionated potential; BB: Bachmann’s bundle.