Returns or sets the style of the arrowhead at the beginning of the specified line. Can be one of the following MsoArrowheadStyle constants: msoArrowheadDiamond, msoArrowheadNone, msoArrowheadOpen, msoArrowheadOval, msoArrowheadStealth, msoArrowheadStyleMixed, or msoArrowheadTriangle. Read/write Long.