getAttribute in a for-loop using querySelector

I have this variable

var carouselItems = document.querySelectorAll(".carouselItem")

that is meant to access this stuff

                %div#carouselMain.row
                %div.col-xs-12.col-sm-3.carouselItem{:data => {:image => "images/art0"}}
                    %a{:href => "#"}
                        %div.featured-number
                            01
                        %div.featured-cat
                            Personal Article
                        %h3
                            TITLE
                %div.col-xs-12.col-sm-3.carouselItem{:data => {:image => "images/art1"}}
                    %a{:href => "#"}
                        %div.featured-number
                            02
                        %div.featured-cat
                            Visual Essay
                        %h3
                            TITLE
                %div.col-xs-12.col-sm-3.carouselItem{:data => {:image => "images/art2"}}
                    %a{:href => "#"}
                        %div.featured-number
                            03
                        %div.featured-cat
                            1st Year Feature
                        %h3
                            TITLE
                %div.col-xs-12.col-sm-3.carouselItem{:data => {:image => "images/art3"}}
                    %a{:href => "#"}
                        %div.featured-number
                            04
                        %div.featured-cat
                            Interview
                        %h3
                            TITLE

I created a function that has a for loop to access each div & URL for something else, here is the JS code for that:

function marqueeGatherData() {
    [].forEach.call(carouselItems, function(index) {
        marqueeVars.totalPanels = index + 1
        for (var j = 0; j < carouselItems.length; j++) {
            if (carouselItems[j].length) {
                var panel_image = this.getAttribute("data-image" + ".png"),
                    panel_caption = this.getElementsByTagName("h3").innerHTML,
                    panel_link = this.getAttribute("href"),
                    panel_category = this.querySelectorAll(".featured-cat").innerHTML,
                    panel_number = this.querySelectorAll(".featured-number").innerHTML
            }
        }
*random stuff*
})
}

But the problem arises when you notice that

console.log(panel_caption)

is returning 4 undefined values, which means the variable is unable to link itself to it's appropriate div. How would I go about solving this problem?