I don't see the initial move reflected in your code. According to my reading of the documentation, shouldn't this be something more like the following?
var doc = new jsPDF();
doc.lines([[24.2384, 43.2816, 22.3952, 46.9968, 18.7376, 50.5104]], 19.0544,25.8288, [1, 1]);
Update
Didn't notice the docs say coords are relative (thanks Pomax), so try this.
var doc = new jsPDF();
var x = 19.0544;
var y = 25.8288;
doc.lines([[24.2384-x, 43.2816-y, 22.3952-x, 46.9968-y, 18.7376-x, 50.5104-y]], x,y, [1, 1]);