Granulomatosis with polyangiitis (GPA) is a systemic necrotizing vasculitis, associated with antineutrophil cytoplasmic autoantibody-associated systemic vasculitis, and it can affect many organ systems via the inflammation of small-to-medium-sized vessels. Cardiac involvements in GPA are relatively rare. We report a 75-year-old woman who was diagnosed with GPA and rapid progressive glomerulonephritis that resulted in a partial posteromedial papillary muscle rupture, but with no coronary angiographic findings. The surgical and pathological findings with regard to the ruptured papillary muscle revealed necrotic muscle and acute ischemic change. The mechanism of papillary muscle rupture in GPA is coronary vasculitis leading to myocardial infarction. The ischemic change is not always detected on coronary angiography, so assessment using an echocardiogram is important.