Severe myocardial ischemia in a patient with diabetes mellitus and left bundle branch block.

We present the case of a 69-year-old woman with diabetes mellitus, left bundle branch block, and obesity who develops cardiogenic shock after undergoing myocardial perfusion imaging and diagnostic left heart catheterization, but prior to coronary revascularization. This case highlights the risk of cardiac decompensation awaiting surgery in patients with multivessel coronary artery disease. It also emphasizes the subtleties involved in imaging patients with diabetes mellitus and left bundle branch block, as well as the risk of developing complete heart block in the setting of ischemia with underlying conduction disease.