Temporary transvenous pacing catheter placement is an important and critical procedure for emergency physicians. Ultrasound can be used to guide placement and to diagnosis correct or incorrect catheter placement. This case report discusses a patient with an acute ST elevation myocardial infarction leading to unstable arrhythmias requiring emergent transvenous cardiac pacing. The pacemaker was inserted using electrocardiographic monitoring through the bipolar pacing catheter. There was some difficulty placing the catheter, but successful capture with a left bundle-branch block pattern was obtained. However, ultrasonographic evaluation after placement showed the pacing wire curled in the Inferior Vena Cava (IVC) with the tip in the right ventricle. Ultrasound examination and guidance can prevent misplacement of the transvenous pacer catheter, which would not be apparent by electrocardiographic means.