In Brief The presence of a persistent left-sided superior vena cava is a rare venous return anomaly. There have been numerous reports in the literature describing placement of central venous catheters and transvenous pacemaker wires successfully into the right side of the heart through a persistent left-sided vena cava and the coronary sinus. An 84-year-old male developed acute cardiogenic pulmonary edema resulting in respiratory failure requiring assisted ventilation. His electrocardiograms revealed findings consistent with left ventricular hypertrophy. Subsequently, he developed cardiogenic shock complicated by asystolic cardiac arrest from which he was quickly resuscitated with epinephrine and atropine. A pulmonary artery catheter was placed via the right internal jugular vein without any complications. A transvenous pacemaker was successfully inserted through the left internal jugular vein for complete heart block. The postprocedure chest radiograph demonstrated a normally placed pulmonary artery catheter and the presence of the pacemaker wire along the left side of the heart. Thoracic computed tomography (CT) confirmed that the pacemaker wire extended through a persistent left-sided superior vena cava into a superficial cardiac vein. We present an unusual and previously unreported case of malposition of a temporary transvenous pacemaker wire into a superficial cardiac vein via a persistent left-sided superior vena cava. Critical care physicians should be aware of this congenital anomaly while placing central venous catheters from the left side, particularly in patients with other congenital cardiac defects. When the position is uncertain, imaging modalities, particularly CT, will be helpful in defining the course of central venous catheter. As critical care practitioners, we routinely place central venous catheters, which are not without risk. An unusual case of malposition of a temporary transvenous pacemaker wire into a superficial cardiac vein via a persistent left-sided superior vena cava is reported. Knowledge of this congenital anomaly during placement of central venous catheters from the left side is imperative, particularly in patients with other congenital cardiac defects. Imaging modalities such as computed tomography, angiography, and echocardiography can be helpful in delineating central venous catheter malposition.