Case Report
A 59-year-old man with history of chronic obstructive pulmonary disease
presented to the emergency room with severe sinus bradycardia and
hypotension. He was diaphoretic and denied any chest pain. He gave a
history of recurrent dizziness and near syncopal episodes. The patient
was not on any atrioventricular nodal blocking agents and initial blood
work showed no reversible cause of his severe sinus bradycardia.
The patient was started on intravenous fluid hydration and a bedside
echocardiogram was obtained. Echocardiogram showed normal biventricular
systolic function and no significant valvular abnormalities. Atropine
was given but resulted in minimal, transient improvement in his heart
rate to the low 50s. The systolic blood pressure remained below 80 mmHg.
Dopamine followed by norepinephrine drips were administered and the
patient was sent to the electrophysiology lab for dual chamber permanent
pacemaker therapy.
During implantation of a permanent pacemaker, the right atrial lead was
appropriately placed via the left subclavian vein into the right atrial
appendage. However, the ventricular lead was placed via the subclavian
artery into the left ventricular cavity. He was admitted to the hospital
overnight and a chest x-ray was obtained the next day, showing no
evidence of pneumothorax (Figure 1 ). Surprisingly, his ECG
showed atrial pacing with long AV delay and intermittent ventricular
pacing with the paced ventricular beats showing right bundle branch
block morphology contrary to the expected left bundle branch block
morphology seen when the lead is inside the right ventricular cavity
(Figure 2 ). A limited bedside Echo was obtained that showed the
ventricular lead clearly crossing the aortic valve to the left
ventricular cavity and fixed into the inferolateral wall of the left
ventricle (Figure 3 ). Early recognition of this serious
pacemaker implantation complication led to pacemaker revision in the
same day with extraction of the arterial lead and reinsertion of the
ventricular lead via the left subclavian vein into the right ventricular
cavity (Figure 4 ). The pacemaker revision went uncomplicated.