A 77 year old man presents with speech disturbances and weakness and numbness of his left arm, which started suddenly 1 hour ago, and completely resolved over the next 30 minutes. He is currently asymptomatic. His medical history is significant for ischemic heart disease, atrial fibrillation, and sick sinus syndrome, for which is he currently on aspirin, warfarin, and metoprolol. He also underwent implantation of a rate-responsive single-chamber ventricular demand pacemaker 8 months ago. He drinks only socially, and denies recreational drug use. His smoking history amounts to 40 pack years. He lives in Italy, and has been visiting his children for the last 3 weeks, during which period he has been poorly compliant with his medications. A complete blood count, serum electrolyte assay, random capillary glucose, and non contrast CT brain are all normal. However a coagulation profile reveals his INR to be 1.2.
You realize that Magnetic Resonance Imaging is contraindicated in this patient.
The ECG shows a paced rhythm with an irregular baseline and a right bundle branch block pattern. His old ECGs are not available right now.
The lateral projection shows the ventricular lead to be in an abnormal configuration.
The transthoracic echocardiogram shows the pacemaker lead positioned in the left ventricular apex instead of the right ventricle, after passing through an interatrial septal defect. Mild mitral regurgitation is noted. No structural abnormalities are present, and there are no intracardiac thrombi or vegetations. The left ventricular ejection fraction is 65%.