Recurrent Transient Ischemic Attacks in a Patient with Multiple Pacemaker Leads.

Venous complications-specifically, stenosis and thrombosis-are both well-known complications of transvenous implantation of pacemakers and defibrillators. Although they are a well-recognized phenomenon, these complications are rarely of clinical significance. One of the most concerning complications is the development of superior vena cava (SVC) syndrome. Studies have found that the incidence of SVC syndrome varies from 1 in 3,100 to 1 in 650 patients. The azygos-hemiazygos venous system is the most commonly observed collateral. We report a case of a 71-year-old female patient who presented with stroke-like symptoms during the injection of agitated saline bubbles while performing an echo and was found to have an unusual venous collateral circulation formed as a result of brachiocephalic and SVC obstruction from multiple pacemaker leads. Our patient's clinical presentation was extremely unique, and we did not find any cases during our literature search reporting a similar presentation. Multiple collaterals formed between the brachiocephalic and subclavian veins, and bilateral pulmonary veins in our patient allowed the injected air bubbles from the venous system to reach the left side of the heart and eventually the cerebrovascular system, resulting in these transient ischemic attacks. These attacks eventually resolved as the air bubbles were dissolved and washed away by the continuous blood flow. It is advisable to monitor the patient for possible venous stenosis and SVC syndrome after any device insertion during regular device follow-up appointments.