Twiddler Syndrome, Situs Inversus and Persistent Left SVC ... Oh My!

In this article, the author provides information on some of the more unusual cases seen at his EP lab. This includes images of cases involving patients with Twiddler Syndrome, situs inversus, and persistent left superior vena cava (PLSVC).

Twiddler Syndrome

The Twiddler Syndrome, recognized since 1968, is an endearing term used to describe those patients that manipulate their implanted device, and while doing so, twist the implanted leads out of their original position. Some manipulate the leads so well that the leads are actually “extracted” from the cardiac tissue. It is not entirely known how the syndrome starts — possibly when the patient is asleep, bored or out of curiosity. The syndrome’s result may not be noticed during routine office visits, but will eventually be discovered. An example of the Twiddler Syndrome presented here involves an 84-year-old female. Her dual chamber pacemaker was implanted in February 2008, with an active lead in the right atrium and a passive lead in the right ventricle. After a normal recovery, the patient was discharged from the Oklahoma Heart Hospital. Her progress was not unusual until a routine rural hometown office visit determined that she had developed diaphragmatic pacing. After the device was reprogrammed appropriately, she was scheduled for a follow-up visit. On that visit it was determined that the ventricular lead had become displaced. Shortly after this visit, the patient was admitted to the Oklahoma Heart Hospital, where the cause of the problem was again documented for OHH medical/surgical staff. As is shown in the x-ray image in Figure 1, the lead tips have been retracted into the right subclavian vein and the remaining leads are twisted around the device. In April 2008, the patient’s OHH attending physician removed the device and fractured leads without incident. A new subclavian access was obtained, and an active lead was once again placed in the right atrium as well as a passive lead in the right ventricle. The patient continues to improve since her discharge from Oklahoma Heart Hospital.

Situs Inversus

Situs inversus, in which the liver, gallbladder, lungs, pulmonary artery, and right and left atrium are reversed, occurs in 0.01% of the general population. Figure 2 shows an x-ray image of this anomaly and an implanted dual chamber pacemaker and leads. Variations of situs inversus can occur, which can include reversal of the ventricles. This particular patient was a 43-year-old female who had a history of back and valvular surgery. Her device was implanted in June 2007 without incident. The device has functioned well ever since; however, she continues to have medical problems associated with her anomaly and general physical condition. As seen in the viewing angle of Figure 2, the right atrial and right ventricle lead are in their corresponding chambers. It is important to note that sternotomy sutures and a Herrington Rod placement are also pictured.

PLSVC

One of the most interesting surprises that can be seen in the EP or cath lab is the persistent left superior vena cava. This anomaly and its variations occur in approximately 0.3% in normal hearts to 4.5% in congenital hearts of the general population. The patient usually does not present with any associated symptoms that would cause the physician to consider the existence of this anomaly. It is often only discovered during the placement of a central line, pacemaker or ICD. In Figure 3, a single pacemaker lead can be traced as it follows the PLSVC path from the device to the right atrium (RA) and then the right ventricle (RV). This patient is an 87-year-old female with a history of chronic atrial fibrillation. She was admitted to Oklahoma Heart Hospital in April 2005 for a single ventricular lead pacemaker implant. The implant procedure proceeded normally until the physician inserted a guidewire into the left subclavian; because the guidewire would not advance to the right side of the chest in a normal position over the heart to the right atrium, contrast was injected into the left subclavian. The result was a contrast visualization of a dominant left superior vena cava and an enlarged CS to the right atrium. The physician successfully implanted a long, single ventricular lead through the PLSVC and right atrium into the right ventricle. Several images of a similar anomaly (Figures 4-6) were rendered on the Carto XP system (Biosense Webster Inc., a Johnson & Johnson company, Diamond Bar, California) for an atrial fibrillation ablation procedure. These images are of a 67-year-old male patient who was scheduled for a procedure in April 2006. The physician, upon seeing the rendered images of the PLSVC a week prior to the intended procedure, decided to delay the procedure and further document the anomaly. An office visit was scheduled with the patient to discuss an alternate treatment plan to include a possible referral. The rendered structures are labeled as pulmonary artery (PA), left atrium (LA), left atrial appendage (LAA), left ventricle (LV), right ventricle (RV), and right atrium (RA). In Figure 5, the left lateral image provides a clear view of the PLSVC position in relation to other structures of and around the heart. Figure 6 shows a near opposing right lateral view of the PLSVC.

Oh My!

Figures 7 through 9 are images of normal structures. These were rendered on a patient scheduled in July of 2008 for an atrial fibrillation ablation procedure. These were processed on Biosense Webster’s Carto XP system from a 64-slice CT scan. The ability to “tease” out the structures such as the bronchus, especially the esophagus, is a rewarding task of its own. Figure 7 shows a right lateral view rotated into a posterior orientation, Figure 8 is an AP view, and Figure 9 is the right lateral view. Note the abbreviations for esophagus (ESO) and bronchus (BRONCH).

Summary

The importance of knowing about these various anomalies provides a basic understanding of structure variation and the adaptation of the body to the variation. Recognition of these variations provides an opportunity to anticipate changes in procedures and allows the staff to assist the physician for a safe and successful completion of the planned procedure.

Acknowledgement. All x-ray images, CT scans and Carto XP rendered images were produced at the Oklahoma Heart Hospital in Oklahoma City.