Three-dimensional mapping in cardiac implantable electronic device - a feasible and effective alternative to fluoroscopy

BACKGROUND

During the last decade, three-dimensional mapping technology has substantially aided the development of cardiac implanted electronic devices (CIEDs). This article intends to present an outline of the use and benefits of three-dimensional (3D) mapping systems in CIEDs.

RESULT

As an alternative to fluoroscopy, 3D mapping greatly minimizes radiation exposure and eliminates the need for contrast dye during the implantation of CIEDs. Based on the visualization of the pacing lead tip and accurate anatomic reconstruction of the chamber of interest and a specialized mapping technique, 3D mapping technology dramatically improves the efficacy and success of the advanced cardiac implantable devices' placement. Additionally, it provides a superior option for those with complex medical conditions.

CONCLUSION

The use of 3D mapping technology in CIEDs has been proven feasible and effective by accumulating evidence. It is fair to anticipate that it will be widely used in CIED implantation in the future.

Progress in zero-fluoroscopy implantation of cardiac electronic device

Fluoroscopy is the imaging modality routinely used for cardiac device implantation. Due to the rising concern regarding the harmful effects of radiation exposure to both the patients and operation staffs, many efforts have been made to develop alternative techniques to achieve zero-fluoroscopy implantation. In this review, we describe the different methods aimed at avoiding the application of fluoroscopy in recent years, and evaluate their feasibility and safety in cardiac electronic device implantation.

The safety and efficacy of electroanatomical mapping (EAM)-guided device implantation

BACKGROUND

The conventional method of device implantation requires fluoroscopic guidance. With the guidance of three-dimensional (3-D) navigation systems, devices can be implanted with minimal use of fluoroscopy. To date, this technique has been reported in several case reports in young, pregnant patients. However, this technique has not been widely utilized by electrophysiologists, despite offering several benefits, including reduced radiation exposure for the patient and the operator.

METHODS

In this study, we evaluated 18 patients who successfully underwent device implantation with limited use of fluoroscopy under the guidance of the EnSite Precision 3-D mapping navigation system (Abbott, St. Paul, MN, USA). In most of the patients, the total fluoroscopy time was 1 s, accounted by a single postprocedural frame to insure appropriate lead placement.

RESULTS

A total of 19 leads were implanted in 18 patients (14 male, four female) using the electroanatomical mapping (EAM)-guided technique. A total of 19 leads were implanted in 15 patients (10 male, five female) using the conventional method. The average length of stay was 1.20 days in the EAM group compared to 1.47 days in the conventional group (P = .10). Majority of the devices implanted in both groups were single-chamber implantable cardiac defibrillators (VVI ICD, Abbott) implanted for cardiomyopathy with left ventricular ejection fraction persistently below 35%, including 88% (16/18) in the EAM group compared to 73% (11/15) in the conventional group. No periprocedural or immediate postprocedure complications were reported in either group. Device parameters, including impedance, capture time, and capture voltage, showed no significant difference in either group. Total radiation time and radiation dose were markedly lower in the EAM-guided implantation group.

CONCLUSIONS

In patients who meet appropriate criteria for device implantation, the use of EAM system offers a safe, practical, efficacious alternative method to device implantation, with significant reduction in radiation time and dose.

Implantation of single lead cardioverter defibrillator with floating atrial sensing dipole in a pregnant patient without using fluoroscopy

In this case report, we look into the implant procedure of a single-lead ICD with floating atrial sensing dipole in a pregnant woman, without using fluoroscopy. This system benefits the proper positioning of the lead. This is possible thanks to the simultaneous display of both the atrial and ventricular dipoles on the electro-anatomical mapping system. This technique may be taken into consideration for the few rare cases where fluoroscopy is absolutely contraindicated.

Zero x-ray cardiac resynchronization therapy device implantation guided by a nonfluoroscopic mapping system: A pilot study

BACKGROUND

Fluoroscopic guidance is the standard tool used in device implantation. This means that both the patient and the operator are exposed to radiation, which may sometimes be high. The possibility of single-lead permanent pacemaker implantation without fluoroscopy has already been demonstrated.

OBJECTIVE

The aim of our study was to investigate the feasibility and reliability of biventricular device implantation guided only by an electroanatomic navigation system.

METHODS

Sixty-one patients with heart failure underwent implantation of a cardiac resynchronization therapy (CRT) device with or without defibrillator (CRT-D; CRT-P). The procedure was performed with or without fluoroscopy guidance (Rx+; Rx0). In the latter case, the EnSite Velocity system was used; this system is able to reconstruct the anatomy and activation of the cardiac chambers by simultaneously collecting a "cloud" of anatomical points from multiple electrodes.

RESULTS

Lead positioning was achieved in 24 of 26 patients undergoing CRT implantation without fluoroscopy (92% success). No complications were observed during the procedure and no catheter dislodgment occurred the day after the implantation or during 1-month follow-up. Procedure time progressively decreased from 136 minutes in the first case to 59 minutes in the last one, suggesting that operators gradually gained confidence while using the new technique.

CONCLUSION

Our study demonstrates the feasibility, efficacy, and safety of lead positioning guided only by the nonfluoroscopic EnSite Velocity mapping system without the use of fluoroscopy in CRT-P or CRT-D implantation. The benefits in terms of significantly reduced fluoroscopy exposure are associated with technical and clinical advantages.

Cardiac Interventions in Pregnant Patients without Fluoroscopy

INTRODUCTION

Cardiac interventions with fluoroscopy during pregnancy carry significant risks for the fetus. This report reviews three pregnant patients: two of them requiring pacemaker implantation and one underwent diagnostic cardiac catheterization without fluoroscopy.

METHODS

The cases were performed using EnSite system (St. Jude Medical Inc., MN, USA) guidance. The necessary cardiac structure geometries were reconstructed with a deflectable quadripolar electrophysiology catheter without fluoroscopy. In two cases, pacemaker leads were connected to the EnSite system for navigation and fixation of leads. In the third case, long sheaths and electrophysiology catheters were used to access the right ventricle and pulmonary artery. Transthoracic echocardiography was also used in all three cases.

RESULTS

A 31-year-old woman at 8-week pregnancy was admitted with ventricular septal defect and significant pulmonary hypertension. The patient underwent catheterization to assess for the risk of continuation of pregnancy. There was partial reactivity, it was decided not to terminate the pregnancy, and an uneventful delivery was succeeded at 35 weeks of gestation without complications. The rest of the two pregnant patients were a 28-year-old pregnant woman at 14 weeks of gestation and a 40-year-old woman at 12-week gestation. Both of them presented with symptomatic complete AV block. A single-chamber pacemaker was implanted in the first one, and a dual-chamber pacemaker was implanted in the latter. Pregnancy continued in both without complications.

CONCLUSION

Successful cardiac catheterization and pacemaker implantation can be performed safely in selected pregnant patients using an electroanatomic mapping system guidance without fluoroscopy.

[Update on arrhythmias and cardiac electrophysiology]

This article contains a review of the most important developments in clinical arrhythmology and interventional cardiac electrophysiology that have been reported during the past year. Special emphasis has been placed on clinical conditions that are most prevalent in the general population as well as on progress that has been achieved using the main therapeutic approaches, whether pharmacologic or interventional.