Just flip it!-CRT implantation in a patient with dextrocardia and situs inversus totalis.

Implantation of a cardiac resynchronization therapy (CRT) device in patients with congenital heart disease may be challenging because of the particular underlying anatomy. We present the case of a right-sided transvenous implantation of a dual-chamber CRT-D device in a patient with situs inversus totalis and mirror image dextrocardia. To facilitate our anatomic orientation and to overcome unusual hand-eye coordination problems, we decided to flip the fluoroscopic image projection by 180° (right-left), creating the optical impression of a "normalized" heart position (levocardia). This simple approach allowed us to successfully implant the device using a conventional left-sided CRT delivery system.

CRT implantation in patients with congenital heart disease may be challenging because of the particular anatomic conditions.

Imaging of the coronary sinus and its branches is recommended prior to CRT implantation in patients with complex congenital heart disease.

Horizontal right/left inversion of fluoroscopic views is useful to facilitate the device implantation in patients with situs inversus related dextrocardia.

INTRODUCTION

The benefits of cardiac resynchronization therapy (CRT) in patients with heart failure are well‐established including significant reduction in cardiac mortality and morbidity and improved quality of life. Implantation of a CRT device in individuals with complex congenital heart disease may be associated with specific technical challenges and is less standardized. We present the case of a patient with situs inversus totalis and dextrocardia requiring CRT for worsening heart failure.

CASE

A 72‐year‐old male patient with progressive heart failure was referred for implantation of a dual‐chamber cardiac resynchronization defibrillator (CRT‐D). He was known for situs inversus totalis with dextrocardia (Figure S1) and also had a long‐standing history of rheumatic valvular cardiomyopathy with remote open‐heart surgery (aortic valve replacement with mechanical prosthesis and mitral annuloplasty). His left ventricular ejection fraction was 20% and his intrinsic QRS duration was 190 ms. Despite optimal medical therapy, the patient remained with a poor functional class (NYHA 3). As part of pre‐procedure planning, a coronary sinus (CS) venogram was performed during a successful transfemoral ablation procedure of frequent premature ventricular contractions (Figure 1A). The transfemoral venogram demonstrated the presence of potential target branches for a left ventricular pacing lead.

Figure 1

Transvenous implantation of a right‐sided CRT‐D system. (A) Pre‐procedure percutaneous transfemoral venogram demonstrating a coronary sinus with several potential target branches. (B) Right‐sided vascular access with guide wire insertion into the right atrium. (C) To facilitate the anatomic orientation, an RAO view with horizontal inversion (180°) is chosen creating the impression of a “normal” heart position (levocardia). The coronary sinus is cannulated using a standard left‐sided delivery system (see text). (D) Venogram of the coronary sinus confirming the presence of a posterolateral target branch in excellent anatomic position. (D) Insertion of a left ventricular quadripolar lead into the posterolateral target branch. (E) Final lead position demonstrates excellent spacing between the left and right ventricular lead

A transvenous dual‐chamber CRT‐D system with quadripolar left ventricular lead was implanted via a right‐sided axillary approach (Figure 1B). To facilitate our anatomic orientation, we decided to flip the fluoroscopic image projection by 180° (right‐left), creating the optical impression of a “normalized” heart position (levocardia). We used a delivery system with a large fixed, pre‐shaped curve for the CS cannulation (Medtronic Attain® Extended Hook 6350‐EH, 50 cm; Medtronic, Minneapolis, MN, USA). Posterior orientation of the delivery system was achieved via clockwise rotation allowing successful guide insertion into the CS (Figure 1C). The selective CS venogram showed opacification of the posterolateral target branch (Figure 1D) and the LV lead was inserted (Figure 1E). Final imaging (no horizontal image flip) demonstrated satisfying spacing between the left and right ventricular lead (Figure 1F). The PA/Lateral chest X‐ray post procedure demonstrated a satisfying postero‐lateral position of the left ventricular lead (Figure 2). The procedure duration was 75 minutes and the dose area product of procedural fluoroscopy was 618 μGy × m2. The patient ECG before and after the procedure are shown in Figure S2.

Figure 2

Post procedure PA/LAT chest X‐ray

DISCUSSION

Due to the medical and surgical progress over the past 25 years, the cohort of patients with adult congenital heart disease is increasing and a significant proportion of those individuals will develop systolic dysfunction of the systemic ventricular over time and may eventually require CRT.1 Although still rare, it is likely that CRT implanters will become more frequently exposed to this particular group of patients with their challenging cardiac anatomy. Situs inversus totalis with mirror image dextrocardia represents a rare condition with an estimated incidence of 2:100 000.2 Implantation of a CRT device in dextrocardia is challenging and potential difficulties include the interpretation of anatomic landmarks with standard fluoroscopy views, a change in hand/eye coordination and need for different manipulation of leads and delivery systems and the CS cannulation. Those technical challenges may result in prolonged procedure times and increased radiation doses.

Epicardial implantation of a left ventricular lead was not considered an option in our patient after multidisciplinary discussion with our surgical colleagues because of significant intrathoracic fibrosis and adherences related to his previous heart surgery. As part of the pre‐procedure planning, we performed a percutaneous transfemoral CS venogram (Figure 1A) to assess the presence and anatomy of the CS and its potential target branches. The importance of pre‐procedural imaging to visualize the CS in patients with complex congenital heart disease cannot be overemphasized and has also been reported previously.1, 3 Multi slice computer tomography with three‐dimensional reconstruction of the CS and its branches will be the imaging of choice for most patients with a similar condition.1, 3 Our choice of a transfemoral venogram was a practical consideration taking advantage of the vascular access during a preceding electrophysiology ablation procedure.

The rationale for the right‐sided venous approach was based on the following considerations: the anticipated difficulties of conventional left‐sided CRT delivery systems in a patient with dextrocardia and a more favorable shocking vector between the right ventricular coil and right‐sided generator location.4

To facilitate our anatomic orientation, we decided to flip the fluoroscopic image projection by 180° (right‐left), creating the optical impression of a “normalized” heart position (levocardia). This simple approach allowed us to overcome concerns about unfamiliar hand‐eye coordination and lead manipulation. This simple approach may also be useful for other fluoroscopy‐dependent intracardiac procedures such as TAVI, MitraClip or structural tricuspid valve procedures and it may also facilitate catheter placement for electrophysiology procedures without 3D‐mapping systems.

Other imaging modalities such as rotational angiography or procedural (real‐time or off‐line) merging of CT images and angiography are also potentially useful tools, but not widely available.

Our results show that horizontal right/left inversion of fluoroscopic views is a simple approach and useful to facilitate the device implantation in patients with situs inversus related dextrocardia. In contrast to right‐sided implantation for patients with levocardia, conventional CRT delivery systems can be used those patients.

CONFLICT OF INTEREST

The authors declare no conflict of interests for this article.

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