Permanent pacemaker implantation in a patient with situs solitus, dextrocardia, and corrected transposition of the great arteries using a novel angiographic technique

Abstract

Complex congenital heart diseases involving abnormalities of the atrial situs and cardiac malpositions like dextrocardia can pose a considerable challenge to transvenous permanent pacemaker implantation (PPI). Literature describing transvenous PPI techniques in patients with complex cardiac anomalies is scarce. In this report, we describe a novel angiography-guided technique for the implantation of a dual chamber transvenous pacemaker in a patient with complete heart block with situs solitus, dextrocardia, and congenitally corrected transposition of the great arteries.

1 Introduction

Complex congenital heart diseases involving abnormalities of the atrial situs and cardiac malpositions like dextrocardia can pose a considerable challenge to transvenous permanent pacemaker implantation (PPI). The difficulty can be compounded by the presence of abnormal atrioventricular connections. The abnormal relationship of the cardiac chambers and the altered fluoroscopic orientation makes transvenous lead placement extremely challenging. Literature describing transvenous PPI techniques in patients with complex cardiac anomalies is scarce. In this report, we describe a novel angiography-guided technique for the implantation of a dual chamber transvenous pacemaker in a patient with complete heart block (CHB) with situs solitus, dextrocardia, and congenitally corrected transposition of the great arteries (CCTGA).

2 Case Report

A 52-year-old male with known dextrocardia and CCTGA presented with a 2-month history of recurrent presyncope and effort intolerance. His examination revealed a resting pulse rate of 52 beats/min (bpm) and a blood pressure of 130/80 mmHg. The apex beat and heart sounds were appreciated on the right side of the sternum, whereas gastric tympany was noted below the left diaphragm. A 12-lead electrocardiogram (ECG) revealed sinus rhythm with an atrial rate of 80 bpm, complete atrioventricular block, and a narrow QRS escape with a rate of 50 bpm. The normal P wave axis (+60°) indicated normal atrial situs, the progressive decrease in the height of the R waves from V1 to V6 suggested dextrocardia, and the absence of septal q waves in the lateral leads was suggestive of CCTGA (Fig. 1). A posteroanterior chest radiograph confirmed dextrocardia with situs solitus. A transthoracic echocardiogram confirmed the diagnosis of situs solitus, dextrocardia, and CCTGA with adequate systemic ventricular function and no other associated abnormality. The temporary pacemaker lead, which was inserted from the right femoral vein just prior to PPI, was seen to course along a right-sided inferior vena cava, further confirming the atrial situs as solitus. Under local anesthesia using 1% lignocaine hydrochloride, a 3-cm long incision was made one fingerbreadth below the right clavicle across the deltopectoral groove such that two-thirds of the incision was medial and one-third was lateral to the groove, and an attempt was made to isolate the cephalic vein. Since the cephalic vein was not of adequate caliber, venous access was obtained through two separate extrathoracic axillary venous punctures using an 18 G needle and two guide wires that were inserted into the venous system. A 7F active fixation lead (model 4076, 58 cm, Medtronic Inc., Minneapolis, MN, USA) was inserted through a 7F peel-away introducer (Medtronic Inc., Minneapolis, MN, USA) over one guide wire. The lead was manipulated into the pulmonary artery over a stillette that was given a distal curvature. The lead withdrawn from the pulmonary artery into the venous ventricle acquired a position that appeared to be septal in the anteroposterior (AP) view, but appeared to point laterally in the right anterior oblique view (RAO). Since the true position of the lead was not quite clear, angiographic delineation of the right heart chambers was considered an option. Through the second access that was meant for the atrial lead, a 6F valved introducer with a side port (AVANTI^®+, Cordis Corporation, Miami, FL, USA) was inserted, and the distal tip was positioned in the superior vena cava. Through the side port, 10 mL of non-ionic intravenous contrast (iohexol) was rapidly injected by hand, and cine films were acquired in the AP, left anterior oblique (LAO), and RAO views. This was performed to define the position of the venous atrium and its appendage, the relationship of the venous atrium to the venous ventricle, and anatomical details of the venous ventricle. The acquired films confirmed the lateral wall position of the previously placed lead and served as roadmaps to facilitate further lead positioning (Fig. 2). After failed attempts at obtaining a stable lead position in the septal region because of the smooth-walled morphologic left ventricle, the lead was screwed to the apex, where sensed R waves of 18 mV, a threshold of 0.9 V, pulse width of 0.4 ms, and lead impedance of 780 ohms were obtained. The 6F valved introducer was then exchanged over a guide wire for a 7F peel-away introducer, and an atrial straight active fixation lead (model 4076, 52 cm, Medtronic Inc., Minneapolis, MN, USA) was inserted through it. The lead was positioned in the right atrial appendage over a curved stillette, with the previously acquired cine films serving as a roadmap. Satisfactory pacing parameters were obtained, with P waves of 4.4 mV, threshold values of 0.5 V at a pulse width of 0.5 ms, and a lead impedance of 550 ohms (Fig. 3). After confirming the stable positions of both leads, the leads were secured to the muscle. A dual chamber pulse generator (Model Relia DDD, Medtronic Inc., Minneapolis, MN, USA) was attached to the leads and placed in a pre-pectoral pocket, and the wound was closed in layers. A post-procedural 12-lead ECG revealed atrial sense and ventricular paced complexes with a right bundle branch block pattern and left axis deviation. The patient's post-procedural course was uneventful.

Fig. 1. Pre-procedural ECG. Demonstrating normal sinus rhythm with complete heart block. Note the normal P wave axis, the decreasing amplitude of R waves across leads V2–V6, and the absence of septal q waves.

Fig. 2. Right subclavian venous angiography. (A, B) AP and LAO views showing the septum and lateral walls of the ventricle. In both views, the permanent pacemaker lead appears to be midseptal in position. The temporary pacemaker lead is also seen. (C) RAO view. The lead is seen to be pointing away from the septum and towards the lateral wall. (D, E) RAO view showing the RAA (arrow in D) and the morphologic left ventricle (E). Note the normal position of the right atrial appendage in situs solitus. Also note that the morphologic left ventricle is smooth and devoid of trabeculations. The permanent lead has been repositioned and screwed to the apex (AP, Anteroposterior; RAO, Right Anterior Oblique; LAO, Left Anterior Oblique; and RAA, Right Atrial Appendage.).

Fig. 3. Final lead position and post-procedural electrocardiogram. (A, B) AP and RAO views showing the ventricular lead in the apical position and the atrial lead in the right atrial appendage. (C) Schematic representation of the orientation of the cardiac chambers. (D) Post-procedural ECG showing atrial sensed and paced ventricular complexes. Note the RBBB morphology of the paced ventricular complexes as the ventricular lead is pacing the morphologic left ventricle (AP, Anteroposterior; RAO, Right Anterior Oblique; ECG, Electrocardiogram, and RBBB, Right Bundle Branch Block.).

3 Discussion

Dextrocardia is commonly associated with situs inversus totalis (incidence: 2 in 10,000 individuals) and rarely associated with situs solitus (incidence: 1 in 20,000 individuals). While associated cardiac anomalies are seen in approximately 5% of patients with dextrocardia and situs inversus, the majority (>90%) of patients with dextrocardia and situs solitus have associated anomalies, the most common of which are atrioventricular discordance and transposition complexes [1].

Literature describing transvenous pacemaker implantation techniques in patients with congenital heart disease is scarce [2]. There is no description of dual chamber pacemaker implantation techniques in patients with dextrocardia, especially in those with situs solitus and corrected transposition of the great arteries. Since dextrocardia with situs inversus is a mirror image of the normal anatomy, the use of a flipped image and opposite angulated views, that is, RAO in place of LAO and vice versa, has been suggested with no further details on implantation technique [3]. This method, however, cannot be used in dextrocardia with normal situs and other cardiac malpositions in which the heart is not a mirror image of normal. In dextrocardia with normal situs, both atria, with their appendages and connecting veins, retain their normal positions, while the ventricles are rotated to the right (Fig. 4). Since a majority of such malformations have associated cardiac defects in the form of ventricular inversion, fluoroscopic orientation becomes very difficult and lead positioning is extremely challenging. To circumvent this problem and to guide the implantation of the leads, we used venous angiograms that were obtained by inserting a 6F-valved introducer with a side port via the second access. Cine angiograms acquired in the LAO, RAO, and AP views served as roadmaps to facilitate lead positioning in the atria and the ventricle. In addition to serving as roadmaps, the cine films also revealed important anatomical information regarding the orientation of the septum and morphology of the systemic venous chambers. The initial lead position that seemed to be septal in the AP and LAO projections was in fact on the lateral wall, which was evident on the angiogram obtained in the RAO view. The RAO view not only served as a guide to position the ventricular lead, but also provided useful information on the anatomy of the septum and the lack of trabeculation in the venous ventricle. The coexistence of CCTGA has important implications with regard to the mode of lead placement (endocardial vs. epicardial) and the type of lead used for transvenous implantation. In a series of patients with isolated CCTGA requiring pacemaker implantation, endocardial lead placement has been shown to have equally favorable long-term outcomes compared with epicardial lead placement [4]. Active fixation leads are preferred over passive fixation leads for stable transvenous pacing in CCTGA because of the lack of trabeculations in the smooth-walled venous ventricle, which is a morphologically left ventricle. Although septal pacing was attempted with an active fixation lead, the lack of trabeculations and ridges along with the abnormal orientation of the septum made it impossible to obtain a stable position over the septum; therefore, we ultimately fixed the lead to the apex of the ventricle. Angiography was also helpful in identifying the right atrial appendage and assisted in the positioning of the atrial lead.

Fig. 4. Schematic representation of the visceroatrial relationships and orientation of the cardiac chambers in the normal heart and in other common cardiac malpositions.

The technique of using angiography to assist with lead positioning during PPI has not been described previously. This technique has several advantages. It can be performed easily, since a second venous access is usually available. It requires no special equipment or additional assistance as in the case of echocardiography or computed tomography (CT), and is relatively inexpensive. Unlike in echocardiography, a single operator can easily perform the procedure without the involvement of additional personnel. It provides immediate information to the operator during the procedure with no post-processing requirement as in CT or magnetic resonance imaging. In addition to providing valuable information regarding the orientation and relationships of the atria, ventricles, and interventricular septum, angiography provides information regarding the anatomy of the chamber in question. Angiography has been the gold standard for the assessment of various congenital cardiac anomalies, and the angiographic profiles of the various congenital anomalies have been described. Hence, this technique can serve as a useful adjunct to pacemaker implantation in various other complex cardiac anomalies. However, there are two caveats to this technique: (1) there should be no contraindication to angiography and (2) the operator should be knowledgeable about or have been acquainted with the angiographic anatomy of the underlying heart disease.

To the best of our knowledge, PPI in patients with dextrocardia, situs solitus, and CCTGA has not been previously reported. An angiography-guided technique for PPI has also not been previously described. By employing this novel angiography-guided technique, we were able to successfully implant a dual chamber pacemaker in a patient with a complex congenital anomaly. We believe that this technique may also be employed in other congenital heart diseases where transvenous PPI is necessary but may pose a challenge because of distorted anatomy.

4 Conclusions

Transvenous PPI in complex congenital heart diseases is very challenging. We have described the use of a novel angiography-guided technique that employs venous angiography to guide atrial and ventricular lead placement in a patient with dextrocardia, situs solitus, CCTGA, and CHB. This technique may also be used for PPI in other complex heart diseases.

Funding sources

None.

Conflict of interest

None.