Pre-procedural simulation of the right atrium to left ventricle puncture through the inferoseptal process using cardiac computed tomography

Figures

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  Figure 1. Electrocardiograms during ventricular tachycardia. A: The electrocardiogram of ventricular tachycardia 1 shows 536 ms of cycle length with W configuration in V1, left inferior axis, and r wave in lead I, indicating the basal anteroseptal origin. B: The electrocardiogram of the ventricular tachycardia 2 shows 425 ms of cycle length with R wave in V1, right inferior axis, and QS wave in lead I, indicating the basal anterior origin.

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  Figure 2. Multiplanar reconstruction images of multidetector-row computed tomography (A: coronal, B: transverse). The expected three-dimensional route (red dotted line) of the right atrium to left ventricle puncture was drawn on the multiplanar reconstruction images of computed tomography.

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  Figure 3. Volume-rendered reconstruction of the virtual sheath viewed from the en-face and tangential directions. A, C, E: Course of the virtual sheath (green) is viewed from the en-face direction (right anterior oblique 10˚) and B, D, F: tangential direction (left anterior oblique 80˚). Within the virtual fluoroscopic image, the sternal wires, pacing leads, mechanical aortic valve and mitral clips (red) are reconstructed together with a multiplanar reconstruction plane involving the virtual sheath (A, B), with the right coronary artery (black) and the coronary sinus (sky-blue) (C, D), and with the short axis cut slab of the heart (E, F).

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  Figure 4. Clinical procedure. Actual procedure was safely performed under the biplane fluoroscopy (C, D) using the biplane angulation as simulated by pre-procedural computed tomography (A, B). A virtual sheath is reconstructed in green. Approximately 5˚ difference was noted between the computed tomographic simulation and real fluoroscopic image, presumably reflecting the rotational difference of the patient position on the table. In addition, intracardiac markers are more reliable than extracardiac markers as they are not affected by respiration. LAO = left anterior oblique; RAO = right anterior oblique.

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  Figure 5. Intracardiac echocardiography. A, B: The procedure was performed with real-time assistance of an intracardiac echocardiography. The white and yellow asterisks indicate a sheath passing from the right atrium to left ventricle and a catheter placed in the left ventricle, respectively. The red asterisk denotes the intracardiac echocardiography probe. C: replicates the sectional plane of the intracardiac echocardiography (A) with a virtual sheath (green).

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  Figure 6. Transesophageal echocardiography. A: Transesophageal echocardiography shows the catheter (asterisks) placed within the left ventricle after passing through the inferior pyramidal space and inferoseptal process. B: replicates the sectional plane of the transesophageal echocardiography (A) with a virtual sheath (green).

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  Figure 7. Voltage map of the left ventricle. A: After the right atrium to left ventricular puncture, bipolar voltage map of the left ventricle was created, showing dense scar at basal septum. B and C: show corresponding volume-rendered images viewed from the frontal direction, reconstructed from the cardiac computed tomography. A virtual sheath is reconstructed in green. The special gap between the right atrium and left ventricle in the voltage map (asterisk) consists of the right atrial wall, inferior pyramidal space, and inferoseptal process of the left ventricle.

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  Figure 8. Anatomy of the inferior pyramidal space and inferoseptal process. To puncture from the right atrium to the left ventricle, A: the virtual sheath (green) needs to be located anterior to the coronary sinus orifice, B: pass through the inferior pyramidal space covering the inferoseptal process, and C: penetrate the inferoseptal process of the left ventricle. D: Reverse U-turn portion of the distal right coronary artery and/or E: atrioventricular node artery could be located within this inferior pyramidal space, which should be avoided by pre-procedural evaluation of these structural relationships.