The development of the extravascular defibrillator with substernal lead placement: A new Frontier for device‐based treatment of sudden cardiac arrest

Figures

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  Figure 1. Modeling‐predicted defibrillation threshold. Modeling predictions of defibrillation threshold for transvenous, substernal, and subcutaneous leads.

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  Figure 2. Implanted extravascular ICD (EV ICD) system. Representative X‐ray images of the implanted EV ICD system from a patient in the supine position.

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  Figure 3. Preprocedural chest markings. The lateral edges of the sternum (dotted lines) and sternal midline (solid line) are denoted. In this example, a cutaneous patch electrode is positioned on the left midaxillary line to emulate an ICD can.

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  Figure 4. Extravascular ICD (EV ICD) system placement and lead design. EV ICD system with epsilon‐shaped lead implanted within the substernal space and the device positioned on the patient's left midaxillary line (left image). The defibrillation coil segments (Coil 1 and Coil 2) are each 4 cm in length and oriented toward the patient's right; the ring electrodes (Ring 1 and Ring 2) are nearer the cardiac center of mass (right image).

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  Figure 5. Sternal tunneling tool. A 9‐French introducer sheath is backloaded onto the malleable tunneling rod and introduced into the anterior mediastinum. Subsequently, the sternal tunneling tool is removed, and the lead is inserted through the retained introducer sheath.

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  Figure 6. Transverse tunneling tool. The transverse tunneling tool is used to create a tunneling path from the xiphoid incision site to the left midaxillary tissue pocket. Once the tunnel is created, the handle is removed and the lead connector pin is inserted into the tunneling tool channel. The lead connector pin is pulled through the tunneling tract to the pocket for connection to the ICD generator.