Epicardial leads

P-wave amplitudes than their non-drug-eluting counterpart [10, 11]. Another type of drug-eluting lead is designed with a porous ceramic or silicone collar soaked with dexamethasone sodium phosphate positioned immediately proximal to tip electrode. This system is used in steroid-eluting, active fixation screw-in leads and shows similar performance as the MCRD. Steroid elution is available on atrial and ventricular leads and as well as coronary venous and epicardial leads. 

Fig. 2.4 Left panel Multiple endocardial and epicardial leads are visible. A functional lead is connected with a right-sided pacemaker. Right panel Lead erosion. Part of the lead body is exposed. No cellulitis is visible. Infection and lead erosion recurred despite multiple local interventions on the left side without lead removal...

Transvenous device and lead removal but leaving in epicardial leads ... 

Pacing leads can be subdivided into a number of groups based on the area of placement and method of stimolation. Leads can be placed either on the epicardium (external surface) of the heart or, by a transvenous route, onto the endocardium (internal surface) of the right heart atrium or ventricle. Epicardial leads are used for permanent pacing in pediatric cases, where size considerations or congmtal defects prevent transvenous placement, and in patients who have undergone tricuspid valve rqilacement (Mitrani et al., 1999). Transvenous placement of the lead is the preferred route in most patients. 

Byrd CL, Schwartz SJ. Transatrial implantation of transvenous pacing leads as an alternative to implantation of epicardial leads. PACE 1990 13 1856. 

Epicardial leads can be used in a standard bipolar or unipolar configuration. Pacing and sensing thresholds tend to deteriorate over several days. Epicardial leads with specially designed epicardial electrodes (as opposed to uninsulated braided wire) provide lower pacing thresholds (54, 55). The leads are removed by simple traction. The use of temporary epicardial wires is generally safe. In one series of more than 9,000 patients no complications were observed other than inability to remove the electrode in three patients in all three patients the lead wire was simply clipped at the skin without sequelae. The effectiveness and safety of the epicardial system have led to widespread use. 

Fernanda AL, Garda-Boigochea JB, Ledo R, Vega M, Amaro A, Alvarez J, Rubio J, Sierra J, Sanchez D. Minimally invasive surgical implantation of left ventricular epicardial leads for ventricular resynchronization using video-assisted thoracoscopy. Rev Esp Cardiol 2004 57 313-9. 

Disordered electrical and mechanical ventricular activation can compromise cardiac function. Pacing technology has been nsed to att pt to correct the inter- and intraventricular conduction in an effort to optimize cardiac performance. The earliest attempts were performed during surgery when epicardial leads were placed over the lateral left ventricle free wall. Later, the coronary sinus was utilized to activate the left ventricle. Cardiac-resynchronization therapy (CRT) for treatment of patients with congestive heart failure and ventricular dyssynchrony can have a remarkable beneficial effect. Use of this technology continues to evolve. 

Transtelephonic pacemaker foUow-up is also appropriate in children, especially in those who have epicardial leads which function at low lead impedance and often with high thresholds. When such pacemakers are reaching end of service, the progression can be rapid. The provision of a transtelephonic monitor to pediatric pacemaker patients also makes it possible for the family to send transmissions after such events as collisions and other sports injuries, when families often need reassurance that the pacemaker is working normally. 

Horenstein MS, Hakimi M, Walters H, 3rd, Karpawich PP. Chronic performance of steroid-eluting epicardial leads in a growing pediatric population a 10-year comparison. Pacing Chn Electrophysiol 2003 26 1467-71. 

Recently implanted devices (<2-3 months), devices with epicardial leads, abandoned leads, or long leads (>70cm) generally should not be imaged since they have not been included in any studies to date. 

Fig. 18.24 Posteroanterior (A) and lateral (B) chest radiographs demonstrating several kinds of pacing leads, as described in the text. The arrowhead indicates active fixation of the atrial endocardial lead large arrow, an abandoned stab-in epicardial lead medium arrow, an abandoned screw-in epicardial lead and small arrow, a passive fixation transvenous lead.

Numerous epicardial active fixation devices are available but are not commonly used. The radiograph in Fig. 18.24 shows four different types of leads in one patient two epicardial leads and two endocardial leads. In this patient, previous epicardial pacing did not have long-term success. Two types of leads had been used, including a stab-in epicardial-myocardial lead and a screw-in epicardial-myocardial lead. A transvenous ventricular passive fixation lead and an active fixation atrial lead are also visible. Details of these leads are also seen on the lateral view. 

At times, a combination of atrial endocardial and ventricular epicardial leads may be used because a prosthetic tricuspid valve prevents placing a transvenous ventricular lead (Fig. 18.25) or because, in certain congenital cardiac anomalies, transvenous access to a nonsystemic ventricle is not possible. 

Fig. 18.28 Posteroanterior chest radiograph (A) and close-up view (B) from a patient with congenital heart disease and an abandoned dual-chamber endocardial pacing system. Two ventricular epicardial leads are connected with a Y connector to a single chamber ventricular pacemaker. On the close-up view (B) the arrow notes a defect in the lead adaptor just as it exits the connector block.

A 63-year-old federal court judge, with no prior arrhythmia or syncope history, requires a biventricular ICD for Class Iff CHF, with the left ventricular lead via an epicardial route. He wishes only initially to have the basic ICD implant, after which he will clear his schedule and return for the epicardial lead. Two weeks prior to the scheduled epicardial lead placement you are called to interrogate his ICD in a local ER trauma ward. Apparently while driving, the patient passed out and struck a tree, amazingly without significant injury. His potassium is found to be 2.1 mEq/dL. The EGMs leading to an appropriate successful shock are seen below. 

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