Lead placement transvenous

After venous access, some consideration should be given to the sequence of lead placement. Some operators prefer to place the RV electrode first for emergency RV pacing, should heart block ensue because the heart failure patients commonly have a left bundle branch block and any trauma to the conduction system or right bundle may result in complete heart block. Other operators choose to place the coronary sinus lead first and, if necessary, depend on heart rate support via a temporary transvenous pacemaker placed via the femoral vein. The issue of failure speaks for placing the coronary sinus lead first. Should the procedure fail with unsuccessful left-sided left ventricular lead placement and the patient has already received right-sided electrodes, a pacing system may be left without an indication unless a future second attempt is considered. As more and more systems are placed for a primary prevention indication like MADIT II, this has become less problematic (153). 

Fig. 15.1 Typical transvenous active-fixation lead placement in a 5-year-old child with complete congenital AV block. Note the large amount of extra lead that was introduced to allow for future growth, as well as the placement of the ventricular lead high in the ventricle to minimize the effect of future growth.

FIGURE 17-13. Drawing showing automatic implantable cardioverter-defibrillators with newer methods of device placement. It shows an endocardial lead system where the leads are placed transvenously without the need for a thoracotomy. The generator is now small enough to be placed in the pectoral region of the chest. (From DiMarco, with permission.)... 

Successful placement of the LV lead in the target vein has been aided by continuing improvements in the available delivery tools as well as individual operator experience. In CONTAK CD (performed from 1998 to 2000), 79% of attempted implants resulted in successful transvenous implant of the LV lead. In COMPANION (2000 to 2002), the success rate was 89%, with median procedure duration of 2.8 hours. And in CARE-HF (2001-2003), the success rate was 95% (86% on first attempt). Patients who fail to undergo successful transvenous implantation of the LV lead into an optimal target vein have the option to undergo limited thoracotomy for direct implantation of an epicardial LV lead. 

Fig. 7.2 Serial anteroposterior fluoroscopic images taken during transvenous removal of a left-sided dual-chamber implantable cardioverter-defibrillator (ICD) system. After placement of a temporary right-ventricular (RV) pacing system

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. 

Once venous access is obtained, the pacing catheter must be placed into the appropriate intracardiac position to begin pacing. A variety of leads that range from 3 to 6Fr in diameter can be nsed for transvenous temporary pacing. Balloon-tipped flotation electrode catheters nse vascular and intracardiac blood flow to direct them into the right ventricle. Balloon-tipped pacing catheters are very pliable and are also available with preformed curvature to facilitate placement from the femoral vein. Traditional temporary electrode catheters are relatively stiff, and must be placed in the ventricle with the aid of fluoroscopy. Traditional electrode catheters come in a variety of shapes... 

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