Ventricular lead placement

CRT reduces symptoms of CHF and improves cardiac performance in patients with moderate-to-severely symptomatic heart failure, severe left ventricular systolic dysfunction, normal sinus rhythm and a wide QRS complex. Resynchronization therapy significantly reduces hospitalizations in these patients and is highly cost-effective. Perhaps most important, resynchronization therapy for heart failure improves survival for these patients, particularly when employed in conjunction with an implantable defibrillator. However, randomized clinical trials show that a substantial minority of patients are clinical nonresponders. Therefore, critical questions remain with respect to identifying appropriate candidates for CRT, optimal device programming, and left ventricular lead placement. 

Once successful ventricular lead placement has been achieved, the lead must be secured. The first step in this process is withdrawal of the lead stylet to the vicinity of the lower right atrium (89) (Fig. 4.38). The stylet is not totally removed, but retained to add support if a second lead is to be placed. With a straight ventricular lead stylet in the vicinity of the lower right atrium, the lead is anchored at the venous entry site. The lead suture sleeve should be used for anchoring to avoid lead injury. Care is also taken not to cut through the suture sleeve and also injure the lead. Once the ventricular lead is anchored and after no further leads are to be added, the lead stylet is removed. 

Atrial lead placement directly relates to the type of atrial electrode selected, regardless of fixation mechanism. Similar to the ventricular lead, proper placement is a symphony of the lead and stylet. 

Unlike ventricular lead placement, venous access has little effect on atrial lead positioning. Whether from the right or left venous access, the preformed J or straight electrode with preformed J stylet is easily maneuvered into the atrial appendage or desired position. It should be noted that a right lateral atrial position is more easily achieved by a right venous access. Atrial septal positions are more easily achieved from the left. 

Fig. 4.68 Atrial lead placement through atriotomy and purseslring suture. Atrium and ventricular electrodes are positioned and the atriotomy is secured. (Westerman GR, Van Devanter SH. Transthoracic transatrial endocardial lead placement for permanent pacing. Ann Thorac Surg 1987 43(4) 445-446, with permission.)...

Table 4.14 Endocardial approaches for coronary sinus left ventricular lead placement.

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). 

In patients with left bundle branch block, it is advised that right ventricular lead placement be secured before left ventricular lead implantation or coronary sinus osteal localization since traumatic interruption of right bundle branch conduction could lead to the development of catheter-induced complete heart block and the need for urgent ventricular pacing. 

Removal of the Long Vascular Sheath after Left Ventricular Lead Placement... 

Fig. 7.7 (A) Twelve-lead ECG during pacing demonstrates left bundle-branch block morphology and inferiorly directed mean frontal plane axis, suggesting that the pacing electrode is in the right ventricular outflow tract. (B) Pacing lead placement in the right ventricular apex is indicated by the left bundle branch block morphology and the mean frontal plane superior axis. Notice that the pacemaker does not sense the premature ventricular depolarization (fourth QRS complex in all leads), which indicates that the sensitivity should be increased (by reducing the sensitivity value).

Dekker AL, Phelps B, Dijkman B, van der Nagel T, van der Veen FH, Geskes GG, Maessen JG. Epicardial left ventricular lead placement for cardiac resynchronization therapy optimal pace site selection with pressure-volume loops. J Thorac Cardiovasc Surg 2004 127 1641-7. 

Koos R, Sinha AM, Markus K, Breithardt OA, Mischke K, Zarse M, Schmid M, Autschbach R, Hanrath P, Stellbrink C. Comparison of left ventricular lead placement via the coronary venous approach versus lateral thoracotomy in patients receiving cardiac resynchronization therapy. Am J Cardiol 2004 94 59-63. 

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.

In the radiograph shown in Fig. 18.11, ventricular lead placement could be compatible with apical lead placement. However, the lateral view shows a nonapical position, and the lead is in fact positioned in a tributary of the posterior cardiac vein. 

The physical contact of the pacemaker lead with the ICD lead tip can produce potentials that may be sensed and falsely interpreted by the ICD as fast ventricular events. Also, as mentioned earlier, a right ventricular ICD lead placement in the distal apex may improve the shocking vector and DPT. 

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. 

For lead placement in the atrium, the tip must lodge in the right atrium or coronary sinus, as shown below. For placement in the ventricle, it must lodge in the right ventricular apex In one of the interior muscular ridges, or trabeculae (as shown below). 

Removal of noninfected leads is not indicated (Class III) if patients have a life expectancy of less than 1 year and in patients with known anomalous placement of leads through structures other than normal venous and cardiac structures (e.g., subclavian artery, aorta, pleura, atrial or ventricular wall, or mediastinum) or through a systemic venous atrium or systemic ventricle. Additional techniques including surgical backup may be used if the clinical scenario is compelling. 

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

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