Atrial lead

FIGURE 5.2 Typical PA and lateral chest X-ray after implantation of CRT-D system. Note the course of the LV lead via the coronary sinus to reach the lateral epicardial wall of the left ventricle, which is posterior as viewed in the lateral projection. (RA, right atrial lead with tip in right atrial appendage RV, ICD lead with tip in right ventricular apex LV, left ventricular lead with tip at the mid-lateral wall of the left ventricle.)... 

FIGURE I5.I Schematic representation of a dual-chamber ICD. The generator is implanted in the pectoral region. The defibrillation lead (lower) is in the rightventricle, where it is fixed by a helix at the distal (far) end of the lead. The atrial lead (upper) is secured by flexible tines in the right atrial appendage. (Reproduced with permission of Medtronic, Inc.)... 

In many ICD systems, pacing and sensing are hmited to the right ventricle (single-chamber ICDs), and usually, only a single lead is required. More often, a pace-sense lead is also inserted via the same transvenous route and is fixed in the right atrium (dual-chamber ICD). The right atrial lead provides... 

Lloyd MA, Hayes DL, Holmes DR Jr et al (1996) Extraction of the Telectronics Accufix 330-801 atrial lead the Mayo Clinic experience. Mayo Clin Proc 71 230-234... 

Lead location Usually, ventricular leads are more resistant to removal than atrial leads because of their tendency to develop adhesions to the tricuspidal valve and ventricular wall [3]. Moreover, atrial tip detachment from the right appendage may be very challenging for the lead... 

Fig 5.8 Temporal-sequence fluoroscopic images showing (a) the atrial lead being grasped by a tip-deflecting wire inserted through a transfemoral approach, (b) proximal end of the lead now intravascular... 

Fig 5 11 Fluoroscopic images showing the next two steps in the case in the Figure 5.8 (a) atrial-lead-grasping maneuver using a tip-deflecting wire inserted via the transfemoral approach (b) proximal end of the lead, now intravascular, is then caught by a lasso... 

Fig 5 14 (a-d) Temporal-sequence fluoroscopic images (same patient as in Figure 5.8) after exposure of the atrial lead from the internal jugular vein showing introduction and sheath advancement over the lead, overcoming binding sites to the tip. (e-h) The same maneuver on an implantable cardioverter-defibrillator (ICD) ventricular lead... 

From January 1994 through April 1996, extraction of 3,540 leads from 2,338 patients (mean age 64 years, range 5-96) was attempted at 226 centers. Indications for removal were infection (27%), nonfunctional or incompatible leads (25%), Accufix or Encore leads (46%), or other causes (2%). The leads were implanted for a mean of 47 41 months (maximum 26 years) 53% were atrial leads, 46% ventricular leads, and 1% superior vena cava (SVC) defibrillating coils. The conventional technique for mechanical dilatation with Cook extraction-kit tools (Cook Vascular Inc., Leechburg, PA, USA) was used. Extraction was attempted via the implant vein using locking stylets and dilator sheaths and/or transfemorally... 

The physiologic advantages of pacing the atrium were appreciated soon after the establishment of cardiac pacing. Although, atrial leads were available in the 1970s, the problems of where to pace in the atria, specific programmable... 

The next evolutionary step in atrial lead development was the endocardial active-fixation, screw-in lead. Such leads, even without steroid-elution became popular for right atrial use, with the anticipated high stimulation thresholds and exit block accepted as an inevitable consequence of endocardial trauma (31). It was believed that the incidence of lead dislodgement was lower than with the use of fined passive-fixation leads. As experience was obtained with both systems, the actual incidence of lead dislodgement was found to be very low, with high volume implanters reporting an incidence of 1-4% with no clear preference for either design (31). 

Differential AVI Differential AVI is present when there is a difference in the AVI following an atrial-sensed event (PV) compared to the AVI following an atrial-paced event (AV). In most cases, there is a modest delay from the time of onset of the P wave to the time that the atrial depolarization is sensed by the atrial lead. This time varies based on intracardiac conduction properties, the site of spontaneous depolarization, and the location of the atrial lead. By programming the AVI after a sensed atrial event shorter than the AVI after a paced atrial event, the time from onset of depolarization (whether spontaneous or owing to an atrial stimulus) to the end of the AVI will be approximately the same. 

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. 

Fig. 4.40 A well-placed atrial lead in the atrial appendage moves to and fro, medial to lateral radiographically in PA projection. (From Belott PH. A practical approach...

The floppy-tip technique may be used for achieving unusual atrial lead placement with a shaight active fixation lead. This is particularly useful for placement along the right lateral atrial wall. With the curved stylet retracted 1 to 2 in., the lead tip assumes a more lateral position. By simply advancing the lead to a point of contact, the fixation mechanism can be activated and threshold measurements carried out. 

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. 

Once an acceptable atrial lead position has been achieved, the lead is secured. The suture sleeve should always be used. Care should be taken to avoid cutting the lead. Ties should be snug to avoid slippage. 

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.)...

Fig. 4.69 Atrial lead placement. Insert in the upper right shows atrial endocardial lead being placed through the wall of the right atrial appendage with the tip of the pacemaker lead abutting the endocardial surface. A pursestring suture is placed around the lead at the point of entry. The relationship of the atrial lead is also shown. (Hayes DL, Vhetstra RE, Puga FJ, et al. A novel approach to atrial endocardial pacing. Pacing Clin Electrophysiol 1989 12(1 Pt 1) 125-130, with permission.)...

Fig. 6.37 The transatrial approach with limited thoracotomy. An atriotomy incision is made. For an atrial lead, the entire lead is removed retrograde. The ventricular lead is pulled up through the atriotomy with forceps. The lead is grasped and transected. The proximal end is then removed retrograde. A locking stylet is inserted into the remaining distal portion of the lead, which is then removed using the countertraction technique. (From Byrd CL, Schwartz SJ, Sivina M, et al. Technique for the surgical extraction of permanent pacing leads and electrodes. J Thorac Cardiovasc Surg 1985 89(1) 142-144, with permission.)...

Varaia N, Selke FW, Epstein LM. Chronic atrial lead explantation using a staged percutaneous laser and open surgical approach. PACE 1998 21 1483-1485. 

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