Lead placement coronary sinus

Locating the coronary sinus os can be quite problematic, given the heart failure patient s distorted anatomy. Table 4.16 outlines the techniques devised to can-nulate the coronary sinus. If a simple stylet-driven lead coronary sinus placement is undertaken, then coronary sinus access is dependent on the operator s skill, knowledge of the coronary sinus anatomy, and favorable tributaries for safe, reliable placement. Coronary sinus os localization is much easier with a guiding catheter delivery system. The operator simply selects the guiding... 

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). 

Extracardiac stimulation is not life-threatening but can be extremely problematic. Diaphragmatic stimulation is more common with posterolateral coronary sinus branch placement. At time of implant, this problem should always be sought in the unipolar or extended bipolar configurations, testing at lOV. If extracardiac stimulation is encountered, the lead should be repo-... 

IV. Add coronary sinus lead ipsilaterally plus contralateral endocardial pacing and shocking electrode placement... 

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. 

Coronary sinus lead placement was used many years ago but lost favor because of tbe high rate of lead dislodgmenL However, with the advent of CRT, placing a permanent lead in the coronary venous system has become... 

The ventricle or atrium can be paced, depending on where in the coronary sinus the lead is positioned. Figures 18.17-18.19 demonstrate coronary sinus lead placement in the lateral coronary, anterior interventricular, and middle cardiac veins. 

Anatomic variations can alter the placement of the pacing system and therefore the radiographic appearance. It is not possible to discuss all potential anatomic variations. However, one anatomic variation does merit discussion - a persistent left superior vena cava. A permanent pacing system can be implanted via a persistent left superior vena cava (Fig.18.21). (If this anatomic variation is noted before pacemaker implantation, it is easier to implant the system via the right side if the patient has a normal right superior vena cava.) If pacing leads are implanted through a persistent left superior vena cava, the lead in the PA projection descends within the left side of the cardiac shadow and enters the atrium and then the ventricle by communication of the left superior vena cava and the coronary sinus. On the lateral projection, the ventricular lead is seen on the posterior cardiac wall within the coronary sinus. 

In patients being upgraded from an existing pacemaker or ICD to a CRT system, venous access and venous narrowing may hamper placement of the additional coronary sinus lead. One potential complication with difficult passage of a lead is venous perforation. In Fig. 18.36, the sheath used for introduction of the coronary sinus lead has perforated the vein, and dye was injected to determine the sheath position. The dye is shown in the mediastinum. In this patient, the sheath was withdrawn and redirected into the lumen of the vein, and the patient remained hemodynamically stable. 

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). 

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