Coronary sinus accessibility

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... 

The cardiac catheterization procednre reqnires vascnlar access, nsually obtained percutaneonsly at brachial or femoral arteries or veins. Left-sided catheterization provides access to the aorta, left ventricle, and left atrinm. Right-sided catheterization enables the right side of the heart, coronary sinus, pulmonary arteries, and pulmonary wedge position to be reached. Left-sided catheterization is used for coronary angiography and ventriculography, whereas rightsided catheterization is nsed for determination of cardiac performance parameters. 

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). 

Finally, as a general rule, if coronary sinus os cannulation proves to be extremely difficult, it is important to consider alternative catheters and methodology within a reasonable period of time. No more than 15 or 20 min. should be wasted on any given approach. In extreme instances, if a left-sided approach proves unsuccessful, one might consider right-sided venous access in coronary sinus cannulation. 

After venous access is achieved, successful left ventricular lead implantation requires several basic steps (1) coronary sinus ostium localization,... 

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. 

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