Coronary sinus approaches

The AV node lies directly above the insertion of the septal leaflet of the tricuspid valve and anterior to the ostium of the coronary sinus. It is part of the AV junction area, which is divided into three regions. The transitional cells, or nodal approaches, connect the atrial myocardium to the compact portion of the AV node. The slowest conduction time occurs within the AV node [8]. At its distal end, the compact portion of the AV node enters the central fibrous body, becoming the penetrating portion, or His-bundle [9]. 

Transcoronary venous injection is performed with a catheter system threaded percutaneously into the coronary sinus. Initial studies in swine have confirmed the feasibility and safety of this approach [121]. This delivery method has also been used to deliver skeletal myoblasts to scarred myocardium in cardiomyopathy patients [120]. With intravascular ultrasound guidance, this approach allows the operator to extend a catheter and needle away from the pericardial space and coronary artery into the adjacent myocardium. To date, human feasibility studies have had a good safety profile. This technique is limited, however, by coronary venous tortuosity, lack of site specific targeting, and its own technically challenging nature. Unlike the transendocardial approach, in which cells are... 

Fig 9 2 Using a right-sided approach, the electrophysiological catheter is directed to the lateral wall of the right atrium (a) successful cannulation of the coronary sinus in the same patient (b)... 

Tight binding sites into the coronary sinus Difficult dilatation into the coronary sinus, difficult C-shaped lead course Dilators cannot be advanced into the coronary sinus dilatation cannot be advanced to the binding site Transjugular approach reverse Pisa approach dilatalion from the femoral vein... 

Under these conditions, a possible solution is to change the venous approach in order to change the position of the proximal part of the LV lead. The straightest path into the coronary sinus is from the femoral vein. The LV lead can be made free floating by grasping it in the right atrium and then sliding it into the inferior vena cava (IVC). In some... 

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

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. 

With the guide catheter safely positioned in the coronary sinus and the target coronary sinus tributary identified, the coronary sinus lead can be placed. If a stylet-driven approach is used, success depends on operator experience, skill, coronary sinus anatomy, lead stylet selection and stylet management. Stylet... 

Special Considerations Acutely Angled Coronary Sinus Branches By far an away, the most consistently challenging left ventricular lead implant cases are those with acutely angled branch vessel origins. Several approaches have been found useful in these circumstances ... 

Fig. 18.21 Posteroanterior (A) and lateral (B) chest radiographs of a DDD pacing system in a patient with a persistent left snperior vena cava. The atrial lead courses through the left superior vena cava and the coronary sinus and into the right atrium. The ventricular lead follows the same path but is then looped into the right ventricle. (From Hayes DL. Implantation techniques. In Hayes DL, Lloyd MA, Friedman PA, editors. Cardiac pacing and defihrillation a clinical approach. Armonk [NY] Futura Publishing, 2000 159-200. Used with permission of Mayo Foundation for Medical Education and Research.)...

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