pacemaker problem solving

Pacemaker Implant Anatomy – Step-by-Step (Part 4)

Problem Solving

Entanglement in the Pectinate Muscles

The cast of the right atrium (left) gives a good impression of what happens on fluoroscopy. The atrial lead enters the atrium and comes to a halt almost halfway. When pushed further, it curves upwards (right).

The position and typical movement (windscreen wiper) tells the implanting physician that the tines have become entangled in the anterior extension of the atrial appendage, not in the tricuspid valve.

Figure 21: Cast of Right Atrium

Figure 21: Cast of Right Atrium

Figure 22: Atrial Lead curving upwards

Figure 22: Atrial Lead curving upwards

Figure 23: Atrial lead entangled in the pectinate muscles

Figure 23: Atrial lead entangled in the pectinate muscles

Figure 24: Atrial lead entangled in the pectinate muscles

Figure 24: Atrial lead entangled in the pectinate muscles

Valvular Entanglement

When a tined lead is turned around its own axis, the tines can easily get entangled in the chordae. Extensive and delicate manipulation is needed in such cases to liberate the tined lead from the subvalvular chordae. A gentle pull and a second attempt to pass the valve will usually do the trick. (Refer to Figures 25 and 26)

Figure 25: The chordae easily causes entanglement

Figure 25: The chordae easily causes entanglement

Figure 26

Figure 26

Figure 27

Figure 27

Figure 28

Figure 28

The Missing Curve over the Tricuspid Valve

In this x-ray (Figure 27) the typical gentle curve over the tricuspid annulus is absent. The bending of the lead by the valve is absent as well. This lead has been introduced via the coronary sinus into a inter ventricular vein.

The two typical lead positions are depicted here (Figure 28). Above is the typical tricuspid valve curve of the ventricular lead. The coronary sinus is filled with contrast and the drawn line shows a position in the interventricular vein.

 

Continue to Part 5

 

Author:

Stuart Allen
Principal Cardiac Physiologist
Manchester Heart Centre
Manchester, UK