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Role of side holes in guide catheters: observations on coronary pressure and flow
B De Bruyne1, J Stockbroeckx, D Demoor
1Cardiovascular Center, Aalst, Belgium.
Insights
Guide catheters used in coronary angioplasty can alter pressure readings, potentially masking true coronary artery pressure. Side holes in catheters may not fully compensate for flow, impacting accurate hemodynamic assessment.
Area of Science:
- Cardiovascular Interventions
- Interventional Cardiology
- Hemodynamics
Background:
- Guide catheter placement in coronary angioplasty can affect pressure tracings.
- Catheters with side holes often appear to show normal coronary artery pressure.
- This can create a false sense of security regarding coronary hemodynamics.
Observation:
- Trans-ostial pressure gradients were studied at rest and during hyperemia.
- Maximal blood flow through 7F and 8F guide catheters with side holes was measured.
- Blood flow was limited, not exceeding 80 mL/min (8F) and 60 mL/min (7F) at high aortic pressures.
Findings:
- Guide catheter side holes may not fully restore normal pressure tracings.
- A resting or hyperemic trans-ostial pressure gradient can occur.
- The flow supplied by guide catheter side holes is physiologically limited.
Implications:
- Guide catheter pressure may not accurately reflect true coronary artery perfusion pressure.
- Interference with coronary flow by guide catheters should be considered during procedures.
- Accurate hemodynamic assessment requires awareness of potential guide catheter artifacts.
Abstract:
When performing coronary angioplasty, guide catheter intubation of the ostium often leads to a damping of the pressure tracing. In contrast, when a guide catheter with side holes is used, the pressure tracing is most often superimposable to the pressure wave recorded through the side arm of a femoral artery sheath introducer. This pressure wave gives the reassuring impression of normal hemodynamics in the coronary artery. To illustrate the role of guide catheter side holes and that guide catheter pressure does not necessarily equal the actual coronary artery perfusion pressure, we report observations on trans-ostial pressure gradients at rest and during increased coronary flow rates. An abbreviated in vivo study of side holes on the maximal achievable blood flow, employing timed blood flow collections in 7F and 8F side hole guide catheters, was made in 10 patients. At high mean aortic pressure levels, the blood flow through the side holes did not exceed 80 and 60 mL/min for 8 and 7F guide catheters, respectively. These observations suggest that, under some conditions, the guide catheter may produce a resting or hyperemic trans-ostial gradient and that the flow provided only by the side holes of guide catheter is limited. Guide catheter interference with normal flow should be considered in interventional procedures even when arterial pressure appears normal.