In some cases the standard J-tip guidewire cannot deliver the catheter into the aortic root, because of arterial loops or spasm. In these cases a hydrophilic guidewire (Terumo) gives the right lubricity and good shape retention to guide the catheter through the artery. However, the Terumo wire does not give much torque and could therefore easily penetrate side branches and cause dissection or perforation. The latest Silverway guidewire has some new advantages which is easier to guide and could cause less complications while faster delivery of catheters to the aortic valve. The investigators aim to compare both guide wires.

During cardiac catheterization a catheter is threaded through the radial arteries to the aortic root with the support of a guide wire. The standard workhorse to deliver the catheter is a J-tip guidewire (spring coil wire). However, in patients with arterial tortuosity or spasm, this guidewire has low lubricity and no torque to direct the catheter because the outer coil and core are not connected together.

If this problem is encountered, interventional cardiologists will use a hydrophilic polymer-coated guide wire. Up to date there are several hydrophilic coated guide wires available. One of these is the Radifocus Guide Wire M (Terumo, Japan). Although it has better torque transmission than the spring wire, it still has low torque transmission due to a Nitinol core structure, is less supportive and can easily enter side branches because of the high lubricity and therefore might cause dissections or perforations.

In some cases, coronary angioplasty guide wires are needed to negotiate a highly tortuous artery, but they lack the support to advance the catheter.

Recently, the Silverway Guide Wire has been created (Asahi Intecc Co, LTD., Japan) to overcome the problems that a spring- and polymer wire have. Features that this new guide wire provide is hybrid coating and ACT ONE technology that connects the wire core and coil to ensure one to one torque transmission The investigators aim to compare both guide wires in deliverability, workability and complication rate.

Inclusion Criteria:

• Indication for radial artery access for diagnostic cardiac catheterization
• Being able to receive the per standard protocol Verapamil and Nitroglycerin administration via radial artery
• Not able to deliver a diagnostic or guiding catheter to the aortic root by means of the standard J tip wire
• No signs of early complication after initial attempt with the J tip wire such as dissection, perforation or hematoma
• Age ≥ 18 years

Exclusion Criteria:

• Femoral or brachial artery access
• Patients with known CREST syndrome or other forms of scleroderma
• Emergent indication for cardiac catheterization such as an acute coronary syndrome