Cardiac Catheterization

Cardiac catheterization

The procedure is usually done in conjunction with angiography, the injection of radiopaque material into various chambers of the heart. Cardiac catheterization may be diagnostic, interventional, or electrophysiologic. Also see cardiac catheterization of the adult under Other Diagonostic Tests.

Complications

• Dysrhythmias—generally catheter induced
  
• Hemorrhage at site of insertion
  
• Arterial blockage—loss of pulse in extremity used for cannulation; cold, pale mottled extremity
  
• Infection
  
• Allergic reaction to the dye—low-grade fever, nausea, vomiting, flushing

Percutaneous transluminal coronary angioplasty(PTCA)

Percutaneous transluminal coronary angioplasty is a technique used for the treatment of coronary artery disease (CAD). A balloon-tipped catheter is introduced through a guidewire into a coronary vessel with a noncalcified atheromatous lesion. The balloon of the catheter is then inflated, causing disruption of the intima and changes in the atheroma. The result is an increase in the diameter of the lumen of the coronary vessel (as judged by angiographic criteria) and improvement of blood flow below the lesion. Balloon inflation/deflation may be repeated until satisfactory results are achieved Indications

Patients meeting these criteria are generally acceptable candidates for PTCA:

• Stable angina (less than 1 year) or unstable angina (less than 6 months), despite optimal medical therapy
  
• Single-vessel or multivessel disease (balloon dilatation of the most severe “culprit” lesion is initially attempted to determine if successful angioplasty can be achieved); surgery to bypass the lesion may be recommended if PTCA is unsuccessful. 
• Proximal, accessible noncalcified lesions; midvessel lesions may also be attempted with success. 
• Suitable candidate for heart surgery and has consented to heart surgery as an alternative treatment 
• Evolving MI (may be in combination with thrombolytic therapy) and obstructed coronary bypass grafts

Contraindications

• Patients with left main coronary artery disease
  
• Patients with severe left ventricular dysfunction

Complications

• Coronary occlusion, coronary dissection, MI, coronary artery spasm, and prolonged angina may necessitate immediate coronary artery bypass graft surgery. A cardiac surgical team must be on standby during all PTCA procedures. 
• PTCA is associated with a restenosis rate of 30% to 40%. Restenosis may occur acutely (within 24 hours) or within 6 months. A second angioplasty may be performed with improved long-term results.

Recent Advances

1.  
   1. Laser-assisted balloon angioplasty
      • A laser light is directed by a percutaneously inserted flexible fiberoptic catheter and is able to “vaporize” atheromatous lesions in the coronary vessels.
      • Balloon angioplasty of the vessel may then be performed.
      • This new technique may minimize damage to the intimal lining, open diseased vessels more effectively, prevent early and long-term restenosis, and expand the use to calcified, unusual lesions and total occlusions.
   2. Atherectomy
      • A burr-tipped high-speed rotating catheter is inserted percutaneously into a coronary vessel and “drills” through the atheromatous lesion, changing it to microscopic debris.
      • This new technique may open diseased vessels more effectively, especially in patients who have coronary lesions not amenable to standard angioplasty.
   3. Intracoronary stenting
   4. A tiny coil or diamond mesh tubular device (stent) is placed in the coronary artery immediately after successful balloon angioplasty.
   5. The stent remains in the vessel to prevent restenosis.