1. What is CTCA (CT Coronary Angiography)?
CT Coronary Angiography (CTCA) is a non-invasive imaging test that uses CT scanning and intravenous contrast to visualize the coronary arteries.
Purpose
CTCA is used to:
- Detect coronary artery disease (CAD)
- Identify atherosclerotic plaques (calcified and non-calcified)
- Assess coronary artery stenosis
- Rule out CAD in patients with chest pain
- Evaluate congenital coronary anomalies
- Assess coronary stents or bypass grafts (selected cases)
Advantages
- Non-invasive (no catheter insertion into arteries)
- High diagnostic accuracy
- Quick procedure (usually < 15 minutes)
2. How CTCA is Performed (Radiology Perspective)
Step-by-Step Procedure
- Patient Positioning
- Patient lies supine on the CT table
- ECG leads attached for cardiac gating
- Arms raised above the head
- Heart Rate Control
- Ideal heart rate: ≤ 60 beats/min
- Beta blockers may be administered if heart rate is high
- IV Contrast Injection
- Non-ionic iodinated contrast injected via 18–20G cannula
- Usually placed in antecubital vein
- Injection rate: 4–6 ml/sec using a power injector
- Breath-Holding
- Patient instructed to hold breath for 5–10 seconds
- Motion-free imaging is essential
- ECG-Gated CT Scan
- Images acquired during specific phases of the cardiac cycle
- Scanner synchronizes with ECG to reduce motion artifacts
- Image Reconstruction
- Images reconstructed in multiple planes
- Coronary arteries evaluated for:
- Stenosis
- Plaque type
- Vessel course
3. Nursing Preparation for CTCA
A. Pre-Procedure Nursing Preparation
1. Patient Assessment
- Check:
- History of contrast allergy
- Asthma
- Renal function (serum creatinine, eGFR)
- Pregnancy status
- Review medications:
- Beta blockers
- Metformin (may need temporary withholding)
2. Patient Instructions
- NPO for 4–6 hours before scan
- Avoid:
- Caffeine (24 hours)
- Smoking
- Explain procedure to reduce anxiety
3. IV Access
- Insert large bore IV cannula (18–20G)
- Ensure good vein patency
4. Heart Rate Control
- Administer oral or IV beta blockers as prescribed
- Monitor:
- Blood pressure
- Heart rate
- Contraindications for beta blockers:
- Severe asthma
- Bradycardia
- Hypotension
- Heart block
5. Nitroglycerin (If Ordered)
- Sublingual nitroglycerin given just before scan
- Purpose: Dilates coronary arteries
- Monitor BP closely
B. Intra-Procedure Nursing Role
- Monitor:
- ECG
- Blood pressure
- Patient comfort
- Reassure patient during breath-holding
- Watch for contrast reactions
C. Post-Procedure Nursing Care
- Observe patient for 15–30 minutes
- Monitor for:
- Contrast reactions
- Dizziness or hypotension
- Encourage oral hydration
- Resume normal diet unless contraindicated
- Educate patient to report:
- Rash
- Shortness of breath
- Chest discomfort
4. Contraindications to CTCA
- Severe renal impairment
- Known iodinated contrast allergy
- Uncontrolled arrhythmias
- Very high heart rate not controllable
- Pregnancy (relative)
5. Summary (Quick Recall)
| Aspect | Key Point |
|---|---|
| CTCA | Non-invasive coronary artery imaging |
| Contrast | IV iodinated contrast |
| Heart Rate | Ideally ≤ 60 bpm |
| Nursing Prep | NPO, IV line, HR control |
| Scan Time | Very short |