How to Prepare for a CT Angiogram: Checklist

Proper preparation is essential for a successful CT angiogram. Unlike many other imaging tests, coronary CT angiography requires specific steps in the days and hours before your appointment to ensure the clearest possible images of your heart arteries. Following these guidelines closely can mean the difference between a diagnostic scan and one that needs to be repeated.

This checklist covers everything you need to know before your CT angiogram, from dietary restrictions and medication considerations to what happens when you arrive at the clinic.

Why Preparation Matters for a CT Angiogram

A coronary CT angiogram captures images of your heart arteries during a single heartbeat. Because the heart is constantly moving, the scanner needs your heart rate to be slow and steady to produce sharp, motion-free images. Factors like caffeine intake, stress, dehydration, and certain medications can raise your heart rate and reduce image quality.

Additionally, the scan involves intravenous contrast dye that highlights your arteries on the images. This contrast requires adequate kidney function and hydration to be safely processed by your body. Proper preparation addresses all of these factors.

48 Hours Before Your CT Angiogram

Eliminate Caffeine Completely

Caffeine is a stimulant that raises your heart rate and can make it irregular. You should avoid all sources of caffeine for at least 24 to 48 hours before your scan. This includes coffee, tea, energy drinks, chocolate, soft drinks containing caffeine, and certain medications or supplements that contain caffeine.

Many patients underestimate how much caffeine affects their heart rate. Even decaffeinated coffee contains small amounts. If you are a regular caffeine consumer, starting your restriction two full days before the scan gives your body time to adjust and helps avoid withdrawal-related heart rate fluctuations.

We recently had a patient who drank a cup of coffee on the morning of his scheduled CT angiogram, not realizing how significantly it would affect his scan. When he arrived at DCDC, his heart rate was 92 bpm, well above the 65 bpm target needed for clear images. Despite administering beta-blockers, we could not bring his heart rate down sufficiently and had to reschedule the scan for the following week. The patient later told us he wished he had taken the caffeine restriction more seriously. His experience is a reminder that this single preparation step can determine whether your scan happens on schedule or requires a return visit.

"Caffeine is the number one reason we have to reschedule CT angiograms," says Dr. Shahoo Mazhari, Consultant Cardiologist at DCDC. "Patients often think one cup of coffee will not matter, but even a small amount can raise the heart rate enough to compromise image quality. The 48-hour caffeine-free window is not optional — it is essential."

Review Your Medications with Your Doctor

Certain medications may need to be adjusted before your CT angiogram. Discuss all current medications with your cardiologist or the imaging center, including:

Beta-blockers: If you are already taking beta-blockers, your doctor may adjust the dose to help achieve a target heart rate below 65 bpm.
Metformin: Patients with diabetes taking metformin may be advised to pause it for 48 hours after the scan due to potential interaction with contrast dye and kidney function.
Erectile dysfunction medications: Medications like sildenafil (Viagra) should typically be stopped 48 hours before, as they can interact with nitroglycerin that may be used during the scan.
Blood thinners: Generally continue as normal, but inform the team about all anticoagulants or antiplatelet agents you take.

Stay Well Hydrated

Good hydration supports kidney function, which is important for processing the contrast dye used during the scan. Drink plenty of water in the two days leading up to your appointment. Avoid alcohol, as it can cause dehydration and may affect heart rhythm.

The Day Before Your CT Angiogram

Continue avoiding caffeine and alcohol
Drink at least 1.5 to 2 liters of water throughout the day
Prepare comfortable, loose-fitting clothing without metal zippers, snaps, or underwire
Set aside all jewelry, watches, and piercings to leave at home
Confirm your appointment time and any specific instructions from the clinic
Get a good night's sleep; fatigue and poor sleep can raise your resting heart rate

On the Day of Your CT Angiogram

Fasting Requirements

You should fast for 4 to 6 hours before your scheduled scan time. This means no food or beverages other than plain water. Fasting reduces the risk of nausea from the contrast dye and helps maintain stable physiological conditions during the scan.

However, you should continue taking your prescribed medications with small sips of water unless your doctor has specifically instructed otherwise. This is particularly important for blood pressure medications and beta-blockers that help keep your heart rate controlled.

What to Wear and Bring

Wear comfortable, loose-fitting clothing (you may be given a hospital gown)
Remove all metal items: jewelry, watches, belts, hair clips, and piercings
Bring a list of your current medications and dosages
Bring recent blood test results, especially kidney function (creatinine/eGFR) if available
Bring your Emirates ID or passport and insurance card
Bring any previous cardiac imaging reports or referral letters

Heart Rate Target: Why Below 65 BPM Matters

The optimal heart rate for a coronary CT angiogram is below 65 beats per minute (bpm), with some centers preferring below 60 bpm. At these heart rates, the heart is relaxed long enough between beats for the scanner to capture clear, motion-free images of the coronary arteries.

When you arrive at the clinic, your heart rate will be measured. If it is above the target range, the medical team may administer a short-acting beta-blocker (typically metoprolol) orally or intravenously to lower it. This is a routine and safe part of CT angiogram preparation.

Factors that can raise your heart rate and should be avoided on scan day include caffeine, smoking, strenuous exercise, stress, and rushing to your appointment. Arrive 15 to 20 minutes early so you have time to relax before the scan.

"We perform over 1,000 diagnostic scans every month at DCDC, and the patients who get the best results are the ones who follow the preparation steps carefully," says Dr. Shahoo Mazhari, Consultant Cardiologist at DCDC. "Arriving relaxed and well-hydrated with a low heart rate makes all the difference in image clarity."

Kidney Function Check: Why Creatinine Matters

The contrast dye (iodine-based) used during a CT angiogram is processed and eliminated by the kidneys. Before the scan, a blood test measuring creatinine and estimated glomerular filtration rate (eGFR) is required to confirm your kidneys are functioning well enough to handle the contrast safely.

This blood test should ideally be done within 1 to 3 months of your scan. Patients with diabetes, high blood pressure, known kidney disease, or those over 60 years old are at higher risk for contrast-related kidney issues and will be monitored more closely.

If your kidney function is borderline, your doctor may recommend pre-hydration with intravenous fluids before and after the scan to protect your kidneys. In rare cases, the scan may be postponed if kidney function is significantly impaired.

Allergy Considerations

If you have a known allergy to iodine-based contrast dye, shellfish, or have had a previous allergic reaction to any contrast agent, inform the medical team well in advance. Pre-medication with antihistamines and/or steroids can be arranged to reduce the risk of a reaction.

Mild reactions such as a warm sensation, metallic taste, or brief nausea during contrast injection are common and normal. True allergic reactions are rare but manageable when the team is prepared.

CT Angiogram Preparation Checklist

When	Action
48 hours before	Stop all caffeine (coffee, tea, energy drinks, chocolate)
48 hours before	Discuss medications with your doctor (metformin, ED medications)
48 hours before	Avoid alcohol
2 days before	Increase water intake to 1.5-2 liters per day
1 day before	Confirm appointment and preparation instructions
1 day before	Prepare comfortable clothing without metal
Night before	Get adequate sleep; avoid late meals
4-6 hours before	Begin fasting (water is allowed)
Morning of scan	Take prescribed medications with small sips of water
At the clinic	Arrive 15-20 minutes early; bring ID, insurance, and medication list

Follow this timeline to ensure optimal preparation for your CT angiogram.

What Happens During the CT Angiogram

Understanding the procedure helps reduce anxiety. When you arrive, an IV line will be placed in your arm for contrast injection. ECG leads will be attached to your chest to monitor your heart rhythm. You will lie on a narrow table that slides into the CT scanner, which is an open ring shape (not a closed tunnel like an MRI).

You may be given nitroglycerin spray under your tongue to dilate your coronary arteries for better visualization. During the scan, you will be asked to hold your breath for about 10 to 15 seconds while the scanner captures images. The actual scanning time is typically under one minute, though the entire appointment usually takes 30 to 60 minutes.

After the Scan: What to Expect

Drink extra water after the scan to help flush the contrast dye from your system
Resume normal eating and drinking immediately after the scan
If you received beta-blockers, you may feel slightly drowsy; avoid driving for 1-2 hours if affected
Results are typically available within 24-48 hours
Contact the clinic if you experience any unusual symptoms such as skin rash, swelling, or difficulty breathing

Preparing for Your CT Angiogram at DCDC?

At Doctors Clinic Diagnostic Center in Dubai Healthcare City, we guide every patient through proper CT angiogram preparation to ensure the best possible results. With over 1,000 diagnostic scans per month and 13+ years serving patients in Dubai Healthcare City, our experienced team will contact you with personalized instructions before your appointment. We welcome patients from across the UAE and internationally.

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Часто задаваемые вопросы

Yes, you can and should drink plain water before your CT angiogram. Staying hydrated helps your kidneys process the contrast dye safely. You should only avoid food and other beverages for 4-6 hours before the scan.

If your heart rate is above the target (typically 65 bpm), the medical team will administer a beta-blocker medication to slow it down. This is safe and routine. In rare cases where the heart rate cannot be adequately controlled, the scan may be rescheduled.

The actual scan takes less than one minute. However, the entire appointment, including preparation, IV placement, heart rate optimization, and the scan itself, typically takes 30 to 60 minutes.

Iodine-based contrast dye is generally very safe. Your kidney function will be checked beforehand. Mild sensations like warmth or metallic taste during injection are normal. True allergic reactions are rare and the team is prepared to manage them.

No, you should continue taking your blood pressure medications as prescribed. Take them with small sips of water even during the fasting period. Blood pressure medications and beta-blockers actually help achieve the optimal heart rate for the scan.

No, you should avoid strenuous exercise on the day of your scan. Physical activity raises your heart rate, which can compromise image quality. Light walking is acceptable, but avoid running, gym workouts, or any intense activity before your appointment.

Final Thoughts

A coronary CT angiogram is one of the most advanced non-invasive tools for evaluating your heart arteries, but its accuracy depends heavily on proper preparation. By following these guidelines, particularly avoiding caffeine, maintaining hydration, and arriving relaxed, you give the imaging team the best conditions to capture clear, diagnostic images.

If you have any questions about your specific preparation, do not hesitate to contact the imaging center or your cardiologist before your appointment. Every patient's situation is slightly different, and personalized guidance ensures the safest and most effective scan experience. For details on pricing and insurance coverage, see our CT angiogram cost in Dubai guide.

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Автор

Dr. Shahoo Mazhari

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Consultant Cardiologist

MD, Board Certified in Cardiology

Dr. Shahoo Mazhari is a Consultant Cardiologist specializing in non-invasive cardiac imaging, coronary CT angiography, and preventive cardiology at DCDC Dubai Healthcare City.

How to Prepare for a CT Angiogram: Complete Checklist

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