Patient preparation

The core idea

Preparation determines whether the scan can answer the question

Coronary arteries are small, constantly moving targets. The best detector and protocol cannot fully rescue an unstable rhythm, a failed IV injection, poor ECG triggering, or respiratory movement.

Dr Shruthi’s webinar follows this sequence: assess the patient → give clear instructions → control rate and dilate coronaries where appropriate → secure contrast delivery → rehearse breath-hold → verify a final checklist.

Before booking or scanning

Confirm the clinical question and scan feasibility

Read the referral and relevant history. Is the question native coronary stenosis, anomaly, graft/stent assessment, or something else? The answer changes the necessary scan range, temporal demands, contrast timing, and whether an alternative test would be more suitable. A patient should not be labelled “unsuitable” from one number alone; combine clinical urgency, expected image quality, scanner capability, and risk.

• Motion/technical: current rate and rhythm, frequent ectopy or atrial fibrillation, ability to lie flat, raise arms, and cooperate with the scan/breath-hold.
• Clinical: symptoms and stability, prior coronary procedures, heavy calcification or stents, relevant heart failure or valvular disease.
• Safety: pregnancy possibility when relevant, prior contrast reaction and its actual symptoms, kidney history/AKI, current medicines, blood pressure, and known drug contraindications.

Webinar anchor: approximately 01:50–02:55.

Patient-facing preparation

Explain the study; do not turn routine advice into absolute rules

Tell the patient what will happen: ECG electrodes and an IV, possible medication to slow the heart and widen the coronaries, a short breath-hold, and a transient warm/flushed feeling with iodinated contrast. Calm explanations, physical comfort, and a few minutes of quiet rest can improve cooperation and give a truer baseline heart rate.

Many local coronary CTA protocols advise avoiding caffeine, nicotine, and strenuous exertion before the appointment because they can raise heart rate or variability; the exact interval is local. Ask about usual medicines and give specific instructions rather than telling everyone to stop them. Encourage appropriate hydration unless clinically restricted.

Webinar anchor: approximately 02:55–04:10. Evidence note: ACR Manual on Contrast Media, fasting chapter.

Iodinated contrast safety

Ask about the risk that matters, not just a checkbox

ACR–NKF guidance supports particular caution and risk–benefit discussion for AKI or eGFR <30; preventive IV isotonic fluid may be considered/used when indicated and not contraindicated (for example by heart failure). It does not support denying clinically needed contrast by a single threshold. Metformin management depends on kidney status and local policy; it is not a reason for every patient to hold the drug automatically.

Emergency equipment, trained personnel, and a clear reaction-response process must be ready wherever contrast is administered. Record the specific prior reaction instead of writing only “iodine allergy.”

Webinar anchor: approximately 06:30–08:20. Evidence notes: ACR Manual and ACR–NKF consensus.

Motion control

Heart rate and rhythm: measure after rest, then during breath-hold

A slower, regular heart often provides a longer quiet diastolic interval and can enable a narrower, lower-dose prospective scan. The webinar’s “<70 bpm” teaching target is a useful starting goal, not a universal pass/fail cutoff. Some modern systems tolerate higher rates; rate stability and temporal resolution matter as well as the mean.

1. Allow the patient to settle, then measure pulse, blood pressure, rate, and rhythm—not immediately after walking into the department.
2. Check the ECG for ectopy or irregular R–R intervals. A nominal 62 bpm with frequent premature beats may be harder than a steady 72 bpm.
3. Repeat the observation on the scanner during a practice breath-hold; respiratory manoeuvres, anxiety, medication, and positioning can change the rhythm.

Whether pharmacological rate reduction is needed depends on the scanner, acquisition mode, patient factors, and indication. Never choose or repeat medication solely to reach a number while ignoring symptoms, blood pressure, contraindications, or the ECG.

Webinar anchor: approximately 04:10–06:00.

Prescriber-led preparation

Rate-control medicines: know the purpose and the safety screen

Beta-blockers are frequently used to lower rate and variability before coronary CTA. The lecture gives oral metoprolol as a pre-scan example and small titrated IV doses if needed. These are illustrations of supervised protocols, not stand-alone orders. Before use, assess blood pressure, baseline pulse, active bronchospasm, significant bradycardia, high-grade AV block, decompensated heart failure, relevant allergies, and concurrent rate-slowing drugs. Monitor response and follow the institution’s dosing and escalation policy.

Ivabradine may be considered in selected patients when beta-blockade is inappropriate, but it works through the sinus node and is not a universal substitute—particularly not for atrial fibrillation. Its timing and contraindications also need protocol review. The goal is diagnostic quality with acceptable haemodynamic safety, not a reflexive drug sequence.

Webinar anchor: approximately 04:55–06:00. Evidence note: SCCT acquisition guidance.

Coronary calibre

Sublingual nitroglycerin: visualisation with a safety check

Nitroglycerin dilates the epicardial coronaries and can improve assessment of distal vessels and stenosis. The lecture’s example is 0.4 mg sublingually shortly before imaging; SCCT describes 0.4–0.8 mg roughly five minutes before acquisition in suitable patients. Treat these as examples of protocolled practice, not an instruction to administer without assessment.

Check blood pressure and symptoms. Withhold or seek senior review for severe hypotension, preload-dependent conditions such as severe aortic stenosis, and recent phosphodiesterase-5 inhibitor use (for example sildenafil, vardenafil, tadalafil). The relevant drug and timing must be checked before nitrate administration. A transient headache or BP fall can occur; document whether the nitrate was given and any reason it was omitted.

Webinar anchor: approximately 06:00–06:35. Evidence note: SCCT acquisition guidance.

Contrast delivery readiness

A power-injection-safe IV is as important as the programmed bolus

Place and test a peripheral IV capable of the intended power injection, commonly an antecubital site with an appropriate 18–20 G catheter in adult coronary CTA. Confirm patency, secure the tubing, check that the catheter and site are rated for the planned flow, and watch for pain/swelling during injection. Avoid a tight bend at the elbow or tubing crossing the imaging field.

The webinar uses approximately 5–7 mL/s contrast flow, followed by a saline chaser, as typical adult examples. Actual rate, iodine delivery, volume, injection duration, and bolus timing must match scanner speed, patient size/cardiac output, IV access, and the diagnostic question. A good IV is not proof of a good bolus; the contrast still has to arrive at the coronaries during the scan. Detailed timing belongs to Topic 04.

Screen for previous contrast reactions before the syringe is connected. Keep emergency support ready. Explain that a brief internal warmth is common, but new breathing difficulty, widespread hives, throat symptoms, or injection-site pain must be reported promptly.

Webinar anchor: approximately 07:15–08:20. Evidence note: SCCT acquisition guidance.

Respiratory motion

Rehearse the exact breath-hold the scanner will ask for

Give a calm, simple cue and practise on the table before contrast. The patient should know when to start, whether to hold after a gentle inspiration according to the local protocol, and when to breathe again. Avoid a forceful deep breath or Valsalva that can change heart rate, venous return, and contrast flow. Repeat the same instruction for rehearsal, calcium score, bolus monitoring/test bolus, and CTA as applicable.

Check whether the patient can remain still for the actual scan duration and whether the rehearsal changes the ECG. If not, shorten the acquisition if feasible, adapt protocol, or reconsider the examination. The lecture’s 5–10 second breath-hold is a useful example but scan times vary.

Webinar anchor: approximately 08:20–09:20 and 10:45–11:05.

On-table quality control

Position the heart, arms, IV line, and ECG leads deliberately

Supine positioning with arms comfortably raised usually reduces beam-hardening and keeps the arms out of the scan field. Centre the heart in the gantry, not simply the middle of the chest, while avoiding gantry contact, strained shoulders, or trembling. Keep the IV line straight and untethered through a test table movement.

Prepare clean, dry skin; use firm electrode contact and place leads outside the cardiac field where feasible. Watch the displayed trace for a high-amplitude R wave, low baseline noise, and reliable R-wave detection during breath-hold. Loose leads or T-wave mis-detection can mistime ECG triggering even if the printed heart rate looks plausible.

Webinar anchor: approximately 09:20–10:05; Dr Tosha’s planning talk also covers positioning and ECG setup.

Final pause before contrast

One-minute readiness checklist

• Clinical question and appropriate CT protocol confirmed.
• Patient stable, informed, consent/documentation complete as locally required.
• Prior contrast reaction characterised; response plan ready.
• Kidney/AKI and pregnancy considerations reviewed where relevant.
• Medication screen complete: rate-control safety and recent PDE5 inhibitors.
• Resting and breath-hold rate, rhythm, and BP checked.
• Nitroglycerin plan and any omission documented.
• Power-injection-safe IV patent, secure, and matched to intended flow.
• ECG R waves detected reliably; leads out of scan field where possible.
• Comfortable supine position, arms/line clear, no gantry contact.
• Exact breath-hold rehearsed without strain or major rhythm change.
• Contrast and saline, bolus timing, scan range, and emergency support ready.

Apply the framework

Worked preparation scenarios

Case A · 62 bpm at rest, 94 bpm during the trial breath-hold

The resting number does not represent scan conditions. Reassure and retrain the breath-hold, check for Valsalva/deep inspiration, repeat ECG observation, then reconsider timing, rate control, or protocol with the supervising team.

Case B · Prior “contrast allergy” described only as warmth

Clarify the actual event before labelling a reaction. Brief warmth/flushing is a common physiologic effect, not by itself proof of an allergic-like reaction or an automatic reason for premedication.

Case C · eGFR 27 with possible AKI and heart failure

Do not assume either “never contrast” or “hydrate everyone.” Confirm urgency and benefit, alternatives, kidney trajectory, and whether IV fluid prophylaxis would itself be harmful. The qualified team makes an individualised plan.

Case D · Recent tadalafil use, BP 92/58 mmHg

Do not give routine sublingual nitrate. Escalate for a patient-specific plan and document omission. Coronary image quality must not override the risk of clinically important hypotension.

Case E · Good ECG and rate, but the patient cannot hold still for the scan

Practice with the exact cue; assess positioning and anxiety, and whether a faster available protocol can answer the question. If cooperation remains inadequate, reconsider rather than blindly injecting contrast and repeating an unhelpful acquisition.

Educational scenarios—not medication orders or individual clinical advice.

Active recall

Self-test: answer before opening each explanation

Printable quick revision

One-page recall card

• Rate: a slow, regular rhythm helps, but no single bpm cutoff fits every scanner.
• Contrast: characterise prior reactions; eGFR <30 or AKI needs individual review—not automatic denial.
• Fasting: not required solely for routine modern IV contrast; follow any separate sedation/local requirement.
• Drugs: beta-blocker or alternative is prescriber-led; check BP, rhythm, bronchospasm, conduction disease.
• Nitrate: improves coronary calibre; check BP/preload dependence and recent PDE5 inhibitor use.
• IV: patent, power-injection-safe, suitable for intended flow; confirm contrast and saline setup.
• ECG and breath-hold: reliable R wave and a gentle, rehearsed, repeatable cue.

Before contrast, ask: If I press “inject” now, what is most likely to make this scan unsafe or non-diagnostic?

Provenance

Sources and scope

The chapter follows the locally supplied Dr Shruthi CT patient prep Webinar 1 talk (approximately 12½ minutes), with Dr Tosha’s on-table positioning/ECG discussion where relevant. Automated captions include transcription errors; current guidance below was used to qualify fasting, kidney-risk, medication, and breath-hold statements.

1. SCCT Guidelines for Performance and Acquisition of Coronary CTA — screening, heart-rate control, nitrates, IV access, positioning, ECG, and breath-hold.
2. ACR Manual on Contrast Media — fasting, reactions, kidney/metformin considerations, and emergency readiness.
3. ACR–NKF Consensus on IV Iodinated Contrast in Kidney Disease — AKI/eGFR risk assessment and prophylaxis.
4. CAR/CSTR Coronary CTA Practice Guidelines — medication and protocol examples.

Educational material only. This chapter does not authorise medication administration, contrast injection, or a patient-specific scan. Follow current local protocols and qualified clinical supervision. External references require internet; the chapter and self-test work offline.