Myoview (Tetrofosmin)

• Myoview is used in cardiac imaging to evaluate myocardial blood flow and detect coronary artery disease.
• Myocardial perfusion imaging: Provides visualisation of regional blood flow during stress and rest, aiding diagnosis of ischemia.
• Coronary artery disease detection: Helps identify obstructive lesions by comparing perfusion patterns.
• Myocardial viability assessment: Differentiates viable from scarred myocardium to guide revascularisation decisions.

• Technetium‑99m tetrofosmin, the radiolabelled component of Myoview, is a lipophilic cation that readily crosses cell membranes and accumulates in mitochondria of viable myocardial cells in proportion to regional blood flow. After intravenous injection, the tracer distributes rapidly, and its gamma emission is captured by single‑photon emission computed tomography (SPECT) cameras, producing high‑resolution images of myocardial perfusion. The short half‑life of technetium‑99m allows imaging within minutes while minimizing radiation exposure.

Adverse reactions to Myoview are generally infrequent but may occur following intravenous administration.

Common Side Effects

• Nausea: mild transient nausea reported in some patients.
• Headache: brief headache during or after injection.
• Dizziness: occasional light‑headedness.
• Flushing or warmth: sensation of warmth or skin flushing at the injection site.
• Injection site pain: mild discomfort at the venous access point.

Serious or Rare Side Effects

• Anaphylactic reaction: severe allergic response requiring immediate medical intervention.
• Hypotension: marked drop in blood pressure, potentially causing syncope.
• Cardiac arrhythmia: rare occurrence of abnormal heart rhythm.
• Severe chest pain: intense thoracic discomfort suggestive of myocardial ischemia.
• Myocardial infarction: extremely rare acute coronary event temporally associated with the procedure.

Prior to Myoview administration, clinicians should observe several precautionary measures to ensure patient safety and optimal image quality.

• Patient assessment: evaluate renal function and cardiac status before injection.
• Pregnancy: avoid use in pregnant women unless the diagnostic benefit outweighs potential fetal radiation risk.
• Breastfeeding: discontinue breastfeeding for an appropriate period after administration, as advised by a radiopharmacist.
• Concomitant medications: review drugs that may alter myocardial blood flow, such as vasodilators or beta‑blockers.
• Radiation safety: limit exposure to staff and other patients by following standard nuclear medicine protection protocols.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Myoview may interact with other agents that influence myocardial perfusion or radiotracer distribution.

Major Interactions (Avoid)

• Concurrent radiopharmaceuticals: administration of other nuclear imaging agents within 24 hours can cause competitive uptake and inaccurate results.
• High‑dose iodine contrast: recent iodinated contrast studies may interfere with technetium‑99m uptake and should be avoided.
• Severe hypotensive drugs: potent vasodilators administered immediately before Myoview can markedly reduce myocardial blood flow and compromise image quality.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may blunt stress‑induced perfusion changes; dosage timing should be considered.
• Calcium channel blockers and nitrates: can modify coronary vasodilation and affect tracer distribution; monitor hemodynamics.
• Caffeine or methylxanthines: intake before pharmacologic stress testing can reduce hyperemic response, potentially altering imaging results.