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Coronary physiology (fractional flow reserve, FFR) studies how blood flows through the vessels that feed the heart. It provides vital information on whether the degree of narrowing of the artery by cholesterol buildup impedes blood supply to the heart. After all, only artery which is severely blocked needs unblocking, majority of the so called mild or moderate narrowing can be safely treated with optimal medication. It’s like investigating the highways that supply oxygen and nutrients to our heart muscle but not all lane closures may result in traffic jam. Advanced techniques in this field help doctors decide which artery lesion needs ballooning and which one can be safely left alone.
What Is Coronary Physiology?
Coronary physiology is the study of how the blood vessels around the heart, known as coronary arteries, function and contribute to overall heart health. These arteries supply oxygen and nutrients to the heart muscle, ensuring proper function. Coronary physiology investigates various aspects, including blood flow dynamics, oxygen delivery efficiency, and the adaptability of the coronary arteries under different conditions.
Incorporating advanced assessment techniques, such as imaging and diagnostic tools, coronary physiology provides valuable insights for healthcare professionals. This knowledge contributes to more precise diagnoses and tailored treatment plans, ultimately improving the overall understanding and care of heart health.
Key Features of Coronary Physiology:
- Blood Flow Dynamics – Examining how blood flows through the coronary arteries and understanding the factors influencing this dynamic process.
- Coronary Flow Reserve – Assessing the capacity of the coronary arteries to adapt and increase blood flow when needed, providing insights into their flexibility.
- Microvascular Function – Studying the function of the smaller blood vessels (microvasculature) within the heart plays a significant role in overall coronary health.
- Impact of Coronary Artery Disease – Understanding how conditions like coronary artery disease affect the physiological aspects of the coronary arteries, helping in the diagnosis and management of heart-related issues.
- Advanced Assessment Techniques – Utilising sophisticated techniques to assess coronary physiology, such as imaging and diagnostic tools, contributes to more accurate diagnoses and tailored treatment plans.
Who Needs Coronary Physiology?
Coronary physiology assessments benefit individuals facing various cardiac concerns or risk factors. This includes:
- Individuals diagnosed with coronary artery disease can benefit from coronary physiology assessments to understand the impact of the disease on blood flow dynamics and overall heart function.
- Those experiencing chest pain or angina can undergo coronary physiology evaluations to explore the underlying causes and assess the efficiency of blood flow to the heart.
- Individuals who have experienced a heart attack can undergo coronary physiology assessments to gauge the functioning of the coronary arteries and aid in post-heart attack management.
- Individuals with risk factors such as diabetes, hypertension, or a family history of heart disease may undergo coronary physiology assessments to evaluate heart health proactively.
- Patients undergoing interventions like angioplasty or stent placement may benefit from coronary physiology assessments to evaluate the effectiveness of these treatments and guide further management.
- As part of preventive cardiology, coronary physiology assessments can identify early signs of potential heart issues, allowing for proactive measures to maintain cardiovascular health.
Which Medical Conditions Warrant Coronary Physiology?
- Coronary Artery Disease (CAD) – Individuals diagnosed with CAD, characterised by the narrowing or blockage of coronary arteries, benefit from coronary physiology assessments to understand the impact on blood flow and devise targeted interventions.
- Angina Pectoris – Patients experiencing chest pain or angina can undergo coronary physiology evaluations to identify the underlying causes and assess the efficiency of coronary blood flow.
- Coronary Microvascular Dysfunction (CMD) – Conditions affecting the microvasculature of the heart, leading to impaired blood flow. Patients with this condition typically have chest pain symptoms consistent with heart pain but initial investigations such as CT scan or cardiac catheter showed “normal” heart arteries. This is because angiogram can only visualize blood vessels above 1mm in diameter. Smaller arteries or the micro-vessels may still have disease but they are too small to be captured by standard imaging technique. CMD can be assessed through coronary physiology to understand and manage microvascular dysfunction.
If the FFR was found to be abnormal, your cardiologist may proceed to unblock the blood vessels with balloon and stents. On the other hand, if the FFR is within the normal boundary, coronary angioplasty can be safely deferred and you will be treated with medication instead.
Multiple clinical trials and international guidelines have endorsed the use of coronary physiology to guide physicians in managing coronary artery intervention.
What Happens During Coronary Physiology?
This is usually carried out in the special X-ray room called the Catheter Laboratory. You may receive a bit of sedation during the coronary physiology assessment. Coronary angiogram is carried out in the standard manner where a soft catheter is delicately inserted into a blood vessel, usually through the wrist (or groin), and guided towards the coronary arteries. After taking pictures of the heart vessels, a special wire with sensors will be inserted to the heart artery of concern to measure pressure within different segments of the vessel, providing insights into blood flow dynamics and quantify potential blockages.
The assessment includes the evaluation of coronary flow reserve, assessing the arteries’ adaptability to increased blood flow demands, and the function of smaller blood vessels within the heart. Real-time monitoring ensures detailed information is gathered, and the procedure may involve contrast dye injection or medicines to dilate the arteries for the assessment.
Speak to your cardiologist to discuss this investigation should you want to explore this further.
