Related Experiment Videos
[Invasive examination of cardiovascular disease]
M Horimoto1, T Takenaka, K Igarashi
1Division of Cardiology, Sapporo National Hospital.
Insights
Advanced invasive cardiovascular imaging techniques like Doppler and pressure wires, and intravascular ultrasound (IVUS) improve coronary artery assessment. These tools aid in evaluating blood flow, diagnosing functional stenosis using fractional flow reserve (FFRmyo), and guiding interventions.
Area of Science:
- Cardiovascular medicine and interventional cardiology.
Context:
- Invasive cardiovascular examination techniques have significantly advanced.
- Coronary angioscopy, Doppler guide wires, pressure guide wires, and intravascular ultrasound (IVUS) are key diagnostic and interventional tools.
Purpose:
- To review the applications and advancements of invasive coronary imaging modalities.
- To highlight the role of Doppler and pressure wires in assessing coronary blood flow and functional stenosis (FFRmyo).
- To discuss the utility of IVUS in tissue characterization and guiding stent deployment, and angioscopy in acute coronary syndrome research.
Summary:
- Doppler guide wires measure flow velocity and evaluate coronary blood flow, detecting impaired vasodilation in conditions like hypertension.
- Pressure guide wires enable calculation of myocardial fractional flow reserve (FFRmyo) to assess functional coronary stenosis.
- Intravascular ultrasound (IVUS) provides detailed vascular wall imaging for diagnosis and intervention, while coronary angioscopy visualizes plaque and thrombus in acute coronary syndromes.
Impact:
- These technologies enhance the diagnosis of coronary artery disease, optimize interventional strategies, and improve patient outcomes.
- FFRmyo is crucial for determining the need for coronary intervention, with values below 0.75 indicating significant stenosis.
- IVUS aids in achieving optimal stent deployment and assessing restenosis, while angioscopy offers insights into acute coronary syndrome pathogenesis.
Abstract:
Invasive cardiovascular examination by coronary angioscopy and by using a Doppler guide wire, a pressure guide wire and intravascular ultrasound has extensively developed. A Doppler guide wire is used for measurement of flow velocity and evaluation of coronary blood flow. Previous studies demonstrated by assessing maximum coronary vasodilatory capacity that endothelium-dependent or independent vasodilation was impaired in hypertension and hypercholesterolemia or in syndrome X. Elevation of coronary vascular resistance during coronary microvascular spasm has been verified by using a Doppler wire. A pressure guide wire provides coronary transstenotic pressure and is available in calculating myocardial fractional flow reserve(FFRmyo). FFRmyo is an important parameter to assess the coronary functional stenosis that is culprit for myocardial ischemia. It is calculated from the ratio of the mean transstenotic pressure to the mean pressure proximal to the stenosis during maximum coronary hyperemia. The value of FFRmyo considered as necessary for coronary intervention is below 0.75. Intravascular ultrasound(IVUS) is applied as both a diagnostic tool and for intervention purpose. It enabled tissue characterization of the vascular wall as well as measurements of vascular diameter, vascular lumen area and plaque area. It also aided in optimal devise selection, decision of interventional endpoint and assessment of restenosis. IVUS promoted deployment of high-pressure stents to obtain a large post-procedural lumen area as well as abolition of anticoagulation in case of optimal stent deployment. Coronary angioscopy has been developed to investigate the pathogenesis of acute coronary syndrome, where disrupted yellow plaque and overlying thrombus play important roles. Angioscopy has also evidenced regression of intimal hyperplasia after coronary stenting.