Bài giảng Violent collision of Antegrade with retrograde coronary flow causing the first endothelial injury, starting a plaque and breaking the cap of vulnerable plaques

Lecture answers to 3 questions: how to create an animal model for atherosclerosis; it starts with a mechanical injury; the inside of a pipe is damage by air bubble rupture (cavitation).

Violent Collision of Antegrade with Retrograde Coronary Flow Causing the First Endothelial Injury, Starting a Plaque and Breaking the Cap of Vulnerable Plaques The 10th Central Vietnam Open Congress of Cardiology 14:05-14:20 Friday July 12th 2019 Thach Nguyen, MD FACC FSCAI Tan Tao U, School of Medicine, Long An Vietnam, Methodist Hospital Merrillville IN USA, Background How to create an animal model for atheroslerosis hinhanhykhoa.com Background It starts with a mechanical injury Background 3: The inside of a pipe is damage by air bubble rupture (cavitation) http://www.scielo.org.za/pdf/jsai ce/v56n3/08.pdf Background How to show the evidence of the injuries in the endothelium of the (mainly coronary) arteries? What is the mechanism? Background • In hydraulic studies, the damage in the pipelines is due to the bursting of air bubbles • During diastole, bubbles would form when the local dynamic coronary pressure decreases below the vapor pressure (VP) of gases in the blood • WHICH GAS? Background The bubbles explode when the dynamic coronary pressure recovers above the vapor pressure Figue 2: Bubble Formation and Implosion Formation of a bubble and its burst creating micro-jets Background • When the bubbles explode, the endothelial layer is damaged and lets the LDL particles pass through and form the cholesterol plaques hinhanhykhoa.com Methods Figure To review the coronary angiogram frame by frame at 15 frames per second, first right click and then select Key Image option, then use the up and down arrows to move the picture, one at a time hinhanhykhoa.com Methods • In the angiogram of the right coronary artery, the lesion was seen at the mid-segment (arrow) • No lesion was seen in proximal or distal segment (WHY?) Methods • Laminar flow is a well organized flow with peripheral layer, regular border and a pointed tip • It represents uniform distribution of pressure hinhanhykhoa.com Methods • Turbulent flow is defined as coarse mixing of blood in white and contrast in black Methods • To compare the type of flow of same patient between the Right Coronary Artery (RCA) (with turbulent flow) and the Left Circumflex Artery (LCX) without turbulent flow • (same risk factors: HTN, hyperlipidemia, etc) hinhanhykhoa.com Methods • Baseline angiogram of the left circumflex artery without lesion • Methods • The flow at the left circumflex artery was laminar without turbulence flow in systole and in diastole hinhanhykhoa.com Methods • In the angiogram of the right coronary artery, multiple plaques were seen at the midsegment (arrow) • No lesion was seen in proximal or distal segment Methods • The flow study of the right coronary artery with multiple areas of turbulence (coarse mixing of contrast in black and blood in white) at the midsegment This is the same area with multiple plaques in the previous slide hinhanhykhoa.com Methods Methods nd (2 , rd 3th, th frame) Methods th (11 , th 12 , th 14 , th 16 frame) Results • In 20 coronary angiograms we see the following results: • 80% of flow in the mid segment were turbulent and they happened in the area with multiple lesions • Only 10% lesion happened in the area without turbulence CONCLUSIONS TURBULENT FLOW at the mid segment of the right, circumflex and left anterior descending artery arteries coincide with the presence of atherosclerotic lesions This is the indirect evidence of the formation of coronary plaques caused by mechanical injury to the endothelium and the birth of coronary plaques Thank You for Your Attention ... Formation of a bubble and its burst creating micro-jets Background • When the bubbles explode, the endothelial layer is damaged and lets the LDL particles pass through and form the cholesterol plaques. .. descending artery arteries coincide with the presence of atherosclerotic lesions This is the indirect evidence of the formation of coronary plaques caused by mechanical injury to the endothelium and the. .. coronary artery with multiple areas of turbulence (coarse mixing of contrast in black and blood in white) at the midsegment This is the same area with multiple plaques in the previous slide hinhanhykhoa.com