 A few clinical aspects about coronary occlusion and angina myocardial infarction. LED is the most common site of occlusion. The second most common site of occlusion is the RCA. The third most common site of coronary occlusion is circumflex. The fourth most common site of occlusion is the left main coronary artery, LMCA. The fifth most common site of occlusion is the posterior descending artery and the sixth most common site of occlusion is the right posterior coronary artery. So therefore we notice the second most common site, the fifth most common site and the sixth most common site are all pertaining to the right coronary artery. The most common site, the third most common site and the fourth most common site pertain to the left coronary artery. This is by means of worldwide multi-centric studies they have found out the relative percentages of the occlusion. The next point is about angiogram. When we are performing a coronary angiogram in suspected occlusion we cannulate either through the femoral artery or the brachial artery and nowadays also through the radial artery and the cannula then comes to the coronary ostium and from here it is cannulated and the dye is injected into the right coronary artery and it outlines the entire right coronary system. Then the cannula is directed towards the left coronary sinus and it is injected and it outlines the whole left coronary system. So that is how coronary angiogram is performed. This is the right coronary angiogram showing the RCA, the RPCA and the posterior descending artery and this is the left coronary angiogram showing the LAD, diagonal branches and the circumflings and finally this is the digital subtraction coronary angiogram showing the LAD and the circumflings. And nowadays in the same city if a significant block is identified which is amenable to angioplasty that block is removed by means of balloon dilatation and the stent is inserted and that is known as percutaneous transluminal coronary angioplasty. However, if there are multiple blocks in multiple arteries then we cannot possibly do angioplasty for all of them then we do what is known as coronary artery bypass and nowadays we are using the left internal mammary artery to do the bypass. So this is about the coronary circulation and its some clinical relevance. Thank you very much for watching. If you have any questions or comments please put them in the comment section below. Dr. Sanjeev Sanyal signing off. Have a nice day.