TEACHING HUNT CONTESTANT NO 47 ANGINA PECTORIS Dr. ROOPA KUMA

hi this is dr roopkumar and today i am going to explain you about a cardiovascular pathology known as angina pectoris what do you mean by that and in latin the word anger means to strangle the word vectors means chest this is a typical appearance of a patient experiencing anjana this picture shows a person is suffering with pain in his chest region and this pain commonly radiates towards his left jaw region his shoulder and back of his shoulder what made this person to suffer with angina what is the reason behind it so the main culprit is the reduction of blood flow so this reduction of blood flow to the heart makes the heart ischemic and this ischemic heart results in pain why there is a reduction of blood flow there are mainly two reasons the number one is atherosclerosis and the second one is muscle hypertrophy i mean cardiac muscle hypertrophy these are the both masterminds behind the reduction of blood flow to heart how these reasons are related with angina before going further i would like to explain a few points regarding the anatomy of the heart you all know that coronary arteries supply the cardiac muscle among the branches of the coronary arteries the left anterior descending artery which is a branch of left coronary artery is commonly associated with atherosclerosis so we can say that the tissue which is receiving nutrition from the left anterior descending artery is more prone for ischemia this is a picture showing different layers in the wall of the heart there are mainly three layers endocardium myocardium and the pericardium endocardium receives its nutrition directly from the blood which is circulating inside the heart and the myocardium and the pericardium receives its nutrition from the branches of the coronary artery so coming to the first and foremost reason for the reduction of blood flow is atherosclerosis you all know that it is nothing but a fibro fatty tissue deposition inside the blood vessel this decreases the lumen diameter and it makes the blood flow turbulent this picture clearly shows there is a decrease in the diameter of the blood vessel because of atherosclerotic plug this is a classical picture of an atherosclerotic plaque in one of the coronary branches there is a tissue destruction and discoloration because of ischemia and the second important reason for the reduction of blood flow is ventricular muscle hypertrophy because of three reasons we can commonly see that there is a hypertrophy in the ventricles they are chronic hypertension iot stenosis and co-optation of iota in these three reasons there is an increase in afterload afterload is nothing but a resistance against with the blood has to pump so because of increasing the resistance there is a natural adaptation in the ventricular muscle to pump against this higher resistance so ventricular muscle gains its muscle strength because of hypertrophy this is the transverse section of a physiologically normal heart you can clearly see that right ventricle and the left ventricle separated by the interventricular septum this is a coronary artery it gives branches into the muscle of the heart from outside to inside and this is a transverse section of the heart with ventricular hypertrophy you can clearly see that there is an increase in the muscle mass when comparing with the previous normal heart and the coronary artery can't supply the whole muscle because of hypertrophy the sub-endocardial region is more prone for ischemia because it is the last area of the ventricle to receive blood from the coronary artery you can compare like when you are the last person in a buffet you don't you don't get the same food like the first person right so what is the cause for the pain we have already discussed that ischemic heart releases the chemical mediators like adenosine bradykinin and these cause irritation of nerve fibers in the chest region and this cause angina so what are the symptoms chest pain and discomfort is the most common thing and sometimes the pain is felt in your arms neck jaw shoulder region and that's called referred pain other common symptoms are dizziness fatigue shortness of breath and sweating so there are mainly three types of angina stable unstable and variant types stable angina in this type the oxygen demand is greater than supply the tissue demands more oxygen okay but there is less supply of oxygen because of atherosclerosis and it takes place when coronary artery is occluded more than 75 percent because of atherosclerosis so this person experiences pain only during exercise or stress why because during exercise or stress the heart rate increases when there is increase in the heart rate the cardiac muscle has to do more work than normal because of this some portion of the heart muscle don't receive the oxygen properly because of atherosclerosis and this ischemic region of the heart results in pain in the chest region and this is called angina luckily this pain release on taking rest this is an important differentiating feature for stable antenna during comparison with other types crossly we see sub-endocardial ischemia in the ventricular region in ecg we can see st segment depression normally it is flat but we see a depression in the sd segment usually stable engine attacks are commonly seen in people in playground scenarios this is a normal ecg pattern with flat st segment so when sub endocardial ischemia occurs there is a depression in the hd segment when compared to the flat hd segment in normal scenarios coming to the unstable angina in this situation also there is an increase in oxygen demand but there is a decreased supply the main reason is thrombus formation over an atherosclerotic plaque in this case the person experiences pain during rest and exercise when compared to stable antenna pain is present at rest and exercise and pain is relieved not by taking but in stable angina pain is relieved on taking rest grossly we also see that there is subendocardial ischemia and hd segment depression like stable angina so this is a blood vessel cross section of blood vessel with the atherosclerotic plug in the first image and disruption of atherosclerotic plaque followed by thrombus formation so because of thrombus formation there is almost 95 percent of blockage of blood vessel and this causes unstable angina which is not relieved on taking rest and this unstable angina can occur at both rest and exercise situations this is a normal ecg pattern and because of sub endocardial ischemia we see ht segment depression like stable angina third type variant angina physio angina or prince metal nintendo in this situation also there is an oxygen demand which is greater than the supply the reason behind it is coronary artery spasm the person experiences pain during both rest and exercise situations just like unstable angina and pain don't relieve on taking rest grossly there is a transmural ischemia which means all the layers of the cardiac wall that means endocardium myocardium and pericardium shows ischemia and because of transmural ischemia the st segment which is usually flat it elevates and this is a vasospasm in the coronary artery and this narrows the blood vessel diameter this is a normal ecg pattern here there is a transmural ischemia which is involving all three layers in the cardiac wall and this shows st segment elevation in ecg so while combining all three types under one roof we can clearly see these symptoms which are common with unstable angina and variant angina both these types pain episodes are at rest and exercise and they don't relieve by itself but stable antenna occurs only during exercise or stress and it relieves on taking rest coming to the ecg patterns stable engine and unstable antenna share common symptoms like st segment depression in ecg coming to the treatment part all the types can be treated with nitroglycerin which is a potent vasodilator unstable and princimetal types are kind of emergencies and should be treated immediately severe atherosclerosis can be managed by coronary strength placement supportive treatment can be given by statins which are usually called anti-lipid mix this is a balloon catheter stent placement commonly done by the cardiologists for the removal of atherosclerosis and to increase the diameter of the blood vessel this is an important note for differentiating angina pectoris with myocardial infarction angina pectoris is nothing but an ischemia of the tissue but the cells are viable but in infection cells are dead this angina pectoris is reversible unlike myocardial infarction is irreversible and lab investigation is one of the important differentiating feature in angina pectoris there is no rise in the troponin and creatine kinase mb but in myocardial infarction there is significant rise in the troponin and gradient kinase one last question why should we dentists learn about this i mean angina pectoris types for intense examination no just kidding in previous days dentistry is only concerned about the oral cavity but nowadays we are seeing a patient as a whole i mean we are changing our aerotic focus from oral cavity to the whole body from time to time now we know that angina pectoris is an emergency condition it can happen anytime in our dental setup most commonly persons with previous history of attacks or more anxious patients are prone for another attack of angina in our dental setup before concluding our topic i would like to give a few dental management tips the first and foremost is the medical history proper undertaking of medical history is the most important thing in the medical field if they have a positive history of any medical condition we should investigate the present situation along with cardiologist we can give prophylactic nitroglycerin tablets or anxiolytics with previous attacks of angina and also emergency drug it is commonly seen in our dental setups in order to counteract any medical emergencies and thank you it's done stay safe