[Music] welcome to this presentation on the cardiac cycle to begin please review the image shown here that outlines the normal anatomy of the heart try and locate the listed structures as well the cardiac cycle reverts to events related to blood flow that occurs from the beginning of one heartbeat to the beginning of the next during during diast blood fills the ventricles subsequently during syy blood is pumped out into the arteries next we'll review diastolic and systolic events cardiac diast refers to the period of time when the heart relaxes after contraction and refills with circulating blood ventricular diast is when the ventricles are relaxing while atrial dioses when the atrial are relaxing collectively they are known as complete cardiac diast here the term cardiac diast actually describes ventricular diast take the left ventricle for example during ventricular diast the pressure drops from the peak that it reaches in syy when the pressure drops below the pressure in the left atrium the mitrov valve opens and the left ventricle fills with blood this is a blood that was accumulating in the left atrium which occurs by means of three phases rapid filling reduced filling and atrial cyti after diast and during cardiac syy the ventricles begin to contract in order to pump the blood into circulation there are several sequential phases during the systolic stage which are rapid ejection reduced ejection and Proto diesto this diagram shows the respective phases and corresponding pressures in the left ventricle during one cardiac cycle this diagram also shows the corresponding ECG tracing normal heart sounds are generated by the closure of the valves in cardiac oscilation an examiner typically uses a stethoscope to listen for these unique and distinct sounds to evaluate the condition of the heart this image shows the four main cardiac oscilation sights on the chest the first har sound also known as S1 is caused by the sudden block of reverse blood flow due to closure of the AV valves at the beginning of ventricular contraction the second heart sound also known as S2 is caused by the sudden block of reverse blood flow due to closure of the semi lunar valves at the end of ventricular syy or the beginning of ventricular diesto it is important to note that the TIC components of S2 is often referred to as A2 and the pulmonary component is often referred to as P2 this diagram shows that A2 normally precedes P2 especially during inspiration when a physiological split of S2 can be heard this next image shows the pathological split under certain abnormal conditions of the heart this image shows a relationship of the cardiac cycle with all the heart sounds and this image shows that under a pathological condition where the mitro valve sticks together the opening appap of the mitro will be easily Audible and fixed next let's further discuss special heart sounds called murmurs a heart murmur is an extra or unusual sound heard during a heartbeat caused by turbulent blood flow there are two types of heart murmur innocent or harmless murmurs and abnormal murmurs innocent murmurs are not caused by heart problems these murmurs are common in healthy individuals in contrast abnormal heart murmers are caused by certain heart problems in children they are usually caused by congenital heart defects and in adults they're mainly caused by acquired heart valve disease murmurs can be classified by different characteristics the first and most important charistic is timing in regards to timing murmurs can be classified as systolic diastolic and continuous murmurs this image displays three types of systolic murmurs which are audible between S1 and S2 each type of murmur is caused by certain heart diseases this next image shows a common type of systolic murmur known as an ejection type murmur this murmur is caused by aortic Val stenosis and is usually a mid systolic murmur this type of murmur occurs at the start of blood ejection which starts after S1 and ends with the cessation of the blood flow which is before S2 therefore the onset of a mid systolic murmur is separated from S1 by the isov voltric contraction phase the cessation of the murmur and the S2 intervals is referred to as the Artic hangout time the resulting configuration of this murmur is a crescendo de Crescendo murmur it is also found that the severity of thetic stenosis will cause a difference in the shape of the murmur the more severe the extent of the stenosis the more delayed the maximal intensity of the murmur meanwhile different extents of iotic cenosis will cause changes in the relationship between A2 and P2 diastolic murmurs are heart murmur heard during diast they start at or after S2 and end before or at S1 like systolic murmur diastolic murmur may also be classified into three types they're either early mid toate and prolonged mid toate murmurs each type of murmur is mainly caused by regurgitation of the semilunar valves or stenosis of the atrial ventricular valves continuous murmur are unique group of murmurs they begin in syy peak near the second heart sound and continue into all a part of diast a classic example is patent ductus arteriosis which is an abnormal connection from the aort to the pulmonary artery that should be closed after birth since eotic pressure is higher than pulmonary pressure a continuous murmur occurs it is often described as a Machinery murmur it's important to note that this group of murmurs can often be confused with a two and fro murmur which is in fact a combination of a systolic ejection murmur and a murmur of semi lunar valve incompetence recognition of the location and radiation of of the murmur facilitates its accurate identification location refers to where the heart murmur is usually best osculated there are five places on the anterior chest to listen for heart murmur the aortic area pulmonic area left Stone B border or herbs Point mitel area and the TripIt area each location roughly corresponds to a specific part of the heart radiation refers to where the sound of the murmur radiates the general rule of thumb is that the sound radiat in the direction of the blood flow after a murmur is identified subsequent examinations such as an echocardiogram and other Imaging tests are usually ordered if an experienced physician suspects that it is an abnormal murmur therefore a decision related to the management of the murmur will be made based on identifiable heart diseases severity and the general condition of the patient that takes us to the end of this presentation on the cardiac [Music] cycle