[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-657676-105":59,"doc-detail-657676-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","cardiac-cycle-cardiac-physiology-overview-6-phases","CARDIAC CYCLE - Cardiac physiology overview - 6 phases","","Cardiac cycle describes the sequence from one heartbeat to the next, consisting of ventricular systole and diastole, each subdivided into phases defined by characteristic pressure and volume behavior. The material explains how ventricular depolarization and relaxation shape valve states, arterial pulse changes, and electrical patterns in the ECG. It also links cycle timing to heart rate, including normal durations and how diastole shortens more during higher rates.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/cardiac-cycle-cardiac-physiology-overview-6-phases/657676/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/cardiac-cycle-cardiac-physiology-overview-6-phases/657676.png","ImageObject",300,407,{"name":92,"@type":93},"Eliana","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-10-26",true,{"@type":102,"interactionType":103,"userInteractionCount":81},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What are systole and diastole in the cardiac cycle?","Question",{"text":112,"@type":113},"Systole is ventricular contraction, and diastole is ventricular relaxation. The cardiac cycle is the period from the start of one heartbeat to the start of the next.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How do heart rate changes affect the duration of the cardiac cycle?",{"text":117,"@type":113},"Cardiac cycle duration is inversely proportional to heart rate. As heart rate increases, diastole decreases much more than systole, while normal conditions have systole about one-third and diastole about two-thirds.",{"name":119,"@type":110,"acceptedAnswer":120},"Which cardiac phase is associated with valve closure and no blood ejection?",{"text":121,"@type":113},"Isovolumic contraction occurs when all valves are closed and ventricular pressure rises without changing ventricular blood volume, so no blood is ejected.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},657676,1793103497,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":81,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},4398048949847,"https://ap-avatar.wpscdn.com/avatar/400002536579ef2da7f?_k=1778318612642679267","CARDIAC CYCLE  \nThe cardiac cycle is a period from the beginning of one heart beat to the beginning of the next one. It consists of two parts:  \n1. Ventricular contraction called systole.  \n2. Ventricular relaxation called diastole.  \nEach part of the cardiac cycle consists of several phases characterized by either a strong pressure change with constant volume or a volume change with a relatively small change in pressure.  \nSystole includes:  \n1. Isovolumic contraction.  \n2. Ejection.  \nDiastole includes:  \n3. Isovolumic relaxation.  \n4. Rapid ventricular filling.  \n5. Slow ventricular filling (diastasis) .  \n6. Atrial contraction.  \nThe duration of the cardiac cycle is inversely proportional to the heart rate. The cardiac cycle duration increases with a decrease in the heart rate and on the other hand it shortens with increasing heart rate. At a normal heart rate of 75 beats per minute, one cardiac cycle lasts 0.8 second. Under resting conditions, systole occupies ⅓ and diastole ⅔ of the cardiac cycle duration. At an increasing heart rate (e.g. during an intensive muscle work), the duration of diastole decreases much more then the duration of systole.  \nIn the following six chapters the individual phases of the cardiac cycle are described. The description contains:  \n¾ Mechanical events in the heart (the contraction on pictures is represented by a colour change of the myocardium) .  \n¾ Pressure and volume changes in both the atria and the ventricles. The pressure changes in the right atrium are seen in the recording of the venous pulse.  \n¾ Pressure changes in the arteries – arterial pulse.  \n¾ Electrical activity of the heart – electrocardiogram (ECG)  \n¾ Heart sounds or phonocardiogram.  \nThe teaching material contains the animation of the mechanical events in the heart during the cardiac cycle including the arterial pulse, ECG, heart sounds, venous pulse, pressure and volume changes in the right atrium and in the left ventricle.  \n1. Isovolumic Contraction  \n1.1. Heart  \nThe ventricles contract due to the ventricular depolarization and the pressure inside the ventricles rapidly increases. Immediately after a ventricular contraction begins, the pressure in the ventricles exceeds the pressure in the atria and thus the atrioventricular valves shut. Thesemilunar valves are closed because the ventricular pressure is lower than that in the aorta and the pulmonary artery (fig. 1. 1) .  \nFig. 1.1. Isovolumic contraction  \nThe contraction is represented by a colour change of myocardium.  \n1.2. Pressure and volume changes  \nVentricles  \nThe ventricles contract and all valves are closed, so no blood can be ejected. The ventricular pressure rises considerably without any change in the ventricular blood volume – isovolumic contraction (fig. 1.2) . The blood volume in the ventricles equals to the end-diastolic volume (circa 130 ml) .  \nAtria  \nThe atrioventricular valves are bulged backward into the atria because of increasing pressure in the ventricles. This event causes the c wave in the venous pulse (fig. 1.2) .  \nArteries  \nPressures in arteries of both systemic and pulmonary circulations decrease constantly (fig. 1.2) .  \nFigure 1.2. Isovolumic contraction-pressure and volume changes  \nRed line-pressure in the left ventricle, black-the aortic pressure, dark blue-the pressure in the right atrium, light blue-the ventricular volume.  \n1.3. Electrocardiogram  \nThe depolarization spreads from the atrioventricular node to the septum and the walls of both ventricles through the bundle of His and Purkyne fibres. The ventricular depolarization causes the QRS complex in the ECG (fig. 1.3) . At the same moment, the atria are repolarized to produce the atrial T (Ta) wave in the ECG. The atrial T wave is not visible on the physiological ECG because it is covered by the QRS complex.  \nFig. 1.3. Isovolumic contraction – ECG  \n1.4. Heart sounds  \nDuring the isovolumic contraction, the first heart sound appears (fig. 1.4) . This sound is caused by ","cbCaipBT8cG7suzY","https://ap.wps.com/l/cbCaipBT8cG7suzY","pdf",475925,15,"English","# Overview\n## Phases of systole and diastole\n## Cardiac cycle duration vs heart rate\n# Isovolumic contraction\n## Heart\n## Pressure and volume changes\n## Electrocardiogram (ECG)\n## Heart sounds\n# Ejection\n## Heart\n## Pressure and volume changes\n# Future sections","[{\"question\":\"What are systole and diastole in the cardiac cycle?\",\"answer\":\"Systole is ventricular contraction, and diastole is ventricular relaxation. The cardiac cycle is the period from the start of one heartbeat to the start of the next.\"},{\"question\":\"How do heart rate changes affect the duration of the cardiac cycle?\",\"answer\":\"Cardiac cycle duration is inversely proportional to heart rate. As heart rate increases, diastole decreases much more than systole, while normal conditions have systole about one-third and diastole about two-thirds.\"},{\"question\":\"Which cardiac phase is associated with valve closure and no blood ejection?\",\"answer\":\"Isovolumic contraction occurs when all valves are closed and ventricular pressure rises without changing ventricular blood volume, so no blood is ejected.\"}]","CARDIAC CYCLE - Cardiac physiology overview - 6 phases | PDF",1792986189,38]