{"id":376,"date":"2017-01-16T14:02:43","date_gmt":"2017-01-16T14:02:43","guid":{"rendered":"http:\/\/www.deltexmedical.com\/decision_tree\/?page_id=376"},"modified":"2017-11-10T14:48:38","modified_gmt":"2017-11-10T14:48:38","slug":"stroke-volume-and-cardiac-output","status":"publish","type":"page","link":"https:\/\/www.deltex-academy.com\/decision_tree\/stroke-volume-and-cardiac-output\/","title":{"rendered":"Stroke Volume and Cardiac Output"},"content":{"rendered":"<style>.entry-title {display:none;}<br \/><\/style>\n<style>.site-info {display: none;}<br \/><\/style>\n<h2 style=\"text-align: center;\"><strong><span style=\"color: #003087;\">STROKE VOLUME AND CARDIAC OUTPUT\u00a0<\/span><\/strong><\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-377 size-full\" src=\"http:\/\/www.deltexmedical.com\/decision_tree\/wp-content\/uploads\/2017\/01\/Stroke-volume.png\" width=\"1216\" height=\"695\" srcset=\"https:\/\/www.deltex-academy.com\/decision_tree\/wp-content\/uploads\/2017\/01\/Stroke-volume.png 1216w, https:\/\/www.deltex-academy.com\/decision_tree\/wp-content\/uploads\/2017\/01\/Stroke-volume-300x171.png 300w, https:\/\/www.deltex-academy.com\/decision_tree\/wp-content\/uploads\/2017\/01\/Stroke-volume-768x439.png 768w, https:\/\/www.deltex-academy.com\/decision_tree\/wp-content\/uploads\/2017\/01\/Stroke-volume-1024x585.png 1024w\" sizes=\"auto, (max-width: 709px) 85vw, (max-width: 909px) 67vw, (max-width: 1362px) 62vw, 840px\" \/><\/p>\n<p>Illustration from Anatomy &amp; Physiology, Connexions Web site. http:\/\/cnx.org\/content\/col11496\/1.6\/, Jun 19, 2013.<\/p>\n<h3><strong><span style=\"color: #003087;\">Stroke Volume<\/span><\/strong><\/h3>\n<p>Stroke Volume (SV)\u00a0is the volume of blood in millilitres ejected from the\u00a0each ventricle\u00a0due to the contraction of the heart muscle which compresses these\u00a0ventricles.<\/p>\n<p>SV is the difference between end diastolic volume (EDV) and end systolic volume (ESV). Multiple factors can affect SV, eg. factors that change either EDV or ESV will change SV. The three primary factors that regulate SV are <a href=\"http:\/\/www.deltexmedical.com\/decision_tree\/preload-afterload-and-contractility\/\" target=\"_blank\">preload, afterload and contractility.<\/a><\/p>\n<p>Heart rate (HR) also affects SV. Changes in HR alone\u00a0inversely affects SV. However, SV\u00a0can increase when there is an increase in HR (during\u00a0exercise for example)\u00a0when\u00a0other\u00a0mechanisms are activated, but when these mechanisms fail, SV cannot be maintained during an\u00a0elevated HR. These mechanisms include increased venous return, venous constriction, increased atrial and ventricular inotropy and enhanced rate of ventricular relaxation.<\/p>\n<p>The\u00a0ODM+\u00a0calculates SV by multiplying the\u00a0<a href=\"http:\/\/www.deltexmedical.com\/decision_tree\/doppler-specific-parameters\/\" target=\"_blank\">Stroke Distance (SD)<\/a>\u00a0by a constant accessed from the built-in patient\u00a0nomogram.<\/p>\n<p>Normal values for a resting healthy individual would be approximately 60-100mL. Patients undergoing surgery or in critical illness situations may require higher than normal SV and it may be more appropriate to aim for optimal rather than normal SV. See <a href=\"http:\/\/www.deltexmedical.com\/decision_tree\/stoke-volume-optimisation\/\">Stroke Volume\u00a0<\/a> Optimisation and <a href=\"http:\/\/www.deltexmedical.com\/decision_tree\/improved-outcomes\/\" target=\"_blank\">Improved Outcomes<\/a>.<\/p>\n<h3><strong><span style=\"color: #003087;\">Stoke Volume Index<\/span><\/strong><\/h3>\n<p>Stroke Volume Index (SVI) relates SV to body surface area (BSA), thus relating heart performance to the size of the individual. The unit of measurement is millilitres per square metre (ml\/m<sup>2<\/sup>).<\/p>\n<p><strong>SVI = SV\/BSA<\/strong><\/p>\n<p><strong>\u200b<\/strong>Normal values for a resting healthy individual would be approximately 35-65mL\/m2. Patients undergoing surgery or in critical illness situations may require higher than normal SVI and it may be more appropriate to aim for optimal rather than normal SVI.<\/p>\n<h3><strong><span style=\"color: #003087;\">Cardiac Output<\/span><\/strong><\/h3>\n<p>Cardiac Output (CO)\u00a0is the amount of blood the heart pumps from each ventricle per\u00a0minute. It is usually expressed in litres per minute (L\/min).<\/p>\n<p><strong>CO = HR x SV<\/strong><\/p>\n<p>Changes in either HR or SV can alter CO. Impaired regulation\u00a0of SV (including <a href=\"http:\/\/www.deltexmedical.com\/decision_tree\/preload-afterload-and-contractility\/\">preload, afterload and contractility<\/a>) can have a significant adverse affect on CO.<\/p>\n<p>\u200bNormal values for a resting healthy individual would be approximately 5-8L. Patients undergoing surgery or in critical illness situations may require higher than normal CO and it may be more appropriate to aim for optimal rather than normal CO.<\/p>\n<h3><strong><span style=\"color: #003087;\">Cardiac Index<\/span><\/strong><\/h3>\n<p>Cardiac index (CI) is the cardiac output proportional to the body surface area (BSA).\u00a0The unit of measurement is litres per minute per square metre (L\/min\/m2).<\/p>\n<p><strong>CI\u00a0= CO x BSA<\/strong><\/p>\n<p>\u200bNormal values for a resting healthy individual would be approximately 2.5-4.2L\/m2. Patients undergoing surgery or in critical illness situations may require higher than normal CI and it may be more appropriate to aim for optimal rather than normal CI.<\/p>\n<h3><strong><span style=\"color: #003087;\">Suggested Reading<\/span><\/strong><\/h3>\n<p>\u200bDvorak G.O., Hemodynamic Monitoring: Invasive and Non Invasive Clinical Application. 2008 ed 4. Saunders.<\/p>\n<p>Grossman S., and Porth C.M., Porth&#8217;s Pathophysiology: Concepts of\u00a0Altered Health States. 2013 ed 9. Lippincott Williams &amp; Wilkins.\u00a0<\/span><\/p>\n<p>Klabunde R.E., Cardiovascular Physiology Concepts. 2005. Lippincott Williams &amp; Wilkins.<\/p>\n<p>Porter R.S., The Merck Manual of Diagnosis and Therapy. 2011 ed 19. Wiley. See also\u00a0<a href=\"http:\/\/www.merckmanuals.com\/professional\/\" target=\"_blank\" data-cke-saved-href=\"http:\/\/www.merckmanuals.com\/professional\/\">www.merckmanuals.com<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>STROKE VOLUME AND CARDIAC OUTPUT\u00a0 Illustration from Anatomy &amp; Physiology, Connexions Web site. http:\/\/cnx.org\/content\/col11496\/1.6\/, Jun 19, 2013. Stroke Volume Stroke Volume (SV)\u00a0is the volume of blood in millilitres ejected from the\u00a0each ventricle\u00a0due to the contraction of the heart muscle which compresses these\u00a0ventricles. SV is the difference between end diastolic volume (EDV) and end systolic volume &hellip; <a href=\"https:\/\/www.deltex-academy.com\/decision_tree\/stroke-volume-and-cardiac-output\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Stroke Volume and Cardiac Output&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-376","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages\/376","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/comments?post=376"}],"version-history":[{"count":9,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages\/376\/revisions"}],"predecessor-version":[{"id":1211,"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/pages\/376\/revisions\/1211"}],"wp:attachment":[{"href":"https:\/\/www.deltex-academy.com\/decision_tree\/wp-json\/wp\/v2\/media?parent=376"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}