{"id":10222,"date":"2012-04-22T15:14:23","date_gmt":"2012-04-22T15:14:23","guid":{"rendered":"http:\/\/cardiophile.org\/?p=7237"},"modified":"2023-07-17T14:55:47","modified_gmt":"2023-07-17T09:25:47","slug":"av-interval-optimization-in-crt-2","status":"publish","type":"post","link":"https:\/\/johnsonfrancis.org\/professional\/av-interval-optimization-in-crt-2\/","title":{"rendered":"AV Interval Optimization in CRT"},"content":{"rendered":"<p><iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/HTAKo191j8g\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen=\"\"><\/iframe><\/p>\n<h2><span style=\"color: #008000;\">AV interval optimization in CRT<\/span><\/h2>\n<p>The aim of AV interval optimization in cardiac resynchronization therapy is to prevent too early or too late atrial contraction. Too late an atrial contraction will cause it to overlap with ventricular systole so that atrial contraction will occur against a closed AV valve. This will lead to a sudden elevation of atrial and pulmonary as well as systemic venous pressure. This discussion is about the manual methods of AV interval optimization. Modern devices have facility for automatic AV interval optimization, which will of course have to be counterchecked by the physician.<\/p>\n<p>Echocardiographic methods to optimize AV delay are <strong>Ritter\u2019s method and Ishikawa\u2019s method<\/strong>. In Ritter\u2019s method, long AV delay is calculated when there is partial fusion of E and A waves on mitral Doppler and short AV delay is calculated when A wave truncation occurs due to ventricular contraction before completion of A wave. From these two values, the optimal AV delay is calculated using the Ritter\u2019s formula.<\/p>\n<p><em><strong>Ishikawa\u2019s method<\/strong><\/em> is used when there is significant <em>diastolic mitral regurgitation<\/em>. Long AV delay is chosen so that it results in diastolic mitral regurgitation or diastasis until isovolumetric contraction, which is the time at which systolic mitral regurgitation starts. It may be noted that there is no true isovolumetric phase when there is systolic mitral regurgitation as mitral valve starts leaking in the potential isovolumetric phase and reduces the ventricular volume. The duration of diastolic mitral regurgitation is subtracted from the long AV delay to get the optimal AV delay.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Aim of AV interval optimization in CRT (cardiac resynchronization therapy or biventricular pacing) is to prevent too early or too late atrial contraction.<\/p>\n","protected":false},"author":1,"featured_media":60287,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","footnotes":""},"categories":[6],"tags":[],"class_list":["post-10222","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ecg-electrophysiology"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>AV interval optimization in CRT - Ritter &amp; Ishikawa methods<\/title>\n<meta name=\"description\" content=\"Aim of AV interval optimization in CRT (cardiac resynchronization therapy or biventricular pacing) is to prevent too early or too late atrial contraction.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/johnsonfrancis.org\/professional\/av-interval-optimization-in-crt-2\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"AV interval optimization in CRT - Ritter &amp; Ishikawa methods\" \/>\n<meta property=\"og:description\" content=\"Aim of AV interval optimization in CRT (cardiac resynchronization therapy or biventricular pacing) is to prevent too early or too late atrial contraction.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/johnsonfrancis.org\/professional\/av-interval-optimization-in-crt-2\/\" \/>\n<meta property=\"og:site_name\" content=\"All About Cardiovascular System and Disorders\" \/>\n<meta property=\"article:published_time\" content=\"2012-04-22T15:14:23+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-07-17T09:25:47+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2012\/04\/AV-Interval-Optimization-in-CRT.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"897\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Johnson Francis\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Johnson Francis\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/av-interval-optimization-in-crt-2\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/av-interval-optimization-in-crt-2\\\/\"},\"author\":{\"name\":\"Johnson Francis\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#\\\/schema\\\/person\\\/5441d907049b914770f4bd98fb57feec\"},\"headline\":\"AV Interval Optimization in CRT\",\"datePublished\":\"2012-04-22T15:14:23+00:00\",\"dateModified\":\"2023-07-17T09:25:47+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/av-interval-optimization-in-crt-2\\\/\"},\"wordCount\":264,\"publisher\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#\\\/schema\\\/person\\\/5441d907049b914770f4bd98fb57feec\"},\"image\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/av-interval-optimization-in-crt-2\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/wp-content\\\/uploads\\\/2012\\\/04\\\/AV-Interval-Optimization-in-CRT.jpg\",\"articleSection\":[\"ECG \\\/ Electrophysiology\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/av-interval-optimization-in-crt-2\\\/\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/av-interval-optimization-in-crt-2\\\/\",\"name\":\"AV interval optimization in CRT - 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