{"id":66417,"date":"2026-03-15T07:17:35","date_gmt":"2026-03-15T01:47:35","guid":{"rendered":"https:\/\/johnsonfrancis.org\/professional\/?p=66417"},"modified":"2026-03-15T07:17:37","modified_gmt":"2026-03-15T01:47:37","slug":"how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction","status":"publish","type":"post","link":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/","title":{"rendered":"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction"},"content":{"rendered":"<iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/O9G0XsckV7s?si=OXZzRMHrNTGBYnvh\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n\n<p class=\"wp-block-paragraph\">Prinzmetal angina (also known as variant angina) is a fascinating clinical phenomenon because it flips the &#8220;standard&#8221; model of heart disease on its head. While typical angina is caused by a <strong>supply-and-demand<\/strong> mismatch due to a fixed, physical blockage (atherosclerosis), Prinzmetal angina is caused by a <strong>transient, functional<\/strong> obstruction. Here is how the coronary artery spasms work without needing a permanent blockage.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. The Mechanism of the Spasm<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In a healthy heart, coronary arteries dilate or constrict slightly to regulate blood flow. In Prinzmetal angina, a segment of a coronary artery becomes <strong>hyper-responsive<\/strong>.<\/p>\n\n\n\n<p id=\"p-rc_aabf79575414702f-19\" class=\"wp-block-paragraph\">When a spasm occurs, the smooth muscle in the artery wall contracts so forcefully that it temporarily &#8220;shuts&#8221; the vessel.<sup><\/sup> This leads to <strong>transmural ischemia<\/strong>\u2014meaning the lack of blood flow affects the entire thickness of the heart muscle wall, not just the inner layer. This is why you see ST-segment elevation on an ECG during an attack, which usually mimics a heart attack.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. Why it happens without &#8220;Clogging&#8221;<\/h3>\n\n\n\n<p id=\"p-rc_aabf79575414702f-20\" class=\"wp-block-paragraph\">The hallmark of this condition is that it can also occur in <strong>angiographically normal<\/strong> arteries. Several triggers and underlying dysfunctions drive this:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"\"><strong>Endothelial Dysfunction:<\/strong> The inner lining of the blood vessel (the endothelium) normally produces nitric oxide to keep the vessel relaxed. If the endothelium is &#8220;broken&#8221; or sensitive, it may fail to prevent constriction or even trigger it.<\/li>\n\n\n\n<li class=\"\"><strong>Autonomic Nervous System Imbalance:<\/strong> Excessive activity of the sympathetic (fight or flight) or parasympathetic nervous system can trigger the smooth muscle to overreact.<\/li>\n\n\n\n<li class=\"\"><strong>Hyper-reactivity of Smooth Muscle:<\/strong> There is often an exaggerated response to vasoconstrictors like acetylcholine, serotonin, or even cold weather and emotional stress.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. Key Differences: Stable vs. Prinzmetal Angina<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><td><strong>Feature<\/strong><\/td><td><strong>Stable Angina<\/strong><\/td><td><strong>Prinzmetal (Variant) Angina<\/strong><\/td><\/tr><\/thead><tbody><tr><td><strong>Cause<\/strong><\/td><td>Fixed plaque (Atherosclerosis)<\/td><td>Temporary Smooth Muscle Spasm<\/td><\/tr><tr><td><strong>Trigger<\/strong><\/td><td>Physical exertion or stress<\/td><td>Often occurs at rest (cycles at night\/early morning)<\/td><\/tr><tr><td><strong>ECG Change<\/strong><\/td><td>ST-segment depression<\/td><td><strong>ST-segment elevation<\/strong> (Transient)<\/td><\/tr><tr><td><strong>Vessel State<\/strong><\/td><td>Permanently narrowed<\/td><td>Can be completely clear between episodes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Why the timing matters<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">These episodes often happen between <strong><a href=\"https:\/\/www.heart.org\/en\/health-topics\/heart-attack\/angina-chest-pain\/prinzmetal-angina\" type=\"link\" id=\"https:\/\/www.heart.org\/en\/health-topics\/heart-attack\/angina-chest-pain\/prinzmetal-angina\">midnight and early morning<\/a><\/strong>. This is likely due to the circadian rhythm of the autonomic nervous system and changes in &#8220;vagal tone&#8221; <a href=\"https:\/\/e-kcj.org\/DOIx.php?id=10.4070\/kcj.2008.38.1.66\" type=\"link\" id=\"https:\/\/e-kcj.org\/DOIx.php?id=10.4070\/kcj.2008.38.1.66\">during sleep<\/a>, which can make the coronary vessels more prone to snapping shut.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/25262663\/\" type=\"link\" id=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/25262663\/\">ECG Findings in Prinzmetal Angina<\/a><\/h3>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li class=\"\"><strong>Transient ST-Elevation:<\/strong> The most critical sign. If you capture the ECG while the patient has chest pain, you see the elevation. If you repeat it 20 minutes later after the pain subsides, the ECG might look <strong>completely normal<\/strong>.<\/li>\n\n\n\n<li class=\"\"><strong>Increased R-Wave Amplitude:<\/strong> During the peak of a spasm, the R-wave can actually get taller.<\/li>\n\n\n\n<li class=\"\"><strong>T-Wave Peaking:<\/strong> You might see very tall, peaked T-waves immediately before the ST-segment starts to lift.<\/li>\n\n\n\n<li class=\"\"><strong>Arrhythmias:<\/strong> Because the ischemia is transmural (full thickness), these spasms can trigger ventricular arrhythmias or AV blocks, depending on which artery is spasming (e.g., the Right Coronary Artery spasm often causes bradycardia or heart block).<\/li>\n<\/ol>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>&#8220;Pseudo-Normalization&#8221;:<\/strong>  Sometimes, if a patient already has T-wave inversion from a previous issue, a Prinzmetal spasm can make the T-wave look &#8220;upright&#8221; and &#8220;normal&#8221; temporarily. This is a trap! It\u2019s called <strong><a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6932094\/\" type=\"link\" id=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6932094\/\">pseudo-normalization<\/a><\/strong> and actually indicates acute ischemia.<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\">The &#8220;Gold Standard&#8221; Diagnosis<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In the cath lab, <strong>Provocative Testing<\/strong> is done sometimes to induce coronary artery spasm. <strong>Ergonovine<\/strong> or <strong>Acetylcholine<\/strong> can be used to trigger a spasm while watching the ECG and the artery on the monitor, with due emergency care precautions. If the artery narrows and the ECG shows ST-elevation, the diagnosis is confirmed.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Prinzmetal angina (also known as variant angina) is a fascinating clinical phenomenon because it flips the &#8220;standard&#8221; model of heart disease on its head. While typical angina is caused by a supply-and-demand mismatch due to a fixed, physical blockage (atherosclerosis), Prinzmetal angina is caused by a transient, functional obstruction. Here is how the coronary artery [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":66418,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","footnotes":""},"categories":[9],"tags":[],"class_list":["post-66417","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.9 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction - All About Cardiovascular System and Disorders<\/title>\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\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction - All About Cardiovascular System and Disorders\" \/>\n<meta property=\"og:description\" content=\"Prinzmetal angina (also known as variant angina) is a fascinating clinical phenomenon because it flips the &#8220;standard&#8221; model of heart disease on its head. While typical angina is caused by a supply-and-demand mismatch due to a fixed, physical blockage (atherosclerosis), Prinzmetal angina is caused by a transient, functional obstruction. Here is how the coronary artery [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/\" \/>\n<meta property=\"og:site_name\" content=\"All About Cardiovascular System and Disorders\" \/>\n<meta property=\"article:published_time\" content=\"2026-03-15T01:47:35+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-03-15T01:47:37+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2026\/03\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1200\" \/>\n\t<meta property=\"og:image:height\" content=\"678\" \/>\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=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/\"},\"author\":{\"name\":\"Johnson Francis\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#\\\/schema\\\/person\\\/5441d907049b914770f4bd98fb57feec\"},\"headline\":\"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction\",\"datePublished\":\"2026-03-15T01:47:35+00:00\",\"dateModified\":\"2026-03-15T01:47:37+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/\"},\"wordCount\":574,\"publisher\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#\\\/schema\\\/person\\\/5441d907049b914770f4bd98fb57feec\"},\"image\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg\",\"articleSection\":[\"General Cardiology\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/\",\"name\":\"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction - All About Cardiovascular System and Disorders\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg\",\"datePublished\":\"2026-03-15T01:47:35+00:00\",\"dateModified\":\"2026-03-15T01:47:37+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#primaryimage\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg\",\"contentUrl\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/wp-content\\\/uploads\\\/2026\\\/03\\\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg\",\"width\":1200,\"height\":678},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#website\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/\",\"name\":\"All About Cardiovascular System and Disorders\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#\\\/schema\\\/person\\\/5441d907049b914770f4bd98fb57feec\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":[\"Person\",\"Organization\"],\"@id\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/#\\\/schema\\\/person\\\/5441d907049b914770f4bd98fb57feec\",\"name\":\"Johnson Francis\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g\",\"caption\":\"Johnson Francis\"},\"logo\":{\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g\"},\"description\":\"Former Professor of Cardiology, Calicut Govt. Medical Kozhikode, Kerala, India. Editor-in-Chief, BMH Medical Journal\",\"url\":\"https:\\\/\\\/johnsonfrancis.org\\\/professional\\\/author\\\/jf\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction - All About Cardiovascular System and Disorders","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/","og_locale":"en_US","og_type":"article","og_title":"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction - All About Cardiovascular System and Disorders","og_description":"Prinzmetal angina (also known as variant angina) is a fascinating clinical phenomenon because it flips the &#8220;standard&#8221; model of heart disease on its head. While typical angina is caused by a supply-and-demand mismatch due to a fixed, physical blockage (atherosclerosis), Prinzmetal angina is caused by a transient, functional obstruction. Here is how the coronary artery [&hellip;]","og_url":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/","og_site_name":"All About Cardiovascular System and Disorders","article_published_time":"2026-03-15T01:47:35+00:00","article_modified_time":"2026-03-15T01:47:37+00:00","og_image":[{"width":1200,"height":678,"url":"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2026\/03\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg","type":"image\/jpeg"}],"author":"Johnson Francis","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Johnson Francis","Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#article","isPartOf":{"@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/"},"author":{"name":"Johnson Francis","@id":"https:\/\/johnsonfrancis.org\/professional\/#\/schema\/person\/5441d907049b914770f4bd98fb57feec"},"headline":"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction","datePublished":"2026-03-15T01:47:35+00:00","dateModified":"2026-03-15T01:47:37+00:00","mainEntityOfPage":{"@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/"},"wordCount":574,"publisher":{"@id":"https:\/\/johnsonfrancis.org\/professional\/#\/schema\/person\/5441d907049b914770f4bd98fb57feec"},"image":{"@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#primaryimage"},"thumbnailUrl":"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2026\/03\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg","articleSection":["General Cardiology"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/","url":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/","name":"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction - All About Cardiovascular System and Disorders","isPartOf":{"@id":"https:\/\/johnsonfrancis.org\/professional\/#website"},"primaryImageOfPage":{"@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#primaryimage"},"image":{"@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#primaryimage"},"thumbnailUrl":"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2026\/03\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg","datePublished":"2026-03-15T01:47:35+00:00","dateModified":"2026-03-15T01:47:37+00:00","breadcrumb":{"@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#primaryimage","url":"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2026\/03\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg","contentUrl":"https:\/\/johnsonfrancis.org\/professional\/wp-content\/uploads\/2026\/03\/How-Coronary-Artery-Spasms-cause-Prinzmetals-Angina-without-permanent-vessel-obstruction.jpg","width":1200,"height":678},{"@type":"BreadcrumbList","@id":"https:\/\/johnsonfrancis.org\/professional\/how-coronary-artery-spasms-cause-prinzmetal-angina-without-permanent-vessel-obstruction\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/johnsonfrancis.org\/professional\/"},{"@type":"ListItem","position":2,"name":"How Coronary Artery Spasms cause Prinzmetal Angina without permanent vessel obstruction"}]},{"@type":"WebSite","@id":"https:\/\/johnsonfrancis.org\/professional\/#website","url":"https:\/\/johnsonfrancis.org\/professional\/","name":"All About Cardiovascular System and Disorders","description":"","publisher":{"@id":"https:\/\/johnsonfrancis.org\/professional\/#\/schema\/person\/5441d907049b914770f4bd98fb57feec"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/johnsonfrancis.org\/professional\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":["Person","Organization"],"@id":"https:\/\/johnsonfrancis.org\/professional\/#\/schema\/person\/5441d907049b914770f4bd98fb57feec","name":"Johnson Francis","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g","caption":"Johnson Francis"},"logo":{"@id":"https:\/\/secure.gravatar.com\/avatar\/80861b82c3f559be9e413245c5643b6c483c93495507facfe32cf96ccd8bcffd?s=96&d=mm&r=g"},"description":"Former Professor of Cardiology, Calicut Govt. Medical Kozhikode, Kerala, India. Editor-in-Chief, BMH Medical Journal","url":"https:\/\/johnsonfrancis.org\/professional\/author\/jf\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/posts\/66417","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/comments?post=66417"}],"version-history":[{"count":5,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/posts\/66417\/revisions"}],"predecessor-version":[{"id":66426,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/posts\/66417\/revisions\/66426"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/media\/66418"}],"wp:attachment":[{"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/media?parent=66417"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/categories?post=66417"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/johnsonfrancis.org\/professional\/wp-json\/wp\/v2\/tags?post=66417"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}