{"id":8509,"date":"2021-04-12T21:09:56","date_gmt":"2021-04-12T21:09:56","guid":{"rendered":"https:\/\/medicalcriteria.com\/web\/?p=8509"},"modified":"2026-01-06T20:31:24","modified_gmt":"2026-01-06T20:31:24","slug":"acute-myocardial-infarction-lbbb","status":"publish","type":"post","link":"https:\/\/medicalcriteria.com\/web\/acute-myocardial-infarction-lbbb\/","title":{"rendered":"Criteria for Acute Myocardial Infarction in the Left Bundle Branch Block"},"content":{"rendered":"<div class=\"99c380e4b4a7b96c35d7ddf7dcb434e8\" data-index=\"1\" style=\"float: none; margin:0px 0 0px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<!-- MC 2019- Horizontal -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-client=\"ca-pub-0127150553352455\"\r\n     data-ad-slot=\"3806776041\"\r\n     data-ad-format=\"auto\"\r\n     data-full-width-responsive=\"true\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p>In the Emergency Department, the diagnosis of acute myocardial infarction (AMI) relies initially on a patient\u2019s history and the 12-lead electrocardiogram (ECG). Establishing the diagnosis of AMI in the left bundle branch block (LBBB) is difficult and can result in delay of definitive treatment. In 1996, Sgarbossa found 3 ECG criteria to evaluate for AMI in patients with LBBB.<!--more--><\/p>\n<p><strong>Sgarbossa Criteria for Acute Myocardial Infarction in the Left Bundle Branch Block<\/strong><\/p>\n<p>Three criteria are included in Sgarbossa&#8217;s criteria:<\/p>\n<table style=\"border-collapse: collapse; width: 100%; height: 96px;\" border=\"1\">\n<tbody>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73.8295%; height: 24px;\"><strong>Criteria<\/strong><\/td>\n<td style=\"width: 26.1705%; height: 24px; text-align: center;\"><strong>Points<\/strong><\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73.8295%; height: 24px;\">Concordant\u00a0ST elevation \u22651 mm in a lead with a positive QRS complex<\/td>\n<td style=\"width: 26.1705%; height: 24px; text-align: center;\">5 points<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73.8295%; height: 24px;\">Concordant ST depression \u22651 mm in lead V1, V2, or V3<\/td>\n<td style=\"width: 26.1705%; height: 24px; text-align: center;\">3 points<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73.8295%; height: 24px;\">Discordant ST elevation \u22655 mm in a lead with a negative QRS complex<\/td>\n<td style=\"width: 26.1705%; height: 24px; text-align: center;\">2 points<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u22653 points = 90% specificity of STEMI (sensitivity of 36%)<\/p>\n<p><strong>Smith-modified Sgarbossa Criteria for Acute Myocardial Infarction in the Left Bundle Branch Block<\/strong><\/p>\n<p>Patients with LBBB of unknown onset presenting with chest pain can pose a diagnostic challenge in the ED while Smith-Modified-Sgarbossa (SMS) ECG criteria might facilitate AMI diagnosis.<\/p>\n<p>The use of a 5 mm cut-off for excessive discordance was arbitrary and non-specific \u2014 for example, patients with LBBB and large voltages will commonly have ST deviations &gt; 5 mm in the absence of ischaemia. The modified rule is positive for \u201cSTEMI\u201d if there is discordant ST elevation with amplitude &gt; 25% of the depth of the preceding S-wave.<\/p>\n<ul>\n<li>Concordant ST elevation \u2265 1 mm in \u2265 1 lead<\/li>\n<li>Concordant ST depression \u2265 1 mm in \u2265 1 lead of V1-V3<\/li>\n<li>Proportionally excessive discordant ST elevation (STE) in \u2265 1 lead anywhere with \u2265 1 mm STE, as defined by \u2265 25% of the depth of the preceding S-wave<\/li>\n<\/ul>\n<p>Patients with LBBB of unknown onset presenting with chest pain can pose a diagnostic challenge in the ED while Smith-Modified-Sgarbossa (SMS) ECG criteria might facilitate AMI diagnosis.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>References:<\/strong><\/p>\n<ol>\n<li>Di Marco A, Rodriguez M, Cinca J, Bayes-Genis A, Ortiz-Perez JT, Ariza-Sol\u00e9 A, Sanchez-Salado JC, Sionis A, Rodriguez J, Toledano B, Codina P, Sol\u00e9-Gonz\u00e1lez E, Masotti M, G\u00f3mez-Hospital JA, Cequier \u00c1, Anguera I. New Electrocardiographic Algorithm for the Diagnosis of Acute Myocardial Infarction in Patients With Left Bundle Branch Block. J Am Heart Assoc. 2020 Jul 21;9(14):e015573. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/32627643\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<li>Macfarlane PW. New ECG Criteria for Acute Myocardial Infarction in Patients With Left Bundle Branch Block. J Am Heart Assoc. 2020 Jul 21;9(14):e017119. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/32627635\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<li>Sgarbossa EB, Pinski SL, Barbagelata A, Underwood DA, Gates KB, Topol EJ, Califf RM, Wagner GS. Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators. N Engl J Med. 1996 Feb 22;334(8):481-7. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/8559200\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<li>Borovac JA, Orsolic A, Miric D, Glavas D. The use of Smith-modified Sgarbossa criteria to diagnose an extensive anterior acute myocardial infarction in a patient presenting with a left bundle branch block. J Electrocardiol. 2021 Jan-Feb;64:80-84. <a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/33359958\/\" target=\"_blank\" rel=\"noopener noreferrer\">[Medline]<\/a><\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<p>Created: Apr 09, 2021.<\/p>\n\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Sorry, this entry is only available in Espa\u00f1ol.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"no","_lmt_disable":"no","_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[26],"tags":[231,593,2341,2342,2340,2339,16,15,350,349,1476,1475,347,346,2343,2338],"class_list":["post-8509","post","type-post","status-publish","format-standard","hentry","category-cardiology","tag-acute","tag-agudo","tag-block","tag-bloqueo","tag-branch","tag-bundle","tag-criteria","tag-criterios","tag-infarction","tag-infarto","tag-izquierda","tag-left","tag-miocardio","tag-myocardial","tag-rama","tag-sgarbossa"],"modified_by":"Guillermo Firman","_links":{"self":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts\/8509","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/comments?post=8509"}],"version-history":[{"count":11,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts\/8509\/revisions"}],"predecessor-version":[{"id":9474,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/posts\/8509\/revisions\/9474"}],"wp:attachment":[{"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/media?parent=8509"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/categories?post=8509"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/medicalcriteria.com\/web\/wp-json\/wp\/v2\/tags?post=8509"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}