{"id":3956,"date":"2026-02-13T18:42:07","date_gmt":"2026-02-14T00:42:07","guid":{"rendered":"https:\/\/drakarlacastolo.com\/?p=3956"},"modified":"2026-02-13T18:42:09","modified_gmt":"2026-02-14T00:42:09","slug":"ecg-smartwatches","status":"publish","type":"post","link":"https:\/\/drakarlacastolo.com\/en\/blog\/technology-news\/ecg-smartwatches\/","title":{"rendered":"Smartwatches and ECGs at home: what are they for and when to consult them?"},"content":{"rendered":"<p>ECG-enabled smartwatches (Apple Watch, some Galaxy Watches and the like) can be very useful...if you understand <strong>what they are used for<\/strong> and, above all, <strong>why NOT<\/strong>. The typical mistake is to use the watch as the \u201cdefinitive diagnosis\u201d or, conversely, to ignore it altogether.<\/p>\n\n\n\n<p>Think of it this way: the watch can help you to <strong>capture a rhythm<\/strong> at the right time. Medicine decides the diagnosis with the context, symptoms and clinical studies.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">The most important<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The ECG of the watch is <strong>single-tap<\/strong>can help detect some rhythms (especially atrial fibrillation), but does not replace a clinical 12-lead ECG.<\/li>\n\n\n\n<li>The watch <strong>does not rule out heart attack<\/strong>, does not \u201cmeasure arteries\u201d and may fail due to artifact (movement, bad contact, bad signal).<\/li>\n\n\n\n<li>If there are relevant symptoms (chest pain, fainting, marked shortness of breath) the decision does not depend on the watch: consultation\/emergency.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">What does an \u201cECG\u201d watch actually measure?\u201d<\/h2>\n\n\n\n<p>There are two distinct functions that are confused:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1) Irregular pulse notifications (PPG)<\/h3>\n\n\n\n<p>The watch uses light to estimate the pulse and can alert \u201cirregular rhythm\u201d. This <strong>not ECG<\/strong>is a screening. It can be triggered by motion, misreading or extrasystoles.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2) ECG on the clock (when you activate it)<\/h3>\n\n\n\n<p>Here a \u201clead I\u201d (single lead) type trace is recorded. In several devices, the main objective is <strong>classifying rhythms compatible with atrial fibrillation vs. regular\/sinus rhythm<\/strong>, and the result is informative, not a complete diagnosis.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What it DOES work for (clinically useful use)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Capture an episode that \u201cdoesn't come up\u201d in a query<\/h3>\n\n\n\n<p>If your symptoms are intermittent (palpitations, \u201cjumpy\u201d feeling, brief tachycardia), the watch can help record what was happening <strong>at that time<\/strong>. Then you confirm it with evaluation.<\/p>\n\n\n\n<p>Lean on: <a href=\"https:\/\/drakarlacastolo.com\/en\/blog\/diagnostic-evaluation\/palpitations-common-causes-and-when-to-worry\/\">Palpitations: common causes and when to worry about them<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Suspected atrial fibrillation<\/h3>\n\n\n\n<p>If the watch repeats irregularity alerts or an ECG from the watch suggests atrial fibrillation, it may be a signal to confirm with medical study (ECG, Holter) and decide on management.<\/p>\n\n\n\n<p>For context: <a href=\"https:\/\/drakarlacastolo.com\/en\/blog\/cardiac-conditions\/atrial-fibrillation-arrhythmias\/\">Arrhythmias: atrial fibrillation<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Symptom and trigger tracking<\/h3>\n\n\n\n<p>Although the algorithm does not \u201cdiagnose,\u201d a consistent record (time, activity, caffeine\/alcohol, stress, sleep) goes a long way in guiding the study.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What it is NOT good for (and this is where people get into trouble)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Not useful to rule out infarction<\/h3>\n\n\n\n<p>You can have chest pain with a \u201cnormal\u201d ECG on the watch and still require evaluation. If there is chest pain\/oppression, do not negotiate with the watch.<\/p>\n\n\n\n<p>Internal reference: <a href=\"https:\/\/drakarlacastolo.com\/en\/blog\/emergencies\/chest-pain-in-an-emergency\/\">Chest pain: when is it an emergency?<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">It does not serve to \u201ccertify\u201d that all is well.<\/h3>\n\n\n\n<p>A single-lead ECG can be \u201cregular\u201d and still exist:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>intermittent arrhythmias that did not occur in that minute,<\/li>\n\n\n\n<li>structural problems,<\/li>\n\n\n\n<li>undetected hypertension,<\/li>\n\n\n\n<li>or non-cardiac causes that also matter.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">It is not useful for adjusting medications on your own<\/h3>\n\n\n\n<p>Anticoagulants, antiarrhythmics or beta-blockers are not decided by a notification.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How to use the watch ECG to really help<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Register when you have symptoms<\/strong>, not \u201cout of curiosity\u201d all day long.<\/li>\n\n\n\n<li>If you get warning\/reading, repeat <strong>2-3 times<\/strong> at rest (if you are stable).<\/li>\n\n\n\n<li><strong>Save\/export PDF<\/strong> or capture and annotate:\n<ul class=\"wp-block-list\">\n<li>date and time,<\/li>\n\n\n\n<li>what you were doing,<\/li>\n\n\n\n<li>symptoms (palpitations, dizziness, shortness of breath, pain),<\/li>\n\n\n\n<li>coffee\/energy\/alcohol, poor sleep, stress.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>If there are frequent episodes or doubts, don't just say \u201cI got scared\u201d: take him\/her for consultation.<\/li>\n<\/ol>\n\n\n\n<p>If you need studies, here are the routes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/studies\/electrocardiogram-echocardiogram\/\">Electrocardiogram (ECG)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/studies\/24h-holter-echocardiography\/\">Holter ECG 24h<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/studies\/?utm_source=chatgpt.com\">Cardiological studies<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">When to consult (even if the clock is not \u201cticking\u201d)<\/h2>\n\n\n\n<p>Query if:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>repeated, sustained palpitations or palpitations with discomfort,<\/li>\n\n\n\n<li>episodes with dizziness, near fainting or fainting,<\/li>\n\n\n\n<li>new shortness of breath on exertion or at rest,<\/li>\n\n\n\n<li>family history of arrhythmias\/early cardiovascular events,<\/li>\n\n\n\n<li>repeated \u201cirregular rhythm\u201d alerts or clock ECG suggestive of atrial fibrillation.<\/li>\n<\/ul>\n\n\n\n<p>Support guides:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/blog\/diagnostic-evaluation\/dizziness-and-fainting-syncope-causes-and-cardiology-study\/\">Dizziness and fainting: syncope<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/blog\/cardiac-conditions\/shortness-of-breath-when-it-is-of-the-heart\/\">Shortness of breath: when it may be heart-related<\/a><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">When is urgency (not \u201cschedule when you can\u201d)<\/h2>\n\n\n\n<p>If there is <strong>chest pain\/pressure<\/strong>, If you experience severe shortness of breath, sudden weakness, confusion, fainting, or rapidly worsening symptoms, treat it as an emergency regardless of the clock.<\/p>\n\n\n\n<p>Lean on: <a href=\"https:\/\/drakarlacastolo.com\/en\/blog\/emergencies\/chest-pain-in-an-emergency\/\">Chest pain: when is it an emergency?<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What the appraisal usually includes (to leave with a plan, not with more doubts)<\/h2>\n\n\n\n<p>In consultation is integrated:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>history of symptoms + triggers,<\/li>\n\n\n\n<li>examination and blood pressure,<\/li>\n\n\n\n<li>review of clock traces (if available),<\/li>\n\n\n\n<li>and, as the case may be, studies such as:\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/studies\/electrocardiogram-echocardiogram\/\">Electrocardiogram (ECG)<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/studies\/24h-holter-echocardiography\/\">Holter ECG 24h<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/drakarlacastolo.com\/en\/studies\/doppler-echocardiogram\/\">Doppler echocardiogram<\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>If the goal is to integrate all risk and not just \u201cone symptom\u201d, this also applies: <a href=\"https:\/\/drakarlacastolo.com\/en\/cardiac-checkup\/\">Cardiac checkup<\/a> y <a href=\"https:\/\/drakarlacastolo.com\/en\/cardiology-consultation\/\">Cardiology consultation<\/a>.<\/p>\n\n\n\n<p>Practical closing: if your watch is causing you doubts (due to symptoms or alerts), the most efficient thing to do is to review your case with your medical history and decide on the correct study. You can <a href=\"https:\/\/drakarlacastolo.com\/en\/contact\/?utm_source=chatgpt.com\">schedule an appointment here<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">References<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/www.accessdata.fda.gov\/cdrh_docs\/reviews\/DEN180044.pdf?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">FDA - Apple ECG App (De Novo DEN180044): Indications and Scope<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.accessdata.fda.gov\/cdrh_docs\/reviews\/DEN180042.pdf?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">FDA - Apple Irregular Rhythm Notification Feature (De Novo DEN180042): suggestive detection of AFib<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/www.accessdata.fda.gov\/cdrh_docs\/pdf20\/K201168.pdf?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">FDA - Samsung ECG Monitor App (510(k) K201168): Single-lead ECG and limitations<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1002\/ejhf.2194?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">European Journal of Heart Failure - Can we trust a smartwatch ECG? Potential and limitations <\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC8854369\/?utm_source=chatgpt.com\" target=\"_blank\" rel=\"noopener\">NIH\/PMC - Smartwatch ECGs: Performance and Challenges (2022 Review)<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Los relojes inteligentes con ECG (Apple Watch, algunos Galaxy Watch y similares) pueden ser muy \u00fatiles\u2026 si entiendes para qu\u00e9 sirven y, sobre todo, para qu\u00e9 NO. El error t\u00edpico es usar el reloj como \u201cdiagn\u00f3stico definitivo\u201d o, al rev\u00e9s, ignorarlo por completo. Pi\u00e9nsalo as\u00ed: el reloj puede ayudarte a capturar un ritmo en el [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[44],"tags":[],"class_list":["post-3956","post","type-post","status-publish","format-standard","hentry","category-tecnologia-actualidad"],"acf":[],"_links":{"self":[{"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/posts\/3956","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/comments?post=3956"}],"version-history":[{"count":1,"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/posts\/3956\/revisions"}],"predecessor-version":[{"id":3957,"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/posts\/3956\/revisions\/3957"}],"wp:attachment":[{"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/media?parent=3956"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/categories?post=3956"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/drakarlacastolo.com\/en\/wp-json\/wp\/v2\/tags?post=3956"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}