The Mystery of the Missing P Waves

The Mystery of the Missing P Waves | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report The Mystery of the Missing P Waves yuanguo chen, Haibo Zhang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4579897/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This case report discusses a 60-year-old female with a history of rheumatic heart disease, mitral stenosis, and atrial fibrillation, who presented with fatigue and was discovered to have significant bradycardia without visible P waves on ECG. The diagnosis and management involving electrophysiological studies highlight the complexities of treating atrial arrhythmias in the presence of mechanical valve replacements and extensive atrial fibrosis. Atrial Flutter Electrophysiological Study (EPS) Radiofrequency Ablation Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The patient, a 60-year-old woman with a complex cardiac history including rheumatic heart disease, mitral stenosis, and previous surgical interventions such as mitral valve replacement and Maze procedure for atrial fibrillation, was managed on long-term warfarin therapy. Her presentation of fatigue and unusual ECG findings posed a diagnostic challenge. Case Presentation Upon admission, the patient's INR was 2.1, and she exhibited bradycardia with a heart rate of approximately 47 bpm. Initial investigations with a 12-lead ECG (Fig. 1 A) and modified Lewis lead ECG (Fig. 1 B) showed no P waves, raising concerns for sinus arrest or complete atrioventricular block. Holter monitoring further confirmed the bradycardia and recorded a maximum RR interval of up to 7.7 seconds (Fig. 2 ). Diagnostic Assessment The absence of P waves and prolonged RR intervals necessitated an invasive electrophysiological study (EPS), which uncovered atrial flutter and a significant low-voltage area in the right atrium indicative of severe atrial fibrosis (Fig. 3 ). This was critical in understanding the lack of visible atrial activity on the surface ECGs. Therapeutic Intervention: Radiofrequency ablation of the cavotricuspid isthmus was performed, which successfully terminated the atrial flutter, followed by a significant pause of 6082 ms, after which sinus rhythm was restored (Fig. 4 ). Follow-up and Outcomes The patient’s heart rate improved post-procedure to 59 bpm, as observed on a follow-up modified Lewis lead ECG, although P waves were still not visible (Fig. 5 ). The patient reported an improvement in symptoms and was discharged in a stable condition. Discussion This case illustrates the complex interplay between advanced cardiac structural changes and the diagnostic challenges they pose, particularly in the detection and management of atrial arrhythmias. In patients with extensive atrial fibrosis, traditional diagnostic methods like surface ECGs and even enhanced approaches such as the modified Lewis lead ECG 1 may fail to detect atrial activity. This failure is often due to the presence of significant scarring and low-voltage areas within the atrium 2 , as confirmed by the electrophysiological study (EPS) in this patient. The EPS was pivotal, not only in identifying these structural abnormalities but also in uncovering the underlying atrial flutter that was not apparent on the initial ECG assessments 3 . Given the patient's bradycardia and prolonged RR intervals, the initial clinical consideration might typically lean towards pacemaker implantation 4 . This conventional approach, however, could have led to inappropriate treatment and potential complications like pacemaker syndrome 5 , characterized by atrioventricular dyssynchrony. Instead, the EPS guided the therapeutic strategy towards a more precise intervention—radiofrequency ablation of the cavotricuspid isthmus. This procedure successfully restored sinus rhythm and normalized the heart rate to 59 beats per minute, illustrating the critical role of targeted intracardiac interventions in cases where extracardiac cues are misleading. This case reinforces the essential role of thorough electrophysiological evaluations before proceeding with pacemaker implantation in patients with unexplained bradycardia and arrhythmias. By correctly identifying the atrial flutter and addressing it with appropriate ablation, the need for a pacemaker was obviated, thereby avoiding the risk of pacemaker syndrome and highlighting the importance of precision in cardiac arrhythmia management. Such insights are crucial for advancing our understanding and treatment of complex arrhythmias in the context of significant atrial fibrosis, ensuring that interventions are both appropriate and effective. Conclusion Electrophysiological studies provide crucial insights in cases where atrial activity is obscured on standard ECGs, guiding appropriate interventions such as radiofrequency ablation over pacemaker implantation, thereby ensuring synchronized atrial and ventricular contractions and improving patient outcomes. Abbreviations ECG Electrocardiogram INR International Normalized Ratio EPS Electrophysiological Study RR RR Interval Declarations Authors’ contributions YGC drafted and corrected the manuscript, HBZ were involved in investigation and data collection. All authors read and approved the final manuscript for publication. Funding This work was supported by a grant from the Key Science and Technology Project of Ya'an City, with project number 22KJJH0038. Availability of data and materials All relevant data supporting the conclusions of this article are included within the article. Ethics approval and consent to participate This study was approved by the ethics committee, with the approval number 2024010. Written informed consent was obtained from the patient for publication of this case report. Consent for publication Written informed consent was obtained from the individual for the publication of any potentially identifiable images or data included in this article. Competing interests The authors declare no competing interests. During the preparation of this work, the author(s) used ChatGPT-4 to assist in modifying the language and improving the clarity of sentences. The AI was not used to alter the conceptual framework or specific content of the manuscript. After utilizing this tool, the author(s) thoroughly reviewed and edited the content as needed and take full responsibility for the content of the publication. References Peddibhotla B, Ellenbogen KA, Pillai A, Pursuing P, Waves. Circulation. 2024;149:1689–92. Filos D, Tachmatzidis D, Maglaveras N, Vassilikos V, Chouvarda I. Understanding the Beat-to-Beat Variations of P-Waves Morphologies in AF Patients During Sinus Rhythm: A Scoping Review of the Atrial Simulation Studies. Front Physiol. 2019;10. Singh SM, Webster L, Calzavara A, Wijeysundera HC. Validation of Algorithms to Identify Invasive Electrophysiology Procedures Using Administrative Data in Ontario, Canada. Med Care. 2017;55:e44–50. Glikson M, Nielsen JC, Kronborg MB, Michowitz Y, Auricchio A, Barbash IM, Barrabés JA, Boriani G, Braunschweig F, Brignole M, Burri H, Coats AJS, Deharo J-C, Delgado V, Diller G-P, Israel CW, Keren A, Knops RE, Kotecha D, Leclercq C, Merkely B, Starck C, Thylén I, Tolosana JM, Leyva F, Linde C, Abdelhamid M, Aboyans V, Arbelo E, Asteggiano R, Barón-Esquivias G, Bauersachs J, Biffi M, Birgersdotter-Green U, Bongiorni MG, Borger MA, Čelutkienė J, Cikes M, Daubert J-C, Drossart I, Ellenbogen K, Elliott PM, Fabritz L, Falk V, Fauchier L, Fernández-Avilés F, Foldager D, Gadler F, De Vinuesa PGG, Gorenek B, Guerra JM, Hermann Haugaa K, Hendriks J, Kahan T, Katus HA, Konradi A, Koskinas KC, Law H, Lewis BS, Linker NJ, Løchen M-L, Lumens J, Mascherbauer J, Mullens W, Nagy KV, Prescott E, Raatikainen P, Rakisheva A, Reichlin T, Ricci RP, Shlyakhto E, Sitges M, Sousa-Uva M, Sutton R, Suwalski P, Svendsen JH, Touyz RM, Van Gelder IC, Vernooy K, Waltenberger J, Whinnett Z, Witte KK. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. EP Europace . 2022;24:71–164. Schüller H, Brant J, Camm AJ. The pacemaker syndrome: Old and new causes. Clin Cardiol. 2009;14:336–40. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4579897","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":323518922,"identity":"235d2bba-fceb-4c49-b28d-9cf60213656b","order_by":0,"name":"yuanguo chen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzUlEQVRIiWNgGAWjYBACfvb24z8+/rNhZmNvIFKLZM+ZBMkZbGnsfDwHiNRicCPBQJqD7RC/nEQCsS47cyDBmIHngDSb5OONNxhqbKIJ6mBsbzyQXCBxx5hNOq3YguFYWm4DIS3MPAcSDs8weJbMJp1jJsHYcJiwFjaJBMNmnoTD9W2SZ4jUwiORYAy06TAzmwQPkVokeM6kMc5sSGNm4wH6JYEYv9gfbz/G8LHBhlm+/fDGGx9qbAhrQQYGxEcNQgupOkbBKBgFo2BkAADRQD1+lO+IfwAAAABJRU5ErkJggg==","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"yuanguo","middleName":"","lastName":"chen","suffix":""},{"id":323518923,"identity":"dafbf057-ca4f-485a-b0fb-a9f2535225de","order_by":1,"name":"Haibo Zhang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Haibo","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2024-06-14 06:34:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4579897/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4579897/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":60620774,"identity":"5e3e0c4f-c77d-4e85-9f9e-abf1ef6a4f33","added_by":"auto","created_at":"2024-07-18 20:54:57","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1611324,"visible":true,"origin":"","legend":"\u003cp\u003eThe surface ECG showed no visible atrial waves.\u003c/p\u003e\n\u003cp\u003ePanel A: Initial 12-lead ECG showing the absence of P waves, flutter waves (F waves), or fibrillation waves (f waves).\u003c/p\u003e\n\u003cp\u003ePanel B: Modified Lewis lead ECG with no clearly visible P waves.\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-4579897/v1/51a98e5ba7c260fb29e289e2.png"},{"id":60621662,"identity":"608f52ca-7b8a-4623-bb96-0f3ca87351c8","added_by":"auto","created_at":"2024-07-18 21:02:57","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":997537,"visible":true,"origin":"","legend":"\u003cp\u003eHolter monitor results showing no P waves, a ventricular rate around 47 bpm, and the longest cardiac pause of 7.7 seconds occurring at night.\u003c/p\u003e","description":"","filename":"figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-4579897/v1/6dc87fd24b7f80c3e694a9d3.png"},{"id":60620775,"identity":"9f88e30b-1f96-4f34-88d3-d833e93c1ea2","added_by":"auto","created_at":"2024-07-18 20:54:57","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1403063,"visible":true,"origin":"","legend":"\u003cp\u003eInvasive electrophysiological study (EPS) revealing atrial flutter along with a large low-voltage area in the right atrium.\u003c/p\u003e","description":"","filename":"figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-4579897/v1/3edd1e52f39642b34e3be822.png"},{"id":60620777,"identity":"0cc7bce3-6508-4135-a7ee-676ea10c63f1","added_by":"auto","created_at":"2024-07-18 20:54:57","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1369478,"visible":true,"origin":"","legend":"\u003cp\u003ePost-radiofrequency ablation of the cavotricuspid isthmus, showing the termination of atrial flutter, followed by a 6082 ms pause and subsequent restoration of sinus rhythm.\u003c/p\u003e","description":"","filename":"figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-4579897/v1/218b3d0d12160ddf3b2f75f6.png"},{"id":60620778,"identity":"9027d89d-5fc7-46bc-965e-d05f5ceacf2a","added_by":"auto","created_at":"2024-07-18 20:54:57","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1361081,"visible":true,"origin":"","legend":"\u003cp\u003eThe patient's heart rate restored to 59 bpm with sinus rhythm after the procedure.\u003c/p\u003e\n\u003cp\u003ePanel A: Intracardiac recording during the procedure showing the restoration of sinus rhythm.\u003c/p\u003e\n\u003cp\u003ePanel B: Postoperative modified Lewis lead ECG showing a ventricular rate of 59 bpm, still without visible atrial waves.\u003c/p\u003e","description":"","filename":"figure5.png","url":"https://assets-eu.researchsquare.com/files/rs-4579897/v1/d3ed3e2bcc34e3d2c6023255.png"},{"id":69055380,"identity":"481c00fe-d2f7-4871-a74a-800992acae69","added_by":"auto","created_at":"2024-11-15 06:18:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6877085,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4579897/v1/3bb39802-ae8c-4a47-81e7-5ff2bd9ac616.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Mystery of the Missing P Waves","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe patient, a 60-year-old woman with a complex cardiac history including rheumatic heart disease, mitral stenosis, and previous surgical interventions such as mitral valve replacement and Maze procedure for atrial fibrillation, was managed on long-term warfarin therapy. Her presentation of fatigue and unusual ECG findings posed a diagnostic challenge.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003eUpon admission, the patient's INR was 2.1, and she exhibited bradycardia with a heart rate of approximately 47 bpm. Initial investigations with a 12-lead ECG (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eA) and modified Lewis lead ECG (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eB) showed no P waves, raising concerns for sinus arrest or complete atrioventricular block. Holter monitoring further confirmed the bradycardia and recorded a maximum RR interval of up to 7.7 seconds (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\n\u003ch3\u003eDiagnostic Assessment\u003c/h3\u003e\n\u003cp\u003eThe absence of P waves and prolonged RR intervals necessitated an invasive electrophysiological study (EPS), which uncovered atrial flutter and a significant low-voltage area in the right atrium indicative of severe atrial fibrosis (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). This was critical in understanding the lack of visible atrial activity on the surface ECGs.\u003c/p\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eTherapeutic Intervention:\u003c/h2\u003e \u003cp\u003eRadiofrequency ablation of the cavotricuspid isthmus was performed, which successfully terminated the atrial flutter, followed by a significant pause of 6082 ms, after which sinus rhythm was restored (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eFollow-up and Outcomes\u003c/h3\u003e\n\u003cp\u003eThe patient\u0026rsquo;s heart rate improved post-procedure to 59 bpm, as observed on a follow-up modified Lewis lead ECG, although P waves were still not visible (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). The patient reported an improvement in symptoms and was discharged in a stable condition.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis case illustrates the complex interplay between advanced cardiac structural changes and the diagnostic challenges they pose, particularly in the detection and management of atrial arrhythmias. In patients with extensive atrial fibrosis, traditional diagnostic methods like surface ECGs and even enhanced approaches such as the modified Lewis lead ECG\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e may fail to detect atrial activity. This failure is often due to the presence of significant scarring and low-voltage areas within the atrium\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e, as confirmed by the electrophysiological study (EPS) in this patient. The EPS was pivotal, not only in identifying these structural abnormalities but also in uncovering the underlying atrial flutter that was not apparent on the initial ECG assessments\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eGiven the patient's bradycardia and prolonged RR intervals, the initial clinical consideration might typically lean towards pacemaker implantation\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. This conventional approach, however, could have led to inappropriate treatment and potential complications like pacemaker syndrome\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e, characterized by atrioventricular dyssynchrony. Instead, the EPS guided the therapeutic strategy towards a more precise intervention\u0026mdash;radiofrequency ablation of the cavotricuspid isthmus. This procedure successfully restored sinus rhythm and normalized the heart rate to 59 beats per minute, illustrating the critical role of targeted intracardiac interventions in cases where extracardiac cues are misleading.\u003c/p\u003e \u003cp\u003eThis case reinforces the essential role of thorough electrophysiological evaluations before proceeding with pacemaker implantation in patients with unexplained bradycardia and arrhythmias. By correctly identifying the atrial flutter and addressing it with appropriate ablation, the need for a pacemaker was obviated, thereby avoiding the risk of pacemaker syndrome and highlighting the importance of precision in cardiac arrhythmia management. Such insights are crucial for advancing our understanding and treatment of complex arrhythmias in the context of significant atrial fibrosis, ensuring that interventions are both appropriate and effective.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eElectrophysiological studies provide crucial insights in cases where atrial activity is obscured on standard ECGs, guiding appropriate interventions such as radiofrequency ablation over pacemaker implantation, thereby ensuring synchronized atrial and ventricular contractions and improving patient outcomes.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eECG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eElectrocardiogram\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eINR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInternational Normalized Ratio\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEPS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eElectrophysiological Study\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eRR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eRR Interval\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYGC drafted and corrected the manuscript, HBZ were involved in investigation and data collection. All authors read and approved the final manuscript for publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by a grant from the Key Science and Technology Project of Ya\u0026apos;an City, with project number 22KJJH0038.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll relevant data supporting the conclusions of this article are included within the article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the ethics committee, with the approval number 2024010. Written informed consent was obtained from the patient for publication of this case report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the individual for the publication of any potentially identifiable images or data included in this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003eDuring the preparation of this work, the author(s) used ChatGPT-4 to assist in modifying the language and improving the clarity of sentences. The AI was not used to alter the conceptual framework or specific content of the manuscript. After utilizing this tool, the author(s) thoroughly reviewed and edited the content as needed and take full responsibility for the content of the publication.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003ePeddibhotla B, Ellenbogen KA, Pillai A, Pursuing P, Waves. Circulation. 2024;149:1689\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFilos D, Tachmatzidis D, Maglaveras N, Vassilikos V, Chouvarda I. Understanding the Beat-to-Beat Variations of P-Waves Morphologies in AF Patients During Sinus Rhythm: A Scoping Review of the Atrial Simulation Studies. Front Physiol. 2019;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh SM, Webster L, Calzavara A, Wijeysundera HC. Validation of Algorithms to Identify Invasive Electrophysiology Procedures Using Administrative Data in Ontario, Canada. Med Care. 2017;55:e44\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlikson M, Nielsen JC, Kronborg MB, Michowitz Y, Auricchio A, Barbash IM, Barrab\u0026eacute;s JA, Boriani G, Braunschweig F, Brignole M, Burri H, Coats AJS, Deharo J-C, Delgado V, Diller G-P, Israel CW, Keren A, Knops RE, Kotecha D, Leclercq C, Merkely B, Starck C, Thyl\u0026eacute;n I, Tolosana JM, Leyva F, Linde C, Abdelhamid M, Aboyans V, Arbelo E, Asteggiano R, Bar\u0026oacute;n-Esquivias G, Bauersachs J, Biffi M, Birgersdotter-Green U, Bongiorni MG, Borger MA, Čelutkienė J, Cikes M, Daubert J-C, Drossart I, Ellenbogen K, Elliott PM, Fabritz L, Falk V, Fauchier L, Fern\u0026aacute;ndez-Avil\u0026eacute;s F, Foldager D, Gadler F, De Vinuesa PGG, Gorenek B, Guerra JM, Hermann Haugaa K, Hendriks J, Kahan T, Katus HA, Konradi A, Koskinas KC, Law H, Lewis BS, Linker NJ, L\u0026oslash;chen M-L, Lumens J, Mascherbauer J, Mullens W, Nagy KV, Prescott E, Raatikainen P, Rakisheva A, Reichlin T, Ricci RP, Shlyakhto E, Sitges M, Sousa-Uva M, Sutton R, Suwalski P, Svendsen JH, Touyz RM, Van Gelder IC, Vernooy K, Waltenberger J, Whinnett Z, Witte KK. 2021 ESC Guidelines on cardiac pacing and cardiac resynchronization therapy. \u003cem\u003eEP Europace\u003c/em\u003e. 2022;24:71\u0026ndash;164.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSch\u0026uuml;ller H, Brant J, Camm AJ. The pacemaker syndrome: Old and new causes. Clin Cardiol. 2009;14:336\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Atrial Flutter, Electrophysiological Study (EPS), Radiofrequency Ablation","lastPublishedDoi":"10.21203/rs.3.rs-4579897/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4579897/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis case report discusses a 60-year-old female with a history of rheumatic heart disease, mitral stenosis, and atrial fibrillation, who presented with fatigue and was discovered to have significant bradycardia without visible P waves on ECG. The diagnosis and management involving electrophysiological studies highlight the complexities of treating atrial arrhythmias in the presence of mechanical valve replacements and extensive atrial fibrosis.\u003c/p\u003e","manuscriptTitle":"The Mystery of the Missing P Waves","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-18 20:54:52","doi":"10.21203/rs.3.rs-4579897/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5caf408a-f400-4890-9690-a1ec2be04d8b","owner":[],"postedDate":"July 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-11-15T06:09:18+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-18 20:54:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4579897","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4579897","identity":"rs-4579897","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}