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We developed a 12-lead, blue-tooth\/Smart-Phone (Android) based electrocardiogram (ECG) acquisition and monitoring system (cvrPhone), and an application to estimate RA, in real-time. In <jats:italic>in-vivo<\/jats:italic> swine studies (N\u2009=\u200917), 12-lead ECG signals were recorded at baseline and following coronary artery occlusion. RA was estimated using the Fast Fourier Transform (FFT) method using a custom developed algorithm in JAVA. Underlying ischemia was detected using a custom developed ischemic index. RA from each lead showed a significant (p\u2009&lt;\u20090.05) increase within 1\u2009min of occlusion compared to baseline (n\u2009=\u200929). Following myocardial infarction, spontaneous ventricular tachycardia episodes (n\u2009=\u20094) were preceded by significant (p\u2009&lt;\u20090.05) increase of RA prior to the onset of the tachy-arrhythmias. Similarly, the ischemic index exhibited a significant increase following myocardial infarction (p\u2009&lt;\u20090.05) and preceding a tachy-arrhythmic event. In conclusion, RA can be effectively estimated using surface lead electrocardiograms by analyzing beat-to-beat variability in ECG morphology using a smartphone based platform. cvrPhone can be used to detect myocardial ischemia and arrhythmia susceptibility using a user-friendly, clinically acceptable, mobile platform.<\/jats:p>","DOI":"10.1038\/s41598-019-50487-4","type":"journal-article","created":{"date-parts":[[2019,10,10]],"date-time":"2019-10-10T10:32:32Z","timestamp":1570703552000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Utility of a Smartphone Based System (cvrPhone) to Predict Short-term Arrhythmia Susceptibility"],"prefix":"10.1038","volume":"9","author":[{"given":"Kwanghyun","family":"Sohn","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven P.","family":"Dalvin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Faisal M.","family":"Merchant","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3185-0484","authenticated-orcid":false,"given":"Kanchan","family":"Kulkarni","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Furrukh","family":"Sana","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5033-8881","authenticated-orcid":false,"given":"Shady","family":"Abohashem","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jagmeet P.","family":"Singh","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E. Kevin","family":"Heist","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chris","family":"Owen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric M.","family":"Isselbacher","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonis A.","family":"Armoundas","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2019,10,10]]},"reference":[{"key":"50487_CR1","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1038\/307159a0","volume":"307","author":"AL Ritzenberg","year":"1984","unstructured":"Ritzenberg, A. L., Adam, D. R. & Cohen, R. J. Period multupling-evidence for nonlinear behaviour of the canine heart. 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