Validation of V4 lead of portable unipolar ECG monitoring with 12 lead ECG record

V diplomskem delu smo validirali enokanalni EKG aparat, namenjen snemanju v domačem okolju. V raziskavo smo vključili 35 bolnikov, obravnavanih v enoti nujne medicinske pomoči, z vključitvenim kriterijem bolečine v prsih. Pri 15 bolnikih so bile diagnosticirane elevacije ali druge nepravilnosti ST spojnice, pri 12 bolnikih odsotnost P valov v večini primerov zaradi atrijske fibrilacije. Ugotavljali smo, ali so si bolniki sposobni sami posneti EKG s prenosnim snemalnikom OMRON HCG 801. Uspešno si ga je posnelo 92% preiskovancev z akutnimi srčnimi težavami. Posnete EKG zapise smo primerjali z zlatim standardom — posnetkom na 12 kanalnem defibrilatorju Lifepak 12, Medtronic. Primerjavo smo napravili s statističnim testom korelacije in Bland Altman statistično metodo ujemanja dveh meritev. Rezultati kažejo visoko stopnjo korelacije med EKG posnetkom 12 kanalnega EKG in posnetkom prenosnega EKG snemalnika. Frekvenca srca korelira s korelacijskim koeficientom 76% (CI=0,57 — 0,88), Bland Altman pa vse izmerjene vrednosti frekvence srca, razen dveh, vključuje v ± dvakratno vrednost standardnega odstopanja. Senzitivnost Omron snemalnika za prepoznavo P valov je znašala 81% (CI=0,58 — 0,95), specifičnost 100% in površina pod ROC krivuljo 90%. Tudi pri primerjavi posameznih odsekov EKG krivulje smo ugotovili visoko stopnjo korelacije. Dolžine PR intervalov so korelirale s korelacijskim koeficientom 91%, širine QRS kompleksov z 89% koeficientom ujemnja ter QT intervali s 94% koeficientom ujemanja. Statistična analiza ujemanja z Bland Altman metodo je pokazala, da so vse dolžine PR intervala pridobljene s prenosnim snemalnikom znotraj dvakratne vrednosti standardnega odstopanja. Širine QRS kompleksov so bile izven dvakratne vrednosti standardnega odstopanja v dveh primerih, dolžine QT intervala pa v treh. Pri ugotavljanju prepoznavnosti aritmij iz enokanalnega EKG posnetka smo ugotovili, da je senzitivnost izkušenega dravstvenega delavca v NMP za prepoznavo atrijske fibrilacije 90% ter specifičnost 96%. Za prepoznavo elevacij ST spojnice je senzitivnost 80% in specifičnost 90%. Iz naše pilotske študije lahko zaključimo, da je enokanalni EKG snemalnik ustrezno orodje za hitro diagnostiko EKG ritmov.In the thesis we validated a single ECG machine, intended for recording at home. The study included 35 patients treated in the emergency medical unit, with the assimilation criteria of chest pain. At 15 patients elevation or other irregularities ST joints were diagnosed . At 12 patients the absence of P waves in most cases were diagnosed because of atrial fibrillation. We examined if the patients are able to record ECG themselves with a portable recorder Omron HCG 801. 92% of persons with acute heart problems were successful. Recorded ECG records were compared with the gold standard - with 12-channel recordings of Lifepak 12, Medtronic. Comparison was made with the statistical test of correlation and Bland Altman statistical method of data plotting. The results show a high degree of correlation between the ECG recording of 12 lead ECG and leadless ECG recorder. Heart rate correlates with a correlation coefficient of 76% (CI = 0.57 to 0.88), Bland Altman all measured values of heart rate, except two, include the double value ± standard deviation. Omron recorder sensitivity to identify the P wave was 81% (CI = 0.58 to 0.95), specificity of 100% and area under the ROC curve of 90%. Even when comparing the individual sections of the ECG curve, we found a high degree of correlation. PR interval lengths correlated with a correlation coefficient of 91%, QRS complex width 89% and QT interval width 94%. Statistical analysis of correlation with the Bland Altman method showed that the length of PR interval obtained with a portable recorder was inside double of the standard deviation values. Width of the QRS complexes have been out of double standard deviation values in two cases and the length of the QT interval in three. In determining the visibility of arrhythmias from single-channel ECG recording we found that the sensitivity of an experienced health worker in NMP to identify atrial fibrillation is 90% and specificity 96%. Sensitivity for the identification of ST elevation joints is 80% and specificity 90%. From our pilot study we can conclude that the single-channel ECG recorder is an appropriate tool for the rapid diagnosis of ECG rhythms