Abstract
Purpose
A paucity of information exists to validate the accuracy and reliability of ECG monitoring in the operating room or ICU. The purpose of this study was to determine the accuracy, sensitivity, specificity, and predictive values of the Marquette ECG monitor for detection of perioperative myocardial ischaemia (PMI) as measured by ST segment changes in a high risk population.
Methods
Monitoring for PMI in 28 patients scheduled for aortocoronary bypass surgery was done with the Cardiodata PR® ambulatory continuous electrocardiography (ACECG) monitor lead V5, and compared with lead V5 of the Marquette® Series 7000 ECG/ Surgical operating room monitor, and ECG/Resp ICU monitor. The Marquette lead V5 was evaluated using current criteria for the assessment of diagnostic tests including concordance, sensitivity, specificity, positive and negative predictive values, false positive and false negative rates and compared with the ACECG monitor which served as the reference or “gold standard.” Agreement beyond chance between the two methods was assessed using the Kappa statistic.
Results
Of the 53 observation data points, 27 were defined as ischaemic episodes by ACECG. Concordance between lead V5 in each system was 83% (44/53 episodes). Discordance was 17% (9/53 episodes), predominantly in the postbypass interval (77%, 7/9; P = 0.0184). The incidences of false negatives and false positives for Marquette lead V5 was 26% (7/27) and 7.7% ( 2/26), respectively. The sensitivity and specificity of the Marquette was 0.74 and 0.92. Positive predictive value was 0.91, negative predictive value was 0.77, and Kappa statistic was 66%.
Conclusion
Automated ST segment analysis with the Marquette® Series 7000 monitoring system demonstrates good diagnostic accuracy, moderate sensitivity, and high specificity. However, clinically significant false negative and false positive rates of ischaemia detection are associated with its use, especially in the postoperative period.
Résumé
Objectif
Peu de données nous permettent de valider la précision et la fiabilité du monitorage électrocardiographique en salle d’opération et à l’unité des soins intensifs. Cette étude avait pour but de déterminer dans une population à haut risque, la précision, la sensibilité, la spécificité et la valeur prédictrice du moniteur d’ECG Marquette destiné à la détection de l’ischémie myocardique périopératoire (IMP) telle que mesurée par les altérations du segment ST.
Méthodes
Chez 28 patients programmés pour une chirurgie de revascularisation myocardique, l’IMP était monitorisée par électrocardiographie ambulatoire continue (ECGAC) à l’aide d’un appareil Cardiodata PR® en dérivation V5, pour fin de comparaison à la dérivation V5 d’un moniteur ECG de salle d’opération et d’un moniteur ECG/Resp de soins intensifs Marquette® Series 7000. La dérivation V5 du Marquette était comparée aux critères en vigueur pour l’évaluation des épreuves diagnostiques dont la concordance, la sensibilité, la spécificité, les valeurs prédictrices négatives et positives, le taux de faux positifs et de faux négatifs. L’accord entre les deux méthodes était évaluée par statistique Kappa.
Résultats
Des 53 épisodes observés, 27 ont été décrits par l’ECGAC comme des épisodes ischémiques. La concordance entre la dérivation V5 de chaque système était 83% (44/53 épisodes). La discordance était 17% (9/53 épisodes), avec prédominance pendant l’intervalle post-CEC (77%, 7/9; P =0,0184). Avec le V5 du Marquette, l’incidence de faux négatifs et de faux positifs était respectivement de 26% (7/27) et de 7,7% (2/26). La sensibilité et la spécificité du Marquette étaient de 0,74 et de 0,92. La valeur prédictrice positive était 0,91, et négative, 0,77. La statistique Kappa était calculée à 66%.
Conclusion
L’analyse automatisée du segment ST avec un système de monitorage Marquette Series 7000 est précise, modérément sensible et hautement spécifique. Cependant, un taux cliniquement important de faux négatifs et de faux positifs est associé à son utilisation surtout à la période postopératoire.
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Ansley, D.M., O’Connor, J.P., Merrick, P.M. et al. On line ST-segment analysis for detection of myocardial ischaemia during and after coronary revascularization. Can J Anaesth 43, 995–1000 (1996). https://doi.org/10.1007/BF03011899
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DOI: https://doi.org/10.1007/BF03011899