On line ST-segment analysis for detection of myocardial ischaemia during and after coronary revascularization

Ansley, David M.; O’Connor, J. P.; Merrick, Pamela M.; Ricci, Donald R.; Dolman, John; Kapnoudhis, Paul

doi:10.1007/bf03011899

Cited by 10 publications

(3 citation statements)

References 15 publications

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“…Ischaemic ECG changes can also be manifested by T wave abnormalities, but the interpretation of any ECG changes in the perioperative period remains difficult, especially after cardiac surgery as was noted by Dr. Ansley et al in their work also published in this issue of the Journal. 26 Concordance between the presence of perioperative ST segment abnormalities and regional wall motion dysfunction on transoesophageal echocardiography (TEE) is far from being perfect. 27,28 Continuous monitoring cannot be considered a gold standard for identifying myocardial ischaemia in this setting and the article by Dr. Ansley et al therefore represents a comparison of systems for the detection of ECG changes and not of myocardial ischaemia per se.…”

Section: Detection Of Perioperative Myocardial Ischaemiamentioning

confidence: 99%

Predicting ischaemic events in the perioperative period: in search of the perfect tool

Tardif

Juneau

1996

Can J Anaesth

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Evaluation of patients with coronary artery disease was for many years relatively straightforward. Angina was recognized when chest pain appeared on exertion and this signified the presence of fixed severe narrowings of epicardial coronary arteries. ~ Standardization of exercise electrocardiographic stress testing led to its widespread clinical use for diagnostic and prognostic purposes. 2 Unfortunately, the syndrome and its assessment later proved to be more complicated. Episodes of myocardial ischaemia without chest pain were recognized and the prognostic importance of silent ischaemia was defined. 3 A form of variant angina occuring primarily at rest and caused by coronary vasospasm was identified. 4 It also became obvious that the pathophysiology of unstable angina and myocardial infarction involved plaque rupture and thrombus formation, and not only vasospasm and clearly not simple progression in the accumulation of atherosclerotic material. 5 The importance of coronary endothelial dysfunction in plaque rupture, platelet adhesion and thrombus fomation also became progressively more apparent. 6 The limitations of electrocardiographic stress testing were also identified, as described in Dr. Yang's review in this issue of the Journal. 7Anatomical and physiological assessment of patients with coronary artery disease Accompanying our better understanding of clinical presentation and pathophysiology w.as the development of many diagnostic tools. Selective coronary angiography enabled clinicians to assess the presence and extent of luminal narrowings in patients. 8 Determination of the clinical importance of coronary stenoses was possible at both ends of the spectrum, but it was eventually recognized that the haemodynamic importance of lesions of intermediate severity was not as readily defined. 9 ConFrom the Department of Medicine, Montreal Heart Institute, 5000 Belanger Street East, Montrtal, Qutbec, Canada H1T1C8. siderable interobserver variability in the interpretation of coronary angiograms represented another limitation? ~ Although the advent of quantitative coronary angiography has reduced the variability of the technique, it has not improved the ability to evaluate the physiological significance of intermediate lesions.Diagnostic methods to assess the physiological relevance of coronary narrowing were developed. Myocardial lactate production was measured during periods of increased oxygen demand, ~ but this technique requiring coronary sinus catheterization has fallen out of interest. Determination of coronary flow reserve, defined as the ratio between hyperaemic and baseline flow, then became possible. Early assessment of the absolute coronary flow reserve was performed after transient arterial occlusion and measurement of hyperemic flow with an electromagnetic flowmeter. 12 It was observed that normal coronary arteries could increase their flow fourfold during hyperaemia, whereas stenosed vessels lost that ability. However, this specific method obviously could not be used clinically.Positive-emission to...

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Section: Detection Of Perioperative Myocardial Ischaemiamentioning

confidence: 99%

Predicting ischaemic events in the perioperative period: in search of the perfect tool

Tardif

Juneau

1996

Can J Anaesth

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“…However, their diagnostic value depends on the appropriate selection and combination of the rules and the method for the extraction of feature values used in the rules. Some rule-based techniques (LACHTERMAN et al, 1990a, b;VELDKAMP et al, 1994;ANSLEY et al, 1996;YANG, 1996) used the ST deviation from the isoelectric line, while others (WATANABE et al, 1980;WEISNER et al, 1982;HSIA et al, 1986) combined the ST deviation with ST segment slope and other parameters like the ST index, ST level and ST integral (or ST area). More specifically, if the slope is lower than a certain threshold and the ST deviation is higher than 0.1 mV then an ischaemic beat is detected.…”

Section: Introductionmentioning

confidence: 99%

A knowledge-based technique for automated detection of ischaemic episodes in long duration electrocardiograms

Papaloukas

Fotiadis

Liavas

et al. 2001

Med. Biol. Eng. Comput.

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A novel method for the detection of ischaemic episodes in long duration ECGs is proposed. It includes noise handling, feature extraction, rule-based beat classification, sliding window classification and ischaemic episode identification, all integrated in a four-stage procedure. It can be executed in real time and is able to provide explanations for the diagnostic decisions obtained. The method was tested on the ESC ST-T database and high scores were obtained for both sensitivity and positive predictive accuracy (93.8% and 78.5% respectively using aggregate gross statistics, and 90.7% and 80.7% using aggregate average statistics).

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“…The V 5 lead is most sensitive to ST-segment changes, capturing 75% of events; V 4 captures about 60% of ST-segment changes; the other precordial locations are significantly less sensitive [ 11 ]. Most electrocardiography systems use computerised ST-segment algorithms that compare the ST-segment and the iso-electric point from the PR-interval [ 12 ]. In addition to electrocardiography, photoplethysmography and intraarterial blood pressure waveforms can be used to derive pulse rate that equals heart rate when the patient has no pulse deficit.…”

Section: Introductionmentioning

confidence: 99%

Haemodynamic monitoring during noncardiac surgery: past, present, and future

Kouz,

Thiele,

Michard

et al. 2024

J Clin Monit Comput

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During surgery, various haemodynamic variables are monitored and optimised to maintain organ perfusion pressure and oxygen delivery – and to eventually improve outcomes. Important haemodynamic variables that provide an understanding of most pathophysiologic haemodynamic conditions during surgery include heart rate, arterial pressure, central venous pressure, pulse pressure variation/stroke volume variation, stroke volume, and cardiac output. A basic physiologic and pathophysiologic understanding of these haemodynamic variables and the corresponding monitoring methods is essential. We therefore revisit the pathophysiologic rationale for intraoperative monitoring of haemodynamic variables, describe the history, current use, and future technological developments of monitoring methods, and finally briefly summarise the evidence that haemodynamic management can improve patient-centred outcomes.

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On line ST-segment analysis for detection of myocardial ischaemia during and after coronary revascularization

Abstract: On line ST-segment analysis for detection of myocardial ischaemia during and after coronary revascularization

Cited by 10 publications

References 15 publications

Predicting ischaemic events in the perioperative period: in search of the perfect tool

Predicting ischaemic events in the perioperative period: in search of the perfect tool

A knowledge-based technique for automated detection of ischaemic episodes in long duration electrocardiograms

Haemodynamic monitoring during noncardiac surgery: past, present, and future

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