Change search
ReferencesLink to record
Permanent link

Direct link
Comparison of hemodynamic, electrocardigraphic, mechanical, and metabolic indicators of intraoperative myocardial ischemia in vascular surgical patients with coronary artery disease.
Umeå University, Faculty of Medicine, Surgical and Perioperative Sciences.
Show others and affiliations
1989 (English)In: Anesthesiology, ISSN 0003-3022, Vol. 70, no 1, 19-25 p.Article in journal (Refereed) Published
Abstract [en]

To compare mechanical, electrocardiographic, and metabolic indices of myocardial ischemia, the cardiokymogram (CKG), the V5 ECG, left anterior descending coronary artery territory lactate extraction, and pulmonary capillary wedge pressure (PCWP) were measured in 53 vascular surgical patients with coronary artery disease. Measurements were performed preoperatively and at four specific intraanesthetic intervals: after tracheal intubation, before surgery, and 10 and 30 min after incision. Measurements and sampling sequence took 5-7 min, and therapy for the probable cause of ischemia was instituted following completion of this sequence. Myocardial ischemia was defined as type II or III CKG, 0.1 mV or greater horizontal or downsloping depression of V5 ECG ST segment, 0.2 mV or greater elevation of V5 ECG ST segment, or myocardial lactate production. Thirty-nine patients (74%) had a total of 89 episodes of myocardial ischemia. Seventy-four episodes (83%) were detected by the CKG, 31 (44%) were evident on the ECG, and 13 (15%) by evidence of lactate production. The concordance among the indices of myocardial ischemia was poor. Patients with an abnormal preoperative ECG experienced a greater number of ischemic episodes (P less than 0.001). Elevation of PCWP or the presence of A-C or V-waves greater than 5 mmHg above the mean did not individually reflect ischemia reliably. Intraoperative myocardial ischemia is common in vascular surgical patients and is most sensitively detected by ventricular wall motion abnormality.

Place, publisher, year, edition, pages
1989. Vol. 70, no 1, 19-25 p.
URN: urn:nbn:se:umu:diva-4702PubMedID: 2912311OAI: diva2:143915
Available from: 2005-09-23 Created: 2005-09-23 Last updated: 2010-02-05Bibliographically approved
In thesis
1. Detection of myocardial ischemia: clinical and experimental studies with focus on vectorcardiography, heart rate and perioperative conditions.
Open this publication in new window or tab >>Detection of myocardial ischemia: clinical and experimental studies with focus on vectorcardiography, heart rate and perioperative conditions.
2005 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Introduction. Multiple clinical methods for detecting myocardial ischemia are utilised in the hospital setting each day, but there is uncertainty about their diagnostic accuracy. In the operating room, multiple methods may be employed, while in the CCU advanced electrophysiological (ECG) techniques for myocardial ischemia detection, and in particular, ST segment analysis, are common. Vectorcardiography (VCG) is one form of ECG.

Several conditions other than ischemia may cause marked ST changes, which can impair the process of diagnosis of clinical ischemia. Elevated HR is one of these factors, which is studied here. The hypotheses were about concordance of different methods to detect ischemia, and relation of ECG ST levels to HR with and without myocardial ischemia.

Methods. Study I. Anesthetised vascular surgical patients with coronary artery disease were studied during the start of anesthesia and surgery: ECG, hemodynamic, mechanical, and metabolic parameters were measured and categorised as positive or negative with reference to a specific definition of myocardial ischemia. Study II. Awake patients with no ischemic heart disease were paced in graded steps, and VCG ST analyses were performed.

Study III. Anesthetised pigs were studied for local metabolic and VCG ST changes related to controlled HR levels and transient coronary occlusion. Study IV. Thirty five anesthetised coronary artery disease (CAD) patients and ten non-CAD patients were paced at controlled levels, and great coronary artery vein (GCV) lactate measurement was used to determine presence or absence of myocardial ischemia. The CAD patients were paced up to HR levels where myocardial ischemia could be confirmed. The relation of HR-related VCG ST levels to presence or absence of ischemia was analysed. In Studies II,, III, and IV the ST vector magnitude (ST-VM), the change from baseline in ST-VM (STC-VM), and the vector angle change from baseline (STC-VA) were analysed for each step.

Results. Study I. Poor concordance was demonstrated for positive events (presumed myocardial ischemia) between the hemodynamic, ECG, mechanical, and metabolic detection methods. Study II. STC-VM but not ST-VM levels demonstrated HR-related increases in the presumed absence of myocardial ischemia in 18 awake subjects. J point time to ST measurement did not affect the response of VCG ST to HR. Study III. STC-VM levels showed HR-related increases in the absence of ischemia (tested by local metabolic observations). VCG ST parameters responded positively to transient regional ischemia. Study IV. CAD patients, which demonstrated a clear pattern of onset and progress of ischemia during pacing, were further analysed for the relation of VCG ST level to ischemia. Sensitivity and specificity of STC-VM levels were described by ROC analysis for a range of STC-VM levels.

Conclusions. Concordance of different measures for detection of onset of myocardial ischemia is difficult to assess in the absence of a very reliable reference method. The contribution of HR and ischemia to VCG ST levels were estimated in study subjects. HR-related increases in STC-VM occur in the absence of ischemia. HR levels need to be considered when interpreting STC-VM as a diagnostic test for ischemia. Further study is needed to establish criteria that take into account multiple clinical factors in order to improve the predictive value of our tests for myocardial ischemia.

Place, publisher, year, edition, pages
Umeå: Kirurgisk och perioperativ vetenskap, 2005. 69 p.
Umeå University medical dissertations, ISSN 0346-6612 ; 982
Anaesthesiology and intensive care, myocardial ischemia, pacing, vectorcardiography, electrocardiography, heart rate, myocardial lactate, Anestesiologi och intensivvård
National Category
Anesthesiology and Intensive Care
Research subject
urn:nbn:se:umu:diva-598 (URN)91-7305-942-0 (ISBN)
Public defence
2005-10-15, Hörsal BETULA, 6M, NUS, Norrlands Universitetssjukhus, Umeå, 09:00 (English)
Available from: 2005-09-23 Created: 2005-09-23 Last updated: 2009-11-16Bibliographically approved

Open Access in DiVA

No full text

Other links


Search in DiVA

By author/editor
Häggmark, Sören
By organisation
Surgical and Perioperative Sciences
In the same journal

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 110 hits
ReferencesLink to record
Permanent link

Direct link