Vectorcardiography: A Tool for Non-invasive Detection of Reperfusion and Reocclusion?

Abstract

SummaryIn acute myocardial infarction, the perfusion status frequently fluctuates with rapid occurrences of coronary occlusion followed by myocardial ischemia. In patients with unstable angina, most episodes of ischemia are not accompanied by chest pain. In these patients it is important to be able to monitor the results of medical treatment non-invasively to establish the need for further intervention. It is not feasible to perform coronary angiography in all patients with acute myocardial infarction to evaluate patency of the infarct-related artery. Furthermore, even in a patent artery, no reflow may be present in the myocardial tissue. Angiography is therefore not the perfect golden standard to compare noninvasive ischemia monitoring with. Prognosis seems to be a better standard for comparison. This review indicates that vectorcardiography monitoring may identify myocardial reperfusion at an early stage and gives valuable prognostic information both in patients with unstable angina and acute myocardial infarction with low interobserver variability.

Novel set of vectorcardiographic parameters for the identification of ischemic patients

“…Several researchers have proposed the analysis of the VCG for studying cardiac diseases, such as myocardial ischemia and infarction [6][7][8][9][10].…”

“…Angle between the XY-plane and the Optimum Plane ST-Vector Magnitude (ST VM ): It is a widely used parameter when monitoring cardiac ischemia [8,9] and is defined as the magnitude of the vector composed of the (X, Y and Z) ST-segment deviations from the isoelectric level (…”

“…Sederholm et al demonstrated that spatial ST-Vector Magnitude (ST VM ) and QRS-Vector Difference (QRS VD ) behave as complementary measures in the quantification of evolving myocardial injury after acute coronary occlusion and in the determination of sequels to therapeutic interventions [7]. Eriksson used VCG monitoring to identify myocardial reperfusion at an early stage and to give valuable prognostic information in patients with unstable angina and acute myocardial infarction [8]. Kawahito et al concluded that monitoring ST VM along with its QRS VD may be useful for identifying myocardial ischemia during carotid endarterectomy [9].…”

Characterization of the Location and Extent of Myocardial Infarction Using Heart Vector Analysis

“…Important electrophysiologic properties such as large negative region in the epicardial potential map and deep negative Q-waves on the electrograms (EGMs) were reconstructed over the infarcted region in this research. Also, Eriksson (1999) used VCG monitoring to identify myocardial reperfusion at an early stage and valuable prognostic information was offered in patients with unstable angina and acute myocardial infarction. In the more recent study, Jensen et al (2003) monitored patients with rigorous continuous ischemia using computerized vectorcardiography and introduced a new electrocardiographic method called STC-VM.…”

Electrocardiographic imaging of myocardial infarction using heart vector analysis

“…Recently, RA Warner et al (1997) proposed a new method for calculation of the direction of the instantaneous vectors of heart electrical forces and used that to develop some useful criteria for healed inferior myocardial infarction (IMI) [6]. Also, SV Eriksson (1999) used VCG monitoring to identify myocardial reperfusion at an early stage and valuable prognostic information was offered in patients with unstable angina and acute myocardial infarction [7]. In the more recent study, SM Jensen et al (2003) monitored patients with rigorous continuous ischemia using computerized vectorcardiography and introduced a new electrocardiographic method called STC-VM [1].…”