Aims: To objectively characterize the spatial-velocity dynamics of the QRS-loop in the vectorcardiogram (VCG) of patients with acute myocardial infarction (AMI).
Methods: VCG was constructed as a space curve directly with three quasi-orthogonal leads I, aVF and V2 recorded by conventional ECG of 25 healthy individuals and 50 AMI patients. Spatial velocity (SV) of the dynamic QRS loop, spatial distance (SD), and spatial magnitude (SM) were recorded, along with axis-specific component attributes of vector magnitude such as ΔX, ΔY, and ΔZ.
Results: Decreased SV (12-25%, p = 0.02) and SD (10-26%, p = 0.02) and altered spatial propagation patterns of ventricular vectors in AMI were recorded, with changes in specific axes based on infarct location. Significant vector changes were found in the Y-Axis in IWMI (p = 0.005) and X-Axis in cases of AWMI (p = 0.02), as compared to controls. There was no apparent alteration of SM in AMI.
Conclusion: Decreased SV and SD without any significant alteration of SM indicates close approximation and clustering of the tips of the ventricular vector in AMI. This may be due to dilation, thinning, and stress of the ventricular wall in early post infarction ventricular remodeling, along with relative ischemia due to associated tachycardia and higher myocardial oxygen demand.
Keywords: AMI; SV; VCG; Vectorcardiogram; cardiac vector; myocardial infarction; spatial VCG; spatial velocity.
The purpose of the present study was to analyze the movement of electrical signals (vectors) in the heart in patients with heart attack. Heart signal recordings (ECGs) from 25 healthy individuals and 50 heart attack patients were collected and were used to construct a three-dimensional entity in the space by joining the vector tips in a serial manner. When the whole procedure is animated the velocity of the moving cursor from one tip to another is measured as a velocity of electric signal movement. It is found that,1. Heart attack patients had slower and shorter electrical signal movements.2. The direction of these movements changed depending on the location of the heart damage.3. Specific changes were seen in the signals’ movement patterns, which can discriminate between the types of heart attack.This research offers new insights into the impact of heart attacks on the heart’s electrical activity, potentially enhancing early detection methods and our understanding of the heart’s recovery process following such events.