Electrocardiogram (ECG) is currently the most widely used in clinical practice for the diagnosis of heart disease. However, there is a vectorcardiography (VCG) method that in certain cases can detect some pathologies with higher accuracy than a 12 lead ECG. In this work, we present a new method of QRS complex detection based on the octant theory introduced by Laufberger. The presented algorithm is based on the principle of numerical sequence analysis. This search algorithm consists of three main parts: Window search in number series, Modification of window search in number series due to a longer search window, and modification of number series due to a shorter search window. These individual parts form one whole of the whole algorithm. The accuracy of the presented algorithm was tested on 80 physiological records from the PTB database by calculating accuracy, sensitivity and specificity. The percentage accuracy for healthy records was 98.28% sensitivity 98.2% and specificity 98.1%.This algorithm has low computational complexity and can be a useful tool to simplify the work of cardiologists in the analysis of long records.