Figure 4
An example of the P wave detection procedure and the application of decision rules in the case of ECG signal with second-degree AV block. In the first stage (left image), three P waves (before QRS complexes) are found. In the second stage, the fourth P wave is detected as a result of the decision rules. Specifically, (a) R(i) is not PVC; (b) P wave follows T wave; (c) RR(i) is longer than 1.6 × RR(i-1). This means that additional searching for the P wave within the area from T(i)-200 ms to R(i)-300 ms is provided and a new P wave is found (the QRS complex following this beat was blocked due to the second-degree AV block; (d) RR(i-1) is not shorter than 0.85 × RR(i-2); (e) UP(i) is higher than 0.1 × UR(i).
