QRS detection on contaminated rodent ECG. (a) Mouse ECG recorded during an IRSE sequence and processed with coif3. Despite the low SNR and the very large base line drift, the algorithm succeeded in ensuring a perfect QRS detection. (b) ECG of a hypertensive rat with bundle branch block beat recorded during a FSE sequence, where one can clearly depict the effect of the pathology on the QRS morphology. After processing with the sym4 wavelet, the QRS are very well marked in the extracted reference signal.