Electrocardiographic monitoring in the Gottingen minipig

The purpose of the study reported here was to determine conditions for electrocardiographic monitoring in the Gottingen minipig in view of its use as a second non-rodent species in toxicology studies. Electrocardiograms were recorded from conscious minipigs (6/sex) maintained in a sling. The three standard bipolar limb leads (I, II, III), the three augmented unipolar limb leads (aVR, aVL, aVF), the triangular Nehb-Spori leads (dorsal, axial, ventral) and their corresponding unipolar leads were recorded, and automated analysis of amplitudes and intervals was made. Major QRS patterns were not observed for any of the bipolar and unipolar leads. For triangular leads, the amplitude of waves was higher than that for limb leads, and the rS pattern dominated for dorsal, axial ventral and aVF-Ventral leads. The qR pattern dominated in the aVR-dorsal lead, whereas consistency and dominant patterns were not observed for the aVL-axial lead. For limb leads, the position of the electrode affected the ECG. Electrodes placed on the cubical and stifle joints were the preferred positions since the P- and R-waves were clearly identifiable with amplitudes > 0.2 mV. Also, the T-wave amplitude was (positive or negative) > 0.2 mV in at least two leads, making the determination of the QT-interval accurate. For the triangular leads, the position of the electrode had less influence on the amplitude of deflections. However, if the axial lead is to be used for calculation of intervals and amplitudes, the xyphoid process is the preferred position. In conclusion, the triangular lead system is recommended for recording ECGs in minipigs. Limb leads could be used in connection. The cubital and stifle joints for standard limb leads and the neck, sacrum, and xyphoid process for triangular leads are the preferred positions for electrodes.