Establishment of a 24-hour electrocardiogram recording system using a Holter recorder for miniature swine

A Holter recording system was established for the Göttingen miniature swine. For this purpose, we first developed a jacket to hold a Holter recording set, and subsequently determined a bipolar lead suitable for obtaining stable electrocardiogram (ECG) recording without artifacts. To make the jacket, we measured the lengths of eight sites of the body of 14 miniature swine. Several types of jackets were made and tested. We observed the behaviour of animals with these jackets by videotape recorder (VTR) recording. These observations permitted development of a jacket suitable for Holter recording. The jacket permits easy placement of the recorder, and long-term ECG recording can be performed without difficulty. In order to determine a suitable lead for long-term recording, we recorded ECGs from six adult miniature swine using three types of leads, the M-X, R-L and A-B leads. The R-L lead frequently exhibited baseline drift, and QRS complexes often disappeared in this lead due to low amplitude. ECG recording with the M-X and A-B leads was of sufficient quality to permit analysis. This system is expected to be useful for further cardiovascular research in miniature swine.