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Dual recordings of left ventricular and arterial pressure in conscious rats via telemetry
Author(s) -
McCormick Daniel,
Guild SarahJane,
Lim Mathew,
Pauly Bob,
Kirton Robert,
Budgett David,
Barrett Carolyn J,
Kondo Masahiro,
Stehlin Ellyce,
Malpas Simon C
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.644.7
We have developed a new telemetry device with dual solid state micro‐tip 2 Fr pressure sensors. With particular relevance to cardiovascular research is the possibility that high frequency sampling at 2000 Hz permits determination of dP/dT and pulse wave velocity. The transmitter (weight 11 gm) incorporates digital transmission to a remote receiver. The ability to recharge the batteries inductively whilst monitoring provides the platform for long term and/or repeated use in animals. The frequency response of the system was 500Hz (3 dB point) allowing high fidelity measurement of pressures. We implanted the body of the TRM54PP transmitter in the abdomen of rats and used a transdiaphragmatic approach to implant the tip of the catheter through the apex of the left ventricle with the other catheter in the abdominal aorta. Maximum dP/dT values in conscious rats were between 9,000 mmHg/s and 14,000 mmHg/s on the third day after surgery (average 11,000 mmHg/s). Fractional shortening as measured by echo was not altered by the catheter. Modelling based on the high frequency response indicated the system would be suitable to record dP/dT max values up to 25,000 mmHg/s. This high fidelity system for making direct measurements of internal pressures could provide a valuable research tool for expanding the scope of chronic studies while improving the ease of use of telemetry systems.