Cardiovascular function assessment is required by regulatory authorities for studying potential side effects of drug candidates. In vivo experiments can be performed on either conscious - freely moving or restrained - or anesthetized animals. The selection of the appropriate technique depends on the application while the selection of means is essentially driven by their cost, reliability, rapidity and automation.
NOTOCORD Systems offers a broad range of dedicated software and hardware tools addressing data acquisition and analysis issues in cardiovascular studies, ensuring online computation of relevant parameters with high detection performance and video synchronization.

Adapted hardware solutions
Assessment of cardiovascular parameters in conscious freely moving animals is conventionally done using telemetry recordings of arterial blood pressure and ECG signals. NOTOCORD-hem is compatible with most standard telemetry systems, whether invasive, such as implants developed by DSI and ITS, or noninvasive, through dedicated acquisition servers. 

As an alternative to invasive telemetry devices, Corscience, an innovative manufacturer of medical device, developed an ambulatory multiple lead ECG device for low-cost, ready to use, noninvasive recording of ECG, adapted to cardiac safety and toxicology studies in large animals.
The device may also be used in the selection of animals to be equipped with cardiovascular implants, thus improving data quality. NOTOCORD-hem, through the use of the dedicated CSW10a/b acquisition server, automatically detects Corscience devices and allows configuration and long-term acquisition of up to 14 devices.

Finally, VivoMetrics LifeShirt ® system allows recording of standard lead II ECG along with respiratory signals, thus giving the ability to also assess heart rate variability. The use of this unique technology is totally adapted to a context of number of experiments reduction and analysis refinement.

NOTOCORD-hem is also compatible with most standard stationary data acquisition systems. The PORTI7 device is a multi-channel ambulatory and stationary system recently developed by TMS International and adapted to ECG and biopotentials recordings in anesthetized or restrained animals. TMS31a advanced server allows selection of sampling rates, signal range and filters for each configured output.

Flexible yet powerful analysis software
Accuracy of the analysis, whether automated or manual, and thus confidence in its results, is strongly related to the quality of recording and requires a good knowledge of the signal processing done within the hardware. DSF10a provides a correction for ECG signal distortion induced by filters built in DSI implants.
ECG waveform morphology and durations may vary with experimental subjects and conditions. NOTOCORD-hem provides unique species- and context-dependent ECG analyzers that were developed and validated using an extensive database of real ECG signals that were manually annotated by experts. This new generation of ECG analyzers is easy to use with little or no parameters to set for an efficient detection.
Detection performance of our analyzers is assessed using sensitivity (Se) and positive predictive indexes (P+). For example, averaged Se and P+ > 92% for non human primate ECG analyzer, with values > 99.8% for QRS detection. Our unique VME10e module allows edition, modification and validation of the positioning of ECG fiducial points on user-defined analysis periods. VME10v also includes synchronized video display for a more accurate selection of the analysis periods.
 

Although not systematic in cardiovascular studies, the analysis of left ventricular pressure signal provides essential information on cardiac contractility and may correlate with changes in animal behavior during long-term telemetry studies. LVP30a module uses the left ventricular pressure signal to compute contractility index, left ventricular end-diastolic pressure, etc. For signals recorded with a conductance catheter on small animals, our new PVL10s module allows display an analysis of left ventricular pressure and volume relationships, with user defined-analysis zones, editing of end-systole points and validation of results.

Related bibliography
[1] Hamlin RL. Non-drug-related electrocardiographic features in animal models in safety pharmacology. J Pharmacol Toxicol Methods. 2005 Jul-Aug;52(1):60-76.
[2] Burkhoff D, Mirsky I, Suga H. Assessment of systolic and diastolic ventricular properties via pressure-volume analysis: a guide for clinical, translational, and basic researchers. Am J Physiol Heart Circ Physiol. 2005 Aug;289(2):H501-12.
[3] Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Task Force of the European Society of Cardiology and the North  American Society of Pacing and Electrophysiology. Eur Heart J. 1996 Mar;17(3):354-81.