Micro conductance catheters have been successfully applied to measure left ventricular (LV) function in the mouse to assess cardiac or pharmacological interventions for a number of years. New complex admittance methodologies produce an estimate of the parallel admittance of cardiac muscle that can be used to correct the measurement in real-time. This contrasts with existing conductance technologies that require in vivo calibration using a bolus of hypertonic saline. Here we report the application of this emerging technology in the contact of myocardial infarction and LV remodelling. Using a combination of non-invasive imaging (MRI & high resolution ultrasound) and LV conductance catheters, we have compared measures of LV function using an admittance system (ADVantage system, Scisence, Ca) and a traditional conductance-derived pressure-volume (PV) system in models of cardiac dysfunction following myocardial infarction and pressure overload (Clark JE, et al. J Pharmacol Toxicol Methods. 2009, 59(2):94-9). We have also subjected mice to focal myocardial ischaemia-reperfusion injury while measuring cardiac function with different systems to determine the reliability and accuracy of these methods to distinguish between normal, and dysfunctional LV, contractile performance. We have shown that the ADVantage system, in our hands, provides a straightforward solution for assessing LV function in mice. Using this technique in combination with other established methods we have demonstrated marked LV dysfunction following coronary artery occlusion and reperfusion which can be reversed using preconditioning agents, and found that functional readouts are representative of other methods. We have found that, especially in diseased tissue, LV pressure-volume loops derived from complex admittance provide a reproducible and reliable method of determining LV function without the need for technically challenging calibration. Our data suggest that the ADVantage system records accurate/physiological LV cavity volumes when compared to other invasive methods in the same animal. The ADVantage system is both effective and reproducible in measuring LV function and dysfunction in the mouse, without the need for complicated interventions to calibrate the measurements or training in a new technology. We have also demonstrated the application of this system to adverse remodeling following infarction and LV hypertrophy following pressure overload. This may mark the way toward a fast and accurate assessment of murine cardiac function in normal and disease models.