A stable model of left ventricular dysfunction in an intact animal assessed with high fidelity pressure and cinemagnetic resonance imaging

Objective: Numerous models of acute and chronic left ventricular dysfunction have been used over the years. However, few can produce a rapid onset of global systolic and diastolic dysfunction that is stable and potentially reversible. The aim of this study was to develop such a model. Methods: A model of left ventricular dysfunction was produced in six intact dogs using 1% halothane anaesthesia and pharmacological autonomic blockade with atropine (0.1 mg·kg−1) and propranolol (2 mg·kg−1). Left ventricular function was assessed by combined high fidelity pressure and cinemagnetic resonance imaging (cine-MR) during increases in afterload using infusions of angiotensin. Results: Left ventricular systolic dysfunction was characterised by a diminished resting ejection fraction of 45(SD 4)% and a depressed +dP/dtmax of 1537(100) mm Hg·s−1. Diastolic dysfunction was manifested by an increased left ventricular end diastolic pressure of 16(2) mm Hg, a decreased −dP/dtmax of −1705(369) mm Hg·s−1, and a prolonged time constant of left ventricular relaxation of 42(9) ms. As left ventricular systolic pressure steadily rose with angiotensin infusion from 87(7) to 124(13) to 152(10) mm Hg (p