Guinea pigs

A recent project conducted at several different UK research institutes including Bristol University and the University of Surrey involved a total of 41 guinea pigs1. 18 had clips placed round their aorta, the rest were operated on but weren't given clips. They were kept for between 47 and 57 days before all were killed and their hearts extracted. The research paper does not state how the animals were killed or if anaesthetic was administered, but is inevitable that they will have suffered.

Guinea pigs' hearts are much smaller and beat much faster than humans' and there are other physiological differences which mean they are not an accurate model for chronic heart conditions found in humans. You are a human, not a mouse, a dog or a guinea pig.

1. C.H. Fry, R.P. Gray, P.S. Dhillon, R.I. Jabr, E. Dupont, P.M. Patel, N.S. Peters. Architectural correlates of myocardial conduction: changes to the topography of cellular coupling, intracellular conductance, and action potential propagation with hypertrophy in Guinea-pig ventricular myocardium. Circ. Arrhythm. Electrophysiol., 7 (6) (2014), pp. 1198–1204