Abstract: Provided are animal models of long QT syndrome (LQTS). The animal models are useful, for example, in screening of drugs for adverse effects in subjects with LQTS, in screening candidate therapeutics for the treatment or prevention of LQTS, and in determining gene expression in LQTS.

Abstract: An apparatus for signal analysis of the electrical potential curve of heart excitation, for example in the event of an insufficient blood supply at the heart and/or an abnormality in the cardiac rhythm, measures the potential curve by means of an arrangement of electrodes (2, 3, 4), whereby at least two of the three electrodes can be implanted in the heart (8), with a pole (7) of one electrode (3) being placed in the right ventricle and a pole (6) of another electrode (2) being placed in the right auricle or in the transition to the superior vena cava. A third electrode (4) with its pole (9) is implanted outside of the heart (8) in such a way that the connecting lines of the three poles form a triangle that encompasses a portion of the heart (8). The difference in potential between one of the electrodes and the two electrodes that have been connected together at a given time can be measured and the signal curve can be evaluated or sent to an evaluation device.