[0001] The present invention relates to a family of compounds which are capable of modulating KChIP proteins and are therefore useful for the treatment of heart diseases in which the expression levels of this protein are abnormal. These compounds have the following general formula: (I). [0002] <img class="EMIRef" id="2b023a3f-1a6a-4e82-96f3-29d523dfd478-EMI-C00001" />
1. A compound of formula (I): <img class="EMIRef" id="657948410-ib0097" /> wherein: R<1> and R<2> are independently selected from H, OH, -O-aryl, halogen, aryl or heteroaryl, wherein said aryl or heteroaryl groups can be optionally substituted with (C<1>-C<6>) alkyl, - OH, (C<3>-C<6>) cycloalkyl, -O-(C<1>-C<6>) alkyl or halogen; n has a value of 1 or 2; Ar is selected from the following groups: <img class="EMIRef" id="657948410-ib0098" /> wherein R<3> is selected from -OH or -O-(C<1>-C<6>)-alkyl; R<4> is selected from H, halogen, -O-(C<1>-C<6>)-alkyl, phenyl optionally substituted with (C<1>-C<6>) alkyl; R<5> is selected from H or phenyl optionally substituted with alkyl (C<1>-C<6>), or the salts, isomers or solvates thereof, for use in the treatment of heart diseases which are selected from heart arrhythmia myocardial ischemia, myocardial infarction, cardiac hypertrophy or cardiomyopathy. 2. The compound for use according to claim 1 which is the compound of formula (Ia): <img class="EMIRef" id="657948410-ib0099" /> wherein R<1>, R<2> and n are defined as in claim 1, or the salts, isomers thereof. 3. The compound for use according to claim 2, wherein R<1> is selected independently from O-phenyl, phenyl, quinoline or pyridine, wherein said phenyl is optionally substituted with a group which is selected from (C<1>-C<4>) alkyl, -OH or (C<3>) cycloalkyl and said pyridine is optionally substituted with a group which is selected from -O-(C<1>-C<4>) alkyl, -OH or halogen and R<2> is H. 4. The compound for use according to any of claims 2 or 3, said compound being selected from the following list: • 4-chloro-2-(2-(3-phenoxyphenyl)acetamido)benzoic acid (1) • 2-(2-([1,1'-biphenyl]-3-yl)acetamido)-4-chlorobenzoic acid (2) • 2-(2-(4'-butyl-[1,1'-biphenyl]-3-yl)acetamido)-4-chlorobenzoic acid (3) • 4-chloro-2-(2-(4'-ethyl-[1,1'-biphenyl]-3-yl)acetamido)benzoic acid (4) • 2-(2-(4'-(tert-butyl)-[1,1'-biphenyl]-3-yl)acetamido)-4-chlorobenzoic acid (5) • 4-chloro-2-(2-(4'-hydroxy-[1,1'-biphenyl]-3-yl)acetamido)benzoic acid (6) • 4-chloro-2-(2-(4'-(hydroxymethyl)-[1,1'-biphenyl]-3-yl)acetamido)benzoic acid (7) • 4-chloro-2-(3-(3-phenoxyphenyl)propanamido)benzoic acid (14) • 2-(3-([1,1'-biphenyl]-3-yl)propanamido)-4-chlorobenzoic acid (15) • 2-(3-(4'-butyl-[1,1'-biphenyl]-3-yl)propanamido)-4-chlorobenzoic acid (16) • 4-chloro-2-(3-(4'-ethyl-[1,1'-biphenyl]-3-yl)propanamido)benzoic acid (17) • 2-(3-(4'-(tert-butyl)-[1,1'-biphenyl]-3-yl)propanamido)-4-chlorobenzoic acid (18) • 4-chloro-2-(3-(4'-(hydroxymethyl)-[1,1'-biphenyl]-3-yl)propanamido)benzoic acid (19) • 4-chloro-2-(3-(4'-hydroxy-[1,1'-biphenyl]-3-yl)propanamido)benzoic acid (20) • 4-chloro-2-(2-(4'-cyclopropyl-[1,1'-biphenyl]-3-yl)acetamido)benzoic acid (23) • 4-chloro-2-(2-(3-(pyridin-2-yl)phenyl)acetamido)benzoic acid (24) • 4-chloro-2-(2-(3-(quinolin-2-yl)phenyl)acetamido)benzoic acid (25) • 4-chloro-2-(2-(3-(pyridin-3-yl)phenyl)acetamido)benzoic acid (26) • 4-chloro-2-(2-(3-(5-fluoropyridin-3-yl)phenyl)acetamido)benzoic acid (27) • 4-chloro-2-(2-(3-(6-hydroxypyridin-3-yl)phenyl)acetamido)benzoic acid (28) • 4-chloro-2-(2-(3-(6-ethoxypyridin-3-yl)phenyl)acetamido)benzoic acid (29) • 4-chloro-2-(3-(3-(pyridin-3-yl)phenyl)propanamido)benzoic acid (30) • 4-chloro-2-(3-(3-(6-hydroxypyridin-3-yl)phenyl)propanamido)benzoic acid (31) • 4-chloro-2-(2-(3-(6-ethoxypyridin-3-yl)phenyl)propanamido)benzoic acid (32) • 4-chloro-2-(3-(3-(5-fluoropyridin-3-yl)phenyl)propanamido)benzoic acid (33) • 4-chloro-2-[2-(3-phenoxyphenyl)acetylamino]benzoic acid (9bis) • 4-chloro-2-(2-(3',4'-dichloro-[1,1'-biphenyl]-3-yl) acetylamino)benzoic acid (47bis) 5. The compound for use according to claim 2, wherein R<1> and R<2> are chlorine. 6. The compound for use according to claim 2, wherein R<1> and R<2> are -OH. 7. The compound for use according to claim 1 which is the compound of formula (Ib): <img class="EMIRef" id="657948410-ib0100" /> wherein R<1>, R<2> and n are defined as in claim 1, or the salts, isomers or solvates thereof. 8. The compound for use according to claim 7, wherein R<1> and R<2> are independently selected from O-phenyl, chlorine, phenyl, quinoline or pyridine, wherein said phenyl is optionally substituted with a group which is selected from (C<1>-C<4>) alkyl, - OH or (C<3>) cycloalkyl and said pyridine is optionally substituted with a group which is selected from -O-(C<1>-C<4>) alkyl, -OH or halogen and R<2> is H. 9. The compound for use according to any of claims 7 or 8, which is selected from the following list: • 3-(2-([1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (8) • 3-(2-(4'-butyl-[1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (9) • 3-(2-(4'-ethyl-[1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (10) • 3-(2-(4'-(tert-butyl)-[1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (11) • 3-(2-(4'-hydroxymethyl-[1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (12) • 3-(2-(4'-(hydroxymethyl)-[1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (13) • 3-(3-([1,1'-biphenyl]-3-yl)propanamido)-2-naphthoic acid (21) • 3-(2-(4'-cyclopropyl-[1,1'-biphenyl]-3-yl)acetamido)-2-naphthoic acid (22) • 3-[2-(3-phenoxyphenyl)acetylamino]-2-naphthoic acid (22bis) 10. The compound for use according to claim 9, wherein R<1> and R<2> are chlorine. 11. The compound for use according to any of claims 7 or 10, said compound being selected from the following list: • 3-[2-(3,4-dichlorophenyl)acetylamino]-2-naphthoic acid, (20) • 3-[3-(3-(3,4-dichlorophenyl)propanoylamino)]-2-naphthoic acid, (23) 12. The compound for use according to claim 1, which is a compound of formula (Ic): <img class="EMIRef" id="657948410-ib0101" /> wherein R<3>, R<4> and n are defined as in claim 1, or the salts, isomers or solvates thereof. 13. The compound for use according to claim 12, wherein R<4> and R<5> are independently selected from H, O-(C<1>-C<4>) alkyl or phenyl optionally substituted with a (C<1>-C<4>) alkyl. 14. The compound for use according to any of claims 12 or 13, said compound being selected from the following list: • 2-[2-(3,4-dichlorophenyl)acetylamino]- 4-methoxybenzoic acid (7bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-5-(4'-n-butylphenyl)benzoic acid (34bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-4-(4'-n-butylphenyl)-benzoic acid (35bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-5-(4'-tert-butylphenyl)-benzoic acid (36bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-5-(2'-methylphenyl)-benzoic acid (37bis) • 2-[3-(3,4-dichlorophenyl)propanoylamino]-5-(4'-n-butylphenyl)benzoic acid (38bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-4-phenylbenzoic acid (39bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-4-(2'-methylphenyl)benzoic acid (40bis) • 2-[3-(3,4-dichlorophenyl)propanoylamino]-4-phenylbenzoic acid (41bis) • 2-[2-(3,4-dichlorophenyl)acetylamino]-5-phenylbenzoic acid (42bis) • 2-[3-(3,4-dichlorophenyl)propanoylamino]-5-(4'-tert-butylphenyl)benzoic acid (43bis) • 2-[3-(3,4-dichlorophenyl)propanoylamino]-5-(2'-methylphenyl)benzoic acid (44bis) • 2-[3-(3,4-dichlorophenyl)propanoylamino]-4-(2'-methylphenyl)benzoic acid (45bis)