Method of identifying strategies for treatment or prevention of ventricular fibrillation and ventricular tachycardia

A system for use in identifying treatment therapies as therapeutic strategies for preventing ventricular tachycardia from developing into ventricular fibrillation, said system comprising:

• a medical device programmed to detect ventricular tachycardia in a subject;
• monitor intervals between electrical stimuli in the heart of the subject;
• determine if an initial 3 stimuli in groups of 4 stimuli from said monitoring in the heart correspond to rest interval values (I) predicted to lead to ventricular fibrillation as defined by a first equation as follows:
• I
• n
• +
• 1
• ⁡
• (
• x
• i
• )
• =
• τ
• +
• ∑
• j
• =
• 0
• i
• -
• 1
• ⁢
• Δ
• ⁢
• ⁢
• x
• c
• ⁡
• (
• I
• n
• +
• 1
• ⁡
• (
• x
• j
• )
• )
• -
• ∑
• j
• =
• 0
• i
• -
• 1
• ⁢
• Δ
• ⁢
• ⁢
• x
• c
• ⁡
• (
• I
• n
• ⁡
• (
• x
• j
• )
• )
• -
• D
• n
• +
• 1
• ⁡
• (
• x
• i
• )
• ,
• wherein τ is a time interval between activations applied to a pacing site (xi), Δx is 0.1, In+1 (xj) is a rest interval value of the n+1th action potential at a pacing site (xj), In (xj) is a rest interval value of an nth action potential at a pacing site (xj), Dn+1 (xi) is an action potential duration of an n+1th action potential at pacing site (xi), c is a velocity recovery function of In (xj) and In+1 (xj), respectively;
• identify treatment therapies which prevent occurrence of a fourth stimuli corresponding to the rest interval values;
• and
• identify treatment therapies which prevent said ventricular tachycardia from becoming ventricular fibrillation as therapeutic strategies for prevention of ventricular fibrillation.