Method and medical device for discriminating between a supraventricular tachycardia and a ventricular tachycardia

A medical device, comprising:

• a first electrode pair;
• a second electrode pair having a different distance between its electrodes than the first electrode pair;
• and
• a controller connected with the first electrode pair and the second electrode pair and configured to:
• use the first electrode pair to determine a first cardiac signal of a heartbeat;
• use the second electrode pair to determine a second cardiac signal of the heartbeat;
• apply a first comparison algorithm to the first cardiac signal to determine whether the first cardiac signal is indicative for a supraventricular tachycardia or indicative for a ventricular tachycardia, wherein the first comparison algorithm uses a first template and is configured to compare the first cardiac signal to the first template to identify changes of first heartbeat-specific morphology parameters referring to negative waves and to positive waves;
• apply a second comparison algorithm to the second cardiac signal to determine whether the second cardiac signal is indicative for the supraventricular tachycardia or indicative for the ventricular tachycardia, the second comparison algorithm being different from the first comparison algorithm, wherein the second comparison algorithm uses a second template different from the first template, and is configured to compare the second cardiac signal to the second template to identify changes of second heartbeat-specific morphology parameters referring to S-waves and/or Q-waves only;
• and
• classify the heartbeat as being indicative for the ventricular tachycardia when at least one of the first cardiac signal and the second cardiac signal is determined to be indicative for the ventricular tachycardia.

A computer readable storage medium comprising software code that, when executed by a processor of a medical device further comprising a first electrode pair and a second electrode pair having a different distance between its electrodes than the first electrode pair, causes the medical device to perform a method for automatically discriminating between a supraventricular tachycardia and a ventricular tachycardia, the method comprising:

• sensing a first cardiac signal using the first electrode pair during a heartbeat and sensing a second cardiac signal using the second electrode pair during the heartbeat;
• applying a first comparison algorithm to the first cardiac signal to determine whether the first cardiac signal is indicative for a supraventricular tachycardia or indicative for a ventricular tachycardia, wherein the first comparison algorithm uses a first template and is configured to compare the first cardiac signal to the first template to identify changes of first heartbeat-specific morphology parameters referring to negative waves and to positive waves;
• applying a second comparison algorithm to the second cardiac signal to determine whether the second cardiac signal is indicative for the supraventricular tachycardia or indicative for the ventricular tachycardia, the second comparison algorithm being different from the first comparison algorithm, wherein the second comparison algorithm uses a second template different from the first template, and is configured to compare the second cardiac signal to the second template to identify changes of second heartbeat-specific morphology parameters referring to S-waves and/or Q-waves only;
• and
• classifying the heartbeat as being indicative for the ventricular tachycardia when at least one of the first cardiac signal and the second cardiac signal is determined to be indicative for the ventricular tachycardia.

A method of treating tachycardia, the method comprising:

• determining a far-field EGM signal relating to a heartbeat;
• determining a near-field EGM signal relating to the same heartbeat;
• comparing the far-field EGM signal with a far-field template EGM signal to determine first changes related to positive waves and negative waves;
• comparing the near-field EGM signal with a near-field template EGM signal to determine second changes related to S-waves and/or Q-waves only;
• assigning to a heartbeat-specific indicator a first value indicative for a ventricular tachycardia when at least one of the first changes and the second changes is indicative for the ventricular tachycardia;
• and
• using the heartbeat-specific indicator to determine if an electric stimulation signal is to be delivered to at least two stimulation electrodes.

A method for automatically discriminating between a supraventricular tachycardia and a ventricular tachycardia, the method comprising:

• recording two EGM-signals representing different spatial summation of action potential signals during a heartbeat;
• using an algorithm to determine if morphology parameters of waves in each of the two EGM-signals are indicative for a ventricular tachycardia;
• and
• classifying the heartbeat as being indicative for the ventricular tachycardia when at least one of the morphology parameters is determined to be indicative for the ventricular tachycardia and as being indicative for supraventricular tachycardia when none of the morphology parameters is determined to be indicative for the ventricular tachycardia,
• wherein the morphology parameters in a first of the two EGM-signals refer to negative waves and positive waves, and the morphology parameters in a second of the two EGM-signals refer to S-waves and/or Q-waves only.