Management of ACS for the ALS Provider

Systole vs. Diastole continued

Therefore, the only time blood returns to the heart via the coronary arteries is during diastole.  This is one of the reasons  for tachydysrhythmias in the heart. Supraventricular tachydysrhythmias are often produced by disorders of impulse formation and/or disorders of impulse conduction.  If there is not enough blood returning to the heart, the heart will speed up in an attempt to compensate for the lack of adequate blood flow.