Can cardiac ischemia cause arrhythmias? if so, how?

Yes: Cardiac ischemia causes lack of blood flow to the heart muscle and can trigger ventricular arrhythmia. Premature ventricular contraction is common. In severe cases, it can also lead to ventricular tachycardia ( consecutive fast heart beat from the ventricle of the heart). Sometimes with heart attack, fatal ventricular fibrillation (very fast irregular abnormal beats from ventricle) can occur.