When this happens the artery narrows and blood flow to part of the heart muscle decreases or stops. We're not sure what causes a spasm. A spasm can occur in normal-appearing blood vessels as well as in vessels partly blocked by atherosclerosis.A severe spasm can cause a heart attack.hen this happens the artery narrows and blood flow to part of the heart muscle decreases or stops. We're not sure what causes a spasm. A spasm can occur in normal-appearing blood vessels as well as in vessels partly blocked by atherosclerosis.
If this happens â and you have not executed a durable power of attorney â then the court may decide who will act on your behalf. Known as guardianship and conservatorship proceedings, these court actions can consume time and money and leave the decision of who will handle your affairs in the hands of a judge.
If you don't, in most states, it will automatically end if you later become incapacitated. Or, you can specify that the power of attorney does not go into effect unless a doctor certifies that you have become incapacitated. This is called a springing durable power of attorney. You revoke it. 2  As long as you are mentally competent, you can revoke a durable power of attorney at any time. 3  You get a divorce. 4  In a handful of states, if your spouse is your agent and you divorce, your ex-spouse's authority is automatically terminated.