What is the difference between “sudden cardiac arrest” and a heart attack?

Thank you for having this format; I really appreciate it. Your answers to my questions will help me when I talk to my doctors up here. A brief history is probably needed: I’ve had two heart attacks- 2005 and 2010. According to my doctors, these were related to my severe, chronic PTSD caused by my job and how I responded to stressors. There’s no family history of heart trouble. I’ve been in a formal cardiac rehab program (3 days a week, about 1.5 hours per session) since the first heart attack. My lifestyle is not sedentary. My diet then, and now, is essentially Mediterranean. I’m 6’3″ tall, 70-years-old. In the last year I’ve reduced my weight from 260 to 215 pounds, pant size from 42 to 38 via diet.

Two electrocardiograms, 01/2013 & 03/2013, showed my ejection fraction (EF) was 34 and 44%, respectively. I do not have any of the physical symptoms of low EF. Never have had.

My questions:
1. Will stress and fatigue from a lack of sleep cause EF to change? If so, how will it affect the EF and how much?

2. Is EF the sole criteria for determining if individuals with an EF less than 40% are at a high risk for adverse events leading to sudden incapacitation? From a heart attack…

3. Hate to ask, but cannot get a clear difference of the two… if there is one: What’s the difference between ‘sudden cardiac arrest’ and a heart attack?

Submitted by Frank from Gurnee, Illinois 

1. No, it will not affect your LVEF.

2. Many factors are involved in determining your future health, the most common including cholesterol, cigarettes, sugar diabetes (diabetes mellitus), high blood pressure (hypertension), activity and weight.

3. In a heart attack there may or may not be damage to the tissue of the heart. In sudden cardiac death, the heart totally stops which may or may not be reversible.