While this is an early study with a small sample size, it is the first time this type of anger or emotional stress testing has been shown to correlate with future arrhythmias, he said.

CNN: Anger, stress may be linked to heart problems

Al-Khatib found that many patients who were being implanted with the ICDs had recently experienced arrhythmias or cardiac arrests.

CNN: STORY HIGHLIGHTS

These are voluntary reports from health care providers and consumers linking DMAA use to seizures, arrhythmias, heart attacks, strokes, panic attacks, and deaths, along with exacerbation of psychiatric conditions.

FORBES: Is DMAA Dangerous To Your Health?