Low cardiac output (e.g., congestive heart failure, cardiac arrhythmia [heartbeat irregularities], or pericardial disease [disease of the sac that encloses the heart])

Make this lower case.
low cardiac output (e.g., congestive heart failure, cardiac arrhythmia [heartbeat irregularities], or pericardial disease [disease of the sac that encloses the heart])