Middle back pain: Back pain in the middle back area. See detailed information below for a list of 31 causes of Middle back pain, Symptom Checker, Assessment Questionnaire, including diseases and drug side effect causes. Â» Review Causes of Middle back pain: Causes | Symptom Checker Â» | Assessment Questionnaire Â» Causes of Middle back pain:
Other medical conditions are less frequent causes of left atrial enlargement. For example, a ventricular septal defect -- a hole in the wall that separates the right and left ventricles -- can alter blood flow through the heart such that there is overfilling and enlargement of the left atrium.
Ventricular septal defect is a hole in the wall between the right and left ventricles of the heart. This abnormality usually develops before birth and is found most often in infants.1  The ventricles are the 2 lower chambers of the heart.entricular Septal Defect Causes. No one knows what causes ventricular septal defects, but they probably come from a malformation of the heart that occurs while the infant is developing in the womb. 1  There may be just one hole or several holes in the septum.