Dictionary.net

A disorder characterized by episodes of respiratory distress, usually occurring after several hours of sleep in a reclining position. It is most commonly caused by pulmonary edema resulting from congestive heart failure. The episodes may be accompanied by coughing, a feeling of suffocation, a cold sweat, and tachycardia.

A term applied to sudden attacks of pain and distress, with dyspnea, occurring in subjects of advanced heart disease.