Case Study 1: Mrs. K is a 60-year-old white female who presented to the ER with complaints of her heart "beating out of my chest." She is complaining that she is having increased episodes of shortness of breath over the last month and in fact has to sleep on 4 pillows. She also notes that the typical swelling she's had in her ankles for years has started to get worse over the past two months, making it especially difficult to get her shoes on toward the end of the day. In the past week, she's been experiencing fatigue and decreased urine output. Her past history is positive for an acute anterior wall myocardial infarction and coronary artery bypass surgery. She was a 2-pack-a-day smoker but quit 8 years ago.
On physical examination, auscultation of the heart revealed a rumbling S3 gallop and inspiratory crackles. She has +3 edema of the lower extremities.
1. Discuss the pathophysiology of an S3 heart sound and the pathophysiology of heart failure.