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 include causes for an S3 gallop?
Post your initial discussion by 11:59 PM ET on Thursday. Posts are a minimum of 250 words, scholarly written, APA formatted (with some exceptions due to limitations in the D2L editor), and a minimum of 2 references (which may include the course textbook). Reply to at least one classmate\’s initial discussion post by Saturday at 11:59 PM ET. The initial discussion post and discussion response should occur on two different calendar days of each electronic week. These are not the complete instructions for participating in discussions. See the \”Grading Rubric for Online Discussions – 500 level\” found in the Course Resources module.
NSG 530: Week 4
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Course
Instructor’s Name
Date
NSG 530: Week 4
Introduction
A third heart sound reflects rapid left ventricular distention as well as increased atrioventricular flow. The third heart sound is also called ventricular gallop and happens just after S2 when the mitral valve opens to allow passive filling of the left ventricle (Shono et al., 2019). In the case study, Mrs. K, a 60-year-old White female presents with increased episodes of shortness of breath. Her swollen ankles got worse and have been experiencing fatigue and reduced urine output. Further examination revealed a rumbling S3 gallop and inspiratory crackles. She has +3 edema of the lower extremities.
Discuss the pathophysiology of an S3 heart sound and include causes for an S3 gallop
According to Shono et al. (2019), the third heart sound is commonly created by the early diastolic rapid distention of the left ventricle that occurs along with ventricular filing and abrupt deceleration of the atrioventricular blood flow. As the transmitral inflow rate increases, the steeper the rapid filling wave becomes, leading to increased deceleration of the left ventricular inflow and the more likely that the third heart sound will be generated. Shono et al. (2019) state further that the third heart sound is the most commonly auscultated with mitral regurgitation among valvular diseases. The S3 heart sound is the initial signal suggesting left heart failure and is often associated with severe mitral.
According to Pechetty & Nemani (2020), when ventricular pressure falls below the arterial pressure during early diastole, the ventricular valves open wide, and blood flows rapidly from the arterial (Y descent) into the ventricles. As a result, S3 is produced, which occurs at the beginning of the middle third of ventricular diastole. Pechetty & Nemani (2020) identified some possible causes of S3 (third heart sound), including hyperkinetic circulatory states, S3 in shunt lesions, S3 in mitral regurgitation, S3 in aortic regurgitation, S3 in aortic stenosis, S3 in ventricular systolic dysfunction, and S3 in LV diastolic dysfunction.
Regarding hyperkinetic circulatory states, S3 is often heard in severe anemia, beriberi, thyrotoxicosis, systemic AV fistula, complete A–V block, renal failure, and volume overload from excessive fluids or blood transfusion. Here, S3 is due to increased blood volume into a normal-sized ventricle (Pechetty & Nemani, 2020). S3 may also occur in athletes owing to slow heart rates and increased filling volumes. S3 in shunt lesions is due to increased blood flow and rapid early diastolic filling that may occur in large left to right shunt lesions producing S3. Therefore, the LV S3 is heard in patients with ventricular septal defect and patent ductus arteriosus, and RV S3 in patients with an atrial septal defect. S3 in mitral regurgitation occurs as a result of emptying of large left atrial blood volume into the left ventricle under higher than normal pressure (Pechetty & Nemani, 2020). In heart failure patients, S3 gallop is usually associated with increased left atrial pressures, increased LV end-diastolic pressures, and elevated serum brain natriuretic peptide (BNP) concentrations.
Conclusion
A third heart sound is a reflection of rapid left ventricular distention and increased atrioventricular flow. S3 is commonly created by the early diastolic rapid distention of the left ventricle that occurs along with ventricular filling and abrupt deceleration of the atrioventricular blood flow. There are several causes of S3, including hyperkinetic circulatory states, S3 in shunt lesions, S3 in mitral regurgitation, and others.
References
Pechetty, R., & Nemani, L. (2020). Additional Heart Sounds—Part 1 (Third and Fourth Heart Sounds). Indian Journal of Cardiovascular Disease in Women-WINCARS, 5(02), 155-164. https://doi.org/ 10.1055/s-0040-1713828.
Shono, A., Mori, S., Yatomi, A., Kamio, T., Sakai, J., Soga, F., & Hirata, K. I. (2019). Ultimate Third Heart Sound. Internal Medicine, 58(17), 2535-2538. https://doi.org/10.2169/internalmedicine.2731-19