THE HEART OF THE PROBLEM: FROM HEART ATTACK TO KIDNEY FAILURE
Adapted from Garner and Ree, National Center for Case Study Teaching in Science
Part I – Mrs. Helms came in through the front door of her house with an armful of groceries. She put the bag down on the kitchen counter and called to her husband. “Herb, I’m home! Are you ready for lunch?” She didn’t get an answer, so she walked to the living room and found Mr. Helms lying on the floor.
“Herb! Are you okay?” she asked as she grabbed his shoulder. Mr. Helms responded weakly while clutching his chest. Mrs. Helms frantically called 911. It only took EMS a few minutes to arrive and the paramedics transported Mr. Helms to the hospital. Upon admission to the hospital, Mr. Helms’ vital signs were recorded as follows:
Mr. Helms Normal
Systolic blood pressure (mm Hg) 90 120
Diastolic blood pressure (mm Hg) 52 80
Oral temperature (°F) 98.9 97.8-99.1
Heart rate (beats per minute) 120, irregular 60-80
Respiratory rate 33, labored 12-20
Oxygen saturation (amount of O2 in arterial blood) 89% 95-100%
Mr. Helms was admitted to the hospital with chest pains and shortness of breath. His wife was panicked since her 72 year-old husband had a history of heart disease and had a heart attack two years ago. The admitting physician suspected another heart attack and ordered an echocardiogram. After examination and an echocardiogram, Dr. Collins spoke with Mrs. Helms. “I’m very sorry, but your husband has had another heart attack resulting in valve failure. The heart attack was caused by an occlusion in an artery that provides the heart muscle with blood. Lack of blood flow to the area damaged the papillary muscle that controls a valve in his heart has been severely damaged and is no longer working.”
Questions
What is the function of the papillary muscle and how does it affect heart valve function?
Which valve is affected with damage to the papillary muscle in the left ventricle?
Based on your knowledge of cardiac circulation, which artery is probably occluded to cause damage to the papillary muscle in the left ventricle.
Why is Mr. Helms’ respiratory rate and oxygen saturation altered?
Why is Mr. Helms’ heart rate so high?
does Mr. Helms’ have high blood pressure? Explain.
Part II – Dr. Collins called Nurse Nan from the patient’s room and confided, “Mr. Helms is in bad shape. His left posteromedial papillary muscle was damaged from his heart attack. The papillary muscle is no longer able to maintain closure of the valve, and this has resulted in mitral valve prolapse. With decreasing cardiac output, this patient is in for a fight for his life.” Nurse Nan knew that maintaining cardiac output was necessary for adequate blood flow through the body. As Dr. Collins walked away, Nurse Nan composed herself to tell Mrs. Helms the bad news and returned to the patient’s room. Nurse Nan explained to Mrs. Helms that her husband had left-sided heart failure and that his blood pressure was slowly and steadily decreasing
How is the direction of blood flow disrupted because of mitral valve prolapse?
Stroke volume is defined as the amount of blood exiting the ventricle with each ventricular contraction. How does mitral valve prolapse change stroke volume? Explain your answer.
Cardiac output is defined as the amount of blood exiting the ventricle per minute. How does mitral valve prolapse change cardiac output? Explain your answer.
Part III – Mrs. Helms was very upset with the news of her husband’s condition. As the day progressed, she noticed that Mr. Helm’s breathing was increasingly difficult. He could barely speak without losing his breath. Mrs. Helms called the nurse to her husband’s room. “My husband can’t breathe! What is wrong?
I thought he had a heart attack not a respiratory condition!” Nurse Nan auscultated the patient’s chest listening to Mr. Helms’ respirations, which were rapid and wet, producing rales or crackling sounds. Nurse Nan calmly informed Mrs. Helms, “I’m sorry. Your husband’s condition is worsening. The damage to his heart is causing his respiratory problems.”
The left side of the heart receives blood from which part of the body? How about the right side of the heart?
The damage to Mr. Helms’ valve is only on the left side of the heart. If cardiac output from the right ventricle remains the same, but the left ventricle has altered cardiac output, what happens to the amount of blood in systemic circulation? How about pulmonary circulation?
Based on your answer to question #2, speculate as to the cause of Mr. Helms’ rales (wet breath sounds).
Part IV – The next morning when Nurse Nan started her shift, she immediately checked on Mr. Helms. His cardiovascular and respiratory conditions were still deteriorating, but Nurse Nan discovered something new. Mr. Helms’ urine output was almost nonexistent. Nurse Nan informed Dr. Collins, who was gravely concerned. Dr. Collins met with Mrs. Helms to tell her that her husband could not survive kidney failure. Mrs. Helms looked shocked.
She then became very upset and angry. “What did you do, Dr. Collins? My husband had a heart attack, but his kidneys were fine; he’s never had a kidney problem! How could you let this happen?” Nurse Nan put her arm around Mrs. Helms’ shoulders and Dr. Collins handed her a tissue. Dr. Collins explained, “The damage to your husband’s heart is very serious. The kidneys
rely on blood pressure to work and his heart failure is causing the kidney failure.”
Dr. Collins rushed Mr. Helms into surgery for valve replacement. Mrs. Helms waited anxiously in the waiting area for family for hours until she saw Nurse Nan coming toward her with a big smile. “Your husband is in the recovery room. He’s going to be just fine.” Mrs. Helms sighed with relief and gave Nurse Nan a big hug.
Questions
Helms’s damage to his mitral valve caused left-sided heart failure. What do you think might cause right-sided heart failure?
Describe the blood flow defect associated with right-sided heart failure.
What type of symptoms could be expected with right-sided heart failure?
Adapted from: “The Heart of the Problem”, Garner and Ree, December 2015, published by the National Center for Case Study Teaching in Science
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