Not all medical problems are easy to diagnose, and it can be especially tricky when similar symptoms occur in different diseases. It is important to consider all possible diagnoses, even when a patient has classic signs and symptoms of a very common diagnosis, such as a heart attack. Consider the following case study of a patient with chest pain and other symptoms typical of a heart attack.
Judy, a 67-year-old female, presents to the emergency department with chest pain that is unrelieved by rest. She states that the pain began the day before and has significantly worsened over time. She describes it as a heavy pain in the center of her chest. Judy rates her pain as a 15 on a scale from 1 to 10, with 10 being the worst pain. She also complains of weakness, shortness of breath, and nausea.
Judy also reports being under increased stress, because her father had passed away three days ago. She began having chest pain the evening of his funeral.
Judy has no personal history of heart disease, lung disease, or diabetes. She also denies tobacco, drug, and alcohol use. Judy says that she was not worried about the chest pain at first, because she exercises daily, eats a healthy diet, and does not smoke, but that she became more concerned as it worsened.
Evaluation in the emergency room includes cardiac monitoring, which shows sinus tachycardia with a rate of 110 beats per minute. Judy’s vital signs are stable with her blood pressure at 135/85 mmHg, unlabored respirations of 25 breaths per minute, and normal temperature of 98.8 °F. Her oxygen saturation is 98% on room air. She is given a sublingual nitroglycerin tablet and started on two liters of oxygen per nasal cannula.
A 12 lead electrocardiogram (ECG) is abnormal with a slight ST segment elevation. This can be a sign of cardiac ischemia, a restricted blood supply to the heart muscle. Blood troponin tests, a type of cardiac biomarker, show a slight elevation, which points to heart muscle damage.
The cardiologist orders an echocardiogram, which reveals hypokinesis (decreased movement) of the apical wall of the heart. Judy’s ejection fraction, which measures how well the heart is pumping blood, is abnormal at 35%. (Normal ejection fraction ranges from about 55 % to 70%).
The cardiologist also performs a coronary angiography to assess Judy’s coronary arteries for blockages. The cardiac angiography finds that her coronary arteries are not blocked or occluded. This helps rule out a heart attack (myocardial infarction).
The cardiologist considers the absence of coronary artery disease (CAD), her medical history, the results of all of her tests, and her recent history of extreme stress. Her final diagnosis is takotsubo cardiomyopathy, an uncommon temporary form of cardiomyopathy. It is also known as stress-induced cardiomyopathy and broken heart syndrome.
Judy is admitted to the hospital and prescribed a low-dose angiotension-converting enzyme (ACE) inhibitor and a beta-blocker to reduce the workload on the heart. Judy’s troponin tests return to normal on the second day of her hospital stay. After three days, her condition improves significantly and she has no permanent cardiac damage.
On discharge, Judy is instructed to continue taking the beta-blocker, to reduce stress in her life, and to follow up with the cardiologist in four weeks.
Pathophysiology of takotsubo cardiomyopathy
Takotsubo cardiomyopathy is characterized by reversible, left ventricular dysfunction in the absence of CAD. It is also known as stress-induced cardiomyopathy. Approximately 1-2% of patients (10% of women) admitted to the hospital with a suspected myocardial infarction are eventually diagnosed with takotsubo cardiomyopathy.
Takotsubo cardiomyopathy is triggered by a response to a physical or psychosocial stressor. Associated stressors include death of loved one, domestic abuse, natural disasters (such as earthquakes or tornado), severe pain, receiving a diagnosis of cancer, or even a surprise party. (See Stressors associated with broken heart syndrome [takotsubo cardiomyopathy]).
Stressors associated with broken heart syndrome (takotsubo cardiomyopathy)
The exact cause of takotsubo cardiomyopathy is unknown, but patients with this syndrome have elevated levels of stress hormones, or catecholamines, in their blood during the time of the incident. Normally, when a person is under stress, the sympathetic nervous system releases catecholamines, such as adrenaline, to help the body deal with the stressful event. Elevated levels of stress hormones can sometimes have a toxic effect on the cardiac tissue. It can “stun” the heart, causing decreased contractility and wall movement, especially at the apex, or bottom, of the heart.
This temporary loss of regional left ventricular contraction can lead to a decreased ejection fraction, in which the percentage of blood pumped from the left ventricle decreases with every heartbeat. When the ejection fraction is decreased, the heart does not pump effectively, putting the patient at risk for heart failure or even cardiogenic shock.
Ninety percent of patients diagnosed with takotsubo cardiomyopathy are postmenopausal women age 60 to 80. It remains unclear why more women have takotsubo cardiomyopathy than men do. One theory suggests that women may be more sensitive to the effects of catecholamines than men, especially after menopause.
Patients with takotsubo cardiomyopathy typically have very few risk factors associated with coronary artery disease (CAD), such as diabetes, smoking, high cholesterol, and high blood pressure.
Patients with takotsubo cardiomyopathy often have decreased contractility of the heart, so the signs and symptoms can mimic a myocardial infarction. Symptoms include:
- chest pain
- shortness of breath
- excessive sweating,
- nausea and vomiting
- weakness and fatigue
- irregular heartbeat
In severe cases, a patient can have symptoms of heart failure with fluid overload and pulmonary edema.
Differential diagnosis of takotsubo cardiomyopathy versus myocardial infarction
The symptoms of takotsubo cardiomyopathy can mimic those of a myocardial infarction, which can make diagnosis difficult. On admission, many patients have ECG changes (ECG) with an elevated ST segment or T wave inversion similar to a patient having a myocardial infarction. In addition, the patient will frequently have slightly elevated levels of cardiac biomarkers, such as troponin, which points to an acute myocardial infarction.
ECG changes and cardiac biomarker elevations due to takotsubo cardiomyopathy are generally temporary and will return to normal. In our case study, Judy did have slight elevation of her cardiac biomarkers and her ECG showed ST segment elevation, yet all returned to normal as her condition resolved.
It is important to note that a normal ECG is unusual and occurs in only 2% of patients. An echocardiogram may show hypokinesis (as in Judy’s case) or akinesis (no movement) of the walls of the left ventricle. The most common finding on the echocardiogram is ballooning or bulging out of the apex of the left ventricle. Patient will often have a reduced ejection fraction, which may lead to heart failure.
Coronary angiography or heart catheterization is an important test in making a differential diagnosis. A patient with myocardial infarction will frequently have blockages in the coronary arteries. A patient with Takotsubo cardiomyopathy will not have any blockages of the coronary arteries.
Currently, there are no standard guidelines for the treatment of patients with Takotsubo cardiomyopathy. Many physicians order the patient a beta-blocker and an ACE inhibitor. These drugs reduce the effects of catecholamines and lower the workload on the heart while the heart recovers.
Other drugs used for treatment may include a diuretic, which helps remove extra fluid from the body and reduce stress on the heart. Anticoagulants can also be ordered to reduce the risk of a blood clot. This is more likely to occur due to impaired contraction of the heart resulting in pooling of the blood in the heart.
The mortality rate for takotsubo cardiomyopathy is low, generally 3-5%. Patients are generally monitored in the hospital for two to three days and discharged after their symptoms resolve. Patients will be instructed to reduce or manage stress in their life. Most cases of takotsubo cardiomyopathy will completely resolve within one to four weeks. Physicians generally recommend an echocardiogram after four to six weeks to confirm this and that the patient’s ejection fraction has returned to normal.
Some physicians recommend that patients continue to take a beta-blocker to help reduce the effects of catecholamines and other stress hormones, but this is controversial. Recurrences are not prevented by beta blockers or ace inhibitors. In addition, there is no evidence that beta blockers are beneficial after the left ventricle has recovered.
The chance of a recurrence of Takotsubo cardiomyopathy is 5-10%; however, patients should be instructed to call 911 right away for immediate evaluation and treatment if they have similar symptoms in the future.
Nurses should be aware of this uncommon disorder in postmenopausal women. These women often have no risk factors or history of CAD. Takotsubo cardiomyopathy should be considered as a possible diagnosis in all patients with chest pain, especially with the onset of symptoms after a stressful situation.
The initial nursing care for these patients involves monitoring cardiac and hemodynamic status, providing supportive measures, and assessing for signs of heart failure or cardiogenic shock.
Because stress appears to be a trigger for Takotsubo cardiomyopathy, it is recommended that patients learn healthy coping strategies to manage their stress. There are many resources available to assist a patient in dealing with stress. Resources include self-help books, counseling, support groups, and relaxation exercises. Nurses should help patients assess their stressors and explore which method works best to address them.
A diagnosis of Takotsubo cardiomyopathy can be frightening for a patient and family. Nurses can help reassure then and relieve stress by providing information about Takotsubo cardiomyopathy, including the low rate of recurrence and its reversibility. Patients should also be encouraged to follow-up with their physician to verify the return of normal cardiac function.
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Annette Lynn Ferguson, RN, MS, CNE is an Assistant Professor at Ohio University Southern in Ironton, Ohio.