3-2 clinical review

A 55-year-old woman presents with 2 days of squeezing retrosternal chest pain on walking, lasting 1 hour. Her medical history includes hypertension on lisinopril and hyperlipidemia on atorvastatin, but no diabetes, and she is an ex-smoker, quitting 20 years ago. She has been on a diet and exercise program for 6 months with a weight loss of 14.5 kg (32 lb). She has been under stress lately for financial (credit card) debt and a possible company closure. Her vital signs and physical examination are normal except for a possible S4. An ECG shows anterior T wave inversion (Figure 1) and her troponin has increased to 0.16 ng/mL. The following day she has a normal coronography. What is her diagnosis and how should she be treated?

Figure 1. ECG at presentation showing sinus rhythm at 88 bpm with diffuse T wave inversion.

Discussion

Stress-induced cardiomyopathy is a newly reported clinical syndrome initially described in Japan in case reports from 1991–2001.1 Other nomenclatures include takotsubo cardiomyopathy, transient left ventricular apical ballooning, acute reversible cardiomyopathy, and broken heart syndrome. A tako-tsubo is a Japanese ceramic vessel used to trap an octopus; its shape is similar to the transient left ventricular apical ballooning seen during ventriculography in these patients (Figure 2). More recent case series have now been reported in the United States and Europe in 2003–2005.

Figure 2. Ventriculography showing left ventricular apical ballooning (left) compared with a tako-tsubo (right). Left image reproduced with permission of Internet Scientific Publications LLC at www.ispub.com. From The Internet Journal of Cardiovascular Research. Right image courtesy of Dr. Satoshi Kurisu.

The pathophysiology is not fully elucidated; however, clinically the chest pain is attributed to severe physical or psychological stress. A recent article linked earthquakes in Japan to an increased incidence of stress-induced cardiomyopathy and even possibly sudden death.2 Neurohumoural stimulation with elevated levels of plasma catecholamines and neuropeptides has been documented in this syndrome.3 This sympathetic stimulation, two to three times the level compared with Killip class III myocardial infarction, may possibly result in epicardial or microvascular coronary spasm and myocardial stunning. Similar cardiac dysfunction is known to result from neurohumoural stimulation in subarachnoid hemorrhage and acute stroke. Although possibly related through similar pathophysiology, stress-induced cardiomyopathy is distinguished from cardiac syndrome X, which is characterized by stable ischemic chest pain and normal coronary arteries.

Two recent articles from the United States3,4 and a review of mostly Japanese cases have allowed for the characterization of stress-induced cardiomyopathy and proposal of diagnostic criteria.5,6 Most cases have occurred in women (82–100%) with a mean age of 65 years old (range 27–89 years), presenting with chest pain, dyspnea, and occasionally severe hypotension. The patients frequently had previous coronary risk factors including hypertension (40–70%), smoking (chronic obstructive pulmonary disease), hyperlipidemia, and diabetes mellitus. Prevalence has been estimated at 1.2–2.2% of suspected cases of acute coronary syndrome or myocardial infarction requiring coronary angiography.6 Almost all patients presented after severe psychological stress (e.g., death of a relative) or physical stress from noncardiac critical illness. Transient left ventricular apical ballooning has been described in 28% of patients admitted to a medical ICU for respiratory failure or sepsis.7

Initial ECG changes have shown ST-segment elevation, often in precordial leads, and diffuse T wave inversions. In the following days to weeks, prolonged Q–T interval and diffuse T wave inversion are found. The cardiac enzyme elevations are mostly mild increased troponin levels, found in over 80% of cases. As these cases mimic acute coronary syndrome and ST-segment elevation myocardial infarction, coronography is usually performed, revealing normal arteries. The ventriculography usually shows left apical ballooning with apical akinesis, and decreased left ventricular ejection fraction (LVEF) to 30% (range 15–49%). Echocardiography and cardiac MRI have confirmed this characteristic distal left ventricular apical dysfunction and low ejection fraction. Serial echocardiography shows rapid improvement of LVEF in the subsequent weeks.

The prognosis for stress-induced cardiomyopathy is favourable, with a complete recovery of LVEF in the following month. Complications reported with stress-induced cardiomyopathy are similar to myocardial infarction, including heart failure, ventricular arrhythmias, and cardiogenic shock requiring intra-aortic balloon pump. In addition, significant left intraventricular obstruction from the hyperdynamic basal segment has developed. Less frequently, cases have been reported of ventricular rupture, acute mitral regurgitation, and ventricular thrombus. There has been no mortality in most case series, but the overall reviews indicate a 1% in-hospital death rate. Interestingly, several cases of recurrence have been documented in the follow-up periods.

The management of stress-induced cardiomyopathy has not been studied; however, general supportive care of a cardiac patient would seem appropriate. Vasopressors should be avoided for hypotension as they may exacerbate the syndrome and cause ventricular outflow obstruction. The standard treatment for heart failure would be reasonable with beta-blockers, angiotensin-converting enzyme inhibitors, diuretics, and aspirin. The duration of therapy is not known.

The diagnosis of stress-induced cardiomyopathy should be suspected in postmenopausal women with typical chest pain following severe emotional or physical stress presenting with acute myocardial infarction (AMI) or acute coronary syndrome (ACS). The marked ECG changes and slight increased cardiac enzymes will require management similar to that for AMI or ACS. The normal coronography with transient left ventricular apical ballooning and echocardiography are required to confirm the diagnosis. The proposed criteria for stress-induced cardiomyopathy5 include all of the following:

1. Transient akinesis or dyskinesis of the left ventricular apical and midventricular segments with regional wall-motion abnormalities extending beyond a single epicardial vascular distribution

2. Absence of obstructive coronary disease or angiographic evidence of acute plaque rupture

3. New ECG abnormalities (ST segment elevation or T wave inversion)

4. Absence of recent significant head trauma, intracranial bleeding, pheochromocytoma, myocarditis, or hypertrophic cardiomyopathy

Case Summary

The patient described above had an abnormal ventriculography with apical dyskinesis and her echocardiography performed 3 days after presentation was normal. She was treated with aspirin, heparin (48 hours), and beta-blocker, and her lisinopril and atorvastatin were continued. At her 1 month follow-up she had no further chest pain but her ECG abnormalities were persistent.

References

1. Tsuchihashi K, Ueshima K, Uchida T, et al. Transient left ventricular apical ballooning without coronary artery stenosis: a novel heart syndrome mimicking acute myocardial infarction. Angina Pectoris-Myocardial Infarction Investigations in Japan. J Am Coll Cardiol 2001;38:11.

2. Watanabe H, Kodama M, Okura Y, et al. Impact of earthquakes on Takotsubo cardiomyopathy. JAMA 2005;294:305.

3. Wittstein IS, Thiemann DR, Lima JA, et al. Neurohumoral features of myocardial stunning due to sudden emotional stress. N Engl J Med 2005;352:539.

4. Sharkey SW, Lesser JR, Zenovich AG, et al. Acute and reversible cardiomyopathy provoked by stress in women from the United States. Circulation 2005;111:472.

5. Bybee KA, Kara T, Prasad A, et al. Systematic review: transient left ventricular apical ballooning: a syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med 2004;141:858.

6. Stollberger C, Finsterer J, Schneider B. Transient left ventricular dysfunction (tako-tsubo phenomenon): findings and potential pathophysiological mechanisms. Can J Cardiol 2006;22:1063.

7. Park JH, Kang SJ, Song JK, et al. Left ventricular apical ballooning due to severe physical stress in patients admitted to the medical ICU. Chest 2005;128:296.

Article citation: Robb J. Stress-Induced (Takotsubo) Cardiomyopathy. Can J Gen Intern Med 2008;3(2):58-60