An elderly woman complains that she can't get air into her lungs.
Mrs. B, 80 years old, in good health, and without any history of pulmonary disease or risk factors for coronary heart disease, returned from a vacation in Tahiti. Air temperatures there ranged from 80°F-90°F. Arriving home, she was greeted by an ambient temperature of 15°F, wind, and seven inches of snow on the ground. The next morning, while shoveling snow, Mrs. B noted marked “difficulty getting air into her lungs.” She returned to the house, and over the next 30 minutes, her symptoms resolved. The following morning, she resumed shoveling snow under similar weather conditions and soon experienced the same breathing problem. Once more, the respiratory difficulty subsided 20-30 minutes after she returned to the house. Later in the day, though her symptoms had abated, she came for evaluation.
Assessing the problem
1 Mrs. B had no history of shortness of breath or chest, arm, or jaw pain. Over the years, she had experienced several episodes of vasovagal syncope and near-syncope. Physical examination was unremarkable except for a moderate pectus excavatum. Her BP was 130/80 mm Hg, and her heart rate was 56 beats per minute.
An ECG, essentially normal on other visits, now revealed slight prolongation of the PR interval and ST-segment elevation in the chest leads (V2-V6) (see above) and in leads II, III, and aVF. A marked T-wave inversion in chest leads V4-V6 and in leads I and aVL was consistent with acute left ventricular apical ischemia and injury. Small Q waves in leads II, III, and aVF, low voltage, and counterclockwise rotation in the horizontal plane had been present for 49 years.These findings were thought to be related to her pectus excavatum.
We admitted Mrs. B to the hospital, where angiography revealed normal coronary arteries. Echocardiography showed severe dyskinesia and dilatation of the left ventricular apex as well as akinesia of the anteroseptal and inferoapical area. The base of the heart contracted hyperactively to give the appearance of a balloon. Ejection fraction was normal. MRI confirmed a severe regional wall-motion abnormality involving the cardiac apex and apical left ventricular walls but showed no evidence of MI. There was some question of a possible thrombus at the ventricular apex. Moderate cardiac enlargement was seen on chest x-ray. Troponin level was initially slightly elevated at 1.1 ng/mL but returned to normal within 24 hours.
Follow-up
2 Mrs. B was discharged on pravastatin, ramipril, amlodipine, and 81 mg of enteric-coated aspirin. She
was also prescribed warfarin (Coumadin) for three months, during which time she remained asymptomatic. At her three-month follow-up, her echocardiogram had returned to normal, and at four months, her ECG was back to baseline. Repeat chest x-ray revealed normal heart size and contour.
Five years later, Mrs. B has recovered completely, and her ECG and echocardiogram remain normal. She is physically active and an avid gardener. Any decreased exercise tolerance she feels when climbing steps is relieved with a few minutes' rest. She hopes to live to 100 years of age (as did her mother).
Discussion
3 In 1991, Dote et al reported a syndrome of acute left ventricular ballooning associated with a clinical pre-sentation resembling acute MI.1 They labeled it “Tako-tsubo syndrome” because the configuration of the left ventricle was similar to that of a narrow-necked pot used by Japanese fishermen to trap octopus (tako-tsubo). Since that first report, others have confirmed this entity primarily in postmenopausal, usually elderly, women and triggered by emotional or physical stress.2 The typical clinical picture is that of an acute left chest or retrosternal anginalike pain and/or shortness of breath precipitated by acute emotional or physical stress.
This entity, which has also been observed in younger patients, has been labeled “stress cardiomyopathy” because of its characteristic triggers. ECGs show ST-segment elevations and marked T-wave inversions, sometimes with a prolonged QT interval. The echocardiogram reveals dilatation and hypokinesis of the left (rarely the right) ventricular apex and often hypercontraction of the base. Ventricular thrombi have been identified. MRI findings are similar and can demonstrate gadolinium augmentation in the affected areas. Coronary arteries are normal on angiography. Troponin values are usually normal or slightly elevated.
For most patients, the hospital course is uneventful and the prognosis is good. As a rule, the ECG and echocardiogram return to baseline in the following weeks or months. In the very occasional patient, the initial cardiac insult is severe and the clinical picture can include cardiogenic shock, congestive heart failure, pulmonary edema, and ventricular arrhythmias. Ventricular rupture and death are rare.
Treatment
4 Therapy of the Tako-tsubo syndrome includes appropriate management of the previously noted complications. In Mrs. B's case, we also prescribed pravastatin, ramipril, amlodipine, and aspirin in the hopes of enhancing endothelial function and improving myocardial microvascular perfusion. Warfarin was added because of the suspicious mural thrombus.
Looking for a cause
5 How stress triggers Tako-tsubo cardiomyopathy has yet to be defined. Currently, the problem is thought to be neurohumoral imbalance associated with an initial outpouring of catecholamines.2-4 These may have an adverse effect on myocardial microvascular perfusion. Catecholamine cardiomyopathy has been seen in patients with pheochromocytoma and in patients receiving large dosages of norepinephrine. Furthermore, some individuals with acute subarachnoid hemorrhage have high catecholamine levels and ECG patterns similar to that seen in the Tako-tsubo syndrome. Many clinicians believe that emotional and/or physical stress could cause excessive sympathetic discharge to a very sensitive myocardial vasculature to bring about the Tako-tsubo syndrome.
We are adding “snow shoveling in a very cold and windy atmosphere” to the stresses that have precipitated the Tako-tsubo syndrome. We also wonder whether Mrs. B's sensitive autonomic nervous system (as evidenced by her episodes of vasovagal syncope) and/or the drastic temperature change from warm to very cold could have contributed to the trigger.
Dr. Kaplan and Dr. Miller are professors of clinical medicine (cardiology) at the Feinberg School of Medicine, Northwestern University, in Chicago.
References
1. Dote K, Sato H, Tateishi H, et al. Myocardial stunning due to simultaneous multivessel coronary spasms: a review of 5 cases [in Japanese]. J Cardiol. 1991;21:203-214.
2. Wittstein IS, Thiemann DR, Lima JA, et al. Neuro-humoral features of myocardial stunning due to sudden emotional stress. N Engl J Med. 2005;352:539-548. Available online at content.nejm.org/cgi/content/full/352/6/539, accessed January 23, 2009.
3. Elesber A, Lerman A, Bybee KA, et al. Myocardial perfusion in apical ballooning syndrome: correlate of myocardial injury. Am Heart J. 2006;152:469.e9-e14.
4. Ortak J, Kurowski V, Wiegand UK, et al. Cardiac autonomic activity in patients with transient left ventricular apical ballooning. J Am Coll Cardiol. 2005;46:1959-1961.