A Patient with Hypertrophic Obstructive Cardiomyopathy Presenting with Left Ventricular Apical Ballooning Syndrome

Case Presentation. A 65-year-old female with no known coronary artery disease presented with acute chest tightness and shortness of breath a few days after the death of her husband. She had a personal history of smoking and hypertension, treated with a beta-blocker and a thiazide diuretic. She had a strong family history of hypertrophic obstructive cardiomyopathy (HOCM). Her electrocardiogram (ECG) showed marked T-wave abnormalities in the inferior and precordial leads (Figure 1). Her cardiac biomarkers were mildly positive. An echocardiogram showed asymmetric septal wall thickening of 20 mm, left ventricular outflow tract (LVOT) spontaneous rest gradient of 40 mmHg, and systolic anterior motion of the mitral leaflet (Figure 2A). There was severe mitral regurgitation (MR) on color flow imaging (Figure 2B). A left ventriculogram (Figure 3) was remarkable for hyperkinesis of the ventricle at the base, and akinesis at the apex, with a picture of apical ballooning. Severe mitral regurgitation was evident. On pullback of the catheter from the left ventricular apex to the outflow tract, a 40 mmHg gradient was noted (Figure 4). The aortic pressure tracing showed the typical “spike and dome” configuration seen in obstructive cardiomyopathy (Figure 5). An angiogram showed only mild coronary artery disease. There were no obvious coronary lesions to explain the apical akinesis. A diagnosis was made of apical ballooning syndrome in this patient with preexisting HOCM. The patient later proceeded to undergo surgical septal myectomy. On histopathology, her septal myocardium showed the typical fibrosis and myocyte disarray and hypertrophy seen in hypertrophic cardiomyopathy (Figure 6). A repeat echocardiogram 5 days after the surgery documented the disappearance of the LVOT gradient and MR and a significant improvement in LV apical wall motion. Discussion. Transient apical ballooning syndrome, also known as Takotsubo cardiomyopathy, is an acute cardiac condition that was first described in Japan in 1991.¹ Since then, more cases have been described in the United States and Europe.^2,3 The typical clinical scenario consists of an elderly woman (in more than 80% of the cases) presenting with symptoms and signs mimicking an acute myocardial infarction following significant mental or physical stress. On imaging, the LV apex and the mid ventricle appear aneurysmal — but without real thinning of the ventricular wall — with hypercontractile basal segments and an overall reduced LV ejection fraction. Obstructive epicardial coronary atherosclerotic disease is typically absent. The most common ECG finding on presentation is ST-segment elevation, but ST-depression and nonspecific T-wave changes have also been reported. Cardiac biomarkers are usually mildly elevated. Although many patients with transient apical ballooning syndrome can be very sick on presentation, with pulmonary edema and cardiogenic shock described in some, the prognosis is usually favorable. LV function improves and the wall motion abnormalities correct themselves in almost all patients within 2 weeks of the diagnosis. Recurrence of the syndrome is rare. While the pathophysiology of this condition is unknown, it has been speculated that excess catecholamine levels, microvascular or endothelial dysfunction and possible transient vascular spasm are responsible. In a small series of 5 patients undergoing endomyocardial biopsy, histopathology showed interstitial infiltrates of mononuclear lymphocytes and macrophages and contraction bands without myocyte necrosis.³ Hypertrophic cardiomyopathy is a relatively common genetic cardiovascular disease with a prevalence of about 1 in 500 people. Grossly, there is asymmetric hypertrophy predominantly involving the interventricular septum. Some patients develop dynamic LVOT obstruction and systolic anterior motion of the mitral leaflet with resultant mitral regurgitation.⁴ Apical ballooning syndrome has been previously described in a patient with the apical variant of hypertrophic cardiomyopathy.⁵ Such a variant usually shows no LVOT obstruction. Conversely, not every patient with dynamic LVOT obstruction has HOCM. The development of a dynamic LVOT obstruction in the setting of an acute myocardial infarction and anteroapical akinesis of the LV has been previously reported.⁶ Transient acute LVOT obstruction has also been described in patients presenting with stress-induced anteroapical myocardial stunning.^7,8 These patients had no evidence of HOCM. In our patient, HOCM was diagnosed based on histopathology, thickened septum on echocardiography and her family history. We believe that her presentation with apical ballooning was superimposed on a preexisting HOCM. It is possible that psychosocial stress, coupled with impaired coronary flow reserve and a heightened catecholamine surge related to the LVOT obstruction, may have precipitated the apical myocardial stunning in our patient.

References 1. Dote K, Sato H, Tateishi H, et al. Myocardial stunning due to simultaneous multivessel coronary spasms: A review of 5 cases. J Cardiol 1991; 21:203–214. 2. Bybee KA, Kara T, Prasad A, et al. Left ventricular apical ballooning: A syndrome that mimics ST-segment elevation myocardial infarction. Ann Intern Med 2004;141:858–865. 3. Wittstein IS, Thiemann DR, Lima JAC, et al. Neurohumoral features of myocardial stunning due to sudden emotional stress. N Engl J Med 2005;352:539–548. 4. Nishimura RA, Holmes DR Jr. Hypertrophic obstructive cardiomyopathy. N Engl J Med 2004;350:1320-1327. 5. Miyoshi S, Hara Y, Ogimoto A, et al. Repeated changes of electrocardiogram caused by Takotsubo-type cardiomyopathy: A case with hypertrophic nonobstructive cardiomyopathy. Nippon Ronen Igakkai Zasshi 2005;42:112–115. 6. Haley JH, Sinak LJ, Tajik AJ, et al. Dynamic left ventricular outflow tract obstruction in acute coronary syndromes: an important cause of new systolic murmur and cardiogenic shock. Mayo Clin Proc 1999;74:901–906. 7. 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. J Am Coll Cardiol 2001;38:11–18. 8. Villareal RP, Achari A, Wilansky S, Wilson JM. Anteroapical stunning and left ventricular outflow tract obstruction. Mayo Clin Proc 2001;76:79–83.