Obstructive Hypertrophic Cardiomyopathy and Takotsubo Syndrome: How to Deal With Left Ventricular Ballooning?

Abstract

Currently, there are 2 proposed causes of acute left ventricular ballooning. The first is the most cited hypothesis that ballooning is caused by direct catecholamine toxicity on cardiomyocytes or by microvascular ischemia. We refer to this pathogenesis as Takotsubo syndrome. More recently, a second cause has emerged: that in some patients with underlying hypertrophic cardiomyopathy, left ventricular ballooning is caused by the sudden onset of latent left ventricular outflow tract obstruction. When it becomes severe and unrelenting, severe afterload mismatch and acute supply-demand ischemia appear and result in ballooning. In the context of 2 causes, presentations might overlap and cause confusion. Knowing the pathophysiology of each mechanism and how to determine a correct diagnosis might guide treatment.

Keywords: Takotsubo; acute cardiovascular care; ballooning; hypertrophic cardiomyopathy; left ventricular outflow tract obstruction.

Figure 1. Hypertrophic cardiomyopathy and latent obstruction.

Transthoracic echocardiography in a 60‐year‐old man with angina and a new systolic murmur. Panels on the left show systolic anterior motion (SAM) at rest without mitral septal contact, mild septal bulge, normal 4‐chamber‐view systolic function, long mitral anterior leaflet measuring 30 mm, without resting left ventricular outflow tract (LVOT) gradient. After exercise stress echocardiography, an LVOT gradient of 50 mm Hg, due to SAM and mitral–septal contact, were detected. Mild septal bulge and normal systolic function were appreciated (see also Video S1).

Figure 2. Acute apical ballooning in patient with hypertrophic cardiomiopathy (HCM) and latent obstruction.

Transthoracic echocardiography in the same patient of Figure 1 after access to emergency room for chest pain, dyspnea, and unstable hemodynamic condition (blood pressure = 70/40 mm Hg). Parasternal and apical long‐axis views and apical 4‐chamber views showing acute left ventricular (LV) ballooning (white arrowheads) with severe systolic anterior motion (SAM) and mitral–septal contact (red arrows) (see also Video S2). Continuous‐wave Doppler showing high left ventricular outflow tract (LVOT) gradient of 90 mm Hg in the lower panel on the right. Complete recovery after intravenous beta‐blocker and phenylephrine infusion was observed. This case demonstrates how the course of HCM with latent obstruction can be complicated by apical LV ballooning when the gradient becomes severe and unrelenting.

Figure 3. Lobster claw abnormality.

Midsystolic drop in pulsed‐wave Doppler velocities spectral curve measured 2.5 cm below the mitral valve. The white arrow points to the nadir of the drop, which mimics the aspect of the lobster claw. Left ventricular outflow tract (LVOT) gradient was documented of 90 mm Hg. This sign is ubiquitous in patients with LVOT gradients ≥60 mm Hg and is a manifestation of afterload mismatch. After abolition of the gradient with disopyramide on the same day, the midsystolic drop is no longer detectable.

Figure 4. ECG, left ventricular outflow tract (LVOT) pressure gradient, and tissue Doppler imaging (TDI) velocity curve of basal septum in a patient with obstructive hypertrophic cardiomyopathy.

Note the simultaneous development of LVOT gradient (white arrow) in the post–ventricular complex beat and the midsystolic septal deceleration notch in the tissue Doppler curve (black arrow). This graphical picture defines the phenomenon named paradoxical reversible systolic dysfunction. Reproduced from Breithardt et al with permission. Copyright ©2005 BMJ Publishing Group Ltd.

Figure 5. Management and treatment algorithm.

Diagnostic nodes and therapeutic strategies in patients with apical ballooning and intraventricular obstruction. bb indicates beta‐blocker; HCM, hypertrophic cardiomyopathy; LV, left ventricular; LVOT, left ventricular outflow tract; LVOTO, left ventricular outflow tract obstruction; and TTS, Takotsubo syndrome.