The Role of Optical Coherence Tomography in Clarifying the Mechanisms for Dobutamine Stress Echocardiography‐Induced Takotsubo Cardiomyopathy

Abstract

Takotsubo cardiomyopathy is a clinical disorder characterized by a transient dilatation and akynesis or dyskinesis of the left ventricular (LV) apex, mimicking an anterior wall acute myocardial infarction in the absence of significant coronary artery disease (CAD). It typically occurs during an episode of severe emotional or physical stress. Recent reports suggested the potential of dobutamine stress echocardiography (DSE) in inducing the aforementioned syndrome. The transient dysfunction of the LV does not fit any known coronary distribution. Furthermore, there is no obstructive CAD demonstrated at angiography to account for the observed dysfunction. Consequently, the pathophysiology of this syndrome is still undetermined. Here, we report a case of DSE-induced Takotsubo cardiomyopathy in which high-resolution intracoronary imaging was utilized to exclude possible vessel alterations to help provide potential mechanistic explanations for the development of this condition.

Dobutamine stress echocardiography in the exploration of the pathophysiology of takotsubo syndrome

“…The 3 patients who developed TTS in the setting of a DB stress echocardiography (ECHO) testing (DSE) were a 46-year old man, a 51year old woman, and a 41-year old woman, after receiving standard doses of DB (30 to 40 μg/kg/min), with one developing apical and the other 2 mid-ventricular ballooning [13]. More patients have been reported developing TTS in the setting of DSE, corroborating earlier reports [14][15][16][17][18][19][20][21][22][23]. Unbridled stimulation of adrenergic β-receptors by endogenous/exogenous CATS and synthetic β-adrenergic receptor agonists must be instrumental in the emergence of the regional myocardial contraction abnormalities (RMCAs) observed in TTS, and in this respect the topographic density of such adrenoceptors and their sensitivity to CATS must be important.…”

“…In all these situations, evaluating the infrequent emerging TTS with ECHO in close temporal proximity to the drug administration is impractical, since the emphasis in these emergencies is on the management of the often-lifethreatening clinical problem. In contrast, administration of DB for DSE, with its obligate frequent ECHO, ECG, heart rate (HR), and blood pressure (BP) monitoring, provide the appropriate platform to evaluate the effect of DB on the heart function, in patients with normal and abnormal DSE, and rare TTS [13][14][15][16][17][18][19][20][21][22][23]. DB is a direct-acting synthetic CATS and is the drug of choice for the noninvasive assessment of coronary artery disease (CAD).…”

“…DB is a direct-acting synthetic CATS and is the drug of choice for the noninvasive assessment of coronary artery disease (CAD). Standards of performing the DSE, and quantitative evaluation of the heart's function employing conventional ECHO, and strain ECHO, have been published [35,36] [13][14][15][16][17][18][19][20]. It has been postulated that TTS can arise due to the hyperdynamic basal segments creating an intra-cavity gradient caused by excessive release of CATS, occasionally in the setting of dehydration, particularly in elderly women, resulting in an isolated apical chamber that produces myocardial stunning without infarction, although even herein it is not clear whether the LVOTO or MCO is the cause or consequence of TTS [14-16, 49, 50].…”

“…One could focus on the documentation of the topography of RHMR preceding the emergence of RMCAs (Figure 2), diagnosed as TTS, their evolution and precipitation by given doses of DB, and the associated BP and HR changes. The published cases of DSE-triggered TTS do not provide any insights about such RHMR, but they only report ECHO data from baseline, and subsequent ECHOs, after the diagnosis of TTS had been made [13][14][15][16][17][18][19][20][21][22][23]. Important information may be forthcoming by a systematic analysis of the RHMR preceding the emergence of the TTS phenotype, with or without LVOTO, or MCO (Figure 3).…”

Dobutamine Stress Echocardiography and Takotsubo Syndrome: Could Milder Forms of this Pathology Confound the Diagnostic Value of the Test?

“…The elegant study of Fineschi et al, 1 published ahead of print in the Journal on January 11, 2013, described a patient who, in the process of a routine dobutamine stress echocardiography (DSE), developed Takotsubo syndrome (TTS). Perusal of the vast literature on the topic (1516 items in PubMed as of January 12, 2013, employing the search term "takotsubo") 2 reveals a number of similar reports.…”