Spontaneous Coronary Artery Dissection and Takotsubo Syndrome: Converging Mechanisms, Diagnostic Pitfalls, and a Unified Clinical Algorithm

Figure 1. Proposed shared pathophysiological mechanisms linking spontaneous coronary artery dissection and Takotsubo syndrome. This figure summarizes the hypothesized mechanistic overlap between spontaneous coronary artery dissection (SCAD) and Takotsubo syndrome (TTS). Emotional or physical stress may trigger a catecholamine surge, which represents a central shared pathway between the two conditions. In TTS, excess catecholamine signaling may promote myocardial stunning via shifts in β-adrenergic signaling, microvascular dysfunction, direct myocyte injury, and inflammatory activation, resulting in transient ventricular dysfunction. In SCAD, the same adrenergic and hemodynamic stress may increase coronary shear stress, promote vasospasm, and contribute to arterial wall disruption in predisposed individuals, particularly those with fibromuscular dysplasia, coronary tortuosity, or underlying genetic susceptibility. Hormonal influences may further modulate vulnerability to both conditions. The figure also illustrates the unresolved relationship between SCAD and TTS, which may occur sequentially, with one condition precipitating the other, or simultaneously in response to a shared trigger. The…

Figure 2. Proposed diagnostic algorithm for suspected Takotsubo syndrome–spontaneous coronary artery dissection overlap. This figure outlines a stepwise diagnostic framework for patients with suspected overlap between Takotsubo syndrome (TTS) and spontaneous coronary artery dissection (SCAD), particularly for women presenting with acute coronary syndrome. The initial evaluation incorporates clinical risk factors and electrocardiographic findings to guide the urgency of coronary angiography, with a low threshold for invasive evaluation when SCAD risk features are present. Coronary angiography, supplemented by intracoronary imaging when needed, is followed by assessment of regional wall motion abnormalities (WMA) relative to the suspected coronary territory using transthoracic echocardiography. Two-dimensional speckle-tracking echocardiography (STE) may provide incremental diagnostic value by identifying preserved longitudinal myocardial deformation despite apparent wall-motion abnormalities, thereby supporting myocardial viability and improving differentiation between TTS and acute myocardial infarction. Cardiac magnetic resonance (CMR) imaging performed within 7–14 days helps differentiate…