What is Takotsubo Cardiomyopathy (Broken Heart Syndrome)?
Takotsubo cardiomyopathy is a reversible stress-induced heart condition that mimics a heart attack but occurs without blocked coronary arteries, predominantly affecting postmenopausal women after emotional or physical stress. 1
Core Definition and Pathophysiology
Takotsubo syndrome is formally classified as "stress-induced cardiomyopathy" and represents a unique form of acute heart failure where the left ventricle suddenly weakens and balloons outward, creating a characteristic shape resembling a Japanese octopus trap (takotsubo). 1 The condition is triggered by a massive surge of catecholamines (stress hormones like epinephrine) that temporarily stun the heart muscle rather than causing permanent damage from blocked arteries. 2
The underlying mechanism involves supraphysiological elevations of plasma catecholamines that cause a β2-adrenergic receptor signaling switch from Gs to Gi protein signaling, which protects against cell death but causes negative inotropy (weakened contraction). 2 The apex of the heart is particularly vulnerable because it has increased β2-adrenergic receptor density despite relatively sparse sympathetic nerve supply. 2
Clinical Presentation
Patients present identically to acute myocardial infarction with:
- Chest pain 3
- ST-segment elevation or T-wave inversion on ECG 3
- Elevated cardiac troponin (though modest and disproportionate to the extensive wall motion abnormalities) 3, 1
- Dyspnea, hypotension, or even cardiogenic shock 4
The critical distinguishing feature is that coronary angiography reveals no obstructive coronary artery disease, making urgent angiography essential for diagnosis. 1, 5
Who Gets It?
- Approximately 90% of cases occur in women, with 96% being postmenopausal women ≥50 years of age 2, 1
- Mean age is 66.8 years 2
- Pre-existing psychiatric disorders (anxiety, depression) increase susceptibility 2
Triggers
Emotional stressors (grief, fear, anger) are the classic triggers, earning the "broken heart syndrome" nickname. 2 However, physical stressors are equally common, including acute medical illness, surgery, neurological conditions, respiratory failure, sepsis, chemotherapy, and endocrine disorders. 2
Diagnostic Features
The InterTAK Diagnostic Score helps distinguish Takotsubo from acute coronary syndrome using seven parameters: female sex, emotional trigger, physical trigger, absence of ST-segment depression (except in lead aVR), psychiatric disorders, neurologic disorders, and QT prolongation. 3 A score >70 points indicates 90% probability of Takotsubo syndrome. 3
Key diagnostic findings include:
- Wall motion abnormalities extending beyond a single coronary artery territory 3
- BNP/NT-proBNP substantially elevated, peaking at 24-48 hours 3
- Only slight creatine kinase elevation despite significant wall motion abnormalities 3
- QT interval prolongation (substrate for dangerous arrhythmias) 3
Morphological Patterns
Classic apical ballooning (akinesia of the apex with basal hyperkinesis) occurs most commonly, but variant forms exist: 3, 1
- Mid-ventricular variant (mid-segments affected, apex spared) 3, 2
- Basal variant (inverse takotsubo with apical hyperkinesis) 3, 2
- Focal variant (single segment involved) 3
Prognosis and Recovery
Despite initially appearing benign, Takotsubo has morbidity and mortality rates comparable to acute coronary syndrome. 3 In-hospital mortality is 4-5%. 5 However, complete functional recovery typically occurs within 1-4 weeks in survivors, which is required to confirm the diagnosis. 1, 6
Recurrence occurs in less than 10% of patients. 6 Importantly, transient right ventricular dysfunction can occur and is associated with more complications, longer hospitalization, and worse left ventricular dysfunction. 4
Critical Pitfall
The most dangerous pitfall is misdiagnosing this as a benign condition. 3 Acute complications include cardiogenic shock (20% develop left ventricular outflow tract obstruction), pulmonary edema, life-threatening ventricular arrhythmias from QT prolongation, apical thrombus formation, and death. 3, 7 All patients require the same urgent evaluation as STEMI patients, including emergent coronary angiography, because ECG alone cannot differentiate between the two conditions. 5