Background
Takotsubo cardiomyopathy is characterised by wall motion abnormalities in the apex and mid-regions of the heart, often triggered by physical or emotional stress. Takotsubo cardiomyopathy is more prevalent among the elderly, particularly in postmenopausal women. While Takotsubo cardiomyopathy typically improves within weeks, some cases may develop into cardiogenic shock or death in the worst case, with an associated mortality rate of 4.1% in adults. Reference Templin, Ghadri and Diekmann1 Reports of Takotsubo cardiomyopathy in children are limited, and instances involving single ventricle physiology are exceedingly rare. Reference Watanabe, Shiraishi, Takahashi and Tsuchida2–Reference Takamizawa, Ono, Saito and Ueda4 We report a case of a patient with single ventricle physiology who developed Takotsubo cardiomyopathy following coil embolisation of the minor aortopulmonary collateral arteries.
Case report
A 2-year-old boy weighing 10.2 kg was diagnosed with a single right ventricle, mitral atresia, double outlet right ventricle, and pulmonary atresia. He underwent a 3.5-mm modified Blalock–Taussig shunt at 1 month, which was upsized to 4.0 mm at 6 months, and bidirectional Glenn surgery at 11 months. At 1 year and 9 months, cardiac catheterisation was performed to evaluate the preoperative condition before the total cavopulmonary connection.
At 2 years and 3 months, he was admitted for coil embolisation of minor aortopulmonary collateral arteries. On admission, SpO2 was 88% on room air, respiratory sounds were clear, no heart murmurs were audible, and no lower limb oedema was found. The chest X-ray showed a cardiothoracic ratio of 52%, and the electrocardiogram indicated a first-degree atrioventricular block and incomplete right bundle branch block (Figure 1( a )). A laboratory examination showed brain natriuretic peptide was 12 pg/mL. Echocardiography demonstrated mild tricuspid regurgitation with preserved ventricular systolic function and no regional wall motion abnormalities. Under general anaesthesia, transcatheter coil embolisation was performed with eighteen coils to embolise seven arteries (Figure 1( b )). Arterial oxygen saturation decreased from 90.9% preoperatively (FiO2 0.21) to 84.7% postoperatively. The total anaesthesia time was 256 minutes, including 203 minutes of catheter intervention.
( a ) Twelve-lead electrocardiography. On admission, the heart rate was 133 beats per minute, first-degree AV block and incomplete right bundle-branch block. Two days after coil embolisation, ST-segment elevation was seen in leads II, III, and aVF. Four days after coil embolisation, ST-segment elevation resolved. ( b ) Transcatheter coil embolisation was performed with eighteen coils to embolise seven arteries.
On postoperative day 1, intravenous fluids were required because of poor activity and oral intake. The chest X-ray showed a cardiothoracic ratio of 50.8% with no positional abnormalities of the embolised coils. On day 2, SpO2 decreased to the high 70% range. Blood tests showed elevated brain natriuretic peptide (455 pg/mL), mild elevations in CK-MB (15 U/L, within total CK: 62 U/L), and troponin T (0.049 ng/mL), along with leukocytosis (16,400/µL) and C-reactive protein (15.1 mg/dL). The electrocardiogram showed ST elevation in leads II, III, and aVF (Figure 1( a )). The echocardiogram showed decreased wall motion at the apex. Urgent cardiac catheterisation confirmed the absence of coronary artery lesions via aortography.
After the catheterisation, the patient was admitted to the ICU with deep sedation and intravenous dobutamine and milrinone. Head MRI showed no abnormalities, while cardiac MRI indicated hypokinesis of the apex of the right ventricle without the signs of acute myocarditis (Figure 2). Consequently, a diagnosis of Takotsubo cardiomyopathy was made. Dobutamine was discontinued to avoid the aggravation of Takotsubo cardiomyopathy on the following day, and the patient was transferred to the general ward. By day 4, the electrocardiogram changes had resolved (Figure 1( a )), and the patient’s condition improved with brain natriuretic peptide levels decreasing to 63 pg/mL. On day 9, apical wall motion showed slight improvement. Oxygen therapy was discontinued on day 12; however, SpO2 decreased to the mid-70% range, and the decision was made to initiate home oxygen therapy. The patient was discharged on day 14 with SpO2 in the mid-80% range on 1 L/min of oxygen. A follow-up cardiac MRI 40 days after embolisation showed improvement of wall motion at the apex.
( a ) The cardiac MRI showed hypokinesis at the apex in the cine images. ( b ) T2 mapping showed no increase in T2 values of the myocardium, and there was no enhancement in both early and delayed phases with gadolinium contrast, suggesting that acute myocarditis was unlikely.
After sufficient recovery of cardiac function, the patient underwent total cavopulmonary connection with an 18-mm ePTFE graft four months after embolisation, at 2 years and 7 months of age. No recurrence of Takotsubo cardiomyopathy was observed throughout the clinical course.
Discussion
Takotsubo cardiomyopathy is typically triggered by physical or emotional stress; approximately 70% of patients have experienced such stress-inducing events. Reference Templin, Ghadri and Diekmann1 The “catecholamine surge hypothesis” suggests that the stress hormones such as epinephrine, norepinephrine, and cortisol can directly or indirectly cause transient cardiac contractile dysfunction. Reference Y-Hassan and Tornvall5,Reference Murthy, Shah, Rao, Bershad and Suarez6 In the adult cases, there are reports of Takotsubo cardiomyopathy occurring after patent ductus arteriosus closure. Reference Teramachi, Suda, Nishino, Kanaya, Iemura and Matsuishi9,Reference Li, Yang and Zhou10 The increase in afterload due to patent ductus arteriosus closure raises ventricular and aortic pressures, resulting in sympathetic activation and catecholamine release. In our case, coil embolisation of the minor aortopulmonary collateral arteries may have increased ventricular afterload and contributed to the onset of Takotsubo cardiomyopathy. However, multiple other potential contributors to Takotsubo cardiomyopathy were present, including inflammatory responses related to coil embolisation, prolonged anaesthesia and catheter intervention, and psychological stress associated with hospitalisation; therefore, increased afterload cannot be definitively considered the cause.
The prevalence of Takotsubo cardiomyopathy in children is 3.1 cases per 100,000 discharged patients, with a higher mortality rate than in adults (7% vs 4.1%). Reference Sendi, Martinez, Chegondi and Totapally7,Reference Vazirani, Rodríguez-González and Castellano-Martinez8 In a cohort of 54 paediatric patients with Takotsubo cardiomyopathy excluding cases of single ventricle, left ventricular ejection fraction measured by echocardiography improved in many cases within one month, with recovery ranging from two days to four months. Reference Vazirani, Rodríguez-González and Castellano-Martinez8 In our case, improvement in cardiac function was confirmed by cardiac MRI one month after symptom onset, suggesting that recovery in paediatric Takotsubo cardiomyopathy may follow a similar course even in patients with single ventricle physiology.
Coil embolisation of minor aortopulmonary collateral arteries in single ventricle cases before total cavopulmonary connection is a common clinical practice. In our case, SpO2 decreased from the low-80% range to the high-70% range on postoperative day 2, likely reflecting reduced pulmonary blood flow and decreased cardiac output. Other than our case, only one case has been reported in which a patient with a single right ventricle developed Takotsubo cardiomyopathy after coil embolisation of the minor aortopulmonary collateral arteries. Reference Watanabe, Shiraishi, Takahashi and Tsuchida2 Although the underlying mechanism remains unclear, the occurrence of Takotsubo cardiomyopathy after coil embolisation suggests the importance of careful post-procedural observation.
Conclusion
We report a paediatric case of Takotsubo cardiomyopathy following coil embolisation of minor aortopulmonary collateral arteries in a patient with a single ventricle, in whom early recovery of cardiac function enabled successful Fontan completion.
