The current surgical treatment of dextro-transposition of the great arteries is arterial switch; Reference Jatene, Fontes and Paulista1 before this was the standard of care, the atrial switch surgery was performed, leaving the morphologically right ventricle as the systemic ventricle. Nowadays, we must be prepared to deal with the long-term complications of this procedure.
Clinical case
A 33-year-old male, with good functional status, was submitted to a Senning operation Reference Senning2 by the age of 16 months. He was referred to our Adult CHD Clinic in 2003. He was on permanent junctional rhythm with frequent pauses (the longest 5200 ms), with a mean heart rate of 50 bpm, asymptomatic and with a good functional capacity on serial treadmill exercise tests. It was decided to maintain surveillance. In 2013, he performed an echocardiogram that showed a moderately dilated systemic ventricle, with severe hypertrophy and moderated systolic dysfunction. He was medicated with lisinopril 5 mg once daily (dosage was limited by symptomatic hypotension). On February 2019, the patient was admitted to the Emergency Department complaining of episodic shortness of breath, chest pain and palpitations that lasted for 2 minutes, without syncope. The patient was admitted for rhythm monitoring, as he had a complex CHD with systemic ventricular dysfunction and high risk for arrhythmic events and sudden cardiac death. Reference Baumgartner, De Backer and Babu-Narayan3 The patient presented 2 episodes of symptomatic monomorphic non-sustained ventricular tachycardia, the longest one for 14 seconds (Fig 1), and a basal slow junctional rhythm (minimum heart rate 23 bpm), with frequent premature beats and bigeminy. In the context of a post-Senning patient, with systemic ventricular dysfunction, symptomatic non-sustained ventricular tachycardia and a slow junctional rhythm, a single chamber Implantable Cardioverter Defibrillator (ICD) was implanted in the sub-pulmonary ventricle (morphologically left). An after-procedure echocardiogram was performed with no atrioventricular (AV) valve dysfunction or worsening of systemic ventricle function. He was discharged with medical therapy for heart failure, including low-dose beta-blocker. Therapy was limited by symptomatic hypotension. During a 12-month follow-up, the patient was on New York Heart Association (NYHA) functional class I, with mild systemic atrioventricular valve insufficiency, with a percentage of ventricular pacing of 28% and no arrhythmic events (Figs 2 and 3).
Figure 1. Telemetry monitoring: ( a ) Non-sustained ventricular tachycardia; ( b and c ) basal heart rhythm, minimum heart rate 23 bpm, frequent premature beats, bigeminy and pauses.
Figure 2. ICD implantation.
Figure 3. Echocardiographic follow-up.
Conclusions
Ventricular arrhythmias are the main cause of late-mortality in d-TGA. Reference Baumgartner, De Backer and Babu-Narayan3 Although the complex CHD imposes difficult technical issues, many patients may require cardiac device implantation during adulthood, with important clinical and prognostic impact.
Acknowledgements
None.
Financial support
This research received no specific grant from any funding agency, commercial or not-for-profit sectors.
Conflicts of interest
None.
