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Multiple accessory pathways in a patient with adult congenital heart disease
Dr Albert J Rogers, MD; Dr Mohan N Viswanathan, MD; Dr Sanjiv M Narayan, MD, PhD
Stanford University, Stanford, USA
The prevalence of adult congenital heart disease is increasing rapidly due to improved management of patients with these conditions in earlier life. Arrhythmias associated with the congenital malformations or the treatments associated with them arise throughout life in this population.
Methods & results
A 70-year-old woman conserved for chronically impaired cognitive function presented for evaluation of newly diagnosed heart failure with reduced ejection fraction (33%) and remote stroke six years ago without residua. Her care pathway included a 12-lead ECG, which revealed sinus rhythm with pre-excited QRS (Panel A). An echocardiogram revealed small muscular ventricular septal defects (VSD) with left to right shunting and mitral regurgitation. Coronary angiography was normal except for documented supraventricular tachycardia (SVT). The care pathway included electrophysiology study, which revealed a short HV in sinus rhythm (18ms). Progressive atrial pacing resulted in progressive pre-excitation until pathway AV block cycle length. Short RP SVT was easily induced at cycle length 465ms with eccentric coronary sinus (CS) activation. Ventricular overdrive pacing resulted in a VAV response. Tachycardia terminated with premature ventricular complexes that did not conduct to the atrium. In ventricular pacing, ablation at a site of fused atrial/ ventricular electrograms in the lateral left atrium (Panel B) abruptly eliminated pathway conduction, but sinus rhythm now showed a different pre-excitation pattern (Panel C). A second SVT was easily induced at cycle length 448ms, concentric CS activation, and a VAV response to ventricular pacing. Right atrial mapping in sinus rhythm revealed fused atrial-ventricular signals at the septal tricuspid annulus near the muscular VSD. Ablation eliminated residual pre-excitation (Panel D). SVT was no longer inducible, with no AV nor VA conduction during adenosine administration. The final ECG is shown in Panel E. The patient has improved clinically.
A systematic care pathway is central to managing patients with complex conditions such as adult congenital heart disease. This patient with new onset heart failure and Wolff-Parkinson-White syndrome was found to have muscular VSDs, tricuspid regurgitation and spontaneous SVT. Electrophysiology study revealed atrioventricular reentry with two distinct accessory pathways, one near the VSD. Accessory pathways are more common in patients with VSD than the general population and can occasionally be multiple in such patients. Adult congenital heart disease presents challenges in SVT management but can be successfully managed with a systematic care pathway.