Heart Rhythm Disturbances in Children with Single Ventricle at Different Stages of Defect Hemodynamic Correction

Irina Plotnikova1, Liliya Svintsova1, Olga Dzhaffarova1, Olga Yanulevich1, Anna Tupikina1, Victor Saushkin1, Evgeny Krivoshchekov1, Igor Kovalev1,2
1 Pediatric Cardiology Department, Federal State Budgetary Scientific Institution "Research Institute for Cardiology", Russia
2 Pediatric Cardiology and Arrhythmology Department, Research and Clinical Institute for Pediatrics at the Pirogov Russian National Research Medical University, Russia

Aim: To assess heart rhythm disturbances (HRD) rate and structure in children with single ventricle (SV) at the stages of defect hemodynamic correction.

Methods: 70 patients with CHD with SV that were performed total cavopulmonary connection (TCPC) with extracardiac conduit were examined. All the patients were performed ECG and Holter monitoring. To integrate data, all the patients were divided into 8 groups: 1 – sinus rhythm; 2 – non-sinus rhythm (atrial rate, nodal rhythm, AV-dissociation); 3 - bradyarrhythmia (sinus and atrial bradycardia); 4 – sinus tachycardia; 5 – supraventricular tachycardias (SVT) (paroxysmal and incessant); 6 – extrasystole (supraventricular and ventricular); 7 – atrioventricular block (AVB) of I-II deg.; 8 – AV block, III deg.

Results: Only one patient had 2 SVT paroxysms, broken cordarone bolus dosing, in early postoperative period at the first stage. At the second stage (Glenn operation) HRD was recorded in 14 (20%) pts, in 7 (10%) of them during admission. Non-sinus rhythm (86%) predominated in HRD structure. At the third stage (TCPC) recent HRD was recorded in 36 (51.4%) pts. After TCPC recent HRD was registered in 23 (32.9%) pts, in 13 of them HRD was preserved, and in 34 (48.6%) it was not recorded. Arrhythmias, connected with sinus node dysfunction (bradyarrhythmias, SVT, non-sinus rhythm), predominate in HRD structure in 43.9%. The negative correlation between Sat O2 in capillary blood and arrhythmias frequency was disclosed after TCPC, p=0,02. The older patient at TCPC and lower SV contractile function after it, the oftener arrhythmias, connected with sinus node dysfunction, appeared (p=0,04).

Conclusions: HRD appeared in patients with extracardiac Fontan at any stage of hemodynamic correction. Arrhythmias, connected with sinus node dysfunction, predominated in frequency of occurrence. Low Sat, low SV contractile function and the age of TCPC made their own contributions into HRD appearance after Fontan.