Is Resynchronization Pacing Proarrhythmic Among Congenital Heart Patients? An Evaluation and Review.

BACKGROUND

Cardiac resynchronization therapy (CRT) can be an effective form of heart failure (HF) management among congenital heart disease (CHD) patients (pts) with and without surgically repaired defects. However, very long-term results are limited. Recently, CRT has been implicated to be proarrhythmic among older CRT recipients. This issue is largely unknown among younger CHD-CRT pts. This study presents up to a 20-year (y) continuous review of any arrhythmia (Arr) burden associated with CRT among CHD-HF pts.

METHODS

From 1999 to 2024, outcomes of 45 CHD-HF pts (NYHA II-IV) (age 4-57 y [mean 26]; 31% female) were compared between those on established medical management (MM) (n = 18) and CRT recipients (n = 27) followed continuously for 1-20 years. Pre-existing and any de novo Arr that occurred following CRT were documented. Clinical assessments were continuous.

RESULTS

Follow-up was for 1 to 20 y (mean 7.5 y ± 0.7 sem). Patient demographics (CRT vs. MM groups) were comparable. Pre-existing Arr were found in 16 pts (38%) from both groups: accelerated junction (one CRT), atrial flutter (one CRT; two MM), and ventricular tachycardia (six CRT; six MM). During follow-up, outcomes included 14 pt deaths and 7 heart transplants (HTs). Of these, pre-existing Arr were causative among three CRT recipients: two ≤ 2 y and one > 5 y after CRT. There were no new-onset Arr in any pt groups. CRT significantly improved patient survival free from HT or death at 10 y (44 vs. 13% [p < 0001]).

CONCLUSION

When applied effectively, CRT benefits CHD-HF pts without causing additional arrhythmias. However, pre-existing Arr remain a concern reflecting persistently adverse intrinsic myocellular issues among CHD-HF pts.