Left ventricular hypertrabeculation is a novel predictor of life-threatening arrhythmic events in long QT syndrome...

Long QT syndrome (LQTS) is a malignant cardiac channelopathy for patients with traditionally normal heart structures. Sporadic cases reported left ventricular hypertrabeculation (LVHT) was a deadly double hit in LQTS patients. Here we summarize the prevalence of LVHT within LQTS subjects and analyse the correlation of LVHT with life-threatening arrhythmic events (LAEs).

The study cohort consisted of 170 genotype-confirmed LQTS patients, which were classified to two groups, including non-left ventricular hypertrabeculation LQTS patients(LQTS-N-LVHT group) and LQTS-LVHT co-phenotype individuals (LQTS-LVHT group) according to the diagnosis criteria of LVHT. The primary endpoint was LAEs, defined as arrhythmogenic syncope, sustained ventricular tachycardia (VT), appropriate ICD shocks, sudden cardiac death.

Eight LQTS patients (8/170, 4.7%) in the cohort met diagnostic criteria of LVHT. No statistical difference in symptomatology, Schwartz score, QTc interval in electrocardiograms, and proportion of PVCs or torsade de points (Tdp) in ambulatory Holter monitoring was revealed between two groups. By contrast, LQTS-LVHT subjects had a higher ratio of documented VF in ambulatory Holter monitoring compared with LQTS-N-LVHT patients (LQTS-LVHT 2/8, 25.0% vs. LQTS-N-LVHT 3/111, 2.7%, p = 0.036). In total, 59 patients (59/170, 34.7%) developed LAEs during follow-up duration of 52.8 ± 32.3 months. Significant difference was found between two groups by the log-rank test (p < 0.001).A univariate Cox regression analysis was performed demonstrating that LVHT was a significant predictor of LAEs[HR: 4.02 (1.71-9.45), P = 0.001].A multivariate Cox regression analysis indicated that LVHT remained a predictor of LAEs [hazard ratio: 3.02 (1.24-7.36), p = 0.015].

LVHT is a novel predictor of life-threatening arrhythmic events in LQTS patients. Effective prevention treatment should be emphasized to prevent life-threatening cardiac events in LQTS-LVHT patients.