High incidence of ventricular arrhythmias in patients with left ventricular enlargement and moderate left ventricular dysfunction.
BACKGROUND
Left ventricular ejection fraction (LVEF) ≤35% is the cutoff value used to identify patients at high risk of sudden cardiac death. However, whether patients who have moderate left ventricular dysfunction and left ventricular enlargement (LVE) have a high risk of ventricular arrhythmias (VAs) and cardiac death is unclear.


HYPOTHESIS
Patients with moderate left ventricular dysfunction and LVE may have a high risk of VAs.


METHODS
This study retrospectively analyzed the data of 853 patients who have an implantable cardioverter-defibrillator/cardiac resynchronization therapy cardioverter-defibrillator equipped with home monitoring. The patients were divided into 4 groups: group A, 35% < LVEF ≤ 45% and left ventricular end-diastolic dimension (LVEDD) ≥60 mm; group B, LVEF ≤35% and LVEDD <60 mm; group C, 35% < LVEF ≤ 45% and LVEDD <60 mm; and group D, LVEF ≤35% and LVEDD ≥60 mm.


RESULTS
During a mean follow-up period of 30 ± 13 months, 324 patients (38%) experienced VAs and 125 patients (14.7%) experienced cardiac death. Based on multivariate Cox regression modeling, group A had an increased risk of VAs (A vs B, hazard ratio [HR]: 1.563, 95% confidence interval [CI]: 1.029-2.375, P = 0.036; A vs C, HR: 1.661, 95% CI: 1.204-2.294, P = 0.002) and cardiac death (A vs B, HR: 1.845, 95% CI: 1.013-3.356; A vs C, HR: 2.041, 95% CI: 1.136-3.731, P = 0.021).


CONCLUSIONS
Patients with moderate left ventricular dysfunction and LVE have a high risk of VAs and cardiac death.
['Zhao|Shuang|S|', 'Chen|Keping|K|', 'Su|Yangang|Y|', 'Hua|Wei|W|', 'Yang|Jiefu|J|', 'Chen|Silin|S|', 'Liang|Zhaoguang|Z|', 'Xu|Wei|W|', 'Zhang|Shu|S|']
D058406:Cardiac Resynchronization Therapy D002681:China D005260:Female D005500:Follow-Up Studies D006329:Heart Conduction System D006801:Humans D017379:Hypertrophy, Left Ventricular D015994:Incidence D008297:Male D008875:Middle Aged D012189:Retrospective Studies D012307:Risk Factors D013318:Stroke Volume D017180:Tachycardia, Ventricular D013997:Time Factors D016896:Treatment Outcome D018487:Ventricular Dysfunction, Left D016277:Ventricular Function, Left
ventricular arrhythmias left ventricular ejection fraction left ventricular end-diastolic dimension implantable cardioverter defibrillator