Risk Stratification for Serious Arrhythmic Events Using Nonsustained Ventricular Tachycardia and Heart Rate Turbulence Detected by 24-Hour Holter Electrocardiograms in Patients with Left Ventricular Dysfunction
Annals of Noninvasive Electrocardiology, 08/02/2012
Miwa Y et al. – Heart rate turbulence (HRT) can facilitate the predictive accuracy of nonsustained ventricular tachycardia for identifying patients at risk for serious arrhythmic events in patients with LV dysfunction.Methods
- The authors enrolled 299 consecutive patients with LV dysfunction (ejection fraction ≥ 40%) including ischemic (n = 184) and nonischemic causes (n = 115).
- The presence of NSVT was assessed on Holter electrocardiograms (ECGs).
- HRT was simultaneously measured from Holter ECGs, assessing two parameters: turbulence onset (TO) and turbulence slope (TS). HRT was considered positive when both TO and TS were abnormal.
- The end point was defined as of sudden cardiac death (SCD) and sustained ventricular tachyarrhythmias (VTs).
- NSVT was documented in 93 patients (32.7%).
- For HRT assessment, 17 patients (5.6%) were not utilized.
- Of 282 patients, 68 (24.1%) were HRT positive.
- During follow–up of 960 ± 444 days, 14 patients (5.0%) reached the end point. NSVT, HRT, and diabetes were significantly associated with the end point.
- On multivariate analysis, NSVT had the strongest value for the end point, with an HR of 4.4 (95%CI, 1.4–14.3; P = 0.0138).
- When NSVT combined with HRT, the predictive accuracy is more increased, with an HR of 8.2 (95%CI, 2.9–23.3; P < 0.0001).
- The predictive values of the combination were higher than single use of NSVT or HRT.