Heart rate turbulence and variability in patients with ventricular arrhythmias
Abstract:
Overview
Background. To evaluate the changes in autonomic neural control mechanisms before
malignant ventricular arrhythmias, we measured heart rate variability (HRV) and heart rate
turbulence (HRT) in patients with ventricular tachycardia or fibrillation (Group I; n=6), non sustained
ventricular tachycardia (Group II; n=32), frequent premature ventricular beats (Group III;
n=26) and with ICD implantation (Group IV; n=11).
Methods. Time domain parameters of HRV and turbulence onset (TO) and slope (TS) were calculated
on 24 hour Holter recordings. Normal values were: SDNN > 70 msec for HRV, TO <0%
and TS >2.5 msec/RR-I for HRT.
Results. Whereas SDNN was within normal range and similar in all study groups, HRT parameters
were significantly different in patients who experienced VT/VF during Holter recording. Abnormal
TO and/or TS were present in 100% of Group I patients and only in about 50% of Group
II and IV. On the contrary, normal HRT parameters were present in 40-70% of Group II, III and IV
patients and none of Group I.
Conclusions. These data suggest that HRT analysis is more suitable than HRV to detect those
transient alterations in autonomic control mechanisms that are likely to play a major trigger role
in the genesis of malignant cardiac arrhythmias. (Heart International 2007; 3: 51-7)
Keywords
Sudden cardiac death, Autonomic nervous system, Risk stratification, Ventricular fibrillation, Holter recordings
Article:
Article Information:
Correspondence
Prof. Federico Lombardi, MD, FESC Cardiologia, Dipartimento di Medicina, Chirurgia e Odontoiatria, Osp. San Paolo, Università di Milano, Via A. di Rudinì, 8, 20142 Milano – Italy, Federico.Lombardi@unimi.it