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HRT Parameters (hrt + parameter)
Selected AbstractsHeart Rate Turbulence for Prediction of Heart Transplantation and Mortality in Chronic Heart FailureANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2010Beata Sredniawa M.D. Background: Previous studies have shown conflicting results about the value of heart rate turbulence (HRT) for risk stratification of patients (pts) with chronic heart failure (CHF). We prospectively evaluated the relation between HRT and progression toward end-stage heart failure or all-cause mortality in patients with CHF. Methods: HRT was assessed from 24-hour Holter recordings in 110 pts with CHF (54 in NYHA class II, 56 in class III,IV; left ventricular ejection fraction (LVEF) 30%± 10%) on optimal pharmacotherapy and quantified as turbulence onset (TO,%), turbulence slope (TS, ms/RR interval), and turbulence timing (beginning of RR sequence for calculation of TS, TT). TO , 0%, TS , 2.5 ms/RR, and TT >10 were considered abnormal. End point was development of end-stage CHF requiring heart transplantation (OHT) or all-cause mortality. Results: During a follow-up of 5.8 ± 1.3 years, 24 pts died and 10 required OHT. TO, TS, TT, and both (TO and TS) were abnormal in 35%, 50%, 30%, and 25% of all patients, respectively. Patients with at least one relatively preserved HRT parameter (TO, TS, or TT) (n = 98) had 5-year event-free rate of 83% compared to 33% of those in whom all three parameters were abnormal (n = 12). In multivariate Cox regression analysis, the most powerful predictor of end point events was heart rate variability (SDNN < 70 ms, hazard ratio (HR) 9.41, P < 0.001), followed by LVEF , 35% (HR 6.23), TT , 10 (HR 3.14), and TO , 0 (HR 2.54, P < 0.05). Conclusion: In patients with CHF on optimal pharmacotherapy, HRT can help to predict those at risk for progression toward OHT or death of all causes. Ann Noninvasive Electrocardiol 2010;15(3):230,237 [source] Relationship Between Heart Rate Turbulence and Heart Rate, Heart Rate Variability, and Number of Ventricular Premature Beats in Coronary PatientsJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2004IWONA CYGANKIEWICZ M.D., Ph.D. Introduction: Heart rate variability (HRV) illustrates regulation of the heart by the autonomic nervous system whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity. The aim of this study was to determine the association between HRT and HRV parameters and the relationship between HRT parameters and heart rate and number of ventricular premature beats (VPBs) used to calculate HRT parameters. Methods and Results: In 146 patients (117 males and 29 females; mean age 62 years) with coronary artery disease, a 24-hour ECG Holter monitoring was performed to calculate mean heart rate (RR interval), number of VPBs, time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (TO) and turbulence slope (TS). Univariate and multivariate regression analyses were performed to evaluate the association between tested parameters. Significant correlation between TS and mean RR interval was observed (r = 0.42; p < 0.001), while no association for TO vs. RR interval was found. TS values were significantly higher in patients with less than 10 VPBs/24 hours than in patients with more frequent VPBs. Significant associations between HRT and HRV parameters were found with TS showing stronger correlation with HRV parameters than TO (r value ranging from 0.35 to 0.62 for TS vs. ,0.16 to ,0.38 for TO). Conclusion: HRT parameters correlate strongly with HRV parameters indicating that HRT should be considered as a reflection of both baroreceptors response and overall autonomic tone. Heart rate dependence of turbulence slope indicates the need to adjust this parameter for heart rate. (J Cardiovasc Electrophysiol, Vol. 15, pp. 731-737, July 2004) [source] Heart Rate Turbulence After Short Runs of Nonsustained Ventricular Tachycardia in Chronic Heart FailurePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2007PANAYOTA FLEVARI M.D. Background:Heart rate turbulence (HRT) following isolated premature complexes is a baroreceptor-mediated prognostic marker. Short runs of spontaneous, nonsustained ventricular tachycardia (nsVT) exert a greater hemodynamic effect than extrasystoles and may trigger a more potent turbulence-like response (HRTVT), possibly related to other risk-related markers, such as heart rate variability (HRV), left ventricular ejection fraction (EF), and original HRT parameters (turbulence slope [TS] and turbulence onset [TO]). Methods:We studied 27 patients with heart failure (HF) and nsVT (4,7 beats) on 24-hour Holter electrocardiographic recordings (mean age 58 ± 3.6 years, EF 36%± 5.0%). Following nsVT, TSVT and TOVT were measured according to the original definitions. HRV, TS, and TO were also assessed. Results:HRTVT parameters were related to HRV. A significant relation existed between TSVT and EF (r= 0.66, P < 0.05). HRTVT parameters were related to the originally described (TS and TO), whereas TOVT was higher than TO (1.63 ± 1.6 vs ,1.7 ± 0.65, P < 0.05). Conclusions:In mild-to-moderate HF, turbulence is observed following short nsVT runs and is related to prognostically important HRV indexes and EF. HRTVT is similar to HRT but TOVT is shifted toward more positive values than TO. HRTVT might be prognostically significant. [source] Impact of Preceding Ventricular Premature Beats on Heart Rate TurbulenceANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 4 2009Hung Yi Chen M.D. Background: Heart rate turbulence (HRT) has recently been introduced as a noninvasive tool for studying autonomic dysfunction. It presented short time fluctuation of sinus cycle length following single ventricular premature contraction (VPC). However, HRT parameters may be influenced by different factors. This study aimed to evaluate the possible influence of VPC frequency on HRT. Methods: 24-h Holter recording was performed in patients with VPCs initially detected by 12-lead electrocardiography (ECG) in the outpatient department. The numbers of VPCs in 2- and 5-minute durations preceding each VPC tachogram were calculated. The HRT parameters and the numbers of the VPCs preceding VPC tachograms were analyzed. Results: There were 23,122 available VPC tachograms from 107 healthy subjects included in the study. The turbulence onset (TO) value increased and the turbulence slope (TS) value decreased as VPC's frequency increased. The TO values rapidly increased when the number of VPCs was >15 beats in the 2-minute and >35 beats in the 5-minute durations. There was also a prominent decrease in TS values when the VPCs reached 14 and 30 beats in the 2- and 5-minute durations, respectively. Conclusion: Physiologic baroreflex may be attenuated under intensive stimulation, which is evidenced by blunted HRT parameters by frequent VPCs. Physiologic response to VPC's frequency may be related to baroreflex fatigue and is demonstrated as a sigmoid curve. [source] | ||||||||||