Short-period temporal repolarization dispersion in subjects with atrial fibrillation and decompensated heart failure.

BACKGROUND/OBJECTIVES: The association between chronic heart failure (CHF) and permanent atrial fibrillation is very frequent. The repolarization duration was already found predictive for atrial fibrillation. Aim of this study was to evaluate the influence of atrial fibrillation on short period repolarization variables in decompensated CHF patients. METHOD: We used 5 min ECG recordings to assess the mean, standard deviation (SD), and normalized variance (NV) of the following variables: QT end (QTe), QT peak (QTp), and T peak to T end (Te) in 121 decompensated CHF, of whom 40 had permanent atrial fibrillation, too. We reported also the 30-day mortality. RESULTS: QTpSD (p < .01), TeSD (p < .01), QTpVN (p < .01), and TeVN (p < .01) were higher in the atrial fibrillation than among sinus rhythm CHF subjects. Multivariable logistic analysis selected only TeSD (odd ratio, o.r.: 1.32, 95% confidence interval, c.i.: 1.06-1.65, p: .015) associated with atrial fibrillation. A total of 27 patients died during the 30-days follow-up (overall mortality rate 22%), 7 (18%), and 20 (25%) respectively in the atrial fibrillation and sinus rhythm patients. Furthermore, the following variables were associated to the morality risk: NT-pro Brain Natriuretic Peptide (o.r.: 1.00, 95% c.i.: 1.00-1.00, p: .041), left ventricular end diastolic diameter (o.r.: 0.81, 95% c.i.: 0.67-0.96, p: .010), and Te mean (o.r.: 1.04, 95% c.i.: 1.02-1.09, p: .012). CONCLUSION: In decompensated CHF subjects, Te mean seems be associated to mortality and TeSD to the permanent atrial fibrillation. We could hypothesize that, during severe CHF, the multi-level ionic CHF channel derangement could be critical in influencing these non-invasive markers. (ClinicalTrials.gov number, NCT04127162).

Time- and frequency-domain analysis of repolarization phase during recovery from exercise in healthy subjects.

BACKGROUND/AIM: Recently, data from temporal dispersion of myocardial repolarization analysis have gained a capital role in the sudden cardiac death risk stratification. Aim of this study was to evaluate the influence of heart rate, autonomic nervous system, and controlled breathing on different myocardial repolarization markers in healthy subjects. METHOD: Myocardial repolarization dispersion markers from short-period (5 minutes) electrocardiogram (ECG) analysis (time and frequency domain) have been obtained in 21 healthy volunteers during the following conditions: free breathing (rest); controlled breathing (resp); the first 5 minutes of postexercise recovery phases (exercisePeak ), maximum sympathetic activation; and during the second 5 minutes of postexercise recovery phases (exerciseRecovery ), intermediate sympathetic activation. Finally, we analyzed the whole repolarization (QTe), the QT peak (QTp), and T peak - T end intervals (Te). RESULTS: During the exercisePeak , major part of repolarization variables changed in comparison to the rest and resp conditions. Particularly, QTe, QTp, and Te standard deviations (QTeSD , QTpSD , and TeSD ); variability indexes (QTeVI and QTpVI), normalized variances (QTeVN, QTpVN, and TeVN); and the ratio between short-term QTe, QTp, and Te variability RR (STVQTe/RR , STVQTp/RR, and STVTe/RR ) increased. During exerciseRecovery , QTpSD (P < .05), QTpVI (P < .05), QTeVN (P < .05), QTpVN (P < .001), TeVN (P < .05), STVQTe/RR (P < .05), STVQTp/RR (P < .001), and STVTe/RR (P < .001) were significantly higher in comparison to the rest. The slope between QTe (0.24 ± 0.06) or QTp (0.17 ± 0.06) and RR were significantly higher than Te (0.07 ± 0.06, P < .001). CONCLUSION: Heart rate and sympathetic activity, obtained during exercise, seem able to influence the time domain markers of myocardial repolarization dispersion in healthy subjects, whereas they do not alter any spectral components.

Age, gender and drug therapy influences on Tpeak-tend interval and on electrical risk score.

BACKGROUND AND OBJECTIVES: Electrical risk score (ERS) has been proposed as easy, inexpensive test to stratify of sudden cardiac death (SCD) risk in subjects with normal left ventricular function. Potentially, aging, gender and drugs can influence ERS affecting two on six electrical markers, particularly, those based on the repolarization. Aim of this study was to establish aging, gender and drug therapy possible influences on ERS and mortality in elderly patients. METHOD: 237 consecutive, low SCD risk-outpatients with asymptomatic and treated cardiovascular risk factors were analyzed. Six simple ECG markers composed ERS: heart rate (>75 bpm); left ventricular hypertrophy (Sokolow-Lyon criteria); delayed QRS transition zone (≥V4), frontal QRS-T angle (>90°), long QTBazett; long T peak to T end interval (Tp-e). We obtained ERS in 237 outpatients, grouped according age (<40 ys, ≥40 to <60 ys and ≥60 ys), gender and drug therapy with or without possible influence on the repolarization phase. RESULTS: Two-hundred-thirty-seven patients were grouped respectively in the following age classes: <40 years old; ≥40 to <60 years old and ≥60 years old. ERS (p < 0.05), QTBazett (p < 0.001), Tp-e (p < 0.001) were higher in older subjects independently from gender, drug therapy and cardiovascular comorbidity. After two years we reported a 7.3% of mortality in the older groups; age (deceased versus survivors: 80 ± 4 versus 73 ± 7 years, p < 0.05) and Tp-e (deceased versus survivors: 117 ± 15 versus 93 ± 21 ms, p < 0.05) were significantly lower in survivors, multivariable logistic regression analysis selected only the Tp-e as significant risk factor for total mortality (odd ratio 1.06, 95% CI: 1.01-1.12, p < 0.05). CONCLUSION: Aging was associated to the ERS and repolarization phase derangement. Tp-e should be considered a marker of total mortality rather than SCD in the over sixty years old patients.

Hospital mortality in decompensated heart failure. A pilot study.

BACKGROUND/AIM: Heart failure is a leading cause of morbidity and mortality worldwide and it is a major cause of emergency department access for cardiovascular disease patients. Aim of this study was to identify the electrocardiographic (ECG) markers, based on short-term temporal repolarization dispersion, capable to individuate decompensated chronic heart failure (CHF) patients at high mortality risk. METHODS: We obtained the following variables from an ECG recording, monitored via mobile phone, during 5-minute recordings in decompensated CHF patients: RR, QT end (QTe), QT peak (QTp) and T peak to T end (Te) and we calculated mean, standard deviation (SD) and normalized index (N). RESULTS: In-hospital mortality occurred for 25 subjects on 101 studied (25%). Deceased patients showed higher QTeSD (p < 0.01), Te mean (p < 0.01), TeSD (p < 0.05), QTeVN (p < 0.05) than the surviving group. Logistic multivariable analysis evidenced that Te mean was a significant predictor of in-hospital mortality (odd ratio: 0.09, 95% confidence limit: 0.02-0.35, p: 0.001). At multiple regression analysis, TeSD was significantly and positively related only to the NT-pro BNP levels (r: 0.540; p < 0.001). The Te mean (AUC: 0.677 p < 0.01) and TeSD (AUC: 0.647, p: 0.05) showed significant sensitivity/specificity for the event. CONCLUSIONS: The Te mean and TeSD seem to be a promising noninvasive clinical marker able to identify patients with decompensated CHF at high risk of in-hospital mortality.

Artificial Intelligence Applied to Electrical and Non-Invasive Hemodynamic Markers in Elderly Decompensated Chronic Heart Failure Patients.

OBJECTIVES: The first aim of this study was to assess the predictive power of Tend interval (Te) and non-invasive hemodynamic markers, based on bioimpedance in decompensated chronic heart failure (CHF). The second one was to verify the possible differences in repolarization and hemodynamic data between CHF patients grouped by level of left ventricular ejection fraction (LVEF). Finally, we wanted to check if repolarization and hemodynamic data changed with clinical improvement or worsening in CHF patients. METHODS: Two hundred and forty-three decompensated CHF patients were studied by 5 min ECG recordings to determine the mean and standard deviation (TeSD) of Te (first study). In a subgroup of 129 patients (second study), non-invasive hemodynamic and repolarization data were recorded for further evaluation. RESULTS: Total in-hospital and cardiovascular mortality rates were respectively 19 and 9%. Te was higher in the deceased than in surviving subjects (Te: 120 ± 28 vs. 100 ± 25 ms) and multivariable logistic regression analysis reported that Te was related to an increase of total (χ2: 35.45, odds ratio: 1.03, 95% confidence limit: 1.02-1.05, p < 0.001) and cardiovascular mortality (χ2: 32.58, odds ratio: 1.04, 95% confidence limit: 1.02-1.06, p < 0.001). Subjects with heart failure with reduced ejection fraction (HFrEF) reported higher levels of repolarization and lower non-invasive systolic hemodynamic data in comparison to those with preserved ejection fraction (HFpEF). In the subgroup, patients with the NT-proBNP reduction after therapy showed a lower rate of Te, heart rate, blood pressures, contractility index, and left ventricular ejection time in comparison with the patients without NT-proBNP reduction. CONCLUSION: Electrical signals from ECG and bioimpedance were capable of monitoring the patients with advanced decompensated CHF. These simple, inexpensive, non-invasive, easily repeatable, and transmissible markers could represent a tool to remotely monitor and to intercept the possible worsening of these patients early by machine learning and artificial intelligence tools.

Effect of Head-Up/-Down Tilt on ECG Segments and Myocardial Temporal Dispersion in Healthy Subjects.

The head-up/-down tilt test acutely modifies the autonomic nervous system balance throughout a deactivation of the cardiopulmonary reflexes. The present study examines the influence of head-up/-down tilt on a number of ECG segments. A total of 20 healthy subjects underwent a 5 min ECG and noninvasive hemodynamic bio-impedance recording, during free and controlled breathing, lying at (a) 0°; (b) -45°, tilting up at 45°, and tilting up at 90°. Heart rate variability power spectral analysis was obtained throughout some ECG intervals: P-P (P), P-Q (PQ), PeQ (from the end of P to Q wave), Q-R peak (QR intervals), Q-R-S (QRS), Q-T peak (QTp), Q-T end (QTe), STp, STe, T peak-T end (Te), and, eventually, the TeP segments (from the end of T to the next P waves). Results: In all study conditions, the Low Frequency/High FrequencyPP and LFPP normalized units (nu) were significantly lower than the LF/HFRR and LFRRnu, respectively. Conversely, the HFPP and HFPPnu were significantly higher in all study conditions. STe, QTp, and QTe were significantly related to the PP and RR intervals, whereas the T wave amplitude was inversely related to the standard deviations of all the myocardial repolarization variables and to the left ventricular end-systolic volume (LVEDV). The T wave amplitude diminished during head-up tilt and significantly correlated with the LVEDV.

Sex Differences in Repolarization Markers: Telemonitoring for Chronic Heart Failure Patients.

Aging and chronic heart failure (CHF) are responsible for the temporal inhomogeneity of the electrocardiogram (ECG) repolarization phase. Recently, some short period repolarization-dispersion parameters have been proposed as markers of acute decompensation and of mortality risk in CHF patients. Some important differences in repolarization between sexes are known, but their impact on ECG markers remains unstudied. The aim of this study was to evaluate possible differences between men and women in ECG repolarization markers for the telemonitoring of CHF patients. METHOD: 5 min ECG recordings were collected to assess the mean and standard deviation (SD) of the following variables: QT end (QTe), QT peak (QTp), and T peak to T end (Te) in 215 decompensated CHF (age range: from 49 to 103 years). Thirty-day mortality and high levels of NT-pro BNP (<75 percentile) were considered markers of decompensated CHF. RESULTS: A total of 34 patients (16%) died during the 30-day follow-up, without differences between sexes. Women showed a more preserved ejection fraction and higher LDL and total cholesterol levels. Among female patients, implantable cardioverter devices, statins, and antiplatelet agents were less used. Data for Te mean showed increased values among deceased men and women compared to survival, but TeSD was shown to be the most reliable marker for CHF reacutization in both sexes. CONCLUSION: TeSD could be considered a risk factor for CHF worsening and complications for female and male patients, but different cut offs should be taken into account. (ClinicalTrials.gov number, NCT04127162.).

Glucose dysregulation and repolarization variability markers are short-term mortality predictors in decompensated heart failure.

As recently reported, elevated fasting glucose plasma level constitutes a risk factor for 30-day total mortality in acutely decompensated chronic heart failure (CHF). Aim of this study was to evaluate the 30-day mortality risk in decompensated CHF patients by fasting glucose plasma level and some repolarization ECG markers. Method: A total of 164 decompensated CHF patients (M/F: 94/71; mean age, 83 ± 10 years) were studied; Tend (Te), QT interval (QT) and 5 min of ECG recordings were obtained, studying mean, SD and normalized index of the abovementioned ECG intervals. These repolarization variables and fasting glucose were analyzed to assess the 30-day mortality risk among these patients. Results: Thirty-day mortality rate was 21%, deceased subjects showed a significant increase in N terminal-pro-brain natriuretic peptide (P < 0.001), higher sensitivity cardiac troponin, fasting glucose, creatinine clearance, QTSD, QTVN, Te mean, TeSD and TeVN than the survivals. Multivariable regression analysis reported that fasting glucose (hazard ratio, 1.59; 95% confidence interval, 1.09-2.10; P < 0.01), Te mean (hazard ratio, 1.03; 95% confidence interval, 1.01-1.05; P < 0.01) and QTSD (hazard ratio, 1.17; 95% confidence interval, 1.01-1.36; P < 0.05) were significantly related to higher mortality risk, whereas only fasting glucose (hazard ratio, 1.84; 95% confidence interval, 1.12-3.02; P < 0.05) and Te mean (hazard ratio, 1.07; 95% confidence interval, 1.02-1.11; P < 0.01) were associated to cardiovascular mortality. Conclusion: Data suggest that two simple, inexpensive, noninvasive markers, as fasting glucose and Te, were capable to stratify the short-term total and cardiovascular mortality risk in acutely decompensated CHF.

Noninvasive Hemodynamic Monitoring in Advanced Heart Failure Patients: New Approach for Target Treatments.

Using bio-impedance to deduce some hemodynamic parameters combined with some short-term ECG temporal dispersion intervals, and measuring myocardial depolarization, intraventricular conduction, and repolarization. A total of 65 in-hospital patients (M/F:35/30) were enrolled, 39 with HFrEF and 26 HFpEF, in New York Heart Association (NYHA) class IV. Stroke volume (SVI), cardiac indexes (CI), left ventricular ejection fraction (LVEFBIO), end diastolic volume (LV-EDV), and other systolic and diastolic parameters were noninvasively obtained at enrollment and at hospital discharge. At the same time, QR, QRS, QT, ST, Tpeak-Tend (Te) interval mean, and standard deviation (SD) from 5 min ECG recordings were obtained. At baseline, HFrEF patients reported significantly lower SVI (p < 0.05), CI (p < 0.05), and LVEF (p < 0.001) than HFpEF patients; moreover, HFrEF patients also showed increased LV-EDV (p < 0.05), QR, QRS, QT, ST, and Te means (p < 0.05) and standard deviations (p < 0.05) in comparison to HFpEF subjects. Multivariable logistic regression analysis reported a significant correlation between hospital mortality and Te mean (odds ratio: 1.03, 95% confidence limit: 1.01−1.06, p: 0.01). Fifty-seven percent of patients were considered responders to optimal medical therapy and, at discharge, they had significantly reduced NT-proBNP, (p < 0.001), heart rate (p < 0.05), and TeSD (p < 0.001). LVEF, obtained by transthoracic echocardiography, and LVEFBIO were significantly related (r: 0.781, p < 0.001), but these two parameters showed a low agreement limit. Noninvasive hemodynamic and ECG-derived parameters were useful to highlight the difference between HFrEF and HFpEF and between responders and nonresponders to the optimal medical therapy. Short-period bioimpedance and electrocardiographic data should be deeply evaluated to determine possible advantages in the therapeutic and prognostic approach in severe CHF.

QT and Tpeak-Tend interval variability: Predictive electrical markers of hospital stay length and mortality in acute decompensated heart failure. Preliminary data.

BACKGROUND: As previously reported, an increased repolarization temporal imbalance induces a higher risk of total/cardiovascular mortality. HYPOTHESIS: The aim of this study was to assess if the electrocardiographic short period markers of repolarization temporal dispersion could be predictive of the hospital stay length and mortality in patients with acutely decompensated chronic heart failure (CHF). METHOD: Mean, standard deviation (SD), and normalized variance (VN) of QT (QT) and Tpeak-Tend (Te) were obtained on 5-min ECG recording in 139 patients hospitalized for acutely decompensated CHF, subgrouping the patients for hospital length of stay (LoS): less or equal 1 week (≤1 W) and those with more than 1 week (>1 W). RESULTS: We observed an increase of short-period repolarization variables (TeSD and TeVN, p < .05), a decrease of blood pressure (p < .05), lower ejection fraction (p < .05), and higher plasma level of biomarkers (NT-proBNP, p < .001; Troponin, p < .05) in >1 W LoS subjects. 30-day deceased subjects reported significantly higher levels of QTSD (p < .05), Te mean (p < .001), TeSD (p < .05), QTVN (p < .05) in comparison to the survivors. Multivariable Cox regression analysis reported that TeVN was a risk factor for longer hospital stay (hazard ratio: 1.04, 95% confidence limit: 1.01-1.08, p < .05); whereas, a longer Te mean was associated with higher mortality risk (hazard ratio: 1.02, 95% confidence limit: 1.01-1.03, p < .05). CONCLUSION: A longer hospital stay is considered a clinical surrogate of CHF severity, we confirmed this finding. Therefore, these electrical and simple parameters could be used as noninvasive, transmissible, inexpensive markers of CHF severity and mortality.

Short-Period Temporal Dispersion Repolarization Markers Predict 30-Days Mortality in Decompensated Heart Failure.

BACKGROUND AND OBJECTIVES: Electrocardiographic (ECG) markers of the temporal dispersion of the myocardial repolarization phase have been shown able to identify chronic heart failure (CHF) patients at high mortality risk. The present prospective single-center study sought to investigate in a well-characterized cohort of decompensated heart failure (HF) patients the ability of short-term myocardial temporal dispersion ECG variables in predicting the 30-day mortality, as well as their relationship with N-terminal Pro Brain Natriuretic Peptide (NT-proBNP) plasmatic values. METHOD: One hundred and thirteen subjects (male: 59, 67.8%) with decompensated CHF underwent 5 min of ECG recording, via a mobile phone. We obtained QT end (QTe), QT peak (QTp) and T peak to T end (Te) and calculated the mean, standard deviation (SD), and normalized index (VN). RESULTS: Death occurred for 27 subjects (24%) within 30 days after admission. Most of the repolarization indexes (QTe mean (p < 0.05), QTeSD (p < 0.01), QTpSD (p < 0.05), mean Te (p < 0.05), TeSD (p < 0.001) QTeVN (p < 0.05) and TeVN (p < 0.01)) were significantly higher in those CHF patients with the highest NT-proBNP (>75th percentile). In all the ECG data, only TeSD was significantly and positively related to the NT-proBNP levels (r: 0.471; p < 0.001). In the receiver operating characteristic (ROC) analysis, the highest accuracy for 30-day mortality was found for QTeSD (area under curve, AUC: 0.705, p < 0.01) and mean Te (AUC: 0.680, p < 0.01), whereas for the NT-proBNP values higher than the 75th percentile, the highest accuracy was found for TeSD (AUC: 0.736, p < 0.001) and QTeSD (AUC: 0.696, p < 0.01). CONCLUSION: Both mean Te and TeSD could be considered as reliable markers of worsening HF and of 30-day mortality. Although larger and possibly interventional studies are needed to confirm our preliminary finding, these non-invasive and transmissible ECG parameters could be helpful in the remote monitoring of advanced HF patients and, possibly, in their clinical management. (ClinicalTrials.gov number, NCT04127162).