Electrocardiographic Ventricular Repolarization Parameters in Chronic Chagas' Disease as Predictors of Asymptomatic Left Ventricular Systolic Dysfunction (original) (raw)
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The prognostic significance of electrocardiographic changes in Chagas disease
Journal of Electrocardiology
Introduction: The meaning of electrocardiographic changes appearing during the clinical follow-up of Chagas disease (ChD) is unknown. In this study, a patient cohort with ChD was followed to describe the electrocardiographic changes that may make it possible to identify patients whose left ventricular function has deteriorated. Methods: The study sample consisted of a prospective cohort followed since 1998 to 1999, involving 220 patients aged 15 to 55 years, 30 controls, and 190 with ChD, without other comorbidities. The group was reexamined between 2004 and 2006, and new electrocardiograms were obtained for 153 patients, 25 (83%) of 30 in the control group and 128 (72%) of 177 in the ChD group. Electrocardiographic variables associated with a significant decrease in ejection fraction (5% or more) were identified. Results: A significant decrease in ejection fraction was observed in 21 patients in the ChD group (18.7%) but in none of the non-ChD group (P = .024). Only the presence of a new electrocardiographic abnormality and an increase in QRS duration correlated with a decrease in an ejection fraction of 5% or more. QRS duration was correlated with both an increase in left ventricle diastolic diameter and a deterioration in the ejection fraction (r s = 0.225, P = .017, and r s = −0.300, P b .001). A QRS increase of 5 milliseconds had 77.8% sensitivity and 62.2% specificity for identifying patients with significant decrease in ejection fraction. Conclusion: The increase in the duration of the QRS complex and the appearance of new electrocardiographic alterations may help in identifying patients with a significant decrease (of 5% or more) in left ventricle ejection fraction.
Prognostic value of signal-averaged electrocardiogram in Chagas' disease
Journal of Electrocardiology, 2007
SAECG in Chagas Disease. Background: The value of signal-averaged ECG (SAECG) in the risk stratification of Chagas disease (ChD), a potentially lethal illness prevalent in Latin America, remains controversial. The aim of this prospective longitudinal study was to determine the prognostic value of SAECG in ChD, using multivariate models with other established prognostic predictors, and to develop a simple prediction risk score.
Computing in Cardiology (CinC), 2012, 2016
Dynamic ventricular repolarization duration (VRD) and phase-rectification-driven RR-interval coupling was investigated aiming at assessing myocardial electrical stability in healthy and chronic Chagas disease (ChD) subjects. All were in sinus rhythm and underwent 60 min head-up tilt table test under ECG recording. ChD group underwent MIBG scintigraphy and confirmed sympathetic denervation. Histogram of RR-interval series was calculated, with 100 ms class, ranging from 500 ms to 1200 ms. For each class, mean of normal RR-intervals (MRR) and mean of the peak-to-peak R-toT wave interval (MRT), representing VRD, were analyzed in RR-intervals pairs of acceleration (AC) and deceleration (DC) phases, reflecting sympathetic and parasympathetic influences on heart rate, respectively. Regression lines of MRT vs. MRR were computed in the whole series, and in DC and AC phases, and respective slopes calculated (sMRT T, sMRT DC and sMRT AC). Student t-test compared groups. RT-interval was larger in ChD group. sMRT T, sMRT DC and sMRT AC function showed no difference between groups, and all increased directly to MRR. In both groups, MRT increased as a linear function of MRR. In ChD, RT-interval analysis was not able to confirm loss of sympathetic driven RRinterval variation.
Electrocardiographic abnormalities and left ventricular systolic function in Chagas' heart disease
International Journal of Cardiology, 1990
In chagasic patients, the electrocardiogram becomes abnormal very late in the course of the disease. Most clinical studies concerning cardiac autonomic function of chagasic patients have been carried out in this very late stage of the disease. The purpose of this study was to assess accurately the left ventricular systolic function of chagasic patients with abnormal electrocardiograms. We performed left ventricular contrast cineangiography in 44 patients with positive complement fixation test for Chagas' disease and abnormal electrocardiograms. On the basis of the electrocardiographic abnormalities found in the electrocardiogram taken the night before the hemodynamic procedure, we divided our patients into three subgroups; those with rhythm disturbances, those with ventricular conduction abnormalities, and those with rhythm disturbances plus ventricular conduction abnormalities. The chagasic patients with only cardiac rhythm disturbances, had left ventricular volumes and ejection fractions which were similar to those of controls. On the other hand, the left ventricular volumes of the chagasic patients with ventricular conduction defects, although slightly larger, were still not different from those of controls. Finally, the chagasic patients, with cardiac rhythm disturbances and left ventricular conduction defects, had the largest left ventricular volumes (P < OAE), and the lowest ejection fractions (P < 0.001) of all three subgroups. These findings clearly indicate that chagasic patients, in this very late stage of the disease, have a very variable degree of left ventricular systolic dysfunction. Furthermore, our results show a distinct tendency for the left ventricular volumes to increase, and for the ejection fraction to decrease; when the electrocardiogram becomes progressively more abnormal, and "mixed" electrocardiographic abnormalities appear. Consequently clinical research concerning Chagas' heart disease, particularly cardiac autonomic function studies, should take into consideration the heterogeneity of the degree of myocardial involvement, and the very variable degrees of left ventricular systolic dysfunction.
Signal-averaged electrocardiogram in chronic Chagas' heart disease
Sao Paulo Medical Journal, 1995
The aim of the study was to register the prevalence of late potentials (LP) in patients with chronic Chagas' heart disease (CCD) and the relationship with sustained ventricular tachycardia (SVT). 192 patients (96 males), mean age 42.9 years, with CCD were studied through a Signal Averaged ECG using time domain analysis. According to presence or absence of bundle branch block (BBB) and SVT, four groups of patients were created: Group I (n = 72): without SVT (VT-) and without BBB (BBB-): Group II (n = 27): with SVT (VT+) and BBB-; Group III (n = 63): VT-and with BBB (BBB+); and Group IV (N = 30): VT+ and BBB+. The LP was admitted, with 40 Hz filter, in the groups without BBB using standard criteria of the method. In the group with BBB, the root-mean-square amplitude of the last 40 ms (RMS) < = 141-lVwas considered as an indicator of LP. Results: In groups I and II, LP was present in 21 (78%) of the patients with SVT and in 22 (31%) of the patients without SVT (p < 0.001), with Sensitivity (S) 78%; Specificity (SP) 70% and Accuracy (Ac) 72%. LP was present in 30 (48%) of the patients without and 20 (67%) of the patients with SVT, in groups III and IV. p = 0.066, with S = 66%; SP = 52%; and Ac = 57%. In the follow-up, there were 4 deaths unrelated to arrhythmic events, all of them did not have LP. Eight (29,6%) of the patients from group II and 4 (13%) from group IV presented recurrence of SVT and 91,6% of these patients had LP. Conclusions: LP occurred in 77.7% of the patients with SVT and without BBB. In the groups with BBB, there was association of LP with SVT in 66,6% of the cases. The recurrence of SVT was present in 21% of the cases from which 91,6% had LP.
Arquivos brasileiros de cardiologia, 2006
To evaluate asymptomatic patients with chronic Chagas disease to determine prevalence of ventricular arrhythmias, left ventricular dysfunction, and B-type natriuretic peptide (BNP) plasma levels. One hundred and six patients from the Chagas disease outpatient clinic underwent clinical evaluation, electrocardiogram (ECG), cardiothoracic index (CTI), ambulatory electrocardiogram (Holter monitoring), echocardiogram, and BNP measurement and then were distributed into three groups: GI, with normal ECG (n = 50); GIIA, with ECG changes characteristic of Chagas disease (n = 31); and GIIB, with other ECG changes (n = 25). The most common electrocardiographic changes were the following. GIIA: complete right bundle branch block (35%), left anterior hemiblock (35%), and electrically inactive areas (32%); GIIB: inferolateral repolarization change (28%), and left ventricular overload (24%). Mean CTI index values were similar (p = 0.383). Ventricular arrhythmia prevalence was higher in the GIIA (7...
International Journal of Cardiology, 2005
Ventricular tachycardia (VT) is common among patients with Chagas' heart disease but the ultimate mechanisms responsible for its sustained and nonsustained forms are not understood. This study aimed at determining which factors differentiate between patients with sustained (S-VT) and nonsustained VT (NS-VT). Fifty-six consecutive chagasic patients with VT were prospectively selected: 28 patients with spontaneous S-VT and 28 patients with NS-VT. The patients underwent clinical, angiographic, electrophysiologic and myocardial perfusion examination. Syncope episodes (S-VT: 43% versus NS-VT: 11%, p=0.007) and induction of S-VT by programmed ventricular stimulation (S-VT: 89% versus NS-VT: 7%, p=0.001) were significantly more frequent in S-VT patients. Evidence of a scarrelated reentry was observed in all 24 S-VT patients who underwent endocardial mapping for attempted radiofrequency ablation of 33 VTs. Overall, 29 VTs arose from the LV (88%) and 4 VTs arose from the RV (12%). Among these, 27 VTs (82%) were related to LV inferolateral scar, 2 VTs (6%) were related to LV apical scar, and 4 VTs (12%) were related to RV scars. A significantly higher prevalence of wall motion abnormalities (S-VT: 82% versus NS-VT: 46%, p=0.005) and myocardial perfusion defects (basal segments, S-VT: 95.5% versus NS-VT: 44%, p=0.001) was documented within the LV inferior and/or posterolateral regions in S-VT patients compared to NS-VT. In conclusion: (a) VT may arise from various regions in both ventricles, but LV inferolateral scar is the main source of S-VT reentrant circuits; (b) there is good topographic correlation between myocardial perfusion, wall motion abnormalities and areas that originate S-VT; (c) although to a lesser extent, wall motion and perfusion defects also occur in a relevant proportion of chagasics with NS-VT.
Journal of Cardiac Arrhythmias, 2020
Introduction: Chagas' disease lacks elements to predict which carriers will evolve into cardiac form and which will remain in undetermined form. Objective: To evaluate the relationship between electrocardiographic evolution and Tpeak-Tend and QT intervals, both corrected for heart rate, in chagasic patients with normal initial electrocardiogram. Method: Chagasic patients admitted to the institution until 2002 were retrospectively evaluated, and the electrocardiogram was normal at the first consultation. The Tpeak-Tend and QT intervals were measured in milliseconds at the V2 and V5 derivations, with the mean values corrected for heart rate (Bazett). The relationship of these values with the electrocardiographic evolution of the individuals was analyzed, considering the gender, time of evolution and whether they received benznidazole or not. Results: The corrected Tpeak-Tend interval showed no statistical significance among those who maintained or not normal electrocardiogram. The corrected QT interval, the treatment with benznidazole and the time of evolution showed significance for the maintenance of normal electrocardiogram. In the multivariate evaluation, treatment with benznidazole, the QTc interval and the time of evolution were independent variables for the maintenance of normal electrocardiogram. Conclusion: The Tpeak-Tend interval showed no predictor of electrocardiographic evolution. The increased QT interval favored changes.
Early detection of left ventricular diastolic dysfunction in Chagas' disease
Cardiovascular ultrasound, 2006
Chagas' disease may cause left ventricular diastolic dysfunction and its early detection in asymptomatic patients would allow to stratify the risk and to optimize medical treatment. The aim of this study is to investigate if transmitral Doppler flow can detect early abnormalities of the diastolic left ventricular function in patients during the indeterminate phase of Chagas' disease, in which the electrocardiogram (ECG), chest x-ray and 2-D echocardiogram (2D-echo) are normal. a group of 54 patients with Chagas' disease was studied and compared to a control group of 27 subjects of similar age. All were assessed with an ECG, chest X-ray, 2-D echo, and transmitral Doppler flow. both groups had similar values in the 2D-echo. In patients with Chagas' disease, the transmitral Doppler showed a higher peak A velocity (control group: 0.44 m/sec, Chagas group: 0.55 m/sec, p = 0.001), a lower E/A ratio (control group: 1.45, Chagas group: 1.22, p < 0.05), and a lengthening o...