Abstract 2148: Abnormal T Wave Alternans Could Provide Additional Risk Stratification in Patients with Prolonged QRS Duration

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Takanao Mine ◽  
Tetsuzou Kanemori ◽  
Hiroaki Nakamura ◽  
Tohru Masuyama ◽  
Mitsumasa Ohyanagi
Keyword(s):  
Heart Rate ◽  
Risk Stratification ◽  
Cardiac Death ◽  
Heart Diseases ◽  
Qt Dispersion ◽  
Additional Risk ◽  
T Wave ◽  
Life Threatening ◽  
Qrs Duration ◽  
T Wave Alternans

QT dispersion, signal averaged electrocardiogram (SAECG) and T wave alternans (TWA) have been found to be increased susceptibility to life-threatening arrhythmias or cardiac death (LTA/CD). Patients with heart diseases often present prolonged QRS duration (p-QRSd), however the risk stratification in patients with p-QRSd still remains. We investigated whether QT dispersion, SAECG and TWA would provide additional risk stratification in patients with p-QRSd. We studied 52 patients (47 males, mean age 66±9 yrs) with QRS duration ≥ 120ms (34 RBBB type and 18 LBBB type) who had heart diseases (45 coronary artery disease and 7 dilated cardiomyopaty). QT dispersion was measured from standard 12-lead ECG. The filtered QRS duration (f-QRS) and root mean square voltage of the terminal 40ms of the QRS complex (RMS40) were obtained by SAECG. TWA was measured with the CH 2000. TWA was considered positive when the alternans with alternans voltage ≥ 1.9μV and alternance ratio ≥ 3 was sustained ≥ 1 minute in vector magnitude, X, Y, Z, V4 or two precordal leads at heart rate ≤ 110bpm. TWA was classified negative when the alternans wasn’t presented at heart rate ≤ 110bpm and considered indeterminate if the record didn’t meet either positively or negatively. Abnormal TWA was defined as positive or indeterminate. An abnormal TWA test was present in 56% (23 patients had negative TWA, 11 had indeterminate and 18 had positive). During the follow-up periods (69±41 months), 15 patients had life-threatening arrhythmias (n=12) and/or cardiac death (n=7). Univariate analysis revealed left ventricular ejection fraction (LVEF), RMS40 and abnormal TWA (n=29) as significant variables, however there was no significant difference in LTA/CD rate between BBB types, and no associations between QT dispersion and LTA/CD. On logistic regression analysis, only LVEF (p=0.02) and abnormal TWA (p=0.02, odds ratio 9.803 [95%CI 1.430 to 67.207]) were independently associated with LTA/CD. Abnormal T wave alternans could provide additional risk stratification in patients with prolonged QRS duration.

Utility of heart rate turbulence and T‐wave alternans to assess risk for readmission and cardiac death in hospitalized heart failure patients

2018 ◽  
Vol 29 (9) ◽  
pp. 1257-1264 ◽  
Author(s):  
Shinya Yamada ◽  
Akiomi Yoshihisa ◽  
Yu Sato ◽  
Takamasa Sato ◽  
Masashi Kamioka ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Cardiac Death ◽  
Heart Rate Turbulence ◽  
Heart Failure Patients ◽  
T Wave ◽  
T Wave Alternans

scholarly journals Microvolt t-wave alternans its clinical significance in the assessment of the risk of sudden cardiac death among patients with hypertrophic cardiomyopathy

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Pawlak ◽  
E Trzos ◽  
M Kurpesa
Keyword(s):  
Heart Rate ◽  
Hypertrophic Cardiomyopathy ◽  
Sudden Cardiac Death ◽  
Left Atrium ◽  
Cardiac Death ◽  
Interventricular Septum ◽  
Effective Prevention ◽  
T Wave ◽  
Unexplained Syncope ◽  
T Wave Alternans

Abstract Summary Some patients with hypertrophic cardiomyopathy (HCM) are at significant risk of premature sudden death. Identification of the risk factors may enable effective prevention of adverse cardiac events in these patients. Assessment of the microvolt T-wave alternans (MTWA) is a recognized non-invasive diagnostic test used in risk stratification of sudden cardiac death (SCD). However, the number of reports on the frequency of occurrence of MTWA in HCM is small. Aim: Evaluation of the prognostic value of MTWA in predicting the risk of arrhythmic events (sudden cardiac death, documented VT/VF, appropriate ICD discharge) in patients with HCM. Material and methods 122 patients with HCM underwent detailed clinical assessment and ECG- and echocardiographic examination. They underwent 24-hour ambulatory ECG monitoring, and the following elements were analysed: 1) arrhythmias, 2) heart rate variability (HRV) and the QT segment, 3) the presence of ventricular late potentials (LP), 4) heart rate turbulence (HRT). MTWA assessment was made during a test on a treadmill (Cambridge Heart). In accordance with the adopted criteria, the test was interpreted as negative, positive or indeterminate. Subsequently, positive and indeterminate results were described collectively as MTWA(+) and negative results as MTWA(−). Then the patients were divided into two groups: Group 1 – 57 patients (46,7%) with MTWA(−), and Group 2 – 65 patients (53,2%) with MTWA(+). In order to stratify the risk, the following were adopted as composite primary endpoints: sudden cardiac death or hospitalization for life-threatening arrhythmias (VT/VF), and appropriate ICD discharge. Results The mean follow-up period of the patients was 57±8 months; during that time, events that met the criteria for the endpoint occurred in 16 patients. On the basis of univariate analysis, 10 variables with a significant influence on the occurrence of an event were selected (unexplained syncope, NT-proBNP values elevated above 411 pg/ml, size of the left atrium over 44mm, diastolic thickness of the interventricular septum over 25 mm, the presence of MTWA(+), the QRS width >90 msec, QTc >467 msec, QTd >70 msec, SDNN <110 msec, and sinus rhythm turbulence parameters TS <2,9 ms/2RR). These variables were then included in a multivariate analysis. The model from a Cox regression analysis showed that the presence of unexplained syncope (HR=1,4), MTWA(+) (HR=1,5), size of the left atrium over 44mm (HR=5), and the thickness of the interventricular septum over 25 mm (HR=1,5) increased the risk of sudden events. Conclusions 1) Patients with hypertrophic cardiomyopathy had a significant percentage of positive results of the microvolt T-wave alternans test (MTWA+), 2) Positive MTWA test result in patients with hypertrophic cardiomyopathy can help to identify patients at risk of sudden cardiac death. FUNDunding Acknowledgement Type of funding sources: None.

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