• MeSH
• Biomarkers diagnostic use   MeSH
• Electrocardiography methods   MeSH
• Ventricular Fibrillation pathology   MeSH
• Fourier Analysis MeSH
• Myocardial Infarction pathology   MeSH
• Humans MeSH
• Death, Sudden, Cardiac prevention & control   MeSH
• Arrhythmias, Cardiac pathology   therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

• MeSH
• Chest Pain MeSH
• Echocardiography MeSH
• Electrocardiography MeSH
• Cardiomyopathies diagnosis   MeSH
• Coronary Angiography MeSH
• Humans MeSH
• Stress, Psychological MeSH
• Aged MeSH
• Check Tag
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

• MeSH
• Biomedical Research MeSH
• Electrophysiology MeSH
• Myocardial Infarction physiopathology   MeSH
• Potentiometry methods   MeSH
• Publication type
• Comparative Study MeSH

• MeSH
• Adrenergic beta-Antagonists adverse effects   therapeutic use   MeSH
• Adult MeSH
• Electrocardiography MeSH
• Hypotonic Solutions adverse effects   therapeutic use   MeSH
• Check Tag
• Adult MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

INTRODUCTION: A reliable electrocardiographic predictor of ventricular fibrillation (VF) in patients with ST elevation myocardial infarction (STEMI) is lacking so far. Previous experimental/simulation study suggested a terminal T-wave inversion (TTWI) in ischemia-related ECG leads corresponding to anterior infarct localization as an independent predictor of reperfusion VF (rVF). This T-wave characteristic has never been tested as a rVF predictor in clinical settings. The aim of this study was to test if terminal T-wave inversion (TTWI) at admission ECG (before reperfusion) can serve as a predictor of ventricular fibrillation during reperfusion (rVF) in patients with anterior STEMI undergoing primary PCI. METHODS AND RESULTS: Study population included consecutive patients with anterior infarct localization admitted for primary PCI (n = 181, age 65 [57; 76] years, 66% male). Of those, 14 patients had rVF (rVF group, age 59 [47; 76] years, 64% male) and patients without rVF comprised the No-rVF group (n = 167, age 65 [57; 76] years, 66% male). Association of TTWI with rVF was analyzed using logistic regression analysis adjusted for relevant clinical and electrocardiographic covariates. The prevalence of TTWI in rVF group was 62% comparing to 23% in the No-rVF group, p = 0.005. TTWI was associated with increased risk of rVF (OR 5.51; 95% CI 1.70-17.89; p = 0.004) and remained a significant predictor after adjustment for age, gender, history of MI prior to index admission, VF before reperfusion, Tpeak-Tend, maximal ST elevation, and QRS duration (OR 23.49; 95% CI 3.14-175.91; p = 0.002). CONCLUSIONS: The terminal T-wave inversion in anterior leads before PCI independently predicted rVF in patients with anterior MI thus confirming the previous experimental/simulation findings.

• MeSH
• Electrocardiography methods   MeSH
• Ventricular Fibrillation etiology   MeSH
• Anterior Wall Myocardial Infarction * MeSH
• ST Elevation Myocardial Infarction * complications   diagnosis   MeSH
• Percutaneous Coronary Intervention * MeSH
• Middle Aged MeSH
• Humans MeSH
• Reperfusion adverse effects   MeSH
• Retrospective Studies MeSH
• Aged MeSH
• Tachycardia MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: Inferolateral early repolarization (ER) is highly prevalent and is associated with idiopathic ventricular fibrillation (VF). OBJECTIVE: The purpose of this study was to evaluate the potential role of T-wave parameters to differentiate between malignant and benign ER. METHODS: We compared the ECGs of patients with ER and VF (n = 92) with control subjects with asymptomatic ER (n = 247). We assessed J-wave amplitude, QTc interval, T-wave/R-wave (T/R) ratio in leads II and V5, and presence of low-amplitude T waves (T-wave amplitude <0.1 mV and <10% of R-wave amplitude in lead I, II, or V4-V6). RESULTS: Compared to controls, the VF group had longer QTc intervals (388 ms vs. 377 ms, P = .001), higher J-wave amplitudes (0.23 mV vs. 0.17 mV, P <.001), higher prevalence of low-amplitude T waves (29% vs. 3%, P <.001), and lower T/R ratio (0.18 vs. 0.30, P <.001). Logistic regression analysis demonstrated that QTc interval (odds ratio [OR] per 10 ms: 1.15, 95% confidence interval [CI} 1.02-1.30), maximal J-wave amplitude (OR per 0.1 mV: 1.68, 95% CI 1.23-2.31), lower T/R ratio (OR per 0.1 unit: 0.62, 95% CI 0.47-0.81), presence of low-amplitude T waves (OR 3.53, 95% CI 1.26-9.88). and presence of J waves in the inferior leads (OR 2.58, 95% CI 1.18-5.65) were associated with malignant ER. CONCLUSION: Patients with malignant ER have a higher prevalence of low-amplitude T waves, lower T/R ratio (lead II or V5), and longer QTc interval. The combination of these parameters with J-wave amplitude and distribution of J waves may allow for improved identification of malignant ER.

• MeSH
• Adult MeSH
• Electrocardiography * MeSH
• Ventricular Fibrillation diagnosis   epidemiology   physiopathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Survival Rate trends   MeSH
• Follow-Up Studies MeSH
• Prevalence MeSH
• Heart Conduction System physiopathology   MeSH
• Retrospective Studies MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH
• Geographicals
• Europe epidemiology   MeSH

Východisko. Přítomnost mikrovolt alternans T-vlny (MTWA) je spojena s vyšším rizikem vzniku maligní arytmie a celkové mortality. K detekci MTWA je nejčastěji využívána bicyklová ergometrie. Toto vyšetření má však řadu limitací. Cíl. Potvrdit že síňová a komorová stimulace při elektrofyziologii umožňuje dosáhnout obdobných výsledků jako bicyklová ergometrie. Zjistit, zda výsledek MTWA koreluje s výskytem maligní arytmie, nebo úmrtí. Metody. U pacientů indikovaných k elektrofyziologickému vyšetření před primárně preventivní implantací kardioverteru defibrilátoru bylo provedeno stanovení MTWA pomocí bicyklové ergometrie, síňové stimulace a komorové stimulace. Výsledky byly porovnány. V průběhu sledování byl monitorován výskyt maligní arytmie a úmrtí. Výsledky. Celkem bylo vyšetřeno 39 pacientů. Výsledky MTWA získané bicyklovou ergometrií, síňovou a komorovou stimulací se nelišily. Nebyl nalezen rozdíl ani v přítomnosti počtu pozitivních svodů a frekvenci nástupu MTWA. Komorová stimulace zvyšuje oproti zbývajícím dvěma metodám absolutní hodnotu MTWA. Nebyl prokázán vztah mezi přítomností MTWA a výskytem maligní arytmie. Závěry. Stanovení MTWA síňovou a komorovou stimulací přináší stejné výsledky jako bicyklová ergometrie a je tak alternativním řešením použitelným pro pacienty, u nichž není možné provedení bicyklové ergometrie.

Background. The presence of a microvolt T wave alternans (MTWA) is linked with increased risk of malignant arrhythmias and overall mortality. The most common method used for MTWA detection is a bicycle exercise test (BET). Method has still several limitations. Aim. To confirm that comparable MTWA results may be obtained by atrial and ventricular pacing during electrophysiology. To identify an anticipated relation between MTWA and malignant arrhythmia occurrence, or a death. Methods. We obtained MTWA during BET and consequently during atrial and ventricular pacing. All patients underwent a routine electrophysiology testing prior to prophylactic ICD implantation. The results were compared. The occurrence of malignant arrhythmias and death were registered during follow-up. Results. The group consisted of 39 patients. The results of MTWA obtained by BET, atrial and ventricular pacing did not show a significant difference. No difference was found among the three methods in the number of positive leads, and onset heart rate. Ventricular pacing increases the magnitude of MTWA comparing to the remaining two methods. No relation between MTWA results and occurrence of malignant arrhythmias or death was found. Conclusions. Atrial and ventricular pacing lead to comparable MTWA results as BET and may be used as alternative methods in patients where BET is not feasible.

• Keywords
• maligní arytmie, komorová stimulace, síňová stimulace, bicyklová ergometrie,
• MeSH
• Ventricular Dysfunction, Left diagnosis   complications   physiopathology   MeSH
• Electrophysiologic Techniques, Cardiac MeSH
• Electrocardiography MeSH
• Cardiac Pacing, Artificial MeSH
• Middle Aged MeSH
• Humans MeSH
• Arrhythmias, Cardiac complications   MeSH
• Exercise Test MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH

The purpose of this trial was to determine whether microvolt T-wave alternans (MTWA) predicts ventricular tachyarrhythmic events (VTEs) in post-myocardial infarction patients with left ventricular ejection fraction (LVEF) < or =30%. BACKGROUND: Previous studies have established MTWA as a predictor for total and arrhythmic mortality, but its ability to identify prophylactic implantable cardioverter-defibrillator (ICD) recipients most likely to experience VTEs remains uncertain. METHODS: This prospective trial was conducted at 50 U.S. centers. Patients were eligible if they met MADIT-II (Multicenter Automatic Defibrillator Implantation Trial II) indications for device implant. All patients underwent MTWA testing followed by ICD implantation, with pre-specified programming to minimize the likelihood of therapies for non-life-threatening VTE. Minimum follow-up was 2 years with annual MTWA testing. Initially indeterminate MTWA tests were repeated. RESULTS: Analyses were conducted on 575 patients (84% male; average age +/- SD = 65 +/- 11 years; average LVEF +/- SD = 0.24 +/- 0.05). The final distribution of MTWA results were: MTWA positive in 293 (51%), MTWA negative in 214 (37%), and indeterminate in 68 patients (12%). Over an average follow-up of 2.1 +/- 0.9 years, there were 70 VTEs. A VTE occurred in 48 of 361 (13%, 6.3%/year) MTWA non-negative and 22 of 214 (10%, 5.0%/year) MTWA negative patients. A non-negative MTWA test result was not associated with VTE (hazard ratio: 1.26; 95% confidence interval: 0.76 to 2.09; p = 0.37), although total mortality was significantly increased (hazard ratio: 2.04; 95% confidence interval: 1.10 to 3.78; p = 0.02). CONCLUSIONS: In MADIT-II-indicated ICD-treated patients, the risk of VTE does not differ according to MTWA classification, despite differences in total mortality. (MASTER I-Microvolt T Wave Alternans Testing for Risk Stratification of Post MI Patients; NCT00305240).

• MeSH
• Defibrillators, Implantable MeSH
• Heart Function Tests MeSH
• Myocardial Ischemia diagnosis   complications   therapy   MeSH
• Cardiomyopathies diagnosis   complications   therapy   MeSH
• Tachycardia, Ventricular diagnosis   etiology   prevention & control   MeSH
• Middle Aged MeSH
• Humans MeSH
• Prospective Studies MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH

In the present study we investigated the contribution of ventricular repolarization time (RT) dispersion (the maximal difference in RT) and RT gradients (the differences in RT in apicobasal, anteroposterior and interventricular directions) to T-wave flattening in a setting of experimental diabetes mellitus. In 9 healthy and 11 diabetic (alloxan model) open-chest rabbits, we measured RT in ventricular epicardial electrograms. To specify the contributions of apicobasal, interventricular and anteroposterior RT gradients and RT dispersion to the body surface potentials we determined T-wave voltage differences between modified upper- and lower-chest precordial leads (T-wave amplitude dispersions, TWAD). Expression of RT gradients and RT dispersion in the correspondent TWAD parameters was studied by computer simulations. Diabetic rabbits demonstrated flattened T-waves in precordial leads associated with increased anteroposterior and decreased apicobasal RT gradients (P<0.05) due to RT prolongation at the apex. For diabetics, simulations predicted the preserved T-vector length and altered sagittal and longitudinal TWAD proven by experimental measurements. T-wave flattening in the diabetic rabbits was not due to changes in RT dispersion, but reflected the redistributed ventricular repolarization pattern with prolonged apical repolarization resulting in increased anteroposterior and decreased apicobasal RT gradients.

• MeSH
• Electrocardiography methods   MeSH
• Diabetes Mellitus, Experimental blood   physiopathology   MeSH
• Rabbits MeSH
• Blood Glucose metabolism   MeSH
• Body Surface Potential Mapping methods   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Because risk stratification with electrophysiological study (EPS) improves efficiency but is invasive, we sought to determine whether noninvasive microvolt T-wave alternans (MTWA) testing could identify patients who benefit from implantable cardioverter-defibrillators (ICDs) as well as EPS. BACKGROUND: Prevention of sudden cardiac death on the basis of left ventricular ejection fraction (LVEF) alone is inefficient, because most ICDs never deliver therapy. METHODS: The ABCD (Alternans Before Cardioverter Defibrillator) trial is a multicenter prospective study that enrolled patients with ischemic cardiomyopathy (LVEF < or =0.40) and nonsustained ventricular tachycardia. All patients underwent MTWA and EPS. ICDs were mandated if either test was positive. RESULTS: Of 566 patients followed for a median of 1.9 years, 39 (7.5%) met the primary end point of appropriate ICD discharge or sudden death at 1 year. As hypothesized, primary analysis showed that MTWA achieved 1-year positive (9%) and negative (95%) predictive values that were comparable to EPS (11% and 95%, respectively). In addition, secondary analysis showed that at the pre-specified 1-year end point, event rates were significantly higher in patients with both a positive MTWA-directed strategy (hazard ratio: 2.1, p = 0.03) and a positive EPS-directed strategy (hazard ratio: 2.4, p = 0.007). Moreover, the event rate in patients with both negative MTWA test and EPS was lower than in those with 2 positive tests (2% vs. 12%; p = 0.017). CONCLUSIONS: The ABCD study is the first trial to use MTWA to guide prophylactic ICD insertion. Risk stratification strategies using noninvasive MTWA versus invasive EPS are comparable at 1 year and complementary when applied in combination. Strategies employing MTWA, EPS, or both might identify subsets of patients least likely to benefit from ICD insertion. (Study to Compare TWA Test and EPS Test for Predicting Patients at Risk for Life-Threatening Heart Rhythms [ABCD Study]; NCT00187291).

• MeSH
• Defibrillators, Implantable MeSH
• Electrocardiography MeSH
• Financing, Organized MeSH
• Risk Assessment MeSH
• Myocardial Ischemia therapy   MeSH
• Cardiomyopathies therapy   MeSH
• Tachycardia, Ventricular therapy   MeSH
• Middle Aged MeSH
• Humans MeSH
• Death, Sudden, Cardiac prevention & control   MeSH
• Aged MeSH
• Cardiac Electrophysiology MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Clinical Trial MeSH
• Multicenter Study MeSH
• Comparative Study MeSH