Tpeak-to-Tend/QT is an independent predictor of early ventricular arrhythmias and arrhythmic death in anterior ST elevation myocardial infarction patients.

BACKGROUND: The aim of our study was to analyse the markers of transmural dispersion of ventricular repolarization, especially Tpeak-to-Tend and Tpeak-to-Tend /QT ratio, in patients with anterior ST elevation myocardial infarction on admission and to evaluate their association with in-hospital life-threatening arrhythmias and mortality. METHODS AND RESULTS: A total of 223 consecutive patients with anterior wall ST elevation myocardial infarction admitted to our Division of Cardiology between January 2010 and December 2012 were prospectively evaluated. A standard electrocardiogram was obtained on admission and then analysed. The primary end point was constituted by in-hospital ventricular arrhythmias and arrhythmic death. At univariate analysis heart rate (odds ratio = 1.03; 95% confidence intervals 1.006-1.05; p=0.001), maximal ST elevation (odds ratio =1.25; 95% confidence intervals 1.10-1.43; p=0.0001), QTc Bazett (odds ratio = 1.01; 95% confidence intervals 1.006-1.02; p=0.002), QT dispersion (odds ratio = 1.02; 95% confidence intervals 1.002-1.04; p=0.02) and both Tpeak-to-Tend and Tpeak-to-Tend/QT (odds ratio = 1.02; 95% confidence intervals 1.01-1.03; p<0.0001 and OR = 1.07; 95% confidence intervals 1.03-1.11; p<0.0001 respectively) were significantly associated with ventricular arrhythmias and arrhythmic mortality. Of note, Tpeak-to-Tend /QT remained a predictor of early ventricular arrhythmias and arrhythmic death (odds ratio = 1.04; 95% confidence intervals 1.003 - 1.10; p=0.03) independently from heart rate and maximal ST elevation. Receiver operating characteristic curve analysis showed that Tpeak-to-Tend /QT values <0.31 had a predictive negative value of 92% for the prediction of the composite outcome. CONCLUSIONS: Tpeak-to-Tend /QT was an independent predictor of early ventricular arrhythmias and arrhythmic mortality in patients with anterior ST elevation myocardial infarction. Especially, Tpeak-to-Tend /QT <0.31 may identify a subgroup of ST elevation myocardial infarction patients with low risk of early arrhythmias and arrhythmic death.

Dynamic changes of repolarization abnormalities in takotsubo cardiomyopathy.

OBJECTIVE: This study analyses dynamicchangesin dispersion of ventricularrepolarization over the time course of takotsubo cardiomyopathy (TC), and their relationships with clinical features and life-threatening arrhythmias. METHODS AND RESULTS: All consecutive patients admitted to our division between January 2008 and December 2011 with a diagnosis of TC were analysed. Patients with prior myocardial infarction, symptoms-onset-to-admission time greater than 12 hours, an implanted pacemaker, or under treatment with drugs affecting QTinterval, were excluded. Standard 12-lead ECG recordings during the acute, subacute and chronic phases were collected for each patient. Twenty-four patients (23 women, 63 +/- 14 years) were includedin our analysis. Only one patient experienced ventricular arrhythmias (4.2%). Significant increases were observed in QT and QTc intervals (from 420 ?423 to 505 +/- 66 ms, P < 0.00001, and from 479 +/- 33 to 551 +/- 51 ms, P < 0.00001, respectively), QTdispersion (from 59 +/- 18 to 100 +/- 44 ms, P=0.0006), Tpeak-to-Tend (from 82 +/- 20 to 123 +/- 39 ms, P=0.00006) and Tpeak-to-Tend/QT (from 0.20 +/- 0.33 to 0.26 +/- 0.57, P=0.0003) during the subacute phase. All these parameters returned to baseline values in the chronic phase and did not show any significant differences between the acute and chronic phases. CONCLUSIONS: A marked increase in QTc, QT dispersion, Tpeak-to-Tend and Tpeak-to-Tend/QT was observed during the subacute phase; this increase was transient and reverted in allpatients before hospital discharge. Ofnote, these findings were not associated with an increased risk of life-threatening arrhythmias.

Acute electrocardiographic differences between Takotsubo cardiomyopathy and anterior ST elevation myocardial infarction.

BACKGROUND: The aim of this study was to compare ECG findings between anterior ST elevation myocardial infarction (STEMI) and Takotsubo cardiomyopathy (TC) in a similar sample of postmenopausal women. METHODS: Between 2008 and 2011, 27 patients with TC were retrospectively enrolled and matched with 27 STEMI patients with the same age and sex taken from the prospective database of our laboratory. RESULTS: The absence of abnormal Q waves, the ST depression in aVR and the lack of ST elevation in V1 were significantly associated with TC (respectively: 52% vs 18%, p=0.01; 47% vs 11%, p=0.01; 80% vs 41%, p=0.01). The combination of these ECG findings identified TC with a specificity of 95% and a positive predictive value of 85.7%. CONCLUSIONS: The ECG on admission may be useful to distinguish TC from anterior STEMI. The combination of three ECG findings identifies patients with TC with high specificity and positive predictive value.

Safety and efficacy of the percutaneous radial artery approach for coronary angiography and angioplasty in the elderly.

BACKGROUND: The transradial approach to coronary interventions has been accepted as a safe and effective alternative to the femoral approach due to fewer access site complications and improved patient comfort. In the present study we aimed to investigate the safety and efficacy of transradial procedure in the elderly. METHODS: We analyzed 850 patients who underwent transradial coronary angiography and/or angioplasty. All patients were divided into two groups, according to age. The first group consisted of patients < 70 years (600; 70.5%) and the second group consisted of patients greater than or equal to 70 years (250; 29.5%). RESULTS: Baseline characteristics did not differ between the two groups, except for diabetes mellitus which affected more patients greater than or equal to 70 years of age. Procedure duration, X-ray time and number of catheters used were similar in the two groups. No deaths or acute myocardial infarctions occurred. There were some vascular complications in both groups, with no statistically significant difference between groups. In Group 2 (the older group) 2 TIAs and 1 stroke occurred, whereas in Group 1, there was 1 TIA (p = 0.08). CONCLUSIONS: From our experience, we conclude that the transradial catheterization is a safe and effective technique in the elderly, with a reduced risk of local vascular complications and a noteworthy increase in patient comfort, especially in view of the age-related diseases that frequently affect older patients.