QTc, Tp-e Interval and Tp-e/QTc Ratio in Patients with Hypocalcemia-case Control Study

Abstract Background: To the best of our knowledge, there are studies related to QT and QTc interval in patients with hypocalcemia, but there are no studies evaluating T wave peak and end interval (Tp-e interval), Tp-e/QT and Tp-e/QTc ratios used to evaluate cardiac arrhythmia risk and ventricular repolarization changes rates. Objectives: Therefore, we aimed to investigate whether there is a change in Tp-e interval, Tp-e/QT and Tp-e/QTc ratios in patients with hypocalcemia. Methods: Retrospectively, 29 patients with hypocalcemia in the emergency department were included in the study. Twenty-nine patients with similar age and sex distribution were included in the study as the control group. All patients underwent 12-lead electrocardiography (ECG). In addition to routine measurements, Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were measured on ECG. The study data were grouped as patients with and without hypocalcemia. Results: The mean age of the patients was 66.24 ± 4.95 years. QTc interval, Tp-e interval and Tp-e/QTc values were found to be significantly higher in patients with hypocalcemia (p <0.001 for each). QTc interval, Tp-e interval and Tp-e/QTc ratio showed a significant negative correlation with calcium levels. Conclusion: Tp-e interval and Tp-e/QTc ratios are significantly increased in patients with hypocalcemia compared to those without hypocalcemia and this can be used more effectively in the follow-up of cardiac fatal arrhythmias.

Shortening in the Tp-e/QTc ratio after angioplasty in patients with acute coronary syndrome. / Acortamiento en la relación Tp-f/QTc tras angioplastia en pacientes con síndrome isquémico coronario agudo.

Objetivo: La dispersión transmural de la repolarización ventricular (DTMRV) es un factor de riesgo para muerte en pacientes con síndrome isquémico coronario agudo (SICA). Con el objetivo de conocer el efecto de la realización de angioplastia sobre la DTMRV, se estudió la relación Tp-f/QTc en pacientes con SICA sometidos a angioplastia. Método: Se diseñó un estudio observacional, retrospectivo y descriptivo. Se incluyeron 150 pacientes (N = 150) con diagnóstico de SICA. Se valoró la relación Tp-f/QTc inicial y se evaluó su acortamiento posangioplastia. Como objetivo secundario, se comparó la asociación de dichos cambios en la relación Tp-f/QTc con la mortalidad cardiovascular y los eventos adversos cardiovasculares. Resultados: El promedio en la relación Tp-f/QTc inicial fue de 0.2529, mientras que posangioplastia fue de 0.2397. Por medio de prueba de rangos de Wilcoxon se evidenció un descenso significativo en la relación Tp-f/QTc posterior a la angioplastia, con un valor Z de -2.051 y una p < 0.04. En el análisis secundario se encontró que una Tp-f/QTc ≥ 0.29 posangioplastia es factor de riesgo para presentación de los siguientes eventos adversos: muerte intrahospitalaria (7.4 vs 0%; p < 0.003), nuevo SICA en seguimiento a 1 año (25.9 vs. 18.5%; p < 0.006) y reintervención en seguimiento a 1 año (29.6 vs. 15.0%; p < 0.002). Conclusiones: Existe un acortamiento significativo en la relación Tp-f/QTc posangioplastia en pacientes con SICA. Esta medida de la DTMRV puede servir como un predictor de muerte intrahospitalaria, eventos cardiovasculares y reintervención a 1 año en pacientes con SICA tratados con angioplastia. Objective: Transmural Dispersion of Repolarization (TDR) is a Risk factor for Death in patients with Acute Coronary ­Syndrome (ACS). In order to know the effect of angioplasty on TDR, the Tp-e/QTc ratio was studied in patients with ACS undergoing angioplasty. Method: An observational, retrospective and descriptive study was designed. 150 patients (N = 150) with diagnosis of ACS were included. The initial Tp-e/QTc ratio was assessed and then its post-angioplasty shortening was evaluated. As a secondary objective, we compared the association of these Tp-e/QTc ratio changes with cardiovascular mortality and cardiovascular adverse events. Results: The average in the initial Tp-e/QTc ratio was 0.2529, while post-angioplasty was 0.2397. Through a Wilcoxon rage test, a significant decrease in the Tp-e/QTc ratio after angioplasty was observed, with a Z value of −2.051 and p < 0.04. In the secondary analysis, it was found that a Tp-e/QTc ≥ 0.29 post-angioplasty is a risk factor for presenting the following adverse events: in-hospital death (7.4 vs. 0%; p < 0.003), new ACS in 1-year follow-up (25.9 vs. 18.5%; p < 0.006), and reintervention in 1-year follow up (29.6 vs. 15%; p < 0.002). Conclusions: There is a significant shortening in the Tp-e/QTc ratio post-angioplasty in patients with ACS. This measure of TDR can serve as a predictor of in-hospital death, cardiovascular events and 1-year reintervention in patients with ACS treated initially by angioplasty.

Acortamiento en la relación Tp-f/QTc tras angioplastia en pacientes con síndrome isquémico coronario agudo / Shortening in the Tp-e/QTc ratio after angioplasty in patients with acute coronary syndrome

Resumen Objetivo: La dispersión transmural de la repolarización ventricular (DTMRV) es un factor de riesgo para muerte en pacientes con síndrome isquémico coronario agudo (SICA). Con el objetivo de conocer el efecto de la realización de angioplastia sobre la DTMRV, se estudió la relación Tp-f/QTc en pacientes con SICA sometidos a angioplastia. Método: Se diseñó un estudio observacional, retrospectivo y descriptivo. Se incluyeron 150 pacientes (N = 150) con diagnóstico de SICA. Se valoró la relación Tp-f/QTc inicial y se evaluó su acortamiento posangioplastia. Como objetivo secundario, se comparó la asociación de dichos cambios en la relación Tp-f/QTc con la mortalidad cardiovascular y los eventos adversos cardiovasculares. Resultados: El promedio en la relación Tp-f/QTc inicial fue de 0.2529, mientras que posangioplastia fue de 0.2397. Por medio de prueba de rangos de Wilcoxon se evidenció un descenso significativo en la relación Tp-f/QTc posterior a la angioplastia, con un valor Z de −2.051 y una p < 0.04. En el análisis secundario se encontró que una Tp-f/QTc ≥ 0.29 posangioplastia es factor de riesgo para presentación de los siguientes eventos adversos: muerte intrahospitalaria (7.4 vs 0%; p < 0.003), nuevo SICA en seguimiento a 1 año (25.9 vs. 18.5%; p < 0.006) y reintervención en seguimiento a 1 año (29.6 vs. 15.0%; p < 0.002). Conclusiones: Existe un acortamiento significativo en la relación Tp-f/QTc posangioplastia en pacientes con SICA. Esta medida de la DTMRV puede servir como un predictor de muerte intrahospitalaria, eventos cardiovasculares y reintervención a 1 año en pacientes con SICA tratados con angioplastia.

Abstract Objective: Transmural Dispersion of Repolarization (TDR) is a Risk factor for Death in patients with Acute Coronary Syndrome (ACS). In order to know the effect of angioplasty on TDR, the Tp-e/QTc ratio was studied in patients with ACS undergoing angioplasty. Method: An observational, retrospective and descriptive study was designed. 150 patients (N = 150) with diagnosis of ACS were included. The initial Tp-e/QTc ratio was assessed and then its post-angioplasty shortening was evaluated. As a secondary objective, we compared the association of these Tp-e/QTc ratio changes with cardiovascular mortality and cardiovascular adverse events. Results: The average in the initial Tp-e/QTc ratio was 0.2529, while post-angioplasty was 0.2397. Through a Wilcoxon rage test, a significant decrease in the Tp-e/QTc ratio after angioplasty was observed, with a Z value of −2.051 and p < 0.04. In the secondary analysis, it was found that a Tp-e/QTc ≥ 0.29 post-angioplasty is a risk factor for presenting the following adverse events: in-hospital death (7.4 vs. 0%; p < 0.003), new ACS in 1-year follow-up (25.9 vs. 18.5%; p < 0.006), and reintervention in 1-year follow up (29.6 vs. 15%; p < 0.002). Conclusions: There is a significant shortening in the Tp-e/QTc ratio post-angioplasty in patients with ACS. This measure of TDR can serve as a predictor of in-hospital death, cardiovascular events and 1-year reintervention in patients with ACS treated initially by angioplasty.