Prevalence of QTc prolongation among hypertensive patients and its association with other co-morbidities

Background:Hypertension, an iceberg disease contributes significantly to the global health burden. This pan-endemic disease is a harbinger for cardiovascular events, especially life-threatening arrhythmias. A simple and cost-effective electrocardiogram serves as an effective tool to identifyand evaluate hypertensives with high cardiovascular risk.QTc interval which indicates repolarization abnormality is one such effective tool.The study aimed at describing the prevalence of QTc prolongation among hypertensive individuals and also to assess the association of QTc prolongation with various co-morbidities.Methods:One hundred and fifty-nine hypertensive patients were evaluated in this cross-sectional study for six months. Demographic variables, biochemical parameters, blood pressure and electrocardiogram were recorded for all the patients. Data obtained were statistically evaluated.Results:The mean age of participants was 55.6 years (SD�76). There were 103 males (64.4%) and 43 females (35.6%). QTc prolongation was noted in 52.5% of the population studied.Statistically significant QTc prolongation among poorly controlled hypertensive was 59% when compared to that of controlled hypertensive at 37.5% was noted. About 26% of the participants were smokers, 27% were alcoholics and 60% had co-existing diabetes mellitus. Diabetes and gender were found to have a statistically significant association with QTc prolongation.Conclusions:The study found a positive correlation between prolonged QTc and hypertensives and hypertensives with coexisting diabetes. To mitigate the consequences of hypertension, the study recommends early diagnosis, stringent blood pressure control, efficient and effective use of QTc measurement, and preventive pharmacotherapy.

Effects of different psychotropic drugs on the QTc interval in the elderly population / 中华老年医学杂志

Medications are the main means for the treatment of mental illness, and it is of great significance to be familiar with the adverse reactions of psychotropic drugs for the formulation and optimization of treatment plans.The prolongation of the QT interval corrected by heart rate(QTc interval)is one of the most common cardiotoxic reactions after taking psychotropic drugs and may lead to torsade de pointes and increase the risk of sudden cardiac death.The elderly population is more prone to QTc interval prolongation.In this review, we focus on the relationship between common psychotropic drugs and QTc interval prolongation and influencing factors in the elderly population, so as to help clinicians avoid risk in drug selection.

Lopinavir/ritonavir: is early administration better in Covid-19?

Background: To share the data of coronavirus 2019 (Covid-19) patients started on lopinavir-ritonavir (lopi/r) in relation to time period from the onset of symptoms.Method: Observational descriptive study of 23 Covid-19 patients admitted in a tertiary care center in India from March 2020 to May 2020. Patients categorized into 2 groups based on the timing of initiation of lopi/r from the onset of symptoms. Group 1 were given the drug early (≤7 days) and group 2 late (>7 days). The clinical events (oxygen requirement days and ICU stay) and outcomes of hospital stay between the two groups were evaluated.Results: Patients were started on lopi/r for a period of 14 days on admission, out of which 12 patients were in group 1 and 11 patients in group 2. Underlying co-morbidities were present in 15 patients (65.21%). The mean duration from onset of symptoms to lopi/r initiation was 4 days and 11.1 days in Group 1 and 2 respectively. Requirement for oxygen support (2.16 versus 6.54 days), mean duration of hospitalization (8.58 versus 11.54 days) and mean duration of obtaining first Covid-19 negative report from the onset of symptoms (10.5 versus 19.57 days) were all significantly lesser in group 1 (p<0.05). All patients belonging to Group 1 and eight patients of group 2 recovered completely and were discharged whereas 3 patients of group 2 expired. Diarrhea was the most commonly observed adverse effect of lopi/r in our patients.Conclusion: With no approved weapon to tackle the Covid-19 pandemic, we should keep lopi/r in our armamentarium of drugs and use it at the earliest. More clinical trials are needed in future to ascertain if lopi/r can reduce hospital stay, prompt faster recovery and result in better clinical outcome.

Cardiovascular dysfunction in patients of cirrhosis of liver

Background: Cirrhosis of liver refers to a progressive condition that disrupts the normal architecture of the liver. It is increasingly recognized that cirrhosis per se can cause cardiac dysfunction. The aim was to assess cardiovascular dysfunction electrocardiographically and echocardiographically in patients with cirrhosis of liver and to find the correlation between cardiovascular dysfunction and severity of liver cirrhosis as per child-PUGH score.Methods: Total 90 patients of cirrhosis of liver of both sexes were included in this cross-sectional study conducted from January 2018 to August 2019 in SGRDIMSR, Sri Amritsar. The severity of liver cirrhosis was assessed as per Child Pugh Score. QTc interval was calculated by Bazett抯 formula. Systolic and Diastolic dysfunction was seen on 2D-echocardiography.Results: QTc interval increased linearly with the severity of liver cirrhosis. Mean values of QTc in Child Pugh Class A=425.00(�.97), Class B=437.35(�.60), Class C=479.71(�.48) with p value of 0.04 which is significant. Diastolic dysfunction was also related with the severity of liver cirrhosis. In Child Pugh Class A= 2(33%) patients had grade 1 diastolic dysfunction, Class B=23(59%) patients had grade 1 diastolic dysfunction while in Child Pugh Class C=3(7%) had grade 1 diastolic dysfunction, 33(73%) patients had grade 2 diastolic dysfunction and 1(2%) patients had grade 3 diastolic dysfunction with p value of 0.04 which is significant. Systolic function was found normal in all the patients.Conclusions: Diastolic dysfunction and QTc interval prolongation are both related with the severity of liver cirrhosis and are major criteria of cirrhotic cardiomyopathy.

The evaluation of QTc prolongation and QT dispersion in type 2 diabetes mellitus as an indicator of cardiac autonomic neuropathy

Background: Diabetes mellitus refers to group of metabolic disorders characterized by hyperglycemia due to an absolute or relative deficit in insulin production or action. Diabetes mellitus produces pathological changes in most organs of the body including heart, blood vessels, kidneys, nerves and eyes. Cardiovascular autonomic neuropathy (CAN) is a severely debilitating yet underdiagnosed complication of diabetes. Diabetes-associated cardiovascular autonomic neuropathy damages autonomic nerve fibers that innervate the heart and blood vessels causing abnormalities in heart rate and vascular dynamics.Methods: Total 80 cases of diabetes mellitus were selected. Cardiac autonomic neuropathy in them was diagnosed by a series of tests recommended by Ewing et al, which include - Valsalva ratio, Deep Breath Test, Heart rate response to standing, Postural Hypotension, SHGT Increase in diastolic BP on sustained hand grip. They were divided into 2 groups A and B depending on presence or absence of cardiac autonomic neuropathy. ECG was done to calculate QTc and QTd.Results: In group A mean QTc was 0.344 sec and in group B in patients with mild CAN mean QTc was 0.432, moderate CAN mean QTc was 0.444, and in patients of severe CAN mean QTc was 0.481. p value was 0.001 that it is highly significant. Means more was degree of CAN more was prolongation of QT and similarly more the degree of CAN more was QTd.Conclusions: Diagnosis of cardiac autonomic neuropathy by battery of cardiac autonomic function tests is a comlex procedure. The prolongation of QTc interval and more specifically QTd interval on ECG is a marker in diagnosis of cardiac autonomic neuropathy which can be easily evaluated.

Análisis de parámetros en señales electrocardiográficas de pacientes con Chagas y de variables del dominio del tiempo de la HRV usando polígrafo de alta resolución / Analysis of parameters in electrocardiographic signals of patients with Chagas and time domain variables of the HRV using high resolution polygraph / Análise de parâmetros em sinais eletrocardiográficos de pacientes com variáveis Chagas e de domínio do tempo da VFC utilizando polígrafo de alta resolução

Resumen Este trabajo presenta los resultados obtenidos de un estudio sobre el análisis de parámetros electrocardiográficos en registros de pacientes seropositivos a la enfermedad de Chagas del Departamento del Meta y medición de las variables en el dominio de tiempo de la variabilidad de la frecuencia cardiaca (HRV) y su comparación con registros de población de control. Se obtuvieron un total de 38 registros de 10 minutos en su gran mayoría (57,9%) con un polígrafo de alta resolución entre ambas poblaciones, creándose una base de datos anotada de éstos registros. El presente estudio, permitió encontrar diferencias significativas de parámetros electrocardiográficos para el intervalo QTc entre los grupos, que podría ser consecuencia de alteración de la condución cardiaca que se traduce en un mayor incremento del QTc, así como de afectación de las variables del dominio de tiempo de la Variabilidad de la Frecuencia Cardiaca (HRV), como la SDRR y SEHR, que resultan en valores más bajos para los pacientes seropositivos a enfermedad de Chagas. Se concluye que variables de los registros ECG y de la HRV, presentan alteración en pacientes con enfermedad de Chagas , que podrían ser utilizados como alertas tempranas de la enfermedad no diagnosticada serológicamente.

Abstract This paper presents the results obtained from a study on the analysis of electrocardiographic parameters in records of patients seropositive to Chagas disease of the Department of Meta and measurement of the variables in the time domain of heart rate variability (HRV) and its comparison with population control records. A total of 38 10-minute records were obtained in the vast majority (57,9%) with a high resolution polygraph between both populations, creating an annotated database of these records. The present study allowed us to find significant differences in electrocardiographic parameters for the QTc interval between the groups, which could be a consequence of an alteration of the cardiac conduction that translates into a greater increase in the QTc, as well as the affectation of the time domain variables of Heart Rate Variability (HRV), such as the SDRR and SEHR, which result in lower values ​​for HRV-positive patients with Chagas disease. It is concluded that variables from the ECG and HRV registries present an alteration in patients with Chagas disease, which could be used as early warnings of the serologically undiagnosed disease.

Resumo Este artigo apresenta os resultados obtidos em um estudo sobre a análise de parâmetros eletrocardiográficos em prontuários de pacientes soropositivos para a doença de Chagas do Departamento de Meta e mensuração das variáveis ​​no domínio do tempo da variabilidade da freqüência cardíaca (VFC) e sua comparação com os registros de controle populacional. Um total de 38 registros de 10 minutos foi obtido na grande maioria (57,9%) com um polígrafo de alta resolução entre as duas populações, criando um banco de dados anotado desses registros. O presente estudo permitiu encontrar diferenças significativas nos parâmetros eletrocardiográficos para o intervalo QTc entre os grupos, o que pode ser consequência de uma alteração da condução cardíaca que se traduz em maior aumento no QTc, bem como no comprometimento das variáveis ​​no domínio do tempo Variabilidade da Frequência Cardíaca (VFC), como o SDRR e o SEHR, que resultam em valores mais baixos para pacientes HIV positivos com doença de Chagas. Concluise que as variáveis ​​dos registros de ECG e HRV apresentam alteração nos pacientes com doença de Chagas, que pode ser utilizada como alerta precoce da doença sorologicamente não diagnosticada.

Evaluation of the QTc internal and QT dispersion in patients with newly detected clinical hypothyroidism

Background: Thyroid hormones play an important role in the orchestration of various metabolic functions in the body and thus thyroid dysfunction can produce dramatic cardiovascular effects. Electrocardiographic changes such as bradycardia, low voltage complexes, and varying degrees of heart block are commonly recognized in hypothyroid patients. Hypothyroidism has been found to be associated with increased cardiovascular morbidity and mortality. Hence, it is important to investigate the ECG profile in these patients. The present study was aimed at evaluating the QTc interval and QT dispersion, an indicator of inhomogeneity of ventricular repolarisation and cardiac autonomic modulation in patients with newly detected clinical hypothyroidism.Methods: 50 patients with newly detected clinical hypothyroidism and 50 healthy controls were included in the study. The ECG was recorded and the heart-rate, QTc interval and QT dispersion were calculated.Results: The mean heart-rate was found to be significantly (p <0.05) reduced in hypothyroid patients when compared to healthy controls. The mean QTc interval and QT dispersion were significantly increased in hypothyroid patients when compared to controls. QTmin and QTmax of cases and controls also showed a statistically significant difference.Conclusion: Thus, the present study confirms the role of thyroid hormones on the cardiovascular system, particularly on ventricular repolarisation and cardiac autonomic modulation. Hence, early and prompt therapy with levothyroxine may help to prevent the adverse events resulting from cardiovascular dysfunction.

Effect Of Various Phases Of Menstrual Cycle On Electrocardiogram In 18-22 Years Healthy Females

During the menstrual cycle phases changes in the levels of female sex hormones mainly estrogens and progesterone, have some possible influence over the clotting and fiinolytic activity of the blood, rhythmicity and conductivity of the electrical impulse of heart. Aim: Main objective of the study is to find out the effects of different phases of menstruation on ECG intervals. Methodology: This was a cross sectional descriptive study conducted in female nursing students aging18 to22 years were considered Sample size was decided to be 140 female nursing students from LN Nursing College, Bhopal. Inclusion criteria were normal healthy female aged 18 to 22 years with regular menstrual cycle (30 days +- 3 days) in previous six cycles. There Electrocardiographic changes were accessed in different phases of menstrual cycle. Results- In our study we found longest RR interval in secreatory phase in comparison to proliferative and menstrual phase. Shortest Bleeding Time was found in menstrual phase. The results related to QT and QTc intervals shows that longest clotting time measures in proliferative phase as comparison to Menstrual and secreatory phase. Shortest QT and QTc intervals were found in secreatory phase

Alteration of cardiovascular autonomic activity in type 2 diabetes mellitus

Background: Diabetes mellitus (DM) is a clinical syndrome characterized by hyperglycaemia due to absolute or relative insulin deficiency. Cardiovascular autonomic neuropathy (CAN) invokes potentially life-threatening outcomes especially in poorly controlled diabetic patients. This study was to evaluate the prevalence of CAN in diabetic patients and its relationship with QTc interval.Methods: This observational study of two year duration was included total 123 patients of more than 30 (thirty) years and up to 60 (sixty) years of age who were presented with diabetic mellitus (DM) those were evaluated for CAN using four distinct clinical tests-Resting heart rate (RHR), test for orthostatic hypotension (OH), hand gripping test (HGT) and QTc interval on ECG. Data were analyzed with statistical package for social sciences (SPSS), version 23.Results: The mean age of all 103 studied patients was 48.94±8.69 years; Mostly patients belong to 50-60 years of age and the majority was males (69.0%). Out of 103 72.8% patients were reported with CAN (51 males and 24 females) and without CAN were 27.2.0% (20 males and 8 females), 36% of patients of Definite Parasympathetic neuropathy, 25% Normal and 20% of Sympathetic neuropathic patients. HbA1c level increases the danger of CAN also. QTc interval is a reliable indicator for the presence of CAN.Conclusions: Duration of diabetes is directly proportional to the prevalence of CAN. Various cardiac autonomic function tests detect CAN.

To Study the Prevalence of QTc Interval Prolongation in Cirrhosis of Liver And Its Relationship with the Severity of Disease

Background: Cirrhosis of liver is considered as chronicdisease of liver characterised by the triad of parenchymalinflammation, necrosis and regeneration with diffuse increasein fibrosis and formation of nodules around regenerating liverparenchyma. A retrospective study of 90 patients of livercirrhosis visiting OPD/Indoor of SGRDIMSR, Vallah, SriAmritsar were included in the study conducted from Jan 2017to Aug 2018 to assess QTc interval in patients with cirrhosis ofliver due to any etiology and to find the correlation betweenQTc interval and severity of liver cirrhosis as per Child-PughScore.Methods: The severity of liver cirrhosis was assessed andaccording to the Child Pugh Score, divided into Class A, ClassB and Class C of 30 patients each. QT interval was noted in allthe patients. QTc was calculated by Bazett’s formula. Fromabove parameters we try to find out whether there is anycorrelation between QTc and severity of disease.Results: The mean value of calculated QTc interval in: ClassA=0.474; Class B=0.490 and Class C=0.583. The QTc intervalincreased linearly with the severity of the disease and the pvalue was less than 0.001 which is highly significant.Conclusion: In our study we concluded that the prolongationof QTc interval is co-related with liver function and itsprevalence increases with the severity of liver dysfunction.Prolongation of the QTc interval was statistically confirmed inChild-Pugh C and B. The prolonged Q-T interval predictssevere arrhythmias and sudden death, and they are the idealcandidates for liver transplantation.

Relationship Of Blood Pressure With Qtc Interval And C-Reactive Protein

Background: C-reactive protein (CRP) is a systemic inflammatory marker used extensively. QTc interval representsboth ventricular depolarization and repolarization. Hypertension is one of the foremost leading causes ofmorbidity and mortality globally.Objectives: To explore the relationship of systolic blood pressure with QTc interval and CRP levels. Likewise toinvestigate the association of diastolic blood pressure with QTc interval and CRP levels.Materials and Methods: The study was carried out on 100 randomly selected subjects in the age group of 20-45years. Both genders were included. Hypertensive subjects on treatment were also included. Three records ofblood pressure in the supine position were obtained with 2 minute interval between each and average wasconsidered. QT interval and RR interval were measured from standard 12 lead electrocardiogram (ECG). Tangentmethod was used for QT interval and later it was corrected for heart rate to arrive at QTc interval using Bazett’sformula. CRP levels were obtained using high sensitivity (hs-CRP) assay kits.Results: There was a positive and significant association for systolic blood pressure with both QTc and CRP.Likewise we also found a positive and significant association for diastolic blood pressure with both QTc andCRP.Discussion: The inflammatory modulatory processes are altered in hypertension, thereby increasing CRP levels.CRP increases endothelin-1 and reduces nitric oxide leading to vasoconstriction and hypertension. Further CRPcauses autonomic imbalances by increasing sympathetic activity that lead to hypertension and indirectlyprolonging QTc interval. QTc interval is also lengthened by left ventricular hypertrophy as a complication ofhypertension.Conclusion: Hypertension with left ventricular hypertrophy can cause cardiac arrhythmias and sudden cardiacdeath. This may be prevented by early detection of high risk hypertensive subjects or even those prone todevelop hypertension using QTc and CRP indicators. Further these markers are cheap and widely used and theyprovide valuable diagnostic and prognostic features especially in developing countries like India.

Association between metabolic syndrome with QTc interval prolongation in physical examination subjects / 重庆医学

Objective To explore the relationship between metabolic syndrome(MS) and corrected QT(QTc) interval prolongation.Methods A total of 1 260 participants having electrocardiogram examinations,aged over 18 years old from June 2015 to June 2016 were included and divided into the MS group and non-MS group.QTc was calculated according to the Bazett formula.The Logistic regression model was established for exploring the association between MS and QTc.Results There were 63 cases of QTc interval prolongation in the MS group,however,40 cases in the non-MS group(P＜0.01).In the unadjusted model,MS was a risk factor of QTc interval prolongation[OR =6.36,95 ％ CI(2.34,8.67),P＜ 0.01].After further adjusting confounders,MS was still correlated with QTc interval prolongation[OR =4.11,95 ％ CI(2.09,7.13,P＜ 0.01].In the study of the relationship between the MS groups with QTc interval prolongation,after adjusting confoundingfactors,only abdominal obesity[OR=2.76,95％ CI(1.43,7.56),P＜0.01] and hypertriglyceridemia[OR=1.75,95％CI(1.22,4.31),P=0.013)] were closely correlated with QTc interval prolongation.Conclusion MS is an independent risk factor of QTc interval prolongation.It is especially important to strengthen the management of blood lipid and abdominal circumference.

Situación del intervalo QTc en el período neonatal en un hospital del occidente de México, estudio piloto / QTc interval in the neonatal period in a Mexican population. A pilot study

Resumen Introducción: La prolongación del intervalo QT se asocia con arritmias ventriculares y muerte súbita. Objetivo: Determinar el valor del intervalo QTc en recién nacidos sanos y evaluar su comportamiento durante los primeros meses de vida. Métodos: Recién nacidos sanos a término de marzo-noviembre 2016 en el Hospital General de Occidente del Estado de Jalisco, México. Se les practicó un electrocardiograma de 12 derivaciones a una velocidad de 25 mm/s durante las primeras 48 h. Se midió el intervalo QT en DII y se calculó el QTc mediante la fórmula de Bazett. Los pacientes a los que se detectó prolongación del QTc en sus primeras 48 h se valoraron al mes con ECG y ecocardiograma. Si persistieron con QTc alargado se revaloraron a los 6 meses con ECG, Holter de 24 h y estudio electrocardiográfico a padres y hermanos. Los que persistieron con QTc alargado se revaloraron a los 9 meses con ECG. Resultados: Se incluyeron 548 pacientes. La media del intervalo QTc al nacimiento fue de 459 ms; durante este período 33 pacientes presentaron un QTc mayor de 470 ms, los cuales fueron evaluados al mes mediante un nuevo estudio electrocardiográfico, obteniendo una media del intervalo QTc de 446 ms. A los 6 meses se evaluaron 16 pacientes, con una media del intervalo QTc de 434 ms. A los 9 meses se evaluaron 6 pacientes, con una media del intervalo QTc de 438 ms, y solo 4 pacientes persistieron con QTc prolongado. Conclusiones: El intervalo QTc en nuestros pacientes es más prolongado en comparación con otras poblaciones y muestra una normalización paulatina.

Abstract Introduction: QT interval prolongation is associated with ventricular arrhythmias and sudden death syndrome. Objective: To determine the value of QTc interval in healthy newborns in a general hospital in Jalisco, Mexico, and their outcome during their first months of life. Methods: The study included healthy newborns from March to November 2016, in the Hospital General of Occidente in Jalisco, Mexico. A 12-lead electrocardiogram was performed at a speed of 25 mm/s during the first 48 h of life. The QT interval was measured in lead DII, and the QTc interval was calculated using the Bazett formula. Patients detected with QTc prolongation were assessed monthly with an ECG and echocardiogram. If they persisted with prolonged QTc interval, they were re-evaluated at 6 months with an ECG, 24 h Holter, and electrocardiography study on parents and siblings. Those who persisted with prolonged QTc interval were evaluated with an ECG at 9 months. Results: The study included 548 patients. The mean QTc interval at birth was 459 ms; during this period 33 patients has a QTc greated that 470 ms; which were evaluated monthly with a new electrocardiographic study, obtaining a mean QTc interal of 446 ms. At 6 months 16 patients were evaluated, with a mean QTc interval of 434 ms. At 9 months, 6 patients were found to have a mean QTc interval of 438 ms, and only 4 patients persisted with a prolonged QTc interval. Conclusions: The QTc interval in our population is prolonged compared to other populations and with a gradual return to normal.

The effects of full marathon on hemodynamics related to cardiac electrophysiology of marathon amateurs / 中华急诊医学杂志

Objective To observe and assess the effects of full marathon on hemodynamics and cardiac electrophysiology of marathon amateurs without adverse event after the race.Methods Fiftyone subjects were included in the final analysis of the study,blood pressure,heart rate,body surface electrocardiogram (ECG) of all subjects under static status before the race and within (15-30) min after the race were detected,and sufficient amounts of the peripheral blood and the radial arterial blood specimens of all subjects under static status before the race and within (15-30) min after the race were collected instantly.The peripheral blood was used for measuring markers of muscle injury and NT-proBNP,and the radial arterial blood was taken for blood gas analysis.The QTc interval,QRS,PR interval,and QTd interval were recorded from the 12-lead ECG report.Results Compared with those under static status before the race,the systolic blood pressure,diastolic blood pressure,mean arterial blood pressure and heart rate of all the subjects within (15-30) min after the race were significantly higher (P＜0.05).When the markers of striated muscle injury were compared before and after the competition,levels of CK,cTNI,LDH,and myoglobin after the race were significantly increased compared with them under static status before the race (P ＜0.05),and the level of NT-proBNP after the race was also significantly increased compared with it before the race (P＜0.05).When blood gas analysis before the race was compared with that after the race,the PH values after race were significantly lower than it before race (P＜0.05).The level of lactic acid after the race was significantly higher than it before race (P＜0.05).After the race,the levels of PCO2,SBE and HCO3-decreased significantly compared with those before race (P＜0.05),and the QTc and QTd intervals after the race increased significantly compared with those before the race,however,the QTc interval and QTd interval for all subjects before and after the competition were within the normal range.Conclusions Full marathon significantly affect the myocardial electrophysiological markers of healthy amateur athletes without chronic diseases,but those markers fluctuate within the normal range.

A study on glasgow coma scale score and QTC interval in predicting prognosis and outcome of organophosphate and carbamate poisoning

Background: Poisoning with organophosphorous substances is the commonest cause of inpatient mortality among all poisonings in developing countries like India. This study is undertaken with an aim of assessing simple parameters like GCS and QTc (marker of ventricular arrythmias) in predicting the outcome and complications of organophosphate compound poisoning considering the mortality and sufferings of Organophosphorous poisoning patients. Aim: To assess the utility of GCS score and QTc interval in predicting prognosis in patients who had consumed organophosphate and carbamate poisoning and to assess whether the above parameters helps to identify the high risk groups requiring mechanical ventilation. Materials and methods: This study was conducted among 200 organophosphate and carbamate poisoning patients who were admitted at Government Rajaji Hospital, Madurai from February 2014 to September 2014. After taking detailed history and physical examination and investigations the Glasgow coma scale score and QTc interval at the time of admission was calculated. Patients with GCS score < 13 and QTc interval > 0.44s in males and 0.46s in females as poor outcome. Results: There was a linear relation with QTc interval and severity of Organophosphorous poisoning i.e. as the QTc interval increases the severity of poisoning increases. There was an inverse relationship Prabhakaran R, Marannan N, Ponnusamy Kumar, Vijayakumari Vrinda. A study on glasgow coma scale score and QTC interval in predicting prognosis and outcome of organophosphate and carbamate poisoning. IAIM, 2017; 4(6): 1-7. Page 2 between the GCS score and severity of Poisoning, .i.e. as the GCS decreases the severity of poisoning increases. Conclusion: Our study showed that respiratory failure in patients with OP compound poisoning can be predicted at admission by simple parameters like lower GCS and prolonged QTc interval in ECG.

QTc interval predicts outcome of catheter ablation in paroxysmal atrial fibrillation patients with type 2 diabetes mellitus / 华中科技大学学报（医学）（英德文版）

Catheter ablation has been recommended as a treatment option for paroxysmal atrial fibrillation (PAF) patients complicated with type 2 diabetes mellitus (T2DM). PAF patients with T2DM have a higher recurrence rate after catheter ablation. Prolongation of corrected QT (QTc) interval has been linked to poor outcomes in T2DM patients. Whether the abnormal QTc interval is associated with the ablation outcome in the PAF patients with T2DM remains unknown. In this study, 134 PAF patients with T2DM undergoing primary catheter ablation were retrospectively enrolled. Pre-procedural QTc interval was corrected by using the Bazett's formula. Cox proportional hazards models were constructed to assess the relationship between QTc interval and the recurrence of AF. After a 29.1-month follow-up period, 61 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had a longer QTc interval than non-recurrent patients (425.2±21.5 ms vs. 414.1±13.4 ms, P=0.002). Multivariate Cox regression analysis revealed that QTc interval [hazard ratio (HR)=1.026, 95% confidence interval (CI) 1.012-1.040, P=0.005] and left atrial diameter (LAD) (HR=1.125, 95% CI 1.062-1.192, P=0.003) were independent predictors of recurrent atrial tachyarrhythmia. Receiver operating characteristic analysis demonstrated that the cut-off value of QTc (418 ms) predicted arrhythmia recurrence with a sensitivity of 55.7% and a specificity of 69.9%. A combination of LAD and QTc was more effective than LAD alone (P<0.001) in predicting arrhythmia recurrence after the procedure. QTc interval could be used as an independent predictor of arrhythmia recurrence in T2DM patients undergoing AF ablation, thus providing a simple method to identify those patients who likely have a better outcome following the procedure.

Clinical significance of changes in the corrected QT interval in stress-induced cardiomyopathy

BACKGROUND/AIMS: Although transient changes in the electrocardiogram (ECG) of patients with stress-induced cardiomyopathy (SCMP) are common, there are little data about ECG changes in patients with SCMP and the clinical implications of these variations. METHODS: We investigated a total of 128 patients (age, 63.2 ± 15.4 years; female, 60.9%) diagnosed with SCMP. We compared the ECGs taken after SCMP diagnosis and during the recovery phase to those taken before SCMP diagnosis under baseline conditions. All patients were divided into two groups according to corrected QT (QTc) interval changes: recovered QTc group (QTc in SCMP > QTc in recovery phase, n = 77) and nonrecovered QTc group (QTc in SCMP ≤ QTc in recovery phase, n = 51). RESULTS: In comparison of baseline, SCMP, and recovery phase, we found the mean heart rate (81.5 ± 18.7, 96.8 ± 25.3, and 83.0 ± 19.4/min, respectively; p < 0.001), frequencies of ST segment elevation (0.0%, 8.6%, and 1.6%, p = 0.004), ST segment depression (0.0%, 6.3%, and 1.6%, p = 0.007), T wave inversion (4.4 %, 43.8%, and 61.7%, p < 0.001), and QTc (447.4 ± 35.3, 488.9 ± 67.1, and 468.0 ± 49.5, p < 0.001) showed significant changes. In-hospital mortality (9.1% vs. 25.5%, p = 0.012) and critical care (54.5% vs. 72.5%, p = 0.040) occurred more frequently in the nonrecovered QTc group than in recovered QTc group. CONCLUSIONS: The QTc can be prolonged in patients with SCMP. Short-term mortality was increased in patients where the QTc did not recover.

The evaluation of the quantitative relationship between the healthy volunteers' plasma concentration after continuous administration with moxifloxacin and QTc prolongation / 中国药学杂志

OBJECTIVE: To evaluate the effect on QT interval of the healthy volunteers who was after four consecutive days of oral moxifloxacin. METHODS: The 48 volunteers (24 male and 24 female) of 20-40 years old were selected in accordance with the parameters of physical examination and laboratory test. For four consecutive days, the volunteers take oral moxifloxacin 400 mg qd. Before administration and after, ECGs were traced for each preset time point. Analysis the QT by manual measurement and measuring instruments. While, the blood samples for each preset time point were collected for the analysis of blood concentration by LC-MS/MS. At the end of a cycle do the safety checks for the healthy volunteers according to program requirements. RESULTS: The 48 healthy volunteers were selected in the trial, and 45 (22 males and 23 female) of them completed. After four consecutive days to give oral moxifloxacin qd can cause QT prolongation, the degree of risk of that is possibly dangerous. CONCLUSION: Moxifloxacin can cause QT prolongation, and the quantitative relationship between plasma concentration and QT prolongation is positive correlation, it is suggested that clinicians should pay strict attention to the administration of serious drug reactions.

El análisis del intervalo QT corregido incrementa la capacidad de la ergometría para diagnosticar enfermedad arterial coronaria significativa / The Analysis of the Corrected QT-Interval Increases Exercise Stress Test Capability to Detect Significant Coronary Artery Disease

Introducción: La utilidad clínica de la capacidad de la ergometría para indicar la presencia y gravedad funcional de las obstrucciones coronarias se ve limitada por las relativamente bajas sensibilidad y especificidad del infradesnivel del segmento ST (infra-ST), lo cual hace necesaria la investigación de las modificaciones de otras variables electrocardiográficas durante el esfuerzo que puedan aportar información adicional y complementaria a la del infra-ST. Se ha demostrado que el evento más temprano en la primera fase de la lesión transmural es la prolongación del intervalo QT corregido (QTc). Objetivos: Investigar si las modificaciones del intervalo QTc inducidas por el esfuerzo máximo (QTc máx) sumadas al infra-ST ≥ 1 mm permiten incrementar la capacidad de la ergometría para diagnosticar la presencia de enfermedad arterial coronaria significativa y si otros signos pueden aportar también información útil para identificar a estos pacientes. Material y métodos: Ciento sesenta y seis pacientes con infra-ST ≥ 1 mm durante la fase de ejercicio y/o recuperación de una ergometría a los que posteriormente se les realizó una coronariografía se distribuyeron en dos grupos: Grupo I (GI): 118 pacientes que mostraron prolongación del intervalo QTc máx y Grupo II (GII): 48 pacientes que acortaron normalmente el QTc máx. Se analizaron parámetros clínicos, ergométricos y electrocardiográficos y la angiografía coronaria para comprobar la presencia de enfermedad arterial coronaria significativa. Resultados: En 102 de los 166 pacientes incluidos (61,4%) se diagnosticó enfermedad arterial coronaria significativa, todos ellos pertenecientes al GI. El GI mostró alta prevalencia de pacientes con enfermedad arterial coronaria significativa (86,4% vs. 0%; p < 0,001), bajo umbral isquémico, recuperación tardía del infra-ST, mayor ensanchamiento del complejo QRSmáx, incompetencia cronotrópica y baja tolerancia al ejercicio. Durante la prueba ergométrica graduada los pacientes del GII presentaron mayor prevalencia de hipertensión arterial grave y el infra-ST < 1 mm en el segundo minuto del posesfuerzo. El incremento del intervalo QTc máx resultó un predictor independiente de enfermedad coronaria (p < 0,001). Conclusiones: La prolongación del intervalo QTc máx sumado al infra-ST ≥ 1 mm incrementó notoriamente la capacidad de la prueba ergométrica graduada para diagnosticar la presencia de enfermedad arterial coronaria significativa, patología que estuvo ausente en todos los pacientes con infra-ST que acortaron normalmente el QTc máx.

Background: The clinical usefulness of exercise stress testing to indicate the presence and functional severity of coronary artery stenoses is limited by the relatively low sensitivity and specificity of ST-segment depression. Therefore, the modifications of other electrocardiographic variables during exercise, which may provide additional and complementary information to ST-segment depression, should be investigated. It has been demonstrated that the corrected QT interval (QTc) prolongation is the earliest event during the first stage of transmural ischemia. Objectives: The aim of this study was to investigate whether modifications of the QTc interval induced by maximal exercise (QTcmax) together with ST-segment depression ≥ 1 mm can increase the capability of the stress test to detect significant coronary artery disease and if other signs may also provide useful information to identify these patients. Methods: One hundred and sixty six patients with ST-segment depression ≥ 1 mm during exercise or during the recovery stage of a stress test underwent coronary angiography. They were divided into two groups: Goup I (GI): 118 patients with QTcmax interval prolongation and Group II (GII): 48 patients with normal QTcmax shortening. Clinical, stress test-related and electrocardiographic parameters and coronary angiography were analyzed to identify the presence of significant coronary artery disease. Results: Significant coronary artery disease was detected in 102 of the 166 patients included in the study (61.4%), all from GI. Group I showed high prevalence of patients with significant coronary artery disease (86.4% vs. 0%; p < 0.001), low ischemic threshold, late recovery of ST-segment depression, wider QRSmax complex, chronotropic incompetence and low exercise capacity. During graded exercise stress testing, GII patients presented greater prevalence of severe hypertension and ST-segment depression < 1 mm two minutes after exercise. Increased QTcmax interval resulted as an independent predictor of coronary artery disease (p < 0.001). Conclusions: QTcmax interval prolongation plus ST-segment depression ≥ 1 mm produced a considerable increase in the capability of exercise stress testing to detect significant coronary artery disease, which was absent in all the patients with ST-segment depression and normal QTcmax shortening.

The normal variations in heart rate and QRS complex of healthy individuals in different age groups.

Background: Electrocardiography is the only practical method of recording the electrical behavior of the heart. It is often an independent marker of myocardial disease and occasionally the only indication of the pathologic process. Therefore the present study has been undertaken to find out the degree of normal variations in healthy individuals in different age groups. Methods: This study was conducted after the institutional ethical clearance and informed written consent from all the subjects belongs to age group of 18 to 40 years of either sex. All the ECG was taken in resting and supine position using BPL CARDIART 308 machine. The body weight, the QRS duration, QRS axis, P wave duration, P wave voltage, P wave axis in the frontal plane, QTc interval, T wave voltage and QRS-T angle was calculated. The values are expressed as mean and the percentile was calculated in each parameters. Results: The weight ranges from 56.37 ± 6.53 kg. QRS duration ranged from 0.04 to 0.12 seconds mean of 0.064 seconds. QRS voltage in V6 varied from 0.30 to 2.1 mv with a mean of 1.14 mv. The QTc interval was 0.31 to 0.47 seconds mean was 0.39 seconds. QRS-T angle varied from 0° to 70° with a mean of 30.9°. Conclusion: The study provides the frequency distribution and other statistical data when applied to all components of ECG which are commonly assessed during investigations of healthy young individuals. Having knowledge of these normal variants will be helpful in arriving at correct diagnosis.