QTc Interval In Patients Research Articles

Changes in spatial QRS-T angle and QTc interval in patients with traumatic brain injury with or without intra-abdominal hypertension

IntroductionTraumatic brain injury (TBI) affects cardiac electrical function, and several extra-cerebral factors, including intra-abdominal pressure (IAP), might further modulate this brain-heart interaction. The purpose of this study was to investigate the impact of TBI, and of increased IAP during TBI, on cardiac electrical function as measured by vectorcardiographic (VCG) variables. MethodsSurvival, IAP and changes in VCG variables including spatial QRS-T angle and QTc interval were measured in consecutive adult patients with either isolated TBI (iTBI), or with TBI accompanied by polytrauma to the abdomen and/or limbs (pTBI). For all patients, observations were performed just after the admission to the ICU (baseline) and at 24, 48, 72 and 96h after admission. Results74 patients aged 45±18 were studied. 44 were treated for iTBI and 30 for pTBI. In all patients, spatial QRS-T angle and QTc interval increased after TBI (p<0.001), relatively more so in patients with pTBI. Compared to survivors, non-survivors also ultimately had greater widening of the spatial QRS-T angle (p<0.001), most notably just before foraminal herniation. Wider spatial QRS-T angle and longer QTc interval were also noted in patients with IAP>12mmHg (p<0.001), and with right compared to left hemispheric injury (p<0.001). ST segment level at the J point decreased 24 and 48h after TBI in leads I, II, III, aVR, aVF, V1, V2, V3 and V6, and increased in lead V1, especially in non-survivors. ConclusionsSpatial QRS-T angle and QTc interval increase after TBI. If foraminal herniation complicates TBI, further widening of the spatial QRS-T angle typically precedes it, followed by notable narrowing thereafter. Increased IAP also intensifies TBI-associated increases in spatial QRS-T angle and QTc interval.

Spontaneous Variability of QTc Interval in Patients with Congenital Long QT Syndrome

Introduccion: La medicion del intervalo QTc es una herramienta indispensable para diagnosticar y estratificar el riesgo de eventos cardiacos adversos en los pacientes (p) con los sindromes de QT largo (SQTL) hereditarios. Los intervalos QTc pueden variar en forma ostensible y prolongarse de manera intermitente solo antes, durante o despues de un evento arritmico. Objetivos: Determinar si, en los pacientes con SQTL, existen variaciones significativas de los intervalos QTc cuando se los mide en varias oportunidades. Material y metodos: Se midieron la duracion de los intervalos QTc en tres ECG registrados cada 7 dias, en 25 pacientes con SQTL y 15 controles sanos. Resultados: Los intervalos QTc variaron de manera significativa en ambos grupos. Los valores minimos y maximos de QTc fueron de 492 mseg (rango intercuartil [RIC] 25-75: 463,5-501,5) y 522 mseg (RIC: 503,5-543) en pacientes con SQTL (p < 0,0001), respectivamente. En los individuos sanos, dichos valores fueron de 409 mseg(RIC: 395-418) y 423 mseg (RIC: 413431) (p < 0,001). En el 56% de los pacientes, las mediciones de los intervalos QTc oscilaron por encima y por debajo de 500 mseg. El 24% tuvo un intervalo QTc siempre por debajo de 500 mseg y el 20% siempre por encima. El intervalo QTc siempre fue mayor de 500 mseg en el 50% de los sintomaticos y en el 10,5% de los asintomaticos. Conclusiones: En los pacientes con SQTL, los intervalos QTc varian significativamente. Una unica determinacion no es suficiente para estratificar el riesgo.

The relationship between insulin sensitivity and heart rate-corrected QT interval in patients with type 2 diabetes

BackgroundReduced insulin sensitivity not only contributes to the pathogenesis of type 2 diabetes but is also linked to multiple metabolic risk factors and cardiovascular diseases (CVD). A prolonged heart rate-corrected QT interval (QTc interval) is related to ventricular arrhythmias and CVD mortality and exhibits a high prevalence among type 2 diabetes patients. The aim of the study was to investigate the relationship between insulin sensitivity and the QTc interval in patients with type 2 diabetes.MethodsThis cross-sectional observational study recruited 2927 patients with type 2 diabetes who visited the Affiliated Haian Hospital and Second Affiliated Hospital of Nantong University. The insulin sensitivity index (Matsuda index, ISIMatsuda) derived from 75-g OGTT and other metabolic risk factors were examined in all patients. The QTc interval was estimated using a resting 12-lead electrocardiogram, and an interval longer than 440 ms was considered abnormally prolonged.ResultsThe QTc interval was significantly and negatively correlated with the ISIMatsuda (r = −0.296, p < 0.001), and when the multiple linear regression analysis was adjusted for anthropometric parameters, metabolic risk factors, and current antidiabetic treatments, the QTc interval remained significantly correlated with the ISIMatsuda (β = −0.23, t = −12.63, p < 0.001). The proportion of patients with prolonged QTc interval significantly increased from 12.1% to 17.9%, 25.6% and 37.9% from the fourth to third, second and first quartile of the ISIMatsuda, respectively. After adjusting for anthropometric parameters by multiple logistic regression analysis, the corresponding odd ratios (ORs) for prolonged QTc interval of the first, second and third quartiles versus the fourth quartile of ISIMatsuda were 3.11 (95% CI 2.23–4.34), 2.09 (1.51–2.88) and 1.53 (1.09–2.14), respectively, and p for trend was <0.001.ConclusionsReduced insulin sensitivity is associated with an increase in the QTc interval in patients with type 2 diabetes.

Effect of alisertib, an investigational aurora a kinase inhibitor on the QTc interval in patients with advanced malignancies

SummaryAims A primary objective of this study was to investigate the effect of single and multiple doses of alisertib, an investigational Aurora A kinase inhibitor, on the QTc interval in patients with advanced malignancies. The dose regimen used was the maximum tolerated dose which was also the recommended phase 3 dose (50 mg twice daily [BID] for 7 days in 21-day cycles). Methods Patients received a single dose of alisertib (50 mg) on Day 1, and multiple doses of alisertib (50 mg BID) on Days 4 through to the morning of Day 10 of the first cycle of treatment. Triplicate ECGs were collected at intervals over 10 to 24 h via Holter recorders on Days −1 (baseline), 1 and 10. Changes from time-matched baseline values were calculated for various ECG parameters including QTc, heart rate, PR and QRS intervals. Alisertib pharmacokinetics were also assessed during the study, and an exposure-QTc analysis was conducted. Results Fifty patients were included in the QTc analysis. The upper bounds of the 95% confidence intervals for changes from time-matched baseline QTcF and QTcI values were <5 ms across all study days, time points and correction methods. Alisertib did not produce clinically relevant effects on heart rate, PR or QRS intervals. There was no evidence of a concentration-QTc effect relationship. Conclusions Alisertib does not cause QTc prolongation and can be concluded to not have any clinically relevant effects on cardiac repolarization or ECG parameters at the single agent maximum tolerated dose of 50 mg BID.

QTc interval in patients with schizophrenia receiving antipsychotic treatment as monotherapy or polypharmacy.

Antipsychotics are associated with a polymorphic ventricular tachycardia, torsades de pointes, which, in the worst case, can lead to sudden cardiac death. The QT interval corrected for heart rate (QTc) is used as a clinical proxy for torsades de pointes. The QTc interval can be prolonged by antipsychotic monotherapy, but it is unknown if the QTc interval is prolonged further with antipsychotic polypharmaceutical treatment. Therefore, this study investigated the associations between QTc interval and antipsychotic monotherapy and antipsychotic polypharmaceutical treatment in schizophrenia, and measured the frequency of QTc prolongation among patients. We carried out an observational cohort study of unselected patients with schizophrenia visiting outpatient facilities in the region of Central Jutland, Denmark. Patients were enrolled from January of 2013 to June of 2015, with follow-up until June of 2015. Data were collected from clinical interviews and clinical case records. Electrocardiograms were available for 65 patients, and 6% had QTc prolongation. We observed no difference in average QTc interval for the whole sample of patients receiving no antipsychotics, antipsychotic monotherapy, or antipsychotic polypharmaceutical treatment (p=0.29). However, women presented with a longer QTc interval when receiving polypharmacy than when receiving monotherapy (p=0.01). A limitation of this study was its small sample size. We recommend an increased focus on monitoring the QTc interval in women with schizophrenia receiving antipsychotics as polypharmacy.

QTc interval in patients diagnosed with schizophrenia receiving different defined daily dose (DDD) of antipsychotics

IntroductionBoth 1st and 2nd generation of antipsychotics are associated with prolonged QTc interval. Prolonged QTc can lead to ventricular tachycardia and Torsade's de pointes, ultimatime resulting to cardiac arrest and sudden death. Prolonged QTc interval due to increased DDD has not yet been investigated.ObjectiveTo investigate whether increased DDD of antipsychotics, causes further prolonged QTc, by patients diagnosed with schizophrenia.AimsTo learn more about antipsychotics impact on the QTc interval in patients diagnosed with schizophrenia.MethodsAn observational study of unselected patients diagnosed with schizophrenia. Enrolled from January 2013 through March 2015 with follow-up until June 2015 in the region of central Denmark. Data was collected from ECG records and patient journals.ResultECGs were available in 58 patients. We observed no relation between increased DDD of antipsychotics and prolonged QTc. There were no differences in average QTc interval for the whole sample of patients receiving different DDD of antipsychotics.ConclusionWe do not recommend increased attention to patients treated with higher DDD of antipsychotics.Disclosure of interestThe authors have not supplied their declaration of competing interest.

QTc interval in patients with multiple sclerosis: an inference from the insula of Reil?

The aim of this study was to investigate the correlation between the duration of the QTc interval and the brain lesion load at the level of the structures involved in superior autonomic control (insula, cingulate cortex and amygdala-hippocampus) in multiple sclerosis (MS) patients. Thirty-one consecutive patients with relapsing-remitting MS were recruited. The QT interval was measured manually in all 12 leads by a single blinded observer, with the longest QT value adjusted for heart rate by using the Bazett's formula. All patients performed a brain magnetic resonance imaging (MRI) scan including three-dimensional double inversion recovery and three volumetric fast-field echo sequences. The following MRI measures were obtained: (i) global and regional cortical thickness (CTh); (ii) white matter lesion load volume; (iii) cortical damage blindly assessed by a trained observer who assigned, on the basis of the number of cortical lesions, a score from 0 to 5 for each of the brain areas analysed. In all, 16% of the patients had an increased QTc interval. The QTc interval was correlated with disease duration, cortical insular lesion volume and grey matter lesion volume in the three examined areas and inversely correlated with global and insular CTh. An increased QTc interval in patients with MS may have a cerebral origin possibly driven by involvement of the insular cortex. With the recent introduction in clinical practice of treatments with potential cardiac effects such as fingolimod, the recognition of a long QTc interval could be clinically crucial and should encourage appropriate electrocardiographic monitoring in order to prevent the risk of malignant ventricular pro-arrhythmia and iatrogenic sudden death.

Ventricular Repolarization in Patients with Decompensated Liver Cirrhosis and its Relation to the in-Hospital Outcome: Electrocardiographic Study

Background: Prolonged ventricular repolarization has been documented in patients with chronic liver disease. The objective of this study was to study the electrocardiographic QTc interval in patients with decompensated liver disease and its relation to the in-hospital outcome. Methods: We retrospectively studied 75 patients with hepatic encephalopathy. The QTc interval was measured in a 12-lead electrocardiogram obtained on admission. Results: Patients were divided into two groups according to their clinical outcome during hospitalization. The first group included 53 (70.7%) patients who survived, and the second group included 22 (29.3%) patients who died. QTc interval was significantly prolonged in died patients than patients who survived (p<0.001). There was insignificant difference between two groups regarding age, sex, smoking status, hypertension, diabetes mellitus and basal laboratory findings except for serum creatinine level (p = 0.006) and MELD score (p = 0.033). Conclusions: In patients with hepatic encephalopathy, QTc interval was significantly higher in patients who died than in patients who survived, however, in multivariate logistic regression analysis, QTc interval, was not predictors of survival.

Prolonged Corrected QT Interval as a Predictor of Clinical Outcome in Acute Ischemic Stroke

This study aimed to investigate changes of corrected QT (QTc) interval during acute ischemic stroke and its correlation with high-sensitivity troponin I (hsTnI), brain natriuretic peptide (BNP), neurological outcome, and 1-year mortality. We registered electrocardiogram in 69 patients immediately after admission to the intensive care unit and then after 24 and 48 hours. Computed tomography was performed on admission to determine brain infarct size and localization. Neurological outcome was assessed by modified Rankin scale (mRS) at discharge. Forty-five (65.2%) patients had prolonged QTc at baseline; only 18 (26.1%) patients had prolonged QTc after 48 hours. Baseline QTc was not associated with neurological outcome (P = .27). However, prolonged QTc after 48 hours was associated with worse mRS at discharge (4.5 [4.0-6.0] versus 2.0 [1.0-3.0]; P < .0001). Patients who deceased during hospitalization (n = 7 [10.1%]) as compared with survivors had more frequently prolonged QTc after 48 hours (38.9 versus 0%; P < .0001), higher level of hsTnI (48.4 [36.1-75.0] versus 8.6 [3.4-26.5]; P = .003), and BNP (334 [224-866] versus 109 [30-190]; P = .014). In univariate analysis, 1-year mortality was associated with prolonged QTc after 48 hours, hsTnI, and BNP. In multivariate analysis, only BNP remained to be associated with 1-year mortality (odds ratio 3.41, 95% confidence interval 1.06-11.03). QTc interval in patients with acute ischemic stroke is a dynamic parameter. Prolonged QTc after 48 hours, but not baseline QTc, correlated with neurological outcome and 1-year mortality. Patients with prolonged QTc had higher level of hsTnI.

Evaluation of the effect of dabrafenib on QTc interval in patients with BRAF V600–mutant tumors.

e14119Background: Dabrafenib (DAB) is a BRAF inhibitor approved at a dose of 150 mg twice daily (BID) for treating unresectable or metastatic BRAF V600E/K–mutant melanoma with or without trametinib...

Electrocardiographic Abnormalities and QTc Interval in Patients Undergoing Hemodialysis.

BackgroundSudden cardiac death is one of the primary causes of mortality in chronic hemodialysis (HD) patients. Prolonged QTc interval is associated with increased rate of sudden cardiac death. The aim of this article is to assess the abnormalities found in electrocardiograms (ECGs), and to explore factors that can influence the QTc interval.MethodsA total of 141 conventional HD patients were enrolled in this study. ECG tests were conducted on each patient before a single dialysis session and 15 minutes before the end of dialysis session (at peak stress). Echocardiography tests were conducted before dialysis session began. Blood samples were drawn by phlebotomy immediately before and after the dialysis session.ResultsBefore dialysis, 93.62% of the patients were in sinus rhythm, and approximately 65% of the patients showed a prolonged QTc interval (i.e., a QTc interval above 440 ms in males and above 460ms in females). A comparison of ECG parameters before dialysis and at peak stress showed increases in heart rate (77.45±11.92 vs. 80.38±14.65 bpm, p = 0.001) and QTc interval (460.05±24.53 ms vs. 470.93±24.92 ms, p<0.001). After dividing patients into two groups according to the QTc interval, lower pre-dialysis serum concentrations of potassium (K+), calcium (Ca2+), phosphorus, calcium* phosphorus (Ca*P), and higher concentrations of plasma brain natriuretic peptide (BNP) were found in the group with prolonged QTc intervals. Patients in this group also had a larger left atrial diameter (LAD) and a thicker interventricular septum, and they tended to be older than patients in the other group. Then patients were divided into two groups according to ΔQTc (ΔQTc = QTc peak-stress- QTc pre-HD). When analyzing the patients whose QTc intervals were longer at peak stress than before HD, we found that they had higher concentrations of Ca2+ and P5+ and lower concentrations of K+, ferritin, UA, and BNP. They were also more likely to be female. In addition, more cardiac construction abnormalities were found in this group. In multiple regression analyses, serum Ca2+ concentration before HD and LAD were independent variables of QTc interval prolongation. UA, ferritin, and interventricular septum were independent variables of ΔQTc.ConclusionProlonged QT interval is very common in HD patients and is associated with several risk factors. An appropriate concentration of dialysate electrolytes should be chosen depending on patients’ clinical conditions.

Validity of Electrocardiographic QT Interval in Predicting Left Ventricular Diastolic Dysfunction in Patients with Suspected Heart Failure.

To determine the validity of electrocardiographic QT interval in predicting left ventricular diastolic dysfunction in patients with suspected heart failure using echocardiogram as the gold standard. Cross-sectional validation study. AFIC-NIHD, Rawalpindi, from December 2012 to June 2013. Patients with suspected heart failure undergoing 12-lead electrocardiogram and echocardiography were inducted. All electrocardiograms were analyzed by a single trained reader unaware of the echocardiographic findings. QTc interval was calculated according to the published guidelines. All patients underwent a complete M mode, 2 dimensional, Doppler, and tissue Doppler echocardiography using aiE33 ultrasound system and diastolic dysfunction was calculated. Three hundred patients were studied. Descriptive statistics of age was 61.42 years ±10.43. Of all the patients 218 patients (72.7%) were male and 82 patients were female (27.3%). Mean QT interval (msec) was 427.29 ±54.69. One hundred and eighty patients (60.0%) had diastolic dysfunction and 120 patients (40%) had no diastolic dysfunction. The sensitivity of electrocardiographic QTc interval in predicting diastolic dysfunction was 71.11% and specificity was 88.11%. Prolonged electrocardiographic QTc interval in patients with suspected heart failure is a useful tool in predicting diastolic dysfunction.

Methadone prolongs cardiac conduction in young patients with cancer-related pain.

Methadone prolongs cardiac conduction, from mild corrected QT (QTc) prolongation to torsades de pointes and ventricular fibrillation, in adults. However, methadone use for pain and its effects on cardiac conduction have not been investigated in pediatric populations. A retrospective review of QTc intervals in patients receiving methadone analgesia was conducted. Medical records from a 4-year period (September 2006 to October 2010) at a pediatric oncology institution were reviewed, and correlations were tested between cardiac conduction and methadone dosage and duration of therapy, electrolyte levels, renal and hepatic dysfunction, and concurrent medications. Of the 61 patients who received methadone, 37 met our inclusion criteria and underwent 137 electrocardiograms (ECGs). During methadone treatment, the mean QTc was longer than that at baseline (446.5 vs 437.55 ms). The mean methadone dose was 27.0±24.3 mg/d (range, 5-125 mg/d; median, 20 mg/d) or 0.47±0.45 mg/kg per day (range, 0.05-2.25 mg/kg per day; median, 0.37 mg/kg per day), and the mean duration of therapy was 49 days. The authors identified a correlation between automated and manual ECG readings by two cardiologists (Pearson r=0.649; p<0.0001), but the authors found no correlations between methadone dose or duration and concurrent QTc-prolonging medications, sex, age, electrolyte abnormalities, or renal or hepatic dysfunction. At a clinically effective analgesic dose, methadone dosage and duration were not correlated with QTc prolongation, even in the presence of other risk factors, suggesting that methadone use may be safe in pediatric populations. The correlation between automated and manual ECG readings suggests that automated ECG readings are reliable for monitoring cardiac conductivity during the reported methadone-dosage regimens.

Cardiac arrest after tramadol injection in a polytrauma patient.

Sir, Serious adverse reactions like cardiac arrest have never been reported with isolated tramadol injection. Patient's consent was obtained for reporting this case. A 25-year-old male (65 kg) was admitted in an emergency department with right tibia and fibula fractures including ipsilateral 3–7th ribs fractures with flail chest and lung contusion. On examination, he was conscious, oriented, and hemodynamically stable but mildly tachypnic. His investigations showed normal hemogram, coagulation profile, and renal function. Urine for fat droplets and ophthalmoscopic examination did not suggest any fat globules. Focused assessed sonography for trauma was negative. Electrocardiography (ECG) was normal (QTc of 320 ms). Chest X-ray suggestive of trauma mentioned above showed no visible pneumothorax. On admission to intensive care unit, his oxygen saturation dropped to 90% with PaO281 at 40%. Failure to insert epidural catheter directed us to add tramadol 100 mg 8 hourly with paracetamol. Tramadol (Urgendol, Win Medicare Pvt. Ltd., Modipuram, India) was given 4 h after paracetamol by slow intravenous injection. Ten minutes after tramadol injection the patient developed ventricular tachycardia (VT) with hypotension [Figure 1]. Immediate cardiopulmonary resuscitation (CPR) was initiated. Patient reverted back into sinus rhythm transiently with direct current shock of 200 J but again went into VT. He was intubated, and mechanical ventilation was continued. CPR was continued and repeat shock after magnesium correction resulted into sinus rhythm. Return of spontaneous circulation took 6 min. Adrenaline infusion was initiated and titrated to treat hypotension at the rate of 0.1-0.5 mcg/kg/min. Electrolytes were corrected further. ECG after sinus rhythm showed prolonged QTc interval of 480 ms [Figure 2]. Echocardiography finding was not significant. Tramadol was discontinued and magnesium sulfate 6 g/day was added. His blood tramadol level was 11 mg/L (plasma therapeutic level 0.28-0.61 mg/L). Over next 24 h adrenaline was tapered. He was extubated on 3rd day.Figure 1: Monitor with electrocardiography showed ventricular tachycardia with hypotensionFigure 2: Electrocardiography demonstrated QTc prolongationTramadol is mainly metabolized to O-desmethyltramadol by the cytochrome P450 CYP2D6.[1] Two voltage-gated K+ channels such as rapid repolarizing current (IKr) and slow repolarizing current (IKs) are responsible for rapid and slow repolarization of cardiac muscle action potential and QT interval in the ECG paper. Rapid repolarizing current is encoded by human ether-a-go-go-related gene (HERG). A 5-hydroxytryptamine 3 (5-HT3) receptor antagonists cause cardiac arrhythmias by several mechanisms.[2] Recently, it is reported that the molecular level affinity of 5 HT3 receptor antagonist to the HERG encoded K+ channel causes prolongation of cardiac repolarization and QT prologation.[34] Tramadol inhibits 5-HT2C receptor which may be responsible for K channel related prolonged repolarisation. Blood levels of tramadol and its metabolites can be measured in any serious event. Patient with CYP2D6 genotyping is at risk of tramadol-related cardiotoxicity.[1] De Decker et al. reported tramadol intoxication patient presented with asystole and multi-organ dysfunctions.[5] In our patient, secondary survey excluded the other possibilities of pneumothorax, cardiac tamponade, fat embolism, anaphylaxis with the help of several investigations. We presumed the culprit to be tramadol with electrolytes disorder as precipitating factor. In conclusion, caution must be kept in mind using tramadol in high-risk group like patients with electrolytes disturbance and co-administration of drugs causing prolonged QTc interval in patients with CYP2D6 genotyping.

367 Effects of alisertib (MLN8237), an investigational Aurora A kinase inhibitor (AAKi), on the QTc interval in patients (pts) with advanced malignancies

367 Effects of alisertib (MLN8237), an investigational Aurora A kinase inhibitor (AAKi), on the QTc interval in patients (pts) with advanced malignancies

A Systematic Evaluation of the QTc Interval and Antidepressants in Youth: An Electronic Health Record Study.

The US Food and Drug Administration announced that citalopram was associated with dose-related prolongation of the QTc interval in adults. This study aimed to assess how antidepressants affect QTc intervals in children. The authors hypothesized that some antidepressants would show an association with QTc prolongation. An electronic medical record review was conducted of children aged 5 to 18 years in the Partners Healthcare system with at least 1 prescription of an antidepressant or methadone between February 1990 and August 2011. The authors extracted lifetime diagnoses and QTc interval of patients who had received an electrocardiogram 14 to 90 days after antidepressant or methadone prescription (N = 297). The mean QTc per medication was calculated as compared with the mean of all QTc measurements across medications. The number of patients taking medications who had QTc values in normal, borderline, abnormal, or high were also calculated. Mean QTc values for all medications were in the normal range. The highest mean QTc was in patients on escitalopram (436 milliseconds). The mean QTc for sertraline (416 milliseconds) was significantly lower than all other drugs measured (t(331) = -2.21, p < .05). After controlling for confounding effects, none of the differences in mean QTc compared with other study drugs reached statistical significance. The greatest percentages of abnormal and high QTc values were found among patients taking paroxetine (18.8%), followed by escitalopram (15.4%). None of the children had documented ventricular arrhythmia. The results suggest that most antidepressants are not associated with prolonged QTc at doses typically prescribed for children.

Underestimated and unreported prolonged QTc by automated ECG analysis in patients on methadone: can we rely on computer reading?

Background Recognition of prolonged corrected QT (QTc) interval is of particular importance, especially when using medications known to prolong QTc interval. Methadone can prolong the QTc interval and has the potential to induce torsades de pointes.Objective The objective of this study is to investigate the accuracy of computerized ECG analysis in correctly identifying and reporting QTc interval in patients on methadone.Methods We conducted a retrospective review of ECGs in the Muse electronic database of patients on methadone who are above 18 years old between January 2012 and December 2013 at an urban community hospital. ECGs were analyzed by the Marquette 12SL ECG Analysis Program (GE Healthcare) reviewed by a cardiologist.Results A total of 826 ECGs of patients on methadone were examined manually for the QTc interval, of which 625 (75.7%) had QTc less than 470 ms, 149 (18%) had QTc between 470-499 ms and 52 (6.3%) had QTc more than 499 ms. QTc between 470-499 ms was underestimated by machine in 19 (12.8%) ECGs and QTc more than 499 ms was underestimated in 10 (19.6%) when compared to manually calculated QTc. QTc prolongation was underreported in 63 ECGs (48.5%) of those whose QTc between 470-499 ms and in 1 ECG (2.4%) of those whose QTc was more than 499 ms.Conclusions QTc can be underestimated or unreported by the computer analysis. Physicians not only should calculate QTc manually but also examine the actual QTc value displayed on the report before concluding that this parameter is normal, especially in patients who are at risk of QTc prolongation.

Effects of phenobarbital and levetiracetam on PR and QTc intervals in patients with post-stroke seizure.

Sudden unexplained/unexpected death (SUDEP) is related to high mortality in patients with epilepsy. The prolongation of QT interval, involved in cardiac arrhythmia-related SUDEP, may be precipitated by antiepileptic drugs (AEDs). In this study, we evaluated the effects of phenobarbital and levetiracetam on PR-QTc intervals in patients with post-stroke seizures. We performed an open-label, parallel group, prospective, multicenter study between June 2009 and December 2013 in patients older than 18 years of age with a clinical diagnosis of post-stroke seizure and treated with phenobarbital or levetiracetam. In order to exclude a role of cerebral post-stroke injury on modulation of PR and QTc intervals, patients with cerebral post-stroke injury and without seizures were also enrolled as controls. Interictal electrocardiography analysis revealed no significant difference in PR interval between patients treated with an AED (n = 49) and control patients (n = 50) (181.25 ± 12.05 vs. 182.4 ± 10.3 ms; p > 0.05). In contrast, a significantly longer QTc interval was recorded in patients treated with an AED compared with control patients (441.2 ± 56.6 vs. 396.8 ± 49.3 ms; p < 0.01). Patients treated with phenobarbital showed a significantly longer QTc interval than patients treated with levetiracetam (460.0 ± 57.2 vs. 421.5 ± 50.1 ms; p < 0.05). The study reported that in patients with late post-stroke seizures, phenobarbital prolonged QTc interval more so than levetiracetam.

Prognostic value of prolonged QTc interval in patients with acute pulmonary embolism

Background/objectives Acute pulmonary embolism (PE) can be a life-threatening condition. Right ventricular function evaluated by echocardiography, brain natriuretic peptide levels and several patterns on the electrocardiogram have been utilized to guide treatment and prognosis. Case reports described heart rate corrected QT (QTc) prolongation as an ECG finding associated with PE. However, the prognostic value of QTc prolongation has not been studied.Methods Retrospective chart review of 300 consecutive patients (mean age 60.3 ± 17.6 years; 40.7% men) diagnosed with acute PE by computed tomography pulmonary angiography or ventilation perfusion scan were studied. Patients were divided into two groups: a prolonged QTc group with QTc > 460 milliseconds (n = 178) and a control group (n = 122). We retrospectively reviewed medical records, electrocardiography, echocardiography and radiography results. Statistical analyses included unpaired t-test and Fisher’s exact test using Stata version12.Results The prolonged QTc group demonstrated significantly increased right ventricular dilatation and systolic dysfunction. Additionally, the duration of hospitalization and intensive care unit stay were longer in the prolonged QTc group. Further, the prolonged QTc group had more hypotensive episodes and received thrombolytic treatment more frequently. There was no statistical difference in in-patient mortality rates (4.5% for the study group and 4.2% for the control group, P= 1).Conclusions Prolonged QTc may prove a novel predictor for evaluating prognosis in acute PE. Larger studies will need to confirm this finding.

Effect of Palonosetron on the QTc Interval in Patients Undergoing Sevoflurane Anaesthesia

Abstract Background Palonosetron is a recently introduced 5-HT3 receptor antagonist for postoperative nausea and vomiting. Detailed standardized evaluation of corrected QT (QTc) interval change by palonosetron under sevoflurane anaesthesia is lacking. We evaluated QTc intervals in patients who are undergoing surgery with sevoflurane anaesthesia and receive palonosetron. Methods Our study included 100 patients who were undergoing elective surgery under sevoflurane anaesthesia. The patients were randomly assigned to two groups: those who received an i.v. injection of palonosetron 0.075 mg immediately before induction of anaesthesia (pre-surgery group, n=50) and those who received it after surgery in the recovery room (post-surgery group, n=50). QTc intervals were measured before operation, intraoperatively (baseline, immediately after tracheal intubation, and at 2, 10, 15, 30, 60, and 90 min after administration of palonosetron or placebo), and after operation (before and at 3, and 10 min after administration of palonosetron or placebo). QTc intervals were calculated using Fridericia's, Bazett's, or Hodges formulas. Results The perioperative QTc intervals were significantly increased from the baseline values, but were not affected by the pre- or post-surgical timing of palonosetron administration. Conclusions There was no significant difference in the QTc intervals during the perioperative period, whether 0.075 mg of palonosetron is administered before or after sevoflurane anaesthesia. Palonosetron may be safe in terms of QTc intervals during sevoflurane anaesthesia. Clinical trial registration ClinicalTrials.gov: NCT01650961.