Long QT syndrome (LQT) is a disease of cardiac repolarization caused by alterations in the transmembrane potassium and sodium currents. This results in prolongation of the QT interval on electrocardiography (EKG) and ...Long QT syndrome (LQT) is a disease of cardiac repolarization caused by alterations in the transmembrane potassium and sodium currents. This results in prolongation of the QT interval on electrocardiography (EKG) and can result in torsade de pointes and sudden cardiac death. We present a case of a patient who has Anderson Tawil syndrome;a congenital long QT syndrome, with a history of cardiac arrhythmias who developed acute paranoid schizophrenia that was refractory to treatment with non-QT-prolonging drugs and required institution of neuroleptics to control her psychiatric symptoms.展开更多
Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formul...Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort.展开更多
Identification of sudden cardiac death(SCD)with a structurally normal heart remains an important challenge in forensic pathology.Long QT syndrome(LQTS)is known as an inherited or acquired channelopathy,which is charac...Identification of sudden cardiac death(SCD)with a structurally normal heart remains an important challenge in forensic pathology.Long QT syndrome(LQTS)is known as an inherited or acquired channelopathy,which is characterized with prolonged QT interval,and is likely to cause SCD in young adults.In this circumstance,no specific pathological change in the heart can be found anatomically or histologically in the LQTS victims.Thus,postmortem LQTS diagnosis is mainly based on clinical manifestations and genetic testing.Here,we reported a 26‑year‑old woman who was found dead at home with a history of unexplained syncope.Her clinical records and an electrocardiograph(ECG)obtained 3 months before her death showed a QTc interval of 539 ms which implicates the diagnosis of LQTS.Although the autopsy and pathological examination findings lacked specificity,we noticed enhanced lipofuscin accumulation in cardiomyocytes,which might be related to LQTS.After excluding potential diseases and injuries,we made the postmortem diagnosis as LQTS according to ECG,clinical history,and forensic postmortem findings.In conclusion,we provided clinical and pathological features of an SCD case due to LQTS,which might enrich the understanding of forensic postmortem SCD diagnosis with nonstructural cardiac diseases.展开更多
文摘Long QT syndrome (LQT) is a disease of cardiac repolarization caused by alterations in the transmembrane potassium and sodium currents. This results in prolongation of the QT interval on electrocardiography (EKG) and can result in torsade de pointes and sudden cardiac death. We present a case of a patient who has Anderson Tawil syndrome;a congenital long QT syndrome, with a history of cardiac arrhythmias who developed acute paranoid schizophrenia that was refractory to treatment with non-QT-prolonging drugs and required institution of neuroleptics to control her psychiatric symptoms.
基金This study was reviewed and approved by the New York-Presbyterian Brooklyn Methodist Hospital Institutional Review Committee.The study follows the guidelines outlined in the Declaration of Helsinki.
文摘Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT syndrome.The most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in measurement.The authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR interval.Methods:Descriptive Retrospective Study.We included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in 2017.All participants were healthy patients with no past medical history and no regular med-ications.Results:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically significant difference was observed between every combination of two QTc formulae.The Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each formula.Fridericia method was most independent of HR and RR with the lowest absolute value of correlation coefficients.Bazett and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong correlations.Correlations were positive for Bazett and Computer,reflecting results from prior studies demonstrating an over-correction of Bazett at higher HRs.In the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable values.Alternatively,Fridericia had the linear QTc/RR regression coefficient closest to zero.The Bland-Altman method assessed for bias and the limits of agreement between correction formulae.Bazett and Computer exhibited good agreement with minimal bias along with Framingham and Rautaharju.To account for a possible skewed distri-bution of QT,all the above analyses were also performed excluding the top and bottom 2%of data as sorted by heart rate ranges(N=90).Results from this data set were consistent with those derived from all participants(N=95).Conclusions:Overall,the Fridericia correction method provided the best rate correction in our pedia-tric study cohort.
文摘Identification of sudden cardiac death(SCD)with a structurally normal heart remains an important challenge in forensic pathology.Long QT syndrome(LQTS)is known as an inherited or acquired channelopathy,which is characterized with prolonged QT interval,and is likely to cause SCD in young adults.In this circumstance,no specific pathological change in the heart can be found anatomically or histologically in the LQTS victims.Thus,postmortem LQTS diagnosis is mainly based on clinical manifestations and genetic testing.Here,we reported a 26‑year‑old woman who was found dead at home with a history of unexplained syncope.Her clinical records and an electrocardiograph(ECG)obtained 3 months before her death showed a QTc interval of 539 ms which implicates the diagnosis of LQTS.Although the autopsy and pathological examination findings lacked specificity,we noticed enhanced lipofuscin accumulation in cardiomyocytes,which might be related to LQTS.After excluding potential diseases and injuries,we made the postmortem diagnosis as LQTS according to ECG,clinical history,and forensic postmortem findings.In conclusion,we provided clinical and pathological features of an SCD case due to LQTS,which might enrich the understanding of forensic postmortem SCD diagnosis with nonstructural cardiac diseases.
