Torsades de pointes and myocardial infarction following reversal of supraventricular tachycardia with adenosine: a case report

ABSTRACT Adenosine is an antiarrhythmic drug that slows conduction through the atrioventricular node and acts as a coronary blood vessel dilator. This case report highlights two unusual life-threatening events following the use of adenosine to revert supraventricular tachycardia in a structurally normal heart: non-sustained polymorphic ventricular tachycardia and myocardial infarction. A 46-year-old woman presented to the emergency department with a two-hour history of palpitations and was diagnosed with supraventricular tachycardia. Vagal maneuvers were ineffective, and after intravenous adenosine administration, the patient presented with chest pain and hypotension. The rhythm degenerated into non-sustained polymorphic ventricular tachycardia and spontaneously reverted to sinus rhythm with ST elevation in lead aVR and ST depression in the inferior and anterolateral leads. The patient spontaneously recovered within a few minutes. Despite successful arrhythmia reversal, the patient was admitted to the intensive care unit because of an infarction without obstructive atherosclerosis. This report aims to alert emergency physicians about the potential complications associated with supraventricular tachycardia and its reversal with adenosine.

Taquicardia ventricular polimórfica tipo torsadess de pointes secundaria a estimulación por marcapasos / Polymorphic ventricular taquicardia "torsades de pointes" associated to abnormal pacemaker stimulation

La taquicardia ventricular polimórfica se origina en los ventrículos, cuyos complejos QRS son de morfología, amplitud y dirección variable, con frecuencias que oscilan entre 200 y 250 lpm, pudiendo ser autolimitadas o degenerar en una fibrilación ventricular. La TdP es un tipo de taquicardia ventricular polimórfica caracterizada por complejos con un eje eléctrico que gira alrededor de la línea isoeléctrica y que está asociada a QT largo. Se presenta el caso de una paciente portadora de marcapaso que presenta episodios de taquicardia ventricular polimórfica, con una morfología típica de TdP, sin documentación de QT prolongado previo ni actual, generada por la estimulación ventricular sobre onda T, de forma accidental por desplazamiento del electrodo auricular a Ventrículo Derecho (VD).

Polymorphic ventricular tachycardia is a tachycardia originating in the ventricles, where the QRS complexes have variable morphology, amplitude, and direction, with frequencies ranging between 200 and 250 bpm; it may be self-limited or degenerate into ventricular fibrillation. Torsades de Pointes (TdP) is a type of polymorphic ventricular tachycardia characterized by complexes with an electrical axis that rotates around the isoelectric line and that is associated with long QT interval. We present the case of a patient with a pacemaker who presents episodes of polymorphic ventricular tachycardia, with a typical morphology of TdP, without documentation of previous or current prolonged QT, generated by ventricular stimulation on the T wave, accidentally due to displacement of the atrial electrode to the Right Ventricle (RV).

A Rare Case Report of “Torsades De Pointes” Induced by Fluconazole-Levetiracetam Combined Therapy

Drugs used to treat cardiovascular disease as well as those used in the treatment of multiple other conditions can occasionally produce exaggerated prolongation of the QT interval on the surface electrocardiogram and the morphologically distinctive polymorphic ventricular tachycardia that results is known as «torsade de pointe». «Torsade de pointe» (TDP) is a characteristic polymorphic ventricular arrhythmia associated with delayed ventricular repolarization as evidenced on the surface electrocardiogram by QT interval prolongation. It typically occurs in self-limiting bursts, causing dizziness and syncope, but may occasionally progress to ventricular fibrillation and sudden death. This rare case report showed the potential higher risk of the occurrences of «Tdp» when levetiracetam (KEPPRA) was used in combination therapy with fluconazole, which is already a known medication with the risk of causing polymorphic ventricular arrhythmia.

Severe primary hypothyroidism presenting as polymorphic ventricular tachycardia / Hipotiroidismo primario grave que se presenta como taquicardia ventricular polimórfica

Abstract Introduction: Hypothyroidism may have various cardiovascular manifestations due to morphological, functional and electrical alterations in the heart. The usual electrocardiographic findings being sinus bradycardia, low voltage complexes, and slowed intraventricular conduction. Hypothyroidism manifesting as polymorphic ventricular tachycardia has only been reported in a few case reports. Clinical case. A 60-year-old lady presented to us in the emergency department in an unresponsive and unconscious state and electrocardiogram showed a polymorphic ventricular tachycardia. After initial resuscitation with direct current cardioversion and supportive care, she found to have severe hypothyroidism and responded well to thyroid replacement therapy. Conclusion. Polymorphic ventricular tachycardia is a life threatening emergency that can have various etiologies. Polymorphic ventricular tachycardia secondary to primary hypothyroidism is a rare presentation but it is treatable and reversible with thyroid replacement therapy. In patients presenting with QT interval prolongation and ventricular tachycardia, hypothyroidism should be one of the differential diagnosis.

Resumen Introducción: El hipotiroidismo puede presentar diferentes manifestaciones cardiovasculares dadas por alteraciones morfológicas, funcionales y eléctricas en el corazón, siendo los hallazgos electrocardiográficos usuales son la bradicardia sinusal, los complejos de bajo voltaje y la conducción intraventricular lenta. El hipotiroidismo manifestado como taquicardia ventricular polimórfica solo se ha descrito en unos pocos reportes de caso. Caso clínico: Se trata de una mujer de 60 años que acudió que acurdió al servicio de urgencias en un estado inconsciente y sin respuesta a estímulos, y el electrocardiograma reveló taquicardia ventricular polimórfica. Luego de la reanimación inicial con cardioversión con corriente directa y tratamiento sintomático se le encontró un hipotiroidismo grave, el cual se trató con terapia de reemplazo con hormona tiroidea. y se obtuvo una buena respuesta Conclusión. La taquicardia ventricular polimórfica es una emergencia vital que puede tener varias etiologías. La taquicardia ventricular polimórfica secundaria a un hipotiroidismo primario es una presentación poco común, pero es tratable y reversible con la terapia de reemplazo con hormona tiroidea. En los pacientes que presentan una prolongación del intervalo QT y taquicardia ventricular, es pertinente incluir el hipotiroidismo en el diagnóstico diferencial.

Arritmias graves en el síndrome de takotsubo: ¿cuándo dar de alta? / Severe arrhythmias in Takotsubo syndrome: when to discharge?

Resumen El síndrome de takotsubo o miocardiopatía por estrés es una alteración de la funcionalidad miocárdica, que se asocia con frecuencia a situaciones de estrés físico o emocional. Corresponde entre el 1 y el 2% de todos los ingresos a urgencias por síndrome coronario agudo y tiene una prevalencia y tasa de mortalidad de 4,1% y 2% a 8%, respectivamente. Hasta el 10% de los pacientes presenta algún tipo de complicación. En Colombia los datos epidemiológicos son limitados. En la actualidad se desconoce con exactitud la fisiopatología subyacente y no hay consenso acerca del tratamiento del síndrome y las complicaciones asociadas; por consiguiente, estos interrogantes son posibles temas de investigación. Se expone un caso clínico de características inusuales, que cursó con alteraciones electrocardiográficas, cinéticas y de conducción miocárdica infrecuentes, además de evolución clínica inesperada, que culminó en paro cardiorrespiratorio secundario a taquicardia ventricular polimórfica por persistencia del intervalo QT prolongado. Con base en la experiencia clínica y en la evidencia científica disponible se recomienda monitorizar estrechamente a los pacientes con alteración adquirida de la repolarización miocárdica hasta que esta se normalice y considerar la implantación de un dispositivo cardiaco tipo cardiodesfibrilador en casos de alto riesgo.

Abstract Takotsubo syndrome or stress cardiomyopathy is a myocardial functional disorder, which is often associated with situations of physical or emotional stress. It accounts for between 1% and 2% of all those admitted to the Emergency Department due to acute coronary syndrome, and has a prevalence and mortality rate of 4.1% and 2% to 8%, respectively. Up to 10% of the patients have some type of complication. Epidemiological data are scarce in Colombia. The underlying pathophysiology is still not exactly known, and there is no consensus on the treatment of the syndrome and the associated complications. Therefore, these questions are possible research topics. A clinical case of unusual characteristics is presented, which included rare electrocardiographic, kinetic, and myocardial conduction characteristics. It also had an unexpected clinical outcome, which culminated in cardiorespiratory arrest secondary to a polymorphic ventricular tachycardia due to persistence of the prolonged QT interval. Based on clinical experience and on the available scientific evidence, it is recommended to closely monitor patients with an acquired change in myocardial repolarisation until it returns to normal, and to consider an implantable cardioverter defibrillator in cases of high risk.

Torsade de pointes en una paciente con disfunción de marcapasos VVI / Torsade de pointes in a patient with VVI pacemaker dysfunction

RESUMEN La torsade de pointes es una taquiarritmia ventricular de gran importancia clínica que aparece típicamente en presencia de un intervalo QT prolongado y que, sin identificación y tratamiento puntual, puede conducir a la muerte súbita cardíaca. La prolongación de los intervalos QT y QT corregido aumenta significativamente la posibilidad de que aparezca esta arritmia en los síndromes de QT largo congénitos o adquiridos. En casi todos los pacientes, dichos intervalos se encuentran marcadamente prolongados en el período previo al evento arrítmico. Se describe un caso de una paciente con marcapasos que presentó esta arritmia y sufrió varios episodios sincopales.

ABSTRACT Torsade de pointes is a clinically important ventricular tachyarrhythmia that typically appears in the presence of a long QT interval and which, without prompt identification and treatment, can lead to sudden cardiac death. The prolongation of QT and corrected QT intervals significantly increases the chance of this arrhythmia to appear in congenital or acquired long QT syndromes. In almost all patients, these intervals are markedly long in the period prior to the arrhythmic event. We describe a case of a female patient with a pacemaker who presented this arrhythmia and suffered several syncopal events.

Torsión de puntas en una paciente con síndrome de QT largo congénito durante el puerperio: Presentación de un caso / Torsades de pointes in a patient with congenital long QT syndrome during the puerperium: Case report

RESUMEN El síndrome de QT largo congénito es una enfermedad eléctrica primaria del corazón que predispone a la ocurrencia de arritmias ventriculares malignas. Se traduce en una prolongación del intervalo QT en el electrocardiograma y la torsión de puntas es la arritmia que ocasiona síncope y, en ocasiones, muerte súbita. El embarazo y el puerperio aumentan la incidencia de estos eventos. Se presenta el caso de una puérpera afectada que presentó crisis de ansiedad y desmayos interpretados como psicógenos. Se documentó torsión de puntas sin respuesta a los fármacos antiarrítmicos diponibles y se trasladó al centro de referencia (Instituto de Cardiología y Cirugía Cardiovascular), donde se aumentó la frecuencia de estimulación del marcapasos y, posteriormente, se implantó un desfibrilador automático. Se trata de un caso infrecuente que constituyó un verdadero reto en el tratamiento integral y emergente, todo lo cual posibilitó la supervivencia de la paciente.

ABSTRACT Congenital long QT syndrome is a primary electrical disorder of the heart which predisposes to the occurrence of malignant ventricular arrhythmias. It is characterized by a prolongation of the QT interval on the electrocardiogram and the torsade de pointes is the main associated arrhythmia, resulting in syncope and sudden cardiac death. Pregnancy and puerperium increase the incidence of those events. We present the case of a patient who suffered from this disorder, and during the post-delivery period, she had events of faint and anxiety interpreted as psychogenic. Torsades de pointes without response to the available antiarrhythmic drugs was documented and she was transferred to the reference center (Instituto de Cardiología y Cirugía Cardiovascular), where the pacemaker stimulation frequency was increased and, subsequently, an implantable cardioverter defibrillator was implanted. This is an infrequent case that was a real challenge for the comprehensive and emergent treatment, all of which enabled the survival of the patient.

Cardiomiopatia periparto associada à síndrome do QT longo e síncope por taquicardia ventricular polimórfica: relato de caso / Peripartum cardiomyopathy associated with long QT syndrome and polymorphic ventricular tachycardia syncope: a case report

A cardiomiopatia periparto é uma causa rara de insuficiência cardíaca no período entre o último mês de gestação e os cinco meses após o parto. A síndrome do QT longo caracteriza-se pelo atraso da repolarização ventricular e pode se manifestar com síncope e morte súbita devido a um tipo de taquicardia ventricular polimórfica conhecida como torsades de pointes. Descrição do caso: J.S., 26 anos, sexo feminino, natural e procedente de São Paulo. Paciente puérpera - 40º dia (G3P3A0), procurou o pronto-socorro com queixa de síncope durante amamentação e dispneia em moderados esforços. Durante a avaliação no PS, evoluiu para desconforto torácico e agitação psicomotora, sendo notada taquicardia ventricular não sustentada no monitor cardíaco ( torsades de pointes), que foi controlada com cardioversão elétrica e sulfato de magnésio intravenoso. O eletrocardiograma mostrou ritmo sinusal, alteração difusa da repolarização ventricular e intervalo QTc de 580 ms. O ecocardiograma mostrou disfunção sistólica moderada, com fração de ejeção do ventrículo esquerdo de 43% à custa de hipocinesia difusa. Após avaliação da equipe de arritmologia chegou-se ao diagnóstico de cardiomiopatia periparto associado à síndrome do QT longo. Foi iniciado tratamento otimizado para insuficiência cardíaca e implantado cardiodesfibrilador por causa de episódios recorrentes de arritmia durante a internação. Discussão: A cardiomiopatia periparto é uma doença rara, porém, tem taxa de mortalidade elevada, entre 18% e 56%. A paciente descrita satisfez os quatro critérios para o diagnóstico: sintomas de insuficiência cardíaca nos primeiros 5 meses depois do parto, ausência de cardiomiopatia prévia, etiologia desconhecida e disfunção sistólica com FEVE < 45%. A síndrome do QT longo é uma doença genética de apresentações variáveis. Os fatores que desencadeiam as taquiarritmias são situações de instabilidade elétrica por hiperatividade do sistema simpático e também situações raras, como a cardiomiopatia periparto. Em casos de arritmias ventriculares graves, o tratamento é o implante de cardiodesfibrilador. Conclusão: A associação da cardiomiopatia periparto com a síndrome do QT longo é rara. A gravidade associada a essas condições torna importante o diagnóstico precoce e tratamento imediato pelo potencial risco de morte associado a ambas as condições clínicas

Peripartum cardiomyopathy is a rare cause of heart failure during the period between the last month of pregnancy and five months after delivery. Long QT syndrome is characterized by a delay in ventricular repolarization and may manifest with syncope and sudden death due to a type of polymorphic ventricular tachycardia known as torsades de pointes. Case description: J.S., 26-years-old, female, born and residing in São Paulo, Puerperal - 40th day (G3C3A0), went to the emergency room complaining of syncope during breastfeeding and dyspnea on moderate exertion. During evaluation in the ER, the patient developed thoracic discomfort and psychomotor agitation, with non-sustained ventricular tachycardia on the cardiac monitor (torsades de pointes), which was controlled with electrical cardioversion and intravenous magnesium sulfate. The electrocardiogram showed sinus rhythm, diffuse alteration of ventricular repolarization and QTc interval of 580 ms. The echocardiogram showed moderate systolic dysfunction, with a left ventricular ejection fraction of 43% influenced by diffuse hypokinesia. After evaluation by the arrhythmology team, the diagnosis of peripartum cardiomyopathy associated with long QT syndrome was made. Optimized treatment for heart failure was initiated and a cardioverter-defibrillator was implanted due to recurrent episodes of arrhythmia during hospitalization. Discussion: Peripartum cardiomyopathy is a rare disease, but it has a high mortality rate, between 18% and 56%. The patient described met the 4 diagnostic criteria: symptoms of heart failure in the first 5 months after delivery, absence of prior cardiomyopathy, unknown etiology, and systolic dysfunction with LVEF<45%. Long QT syndrome is a genetic disease of varying presentations. The factors that trigger the tachyarrhythmias are situations of electrical instability due to sympathetic system hyperactivity and rare situations, such as peripartum cardiomyopathy. In cases of severe ventricular arrhythmias, the treatment is a cardioverter-defibrillator implant. Conclusion: The association of peripartum cardiomyopathy with long QT syndrome is rare. The severity associated with these conditions points out early diagnosis and immediate treatment important because of the potential risk of death associated with both clinical conditions

Anti-arrhythmic effects of taurine-magnesium coordination compound on torsades de pointes / 中国应用生理学杂志

OBJECTIVES@#To investigate the effect of taurine magnesium coordination compound (TMCC) on torsades de pointes (TdP) in isolated guinea pig hearts.@*METHODS@#Healthy male guinea pigs weighting 250~300 g were randomly divided into 4 groups:①TdP model group (=7):Isolated hearts were perfused by normal K-H solution 20 minutes, then perfused by slowly activated delayed rectifier potassium current(IKs) blocker 10mol/L Chromanol 293B under hypokalemic solution(1.8 mmol/L) to establish TdP model;②~④ TdP model + TMCC group (=6):Isolated hearts were perfused by normal K-H solution for 20 minutes, then perfused by IKs blocker 10mol/L Chromanol 293B under hypokalemic solution(1.8 mmol/L) for 60 minutes, at the same time TMCC which concentration was 1, 2, 4 mmol/L was administered respectively by Langendorff retrograde aortic perfusion method. Cardiac surface electrocardiogram of guinea pigs was collected and recorded by Biopac electrophysiological recorder. Incidence of TdP, transmural dispersion of repolarization (TDR), instability of QT interval were acquired from Lead Ⅱ electrocardiograph (ECG) wave forms to describe the effect of TMCC on TdP model. Datas were acquired at the time of 20 min and pre-TdP, in case there was no TdP observed, a value of 60 min was entered for calculation purpose.@*RESULTS@#Incidence of TdP in TdP model group was 6/7. TdP incidence could be decreased significantly by 1, 2, 4 mmol/L TMCC, and was 5/6, 1/6, 0/6 respectively. Compared with the pre-drug, Chromanol 293B under hypokalemic solution in TdP model group increased TDR(corrected) evidently(0.05). Compared with the TdP model group, 2, 4 mmol/L TMCC could evidently decrease the instability of QT interval induced by Chromanol 293B under hypokalemic solution(<0.05). During the establishment of TdP model, P waves in more than one cardiac cycle continuously were disappeared in ECG. However, P wave could always be seen independent in ECG acquired from TdP model + TMCC group.@*CONCLUSIONS@#TMCC can play the role against TdP through decreasing TDR and instability of QT interval, and inhibiting early after depolarization(EAD).

Effects of Paroxetine on a Human Ether-a-go-go-related Gene (hERG) K⁺ Channel Expressed in Xenopus Oocytes and on Cardiac Action Potential

K⁺ channels are key components of the primary and secondary basolateral Cl- pump systems, which are important for secretion from the salivary glands. Paroxetine is a selective serotonin reuptake inhibitor (SSRI) for psychiatric disorders that can induce QT prolongation, which may lead to torsades de pointes. We studied the effects of paroxetine on a human K⁺ channel, human ether-a-go-go-related gene (hERG), expressed in Xenopus oocytes and on action potential in guinea pig ventricular myocytes. The hERG encodes the pore-forming subunits of the rapidly-activating delayed rectifier K⁺ channel (I(Kr)) in the heart. Mutations in hERG reduce I(Kr) and cause type 2 long QT syndrome (LQT2), a disorder that predisposes individuals to life-threatening arrhythmias. Paroxetine induced concentration-dependent decreases in the current amplitude at the end of the voltage steps and hERG tail currents. The inhibition was concentration-dependent and time-dependent, but voltage-independent during each voltage pulse. In guinea pig ventricular myocytes held at 36℃, treatment with 0.4 µM paroxetine for 5 min decreased the action potential duration at 90% of repolarization (APD₉₀) by 4.3%. Our results suggest that paroxetine is a blocker of the hERG channels, providing a molecular mechanism for the arrhythmogenic side effects of clinical administration of paroxetine.

Síndrome de QT largo y taquicardia ventricular en torsade de pointes secundarios a hipopituitarismo: una asociación a tener en cuenta: caso clínico / Long QT syndrome and polymorphic ventricular tachycardia due to hypopituitarism: report of one case

Symptoms of hypopituitarism are usually chronic and nonspecific, but rarely the disease can have acute and life threatening manifestations. We report a 53 years old female with a pituitary adenoma that was admitted to our hospital because of syncope. The electrocardiogram showed sinus bradycardia with a prolonged QT interval. Frequent runs of non-sustained polymorphic ventricular tachycardia were noted on telemetry. The patient had a history of severe acute headaches in the previous days and laboratory tests revealed severe secondary hypothyroidism, adrenal insufficiency and a decrease in pituitary hormones. A magnetic resonance imaging of the head showed changes in the size and contrast enhancement of the adenoma. A diagnosis of hypopituitarism secondary to pituitary apoplexy was made and treatment with hydrocortisone and, subsequently, levothyroxine was started. Hormonal disorders such as hypothyroidism, adrenal insufficiency or hypopituitarism should be considered as unusual causes for reversible cardiomyopathy, long QT syndrome and ventricular arrhythmias.

Prevention,management and emergency treatment of children with long QT interval syndrome and its advanced Torsades de Pointes / 中国小儿急救医学

Long QT interval syndrome ( LQTS ) is an ion channelopathy disease which holds the characteristics of the prolongation of QT interval on electrocardiogram ( ECG ) and ventricular arrhythmia ( VT) . The occurrence of this disease is associated with mutations among potassium channel protein,sodium channel protein,calcium channel related factor,and membrane adaptation protein. Now,there were 13 genes that their mutation results in LQTS. The clinical feature is mainly manifested on the abnormal prolongation of QT interval,the giant T wave alternans on the ECG and the syncope or cardiac sudden death resulted from torsades de pointes(TdP) ventricular tachycardia. Arrhythmic events are closely related with the gene type involved. On LQTS1,the arrhythmia was normally triggered by sports and emotional excitement,and LQTS2 was by loud noises. The emergency treatment is required when the TdP occurred, because it will result in rapid deterioration of circulatory perfusion and sudden death. The emergency treatment includes intravenous administration of magnesium sulfate,synchronized or nonsynchronized DC shock for cardioversion,correcting internal environmental disturbance such as hypokalemia,and terminating the use of certain drugs which could cause the prolongation of QT interval. The long term management of LQTS includes lifestyle intervention, oral administration of β-blockers, implantation of implantable cardioverter defibrillator ( ICD ) , left cardiac sympathetic denervation and certain target drugs.

Prevention,management and emergency treatment of children with long QT interval syndrome and its advanced Torsades de Pointes / 中国小儿急救医学

Long QT interval syndrome ( LQTS ) is an ion channelopathy disease which holds the characteristics of the prolongation of QT interval on electrocardiogram ( ECG ) and ventricular arrhythmia ( VT) . The occurrence of this disease is associated with mutations among potassium channel protein,sodium channel protein,calcium channel related factor,and membrane adaptation protein. Now,there were 13 genes that their mutation results in LQTS. The clinical feature is mainly manifested on the abnormal prolongation of QT interval,the giant T wave alternans on the ECG and the syncope or cardiac sudden death resulted from torsades de pointes(TdP) ventricular tachycardia. Arrhythmic events are closely related with the gene type involved. On LQTS1,the arrhythmia was normally triggered by sports and emotional excitement,and LQTS2 was by loud noises. The emergency treatment is required when the TdP occurred, because it will result in rapid deterioration of circulatory perfusion and sudden death. The emergency treatment includes intravenous administration of magnesium sulfate,synchronized or nonsynchronized DC shock for cardioversion,correcting internal environmental disturbance such as hypokalemia,and terminating the use of certain drugs which could cause the prolongation of QT interval. The long term management of LQTS includes lifestyle intervention, oral administration of β-blockers, implantation of implantable cardioverter defibrillator ( ICD ) , left cardiac sympathetic denervation and certain target drugs.

Intervalo QTc prolongado en pacientes adultos

Introducción: el intervalo QTc prolongado ha sido identificado como factor de riesgo en arritmias ventriculares e incluso muerte súbita. Objetivo: establecer la prevalencia de QTc prolongado en pacientes internados. Metodología: estudio observacional, descriptivo, prospectivo que incluyó 123 pacientes internados en el Servicio de Clínica Médica y salas de urgencias del Hospital Nacional en 2014. Se consideró como QTc prolongado un valor > 0,44 seg en varones y >0,46 seg en mujeres en 4 derivaciones: aVL, DII, V5 y V6. Resultados: la prevalencia de QTc prolongado fue 26%, con predominio del sexo masculino (71%). La principal comorbilidad asociada fue la diabetes mellitus. Los electrolitos K+, Ca+2, Mg+ estaban bajos en la mayoría de estos afectados. El 16% de los pacientes con QTc prolongado terminaron en óbito. Conclusiones: se halló alta prevalencia de QTc prolongado (26%). Se requieren estudios más complejos para determinar la asociación de esta patología con las comorbilidades, los cuadros neurológicos, el uso de medicamentos y las alteraciones de los electrolitos detectadas.

Introduction: The prolonged QTc interval has been identified as a risk factor for ventricular arrhythmias and even sudden death. Objective: To establish the prevalence of prolonged QTc in hospitalized patients. Methodology: Prospective descriptive observational study that included 123 patients hospitalized in the Service of Medical Clinic and urgency rooms of the National Hospital in 2014. A value > 0.44 seg in men and >0.46 seg in women for 4 derivations: aVL, DII, V5 and V6Se were considered as prolonged QTc. Results: The prevalence of QTc was 26% with a predominance of men (71%). The main associated comorbidity was diabetes mellitus. K+, Ca+2 and Mg+ electrolytes were low in most patients. A 16% of the patients with prolonged QTc died. Conclusions: A high prevalence (26%) of prolonged Qtc was found. More complex studies are required to determine the association of this pathology with the comorbidities, neurological symptoms, use of medicines and alteration of electrolytes detected.

Medicamentos que podem induzir prolongamento do intervalo QT utilizados por idosos em domicílio / Medications that can induced QT prolongation used by elderly at home

O intervalo QT (iQT), parâmetro eletrocardiográfico, é um biomarcador não invasivo da repolarização ventricular. O aumento do iQT é uma alteração que pode ser de considerável importância clínica, pois predispõe a torsade de pointes e morte cardíaca súbita. O objetivo do presente trabalho é identificar os medicamentos utilizados em domicílio por idosos, que podem induzir o prolongamento do iQT. Trata-se de um estudo quantitativo descritivo exploratório e retrospectivo, realizado em um hospital público de ensino. Foram incluídos 190 idosos com informação sobre uso domiciliar de medicamentos registrada em prontuário. A mediana da idade foi de 69,5 anos, sendo 99 (52,1%) mulheres. O número de medicamentos utilizados por paciente em domicílio apresentou mediana de 4,0. Foram identificados 159 fármacos, sendo que 23 (14,5%) apresentavam capacidade de induzir prolongamento do iQT. Entre os idosos, 39 (20,5%) usavam estes fármacos, sendo os mais prevalentes a amiodarona, amitriptilina, nortriptilina, citalopram e fluoxetina. A hipertensão arterial foi o fator de risco mais frequente dentre aqueles que predispõem a prolongamento do iQT. As utilizações de medicamentos que induzem prolongamento do iQT e a presença de fatores de risco predisponentes mostram que os idosos estão expostos ao risco de desenvolvimento de torsade de pointes. A identificação dos fármacos que induzem prolongamento do iQT, das interações medicamentosas e das condições clínicas que predispõem a esse prolongamento são importantes para garantia da segurança da farmacoterapia de idosos e para evitar eventos adversos graves.(AU)

The QT interval (QTi), an electrocardiographic parameter, is a noninvasive biomarker of ventricular repolarization. Increased QTi is a change that may have clinical importance because predisposes to torsade de pointes and sudden cardiac death. The objective of this study was to identify drugs used by elderly at home which may induce QTi prolongation. This is a quantitative, retrospective, descriptive, exploratory study conducted in a teaching hospital. A total of 190 elderly with information on the use of medications at home available in medical records were included in the study. The median age was 69.5 years, and 99 (52.1 %) were female. The median number of medications used per patient at home was 4.0. A variety of 159 drugs were identified including 23(14.5%) that may induce QTi prolongation. Among the 39 elderly (20.5%) using drugs that may induce QTi prolongation, the most frequent were: amiodarone, amitriptyline, nortriptyline, citalopram and fluoxetine. Hypertension was the most frequent risk factor for QTi prolongation. The use of these drugs and the presence of risk factors place the elderly at increased risk for developing torsade de pointes. The identification of drugs that may induce QTi prolongation, drug-drug interactions and clinical conditions that may lead to this adverse effect reinforces the need for actions to ensure the drug safety in the elderly population and to avoid serious adverse events.(AU)

Impacto do uso de psicotrópicos na dispersão do intervalo QT em pacientes adultos / Impact of Psychotropic Drugs on QT Interval Dispersion in Adult Patients

Fundamento: A dispersão do intervalo QT induzida por fármacos tem sido associada a arritmias ventriculares potencialmente fatais. Pouco se conhece sobre o uso de psicotrópicos, isolados ou em combinação com outros fármacos, na dispersão do QT. Objetivo: Avaliar o impacto do uso psicotrópicos na dispersão do intervalo QT em pacientes adultos. Métodos: Estudo de coorte observacional, envolvendo 161 pacientes hospitalizados em um departamento de emergência de hospital terciário, estratificados em usuários e não usuários de psicotrópicos. Dados demográficos, clínicos, laboratoriais e de fármacos em uso foram coletados à admissão, bem como o eletrocardiograma de 12 derivações, com a mensuração do intervalo e da dispersão do QT. Resultados: A dispersão do intervalo QT foi significativamente maior no grupo de usuário de psicotrópicos comparado ao grupo não usuário (69,25 ± 25,5 ms vs. 57,08 ± 23,4 ms; p = 0,002). O intervalo QT corrigido pela fórmula de Bazzett também se mostrou maior no grupo de usuário de psicotrópicos, com significância estatística (439,79 ± 31,14 ms vs. 427,71 ± 28,42 ms; p = 0,011). A análise por regressão linear mostrou associação positiva entre o número absoluto de psicotrópicos utilizados e a dispersão do intervalo QT, com r = 0,341 e p < 0,001. Conclusão: Na população amostral estudada, o uso de psicotrópicos se mostrou associado ao aumento da dispersão do intervalo QT, e esse incremento se acentuou em função do maior número de psicotrópicos utilizados. .

Background: Drug-induced increase in QT dispersion has been associated with potentially fatal ventricular arrhythmias. Little is known about the use of psychotropic substances, alone or in combination with other drugs on QT dispersion. Objectives: To evaluate the impact of psychotropic drugs on QT interval dispersion in adults. Methods: An observational cohort study was designed involving 161 patients hospitalized from an emergency department at a tertiary hospital, divided into psychotropic users or non-users. Demographic, clinical, laboratory data and drugs used on a regular basis were collected on admission, in addition to 12-lead electrocardiogram with QT dispersion measurement. Results: QT dispersion was significantly higher in the psychotropic user group compared to non-users (69.25 ± 25.5 ms vs. 57.08 ± 23.4 ms; p = 0.002). The QT interval corrected by Bazzett formula was also higher in the psychotropic drugs user group, with statistical significance. (439.79 ± 31.14 ms vs. 427.71 ± 28.42 ms; p = 0.011). A regression analysis model showed a positive association between the number of psychotropic drugs used and QT interval dispersion, with r = 0.341 and p < 0.001. Conclusions: The use of psychotropic drugs was associated with increased QT dispersion and this increase was accentuated, as the number of psychotropic drugs used was higher. .