Implicaciones cardiovasculares de la infección por SARS-CoV-2: revisión de literatura / Cardiovascular implications of SARS-CoV-2 infection: a literature review

En diciembre de 2019 se reportó en Wuhan, China, la aparición de una nueva cepa de coronavirus SARS-CoV-2 que producía un compromiso pulmonar severo y progresaba a estrés respiratorio agudo. A la fecha, son más de diecisiete millones los casos confirmados y más de medio millón los fallecidos en todo el mundo a causa de COVID-19. Los estudios reportan que los pacientes con enfermedad cardiovascular son más susceptibles a contraer esta enfermedad y a presentar más complicaciones. El propósito de esta revisión es proporcionar información actualizada para los profesionales de la salud que atienden a pacientes con COVID-19 y que tienen además enfermedad cardiovascular y por ende un riesgo elevado de complicaciones y mortalidad. Realizamos una búsqueda de bibliografía científica acerca de la asociación de enfermedad cardiovascular y COVID-19 en diferentes bases de datos como Scopus, MEDLINE vía PubMed y Cochrane Library. El tratamiento con inhibidores de la enzima convertidora de angiotensina y bloqueadores del receptor de angiotensina ha sido motivo de discusión y no hay evidencia sólida para contraindicarlo en pacientes con COVID-19. Respecto al tratamiento con hidroxicloroquina asociado o no con azitromicina, hay evidencia que demuestra un mayor riesgo con su utilización, que beneficio clínico y/o disminución de mortalidad. En este contexto, los pacientes con insuficiencia cardíaca representan un grupo importante de riesgo por su condición per se y por el dilema diagnóstico generado al evaluar un paciente con COVID-19, en el que los signos de insuficiencia cardíaca aguda podrían enmascararse. Por otro lado, en los pacientes con síndrome coronario agudo, el enfoque terapéutico inicial podría cambiar en el contexto de la pandemia, aunque sólo sobre la base de opiniones de expertos. Quedan, sin embargo, muchos temas en controversia que serán motivo de investigaciones futuras.

In December 2019, a new strain of the SARS-CoV-2 coronavirus was reported in Wuhan, China, which produced severe lung involvement and progressed to respiratory distress. To date, more than seventeen million confirmed cases and more than half a million died worldwide from COVID-19. Patients with cardiovascular disease are more susceptible to contracting this disease and presenting more complications. We did a literature search on the association of cardiovascular disease and COVID-19 in databases such as Scopus, PubMed/MEDLINE, and the Cochrane Library. The purpose of this review is to provide updated information for health professionals who care for patients with COVID-19 and cardiovascular disease, given that they have a high risk of complications and mortality. Treatment with angiotensin-converting enzyme inhibitors and receptor blockers is controversial, and there is no evidence not to use these medications in patients with COVID-19. Regarding treatment with hydroxychloroquine associated or not with azithromycin, there is evidence of a higher risk with its use than clinical benefit and decreased mortality. Likewise, patients with heart failure are an important risk group due to their condition per se. Patients with heart failure and COVID-19 are a diagnostic dilemma because the signs of acute heart failure could be masked. On the other hand, in patients with acute coronary syndrome, the initial therapeutic approach could change in the context of the pandemic, although only based on expert opinions. Nonetheless, many controversial issues will be the subject of future research.

Effect of eCG on the follicular dynamics and vascularization of crossbred cows with different circulating progesterone concentrations during synchronization of ovulation in an FTAI protocol / Efeito do eCG na dinâmica e na vascularização folicular de vacas mestiças com diferentes concentrações circulantes de progesterona durante a sincronização de ovulação em um protocolo IATF

This study aimed to evaluate the effect of treatment with equine chorionic gonadotrophin (eCG) on the follicular dynamics and function of crossbred cows with different circulating progesterone (P4) concentrations during synchronization of ovulation in a fixed-time artificial insemination (FTAI) protocol. To this end, 30 crossbred cows were submitted to a pre-synchronization protocol to ensure that all of them presented corpus luteum (CL) at the beginning of the protocol, and were evaluated by transrectal ultrasonography (TRUS) to verify the presence of CL. After that, the animals underwent an ovulation synchronization protocol and evaluation of follicular dynamics and vascularization by B-mode and power-Doppler ultrasound (US). High plasma P4 concentrations at the time of ovulation synchronization negatively influenced follicle diameter on day 10 (D10), preovulatory follicle diameter, and preovulatory follicle wall vascularization area (p<0.05). Cows with high P4 concentration at the time of ovulation synchronization that were treated with eCG showed follicle diameter on D10 and preovulatory follicle diameter and wall vascularization area (p>0.05) similar to those of animals with low P4 concentration at the time of ovulation synchronization. Therefore, high P4 concentrations at the time of ovulation synchronization negatively influence follicular diameter and vascularization, and eCG can be used as a strategy to favor better follicular and luteal response in crossbred cows with high P4 concentrations submitted to an FTAI protocol.(AU)

Objetivou-se neste estudo avaliar o efeito do tratamento com gonadotrofina coriônica equina (eCG) sobre a dinâmica e função folicular em fêmeas mestiças com diferentes concentrações circulantes de P4 durante a sincronização da ovulação em um protocolo de IATF. Para tanto, foram utilizadas 30 fêmeas mestiças e submetidas a um protocolo de pré-sincronização para garantir que todos os animais apresentassem corpo lúteo (CL) no início do protocolo, sendo avaliadas por ultrassonografia (US) transretal para a verificação da presença ou não de CL. Em seguida foram submetidas a um protocolo de sincronização da ovulação e avaliação da dinâmica e vascularização folicular por ultrassonografia (US) em modo B e Doppler colorido. Altas concentrações de P4 no momento da sincronização da ovulação impactaram negativamente no diâmetro do folículo no D10, o diâmetro do folículo pré-ovulatório e na área de vascularização da parede do folículo pré-ovulatório (P<0,05). As vacas com alta concentração de P4 no momento da sincronização da ovulação e que foram tratadas com eCG apresentaram diâmetro do folículo no D10 e no diâmetro e a área de vascularização da parede do folículo pré-ovulatório (P>0,05), semelhantes às vacas que com baixa concentração de P4 no momento da sincronização da ovulação. Conclui-se que elevadas concentrações de P4 no momento da sincronização da ovulação impactam negativamente no diâmetro e vascularização folicular e que o eCG pode ser utilizado como uma estratégia para favorecer uma melhor resposta folicular e luteal em fêmeas mestiças com altas concentrações de P4 submetidas a um protocolo de IATF.(AU)

Effects of conventional vs high-dose rocuronium on the QTc interval during anesthesia induction and intubation in patients undergoing coronary artery surgery: a randomized, double-blind, parallel trial

Myocardial ischemia, as well as the induction agents used in anesthesia, may cause corrected QT interval (QTc) prolongation. The objective of this randomized, double-blind trial was to determine the effects of high- vs conventional-dose bolus rocuronium on QTc duration and the incidence of dysrhythmias following anesthesia induction and intubation. Fifty patients about to undergo coronary artery surgery were randomly allocated to receive conventional-dose (0.6 mg/kg, group C, n=25) or high-dose (1.2 mg/kg, group H, n=25) rocuronium after induction with etomidate and fentanyl. QTc, heart rate, and mean arterial pressure were recorded before induction (T0), after induction (T1), after rocuronium (just before laryngoscopy; T2), 2 min after intubation (T3), and 5 min after intubation (T4). The occurrence of dysrhythmias was recorded. In both groups, QTc was significantly longer at T3 than at baseline [475 vs 429 ms in group C (P=0.001), and 459 vs 434 ms in group H (P=0.005)]. The incidence of dysrhythmias in group C (28%) and in group H (24%) was similar. The QTc after high-dose rocuronium was not significantly longer than after conventional-dose rocuronium in patients about to undergo coronary artery surgery who were induced with etomidate and fentanyl. In both groups, compared with baseline, QTc was most prolonged at 2 min after intubation, suggesting that QTc prolongation may be due to the nociceptive stimulus of intubation.

Comparison of effects of sugammadex and neostigmine on QTc prolongation in rabbits under general anesthesia

PURPOSE: To compare the effects of sugammadex and neostigmine, used to antagonize the effects of rocuronium, on the QTc interval. METHODS: This study used 10 adult New Zealand white rabbits of 2.5-3.5 kg randomly divided into two groups: sugammadex group (Group S, n:5) and neostigmine group (Group N, n:5). For general anesthesia administering 2 mg/kg iv propofol and 1 mcg/kg iv fentanyl, 0.6 mg/kg iv rocuronium was given. Later to provide reliable airway for all experimental animals V-Gel Rabbit was inserted. The rabbits were manually ventilated by the same anesthetist. After the V-Gel Rabbit was inserted at 2, 5, 10, 20, 25, 27, 30 and 40 minutes measurements were repeated and recorded. At 25 minutes after induction Group N rabbits were given 0.05 mg/kg iv neostigmine + 0.01 mg/kg iv atropine. Group S were administered 2 mg/kg iv sugammadex. RESULTS: Comparing the QTc interval in the rabbits in Group S and Group N, in the 25th, 27th and 30th minute after muscle relaxant antagonist was administered the QTc interval in the neostigmine group rabbits was significantly increased (p<0.05). CONCLUSION: While sugammadex, administered to antagonize the effect of rocuronium, did not significantly affect the QTc interval, neostigmine+atropine proloned the QTc interval. .

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. .

Efeitos de esmolol, lidocaína e fentanil nos intervalos dispersão da onda P, QT, QTc e respostas hemodinâmicas à intubação endotraqueal durante indução com propofol: um estudo comparativo / Effects of esmolol, lidocaine and fentanyl on P wave dispersion, QT, QTc intervals and hemodynamic responses to endotracheal intubation during propofol induction: a comparative study / Efectos del esmolol, de la lidocaína y del fentanilo en los intervalos dispersión de la onda, QT, QTc y respuestas hemodinámicas a la intubación endotraqueal durante inducción con propofol: un estudio comparativo

JUSTIFICATIVA E OBJETIVOS: Investigar o efeito de esmolol, lidocaína e fentanil na dispersão da onda P (DP), durações dos intervalos QT e QT corrigido (QTc) e as respostas hemodinâmicas à intubação endotraqueal durante a indução com propofol. MÉTODOS: Foram incluídos 80 pacientes adultos, estado físico ASA I ou II, idade entre 18 e 60 anos, neste estudo prospectivo, randômico e duplo-cego. Todos os pacientes foram submetidos a exame eletrocardiográfico (ECG) antes da indução da anestesia. Os pacientes foram randomicamente alocados em quatro grupos iguais. O grupo controle (Grupo C) recebeu 5 mL de solução salina; o grupo esmolol (Grupo E) recebeu 0,5 mg.kg-1 de esmolol; o grupo fentanil (Grupo F) recebeu 2 µg.kg-1 de fentanil e o grupo lidocaína (Grupo L) recebeu 1,5 mg.kg-1 de lidocaína antes da indução anestésica. A anestesia foi induzida com propofol. ECG foi feito em todos os pacientes durante o primeiro e o terceiro minutos de indução, 3 minutos após a administração de relaxante muscular e 5 e 10 minutos após intubação. A DP e intervalos QT foram medidos em todos os ECGs. Os intervalos QTc foram determinados com o uso da fórmula de Bazett. Frequência cardíaca (FC) e pressão arterial média (PAM) foram registradas antes e depois da indução anestésica, imediatamente após a intubação e em 1, 3, 5, 7 e 10 minutos após a intubação. RESULTADOS: Após a intubação, a FC aumentou significativamente nos Grupos C, L e F em comparação com o grupo controle. Porém, não houve diferença significativa nos valores da FC após a intubação entre os grupos E e controle. Nos Grupos C e L, a PAM aumentou significativamente após a intubação em comparação com o grupo controle. No entanto, nos Grupos L, F e E não houve diferença significativa entre os valores da PAM após a intubação em comparação com o grupo controle. A DP foi significativamente mais longa no Grupo C após a intubação em comparação com o grupo controle. Porém, nos grupos L, F e E não houve diferença significativa entre os valores de DP após a intubação em comparação com o grupo controle. A duração do intervalo QTc foi significativamente maior nos grupos C e L após a intubação em comparação com o grupo controle. Porém, não houve diferença significativa na duração do QTc nos grupos F e E após a intubação em comparação com o grupo controle. CONCLUSÃO: Concluímos que a administração de esmolol antes da intubação previne a taquicardia, o aumento da PAM e as durações da onda P e intervalo QTc causados pela laringoscopia e intubação traqueal.

BACKGROUND AND OBJECTIVES: In our study we aimed to investigate the effect of esmolol, lidocaine and fentanyl on P-wave dispersion (Pwd), QT and corrected QT (QTc) durations and hemodynamic responses to endotracheal intubation during propofol induction. METHODS: A total of eighty adult patients, American Society of Anesthesiologists (ASA) Physical Status I or II aged 18 to 60 years were included in this prospective, randomised, double-blind study. All patients had control electrocardiograms (ECGs) done before anesthesia induction. The patients were randomised into four equal groups. The control group (Group C) received saline 5 mL, the esmolol group (Group E) received esmolol 0.5 mg.kg-1, the fentanyl group (Group F) received fentanyl 2 µg.kg-1 and the lidocaine group (Group L) received lidocaine 1.5 mg.kg-1 before anesthesia induction. Anesthesia was induced with intravenous propofol. ECGs for all patients were performed during the 1st and 3rd minutes of induction, 3 minutes after administration of muscle relaxant, and at 5 minutes and 10 minutes after intubation. Pwd and QT intervals were measured on all ECGs. QTc intervals were determined using the Bazett formula. Heart rate (HR) and mean arterial pressure (MAP) were recorded before and after induction of anesthesia, immediately after intubation, and 1, 3, 5, 7 and 10 minutes after intubation. RESULTS: Compared with control, HR significantly increased in Group C, Group L and Group F after intubation. However, in Group E, there was no significant difference in HR values between control and after intubation. Compared with control, MAP significantly increased in Group C and Group L after the intubation. However, in Group E and Group F, there was no significant difference in MAP values between control and after the intubation. Compared with control, Pwd significantly increased in Group C after intubation. In Group L, Group F and Group E, there was no significant difference in Pwd values between control and after the intubation. Compared with control, QTc duration significantly increased in Group C and L after the intubation. In Group F and Group E, there was no significant difference in QTc durations between control and after the intubation. CONCLUSION: We concluded that administration of esmolol before intubation prevents tachycardia and an increase in MAP, Pwd and QTc duration caused by laryngoscopy and tracheal intubation.

JUSTIFICATIVA Y OBJETIVOS: Investigar el efecto del esmolol, lidocaína y fentanilo en la dispersión de la onda P (DOP), duraciones de los intervalos QT y QT corregido (QTc) y las respuestas hemodinámicas a la intubación endotraqueal durante la inducción con propofol. MÉTODOS: En este estudio prospectivo, aleatorio y doble ciego, fueron incluidos 80 pacientes adultos, con estado físico ASA I o II, y edad entre 18 y 60 años. Todos los pacientes se sometieron al examen electrocardiográfico (ECG) antes de la inducción de la anestesia. Los pacientes fueron aleatoriamente divididos en cuatro grupos iguales. El grupo control (Grupo C) recibió 5 mL de solución salina; el grupo esmolol (Grupo E) recibió 0,5 mg.kg-1 de esmolol; el grupo fentanilo (Grupo F) recibió 2 µg.kg-1 de fentanilo y el grupo lidocaína (Grupo L) recibió 1,5 mg.kg-1 de lidocaína antes de la inducción anestésica. La anestesia fue inducida con propofol. El ECG se hizo en todos los pacientes durante el primero y el tercer minuto de inducción, 3 minutos después de la administración del relajante muscular y 5 y 10 minutos después de la intubación. La DOP y los intervalos QT se midieron en todos los ECGs. Los intervalos QTc fueron determinados con el uso de la fórmula de Bazett. La frecuencia cardíaca (FC) y la presión arterial promedio (PAP) fueron registradas antes y después de la inducción anestésica, inmediatamente después de la intubación y en 1, 3, 5, 7 y 10 minutos después de la intubación. RESULTADOS: Después de la intubación, la FC aumentó significativamente en los Grupos C, L y F en comparación con el grupo control. Sin embargo, no hubo diferencia significativa en los valores de la FC después de la intubación entre los grupos E y control. En los Grupos C y L, la PAP aumentó significativamente después de la intubación en comparación con el grupo control. Sin embargo, en los Grupos L, F y E no hubo diferencia significativa entre los valores de la PAP posteriormente a la intubación en comparación con el grupo control. La DOP fue significativamente más larga en el Grupo C después de la intubación en comparación con el grupo control. No obstante, en los grupos L, F y E no hubo diferencia significativa entre los valores de DOP después de la intubación en comparación con el grupo control. La duración del intervalo QTc fue significativamente mayor en los grupos C y L después de la intubación en comparación con el grupo control. Sin embargo, no hubo diferencia significativa en la duración del QTc en los grupos F y E después de la intubación en comparación con el grupo control. CONCLUSIONES: Llegamos entonces a la conclusión, de que la administración del esmolol antes de la intubación previene la taquicardia, el aumento de la PAP y las duraciones de la onda P e intervalo QTc causados por la laringoscopia y por la intubación traqueal.

Efeito de levobupivacaína e bupivacaína nas dispersões da onda P, QT e QT corrigido (QTc) em cesariana / The Effect of levobupivacaine and bupivacaine on QT, corrected QT (Qtc), and P wave dispersions in cesarean section / Efecto de la levobupivacaína y la bupivacaína en las dispersiones de la onda P, QT y QT corregido (QTc) en cesárea

OBJETIVOS E JUSTIFICATIVA: Nosso estudo teve como objetivo investigar o efeito de bupivacaína e levobupivacaína na duração das dispersões do QT, QT corrigido (QTc) e da onda P durante raquianestesia em cesariana. MÉTODOS: Sessenta parturientes programadas para cesariana eletiva ASA I-II foram incluídas no estudo. Exames eletrocardiográficos (ECG) foram feitos após a entrada das pacientes na sala de operação. Frequência cardíaca (FC), pressão arterial não invasiva (PANI), saturação periférica de oxigênio (SpO2) e frequência respiratória (RR) foram registradas. Para o acesso venoso, uma cânula de calibre 18G foi usada. A pré-carga de líquidos foi feita com solução de Ringer com lactato (10 mL.kg-1). Após a pré-carga de líquidos, um segundo exame eletrocardiográfico foi feito e as pacientes foram designadas aleatoriamente para dois grupos. O Grupo B (n = 30) recebeu 10 mg de bupivacaína e o Grupo L (n = 30) recebeu 10 mg de levobupivacaína para raquianestesia. Exames ECG foram repetidos nos minutos um, cinco e 10 após a anestesia. FC, PANI, SpO2, FR e os níveis de bloqueio sensorial também foram registrados nos mesmos intervalos de tempo. Em intervalos de tempo pré-determinados de raquianestesia, as durações da dispersão da onda P (OPd), QT (QTd) e QTc (QTcd) foram medidas a partir dos registros do ECG. As durações de QT e QTc foram calculadas com a fórmula de Bazzett. RESULTADOS: Não houve diferença entre os dois grupos quanto aos níveis de bloqueio, parâmetros hemodinâmicos, OPd, QTd, QTc e QTcd. CONCLUSÃO: Levobupivacaína e bupivacaína podem ser os anestésicos de escolha para raquianestesia em grávidas com dispersões prolongadas da OPd e QTcd no período pré-operatório.

BACKGROUND AND OBJECTIVES: In our study we aimed to investigate the effect of bupivacaine and levobupivacaine on QT, corrected QT (QTc), and P wave dispersion durations during spinal anesthesia in cesarean section. METHODS: Sixty parturients scheduled for elective cesarean section in ASA I-II risk groups were included in the study. Baseline electrocardiographic (ECG) records of the patients were obtained in the operation room. Heart rate (HR), non-invasive blood pressure (NIBP), peripheral oxygen saturation (SpO2) and respiration rates (RR) were recorded. Venous cannulation was performed with 18G cannula and fluid preload made with 10 mL.kg-1. Lactated Ringer solution. After fluid preload, second ECG recordings were taken and the patients were randomly separated into two groups. Group B (n = 30) received 10 mg of bupivacaine and Group L (n = 30) received 10 mg of levobupivacaine for spinal anesthesia. ECG recordings were repeated at 1, 5 and 10 minutes after spinal block. HR, NIBP, SpO2 , RR and sensory block levels were also recorded at the same time intervals. At predetermined time intervals of spinal anesthesia, P wave dispersion (Pwd), QT dispersion (QTd), and QTc dispersion (QTcd) durations were measured from ECG records. QT and QTc durations are calculated with Bazzett formula. RESULTS: There was no difference between two groups according to block levels, hemodynamic parameters, Pwd, QTd, QTc and QTcd durations. CONCLUSION: Bupivacaine and levobupivacaine may be preferred in spinal anesthesia in pregnant patients who have extended Pwd and QTcd preoperatively.

OBJETIVOS Y JUSTIFICATIVA: Nuestro estudio tuvo como objetivo investigar el efecto de la bupivacaína y la levobupivacaína en la duración de las dispersiones del QT, QT corregido (QTc) y de la onda P durante la raquianestesia en cesárea. MÉTODOS: Sesenta parturientes programadas para cesárea electiva en grupos de riesgo ASA I-II fueron incluidas en el estudio. Los exámenes electrocardiográficos (ECG) se hicieron después de la entrada de las pacientes al quirófano. Se registraron la frecuencia cardíaca (FC), presión arterial no invasiva (PANI), saturación periférica de oxígeno (SpO2) y frecuencia respiratoria (RR). Para el acceso venoso, se usó una cánula de calibre 18. La precarga de líquidos fue hecha con una solución de Ringer con lactato (10 mL.kg-1). Después de la precarga de líquidos, un segundo examen electrocardiográfico se hizo y las pacientes fueron designadas aleatoriamente para dos grupos. El Grupo B (n = 30) recibió 10 mg de bupivacaína y el Grupo L (n = 30) recibió 10 mg de levobupivacaína para la raquianestesia. Los exámenes ECG se repitieron en los minutos 1, 5 y 10 después de la anestesia. FC, PANI, SpO2, FR y los niveles de bloqueo sensorial también fueron registrados en los mismos intervalos de tiempo. En intervalos de tiempo predeterminados de raquianestesia, las duraciones de la dispersión de la onda P (OPd), QT (QTd) y QTc (QTcd) fueron medidas a partir de los registros del ECG. Las duraciones de QT y QTc fueron calculadas con la fórmula de Bazzett. RESULTADOS: No hubo diferencia entre los dos grupos en cuanto a los niveles de bloqueo, parámetros hemodinámicos, OPd, QTd, QTc y QTcd. CONCLUSIONES: La levobupivacaína y la bupivacaína pueden ser los anestésicos de elección para la raquianestesia en las embarazadas con dispersiones prolongadas de la OPd y QTcd en el período preoperatorio.

Dexmedetomidine controls junctional ectopic tachycardia during Tetralogy of Fallot repair in an infant.

Dexmedetomidine is a highly selective α2 -adrenergic agonist approved for short-term sedation and monitored anesthesia care in adults. Although not approved for use in the pediatric population, an increasing number of reports describe its use in pediatric patients during the intraoperative period and in the intensive care unit. Dexmedetomidine can potentially have an adverse impact on the cardiovascular system secondary to its negative chronotropic and dromotropic effects. However, it is these cardiac effects that are currently being explored as a therapeutic option for the treatment of perioperative tachyarrhythmias in pediatric patients with congenital heart disease (CHD). We report the use of dexmedetomidine to treat junctional ectopic tachycardia (JET), which developed following cardiopulmonary bypass for surgical correction of Tetralogy of Fallot in a 6-week-old infant. Within 15 min of increasing the dexmedetomidine infusion from 0.5 to 3 μg/kg/h, JET converted to normal sinus rhythm. This case report provides additional anecdotal evidence that dexmedetomidine may have a therapeutic role in the treatment of perioperative tachyarrhythmias in pediatric patients with CHD. The specific effects of dexmedetomidine on the cardiac conduction system are reviewed followed by a summary of previous reports describing its use as a therapeutic agent to treat perioperative arrhythmias.

Prediction of anthracycline induced cardiotoxicity: study of thirty-one Iraqi adult patients

To look for a nearly ideal tool for prediction of anthracycline-induced cardiotoxicity. Thirty-one patients with various hematological malignancies were included in the study which was conducted from Sept. 2005 to Sept. 2006 in Baghdad Teaching Hospital - Hematology Unit. Initial cardiovascular assessment including cardiac troponin I, electrocardiography and echocardiography were done and repeated one month after the commencement of anthracycline-based regimen. Cardiotoxicity was considered present if the patient has clinical and electrocardiographic evidences, troponin positivity, echocardiographic evidence, or any combination of these. The mean age for the study sample was 34.1 +/- 17.2 years comprising of 17 male and 14 female patients. Increasing age, body surface area, anthracycline dose as well as the concomitant use of cyclophosphomide/ All Trans Retinoic were associated with increased risk of cardiotoxicity. The cut-off point of body surface area above which the risk of anthracycline-induced cardiotoxicity is increased was 1.88 m[2] while the cut-off point for anthracyclines dose was 145.5 mg/m[2]. The constellation of clinical data, ECG, and cTnI was 92% predicitive of early evidence of anthracycline-induced cardiotoxicity. More weight is added when echocardiography is used as a diagnostic tool. The incidence of cardiotoxicity attributed to treatment was 38.7%. The predictive power of cardiac troponin I alone was 58.3%, whereas it increases to 91% when combined with electrocardiography and to 95% when combined with echocardiographic study. The age, anthracyclines dose and the use of other chemotherapeutics increase the risk of anthracylince-induced cardiotoxicity. Cardiac troponin I is a simple non-invasive indicator for the presence of anthracycline- induced cardiotoxicity especially when used in combination with other parameters

The Effects of a Single Bolus of Remifentanil on Corrected QT Interval Change during Sevoflurane Induction

PURPOSE: Opioids may affect changes in the corrected QT interval (QTc) during anesthetic induction. This study examine whether a single bolus of remifentanil would prolong QTc after laryngeal mask airway (LMA) insertion during sevoflurane induction. MATERIALS AND METHODS: Forty women of American Society of Anesthesiologists physical status 1 (ASA PS1) undergoing gynecological surgery were studied. All patients were induced using three vital capacity inhalation inductions with 5% sevoflurane. Two minutes after induction, the inspiratory concentration of sevoflurane was reduced to 2%. Using double-blinded randomization, patients were allocated into one of two groups, receiving either saline (placebo group, n = 20) or 0.25 microg.kg-1 remifentanil (remifentanil group, n = 20) over a period of thirty seconds. Sixty seconds later, LMA insertion was performed. Recordings were taken with a 12-lead electrocardiogram at baseline, 2 min after induction and 1 and 3 min after LMA insertion. QTc was calculated by Bazett's formula. The mean arterial pressure (MAP) and heart rate (HR) were also measured at each time point. RESULTS: The QTc interval was significantly prolonged in the placebo group as compared to the remifentanil group at 1 min after LMA insertion (467.8 +/- 16.5 vs. 442.7 +/- 21.3 ms, p < 0.001). However, there was no significant difference in QTc at 3 min after LMA insertion between the two groups. MAP and HR were significantly higher in the placebo group (p < 0.001). CONCLUSION: A single bolus of remifentanil is safe method to attenuate prolonged QTc associated with insertion of LMA.

The effects of volatile induction and maintenance of anesthesia and selective spinal anesthesia on QT interval, QT dispersion, and arrhythmia incidence

OBJECTIVE: The effects of sevoflurane general anesthesia and bupivacaine selective spinal anesthesia on QT dispersion (QTd) and corrected QT (QTc) interval were investigated. METHODS AND MATERIALS: This prospective, randomized, double-blind study was conducted between July and September 2009 in the Urology and General Surgery operating rooms. Forty ASA I-II patients undergoing noncardiac surgery were randomized into two groups: Group R (n=20) and Group V (n=20). In Group R, 5 mg bupivacaine was administered into the spinal space. Anesthesia induction in Group V was established with sevoflurane + 0.1 mg/kg vecuronium using the maximum vital capacity technique. Anesthesia was maintained with 2-3 percent sevoflurane + 50 percent N2O/O2 inhalation. All patients were tested with a 24-hour Holter ECG device. QT, QTc, and QTd intervals were measured using 12-lead ECG records at 1 and 3 minutes during preinduction, postinduction, postincision and postextubation periods. Mean arterial pressure (MAP), heart rate and ECG records were measured simultaneously. RESULTS: None of the patients displayed arrhythmia. There was no significant difference between the groups with regard to QTd values (p>0.05). However, QTc was longer in Group V than in Group R after the induction of anesthesia at 3 minutes, after the intubation at 1 and 3 minutes, and after the incision at 1 and 3 minutes. MAP and heart rate were generally higher in Group V (p<0.05). CONCLUSION: Although Volatile Induction and Maintenance of Anesthesia (VIMA) with sevoflurane might prolong the QTc interval and did not result in arrhythmia, selective spinal anesthesia with bupivacaine was not associated with alterations in the QT interval or arrhythmia.

A comparison of the effects of desflurane, sevoflurane and propofol on QT, QTc, and P dispersion on ECG.

The aim of this prospective, randomized, and double-blinded study was to compare the effects of desflurane, sevoflurane, propofol on both atrial and ventricular wall function by measurement of QT dispersion (QTd), corrected QT dispersion (QTcd), and P dispersion (Pd) on electrocardiogram (ECG). Forty-six patients from the American Society of Anesthesiologists class I−II undergoing noncardiac surgery, were enrolled in this study. Patients were randomly allocated to receive desflurane, sevoflurane or propofol anesthesia. ECG recordings were taken before and after 5 minutes of drug administration. Induction with desflurane significantly increased the QTd compared to baseline (38 ± 2 ms vs. 62 ± 6 ms, P < 0.05). Sevoflurane and propofol anesthesia was not associated with any changes in QTd. QTcd was increased with desflurane induction and decreased with sevoflurane and propofol induction, but this decrease was only significant in the propofol group (67 ± 5 ms vs. 45 ± 3 ms, P < 0.05). Pd was significantly increased after induction with desflurane (34 ± 3 vs. 63 ± 6 ms, P < 0.05). There was a significant increase in QTd and Pd in desflurane group, but this increment did not cause any dangerous arrhythmias. QTcd significantly decreased in propofol group. We believe that further investigations are required for using desflurane as safe as sevoflurane and propofol in noncardiac surgery patients who have high cardiac arrhythmia and ischemia risk.

Locoregional anesthesia for dental treatment in cardiac patients: a comparative study of 2 percent plain lidocaine and 2 percent lidocaine with epinephrine (1:100, 000)

OBJECTIVES: This study analyzes hemodynamic changes in patients with cardiac valvular diseases submitted to dental treatment under local anesthesia containing epinephrine. METHODS: This randomized clinical trial was performed at the Dental Division of the Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (Brazil). Patients were separated into two groups with the help of an aleatory number table: 2 percent plain lidocaine (PL, n= 31) and 2 percent lidocaine with epinephrine (1:100,000) (LE, n= 28). Blood pressure, heart rate, oxygenation and electrocardiogram data were all recorded throughout the procedure. State and trait anxiety levels were measured. RESULTS: Fifty-nine patients were selected for the LE group (n=28), with an average age of 40.3 ± 10.9, or for the PL group (n=31), age 42.2 ± 10.3. No differences were shown in blood pressure, heart rate and pulse oximetry values before, during and after local anesthesia injection between the two groups. State and trait anxiety levels were not different. Arrhythmias observed before dental anesthesia did not change in shape or magnitude after treatment. Complaints of pain during the dental procedure were more frequent within the PL group, which received a higher amount of local anesthesia. CONCLUSION: Lidocaine with epinephrine (1:100,000) provided effective local anesthesia. This treatment did not cause an increase in heart rate or blood pressure and did not cause any arrhythmic changes in patients with cardiac valvular diseases.

Life-threatening overdose with lamotrigine, citalopram, and chlorpheniramine.

Lamotrigine is a commonly used agent for seizure control in epilepsy. There are limited data on the adverse effects of lamotrigine in overdose. We report a number of serious side-effects associated with a large overdose of lamotrigine. A 23-year-old female presented to the emergency department after taking an intentional overdose of 9.2 g of lamotrigine, 56 mg of chlorpheniramine, and 220 mg of citalopram. On admission, she had a reduced level of consciousness and electrocardiographic abnormalities; a widened QRS and a prolonged corrected QT (QTc) interval. Prompt treatment with early intubation, along with the use of magnesium for cardioprotection and administration of sodium bicarbonate may have aided in a quick recovery with a short intensive care stay and good outcome.

Os efeitos da metformina sobre a dispersão do intervalo QT e QTc de ratos diabéticos / Effects of metformin on QT and QTc interval dispersion of diabetic rats

FUNDAMENTO: Diversos fármacos podem causar aumento do intervalo QT, bem como da sua dispersão (QTd) em registros eletrocardiográficos (ECG). O QTd pode ser um marcador potencialmente sensível ao aumento do risco de arritmias cardíacas e morte súbita cardíaca. Metformina é uma substância de eficácia anti-hiperglicêmica utilizada no tratamento do diabete. Entretanto, estudos têm relacionado efeitos dose-dependentes da metformina sobre a glicemia e marcadores de riscos cardiovasculares. OBJETIVO: Avaliar os efeitos dose-resposta da metformina sobre o QT e QTd de ratos diabéticos. MÉTODOS: Ratos Wistar machos foram distribuídos em cinco grupos: controle não-tratado (C), diabético não-tratado (D), diabéticos tratados com metformina nas doses 3,5, 30 e 74 µg/kg/pc (DM 3,5, DM 30 e DM 74). O diabete foi induzido por uma injeção de aloxana (40 mg/kg, i.v.). O ECG foi registrado (1º, 15º e 30º dias) através de quatro eletrodos inseridos na camada subcutânea das patas. Ambos os intervalos, RR e QT, foram medidos, e então os valores do QT corrigido e da dispersão de QT foram calculados. RESULTADOS: Os grupos DM 3,5 e DM 30 mostraram significativa redução da glicemia (p< 0,05) quando comparados à alta dose (DM 74). Ratos do grupo DM 74 apresentaram aumento dos intervalos QTc, QTd e QTcd, enquanto os ratos dos grupos DM 3,5 e DM 30 apresentaram menor prolongamento desses intervalos. CONCLUSÃO: A metformina em altas doses proporcionou maior dispersão do intervalo QT, em razão, provavelmente, do aumento da não-homogeneidade do processo de repolarização ventricular, enquanto em baixas doses houve diminuição do intervalo QT em ratos diabéticos.

BACKGROUND: Several drugs can cause prolonged QT interval, as well as prolonged QT dispersion (QTd) in electrocardiographic (EKG) recordings. QTd may be a potentially sensitive marker of increased risk of cardiac arrhythmias and sudden cardiac death. Metformin is an effective antihyperglycemic agent used in the treatment of diabetes. However, studies have correlated dose-dependent effects of metformin on glycemia and cardiovascular risk markers. OBJECTIVE: To evaluate the dose-response effects of metformin on QT and QTd of diabetic rats. METHODS: Male Wistar rats were distributed in five groups: non-treated control (C), non-treated diabetics (D), diabetics treated with metmorfin at the doses of 3.5, 30 and 74 µg/kg/bw (DM 3.5, DM 30 and DM 74). Diabetes was induced by an alloxan injection (40 mg/kg, IV). EKG was recorded (days 1, 15 and 30) using four electrodes inserted into the subcutaneous layer of the paws. Both RR and QT intervals were measured, and then corrected QT and QT dispersion values were calculated. RESULTS: The DM 3.5 and DM 30 groups showed a significant reduction of glycemia (p< 0.05) when compared with the high dose (DM 74). Rats of the DM 74 group presented prolonged QTc, QTd and QTcd intervals, whereas rats of the DM 3.5 and DM 30 groups presented less prolonged intervals. CONCLUSION: Metformin at high doses provided greater dispersion of the QT interval probably because of the increased ventricular repolarization inhomogeneity, whereas at low doses decreased QT intervals were observed in diabetic rats.

[Effect of oral propranolol on prolonged qtc in cirrhotic patients]

Prolongation of QT interval is one of the most important abnormalities in cardiovascular system of cirrhotic patients. The aim of this survey was determination of propranolol effect on frequency adjusted QT interval [QTc]. Thirty six cirrhotic patients [M/F=20/16, mean age:56 +/- 3.8 years] and 40 healthy age and sex matched controls [M/F=25/15, mean age: 58 +/- 2.4 years] were evaluated for blood pressure, heart rate and QTc before and 90 minutes after receiving 40 mg propranolol, orally. Results: Prolonged QTc [more than 0.440 s1/2] was seen in 27 cirrhotic patients [75%] in contrast with to 2 [5%] ones in healthy control group [P<0.001]. In cirrhotic group, mean QTc before and after propranolol administration were 0.470 +/- 0.024 s1/2 and 0.44 +/- 0.008 s1/2, respectively [P<0.001]. In responder patients [those with 25% reduction in basal cardiac rate], mean QTc before and after propranolol administration were 0.482 +/- 0.005 s1/2 and 0.430 +/- 0.009 s1/2, respectively [P<0.05]. In non-responders, mean QTc before and after propranolol administration were 0.461 +/- 0.012 s1/2 and 0.453 +/- 0.011s1/2, respectively [P>0.05]. Non-selective beta blockers [such as propranolol] reduce QTc in cirrhotic patients.The effect of propranolol on QTc was related to 25% decrease in heart rate

Effects of cisapride on QTc interval in children

Cisapride is a prokinetic drug with different reports on its cardiac side effects. As there might be a genetic susceptibility for the effects of this drug, we studied its effects on QTc interval of children in our region. This semi-experimental study was performed on children aged over one month, who attended Amirkola Children's Hospital from October 2004 to March 2005 and needed to be treated with Cisapride. Patients with risk factors such as cardiac disease, electrolyte disturbance and drug usage interfering with Cisapride metabolism were excluded from the study. Cisapride was prescribed orally 0.6mg/kg/day in 3 doses. ECG was taken in lead II before drug administration and after one week. QTc intervals before and after treatment were compared. P-value >0.05 was considered significant. Among 135 admitted children needing Cisapride, 118 cases fulfilled inclusion criteria and were enrolled in the study. Their mean age was 14.1 [1.5] months. The mean QTc intervals before and after treatment were 377 [20] msec and 380 [22] msec, respectively [P=0.1]. No child had a QTc interval more than 450 msec. Cisapride [0.6mg/kg/day] did not cause a significant prolonged QTc interval in children with no risk factor

Hipokalemia, hipovolemia y repercusión electrocardiográfica secundarias a ingesta prolongada de furosemida: Caso clínico / Hypokalemia, hypovolemia and electrocardiographic changes due to furosemide abuse: Report of one case

Hypokalemia (serum K+ < 3.5 mEq/1) is a potentially serious adverse effect of diuretic ingestión. We report a 27 year-old woman admitted with muscle weakness, a serum potassium of 2.0 mEq/1, metabolic alkalosis and EKG abnormalities simulating cardiac ischemia, that reverted with potassium chloride administration. She admitted high dose furosemide self-medication for edema. Glomerular filtration rate, tubular sodium reabsortion, potassium secretion, the renin-aldosterone system, total body water distribution and capillary permeability, were studied sequentially until 90 days after her admission. There was hyperactivity of the renin-aldosterone axis, reduction in extracellular and intracellular volumes, normal capillary permeability and high sodium tubular reabsorption, probably explained by a "rebound" salt retention associated with her decreased extracellular volume.

Prevenção de fibrilação atrial com amiodarona em moderada dosagem no pós-operatório de cirurgia cardíaca é segura e eficaz em pacientes de alto risco para desenvolver essa arritmia / Prevention of atrial fibrillation with moderate doses of amiodarone in the postoperative period of cardiac surgery is safe and effective in patients with high risk for developing this arrhythmia

OBJETIVO: Avaliar se a profilaxia com amiodarona em moderada dosagem, no pós-operatório de cirurgia cardíaca (revascularização miocárdica e/ou cirurgia valvar), reduz a incidência de fibrilação atrial em pacientes de alto risco para desenvolver essa arritmia. MÉTODOS: Estudo clínico, randomizado e prospectivo, realizado em 68 pacientes submetidos a cirurgia cardíaca eletiva. A média de idade foi de 64 anos e 59 por cento dos participantes eram do sexo masculino. Os pacientes com três ou mais fatores de risco para fibrilação atrial, de acordo com a literatura, foram randomizados em dois grupos, para receber ou não profilaxia com amiodarona no primeiro dia de pós-operatório. A dose administrada foi de 600 mg/dia a 900 mg/dia, por via intravenosa, no primeiro dia de pós-operatório, seguida de 400 mg/dia por via oral até a alta hospitalar ou até completar sete dias. Os demais pacientes, com dois ou menos fatores de risco, foram seguidos até a alta hospitalar. Todos os pacientes foram observados por monitorização cardíaca e/ou eletrocardiografia. RESULTADOS: No grupo que recebeu amiodarona, 7 por cento dos pacientes apresentaram fibrilação atrial, enquanto no grupo controle 70 por cento desenvolveram a arritmia. Nos indivíduos não-randomizados (com dois ou menos fatores de risco), apenas 24 por cento apresentaram fibrilação atrial. CONCLUSÃO: O uso profilático de amiodarona foi eficaz na prevenção de fibrilação atrial nos pacientes com três ou mais fatores de risco para essa arritmia. Esse tratamento pode ser benéfico na redução da permanência na Unidade de Terapia Intensiva e, conseqüentemente, nas complicações advindas do maior tempo de internação hospitalar.

OBJECTIVE: To assess if prophylaxis with moderate doses of amiodarone in the postoperative period of cardiac surgery (coronary artery bypass grafting and/or valve surgery), reduces the incidence of atrial fibrillation in patients with high risk for developing this arrhythmia. METHODS: A randomized and prospective clinical study involving 68 patients who underwent elective cardiac surgery. Mean age was 64 years and 59 percent of participants were males. Patients with three or more risk factors for atrial fibrillation, according to the literature, were randomized into two groups to receive or not prophylaxis with amiodarone in the first postoperative day. The dose administered ranged from 600 mg/day to 900 mg/day, intravenously, on the first postoperative day, followed by 400 mg/day orally until hospital discharge or until completing seven days. The other patients, who presented two or fewer risk factors, were followed up until hospital discharge. All patients were evaluated by means of cardiac and/or electrocardiographic monitoring. RESULTS: In the group treated with amiodarone, 7 percent of patients presented atrial fibrillation, whereas in the control group 70 percent of patients developed arrhythmia. Among the non-randomized individuals (with two or fewer risk factors), only 24 percent presented atrial fibrillation. CONCLUSION: The prophylactic use of amiodarone was effective in the prevention of atrial fibrillation in patients with three or more risk factors for this arrhythmia. This treatment can be useful to reduce stay at the Intensive Care Unit and, consequently, the complications originating from longer hospitalization.