Whole-Body Vibration Training Increases Myocardial Salvage Against Acute Ischemia in Adult Male Rats / Treinamento de Vibração de Corpo Inteiro Aumenta o Resgate Miocárdico contra Isquemia Aguda em Ratos Machos Adultos

Abstract Background: Whole body vibration training (WBV) is a new training program, which is safe and effective. It can be followed by the public. However, data on the safety and efficacy of vibration on myocardial ischemia reperfusion (IR) injury are lacking. Objective: To examine the effect of WBV on the tolerance of the myocardium to acute IR injury in an experimental rat model. Methods: Twenty-four male Wistar rats were divided into control and vibration groups. Vibration training consisted of vertical sinusoidal whole body vibration for 30 min per day, 6 days per week, for 1 or 3 weeks (WBV1 and WBV3 groups, respectively). All the rats were submitted to myocardial IR injury. Myocardial infarct size and ischemia-induced arrhythmias were assessed. Differences between variables were considered significant when p < 0.05. Results: No differences were observed between the groups regarding the baseline hemodynamic parameters. Infarct size was smaller in the experimental group (control, 47 ± 2%; WBV1, 39 ± 2%; WBV3, 37 ± 2%; p < 0.05, vs. control). Vibration produced a significant decrease in the number and duration of ventricular tachycardia (VT) episodes compared to the control value. All ventricular fibrillation (VF) episodes in the vibration groups were self-limited, while 33% of the rats in the control group died due to irreversible VF (p = 0.02). Conclusion: The data showed that vibration training significantly increased cardiac tolerance to IR injury in rats, as evidenced by reduction in the infarct size and cardiac arrhythmias, and by facilitating spontaneous defibrillation.

Resumo Fundamento: O treinamento com vibração de corpo inteiro (WBV) é um novo programa de treinamento seguro e eficaz, e pode ser seguido pelo público. No entanto, dados sobre a segurança e eficácia da vibração na lesão de isquemia e reperfusão (IR) do miocárdio estão em falta. Objetivo: Examinar o efeito da WBV na tolerância do miocárdio à lesão aguda por IR em um modelo experimental em ratos. Métodos: Vinte e quatro ratos Wistar machos foram divididos em 2 grupos: controle e vibração. O treino de vibração consistiu em vibração sinusoidal vertical de corpo inteiro durante 30 min por dia, 6 dias por semana, durante 1 ou 3 semanas (grupos WBV1 e WBV3, respectivamente). Todos os ratos foram submetidos a lesão por IR do miocárdio. O tamanho do infarto do miocárdio e as arritmias induzidas por isquemia foram avaliados. As diferenças entre as variáveis foram consideradas significativas quando p < 0,05. Resultados: Não foram observadas diferenças entre os grupos em relação aos parâmetros hemodinâmicos basais. O tamanho do infarto foi menor no grupo experimental (controle, 47 ± 2%; WBV1, 39 ± 2%; WBV3, 37 ± 2%; p < 0,05, vs. controle). A vibração produziu uma diminuição significativa no número e duração das taquicardia ventriculares (TV) em comparação com o valor de controle. Todos os episódios de fibrilação ventricular (FV) nos grupos de vibração foram autolimitados, enquanto 33% dos ratos do grupo controle morreram devido a FV irreversível (p = 0,02). Conclusão: Os dados mostraram que o treinamento com vibração de corpo inteiro aumentou significativamente a tolerância cardíaca à lesão de IR em ratos, como evidenciado pela redução do tamanho do infarto e arritmias cardíacas, e pela facilitação da desfibrilação espontânea.

Experience in ICD implantation and follow-up in Ibn-Albitar Hospital

Survivals of sudden cardiac death [SCD] episodes have recurrence rate of 30-50% within two years, with malignant ventricular arrhythmias most often responsible. The overall survival rate for SCD in USA is 5%. Ninety-five percent of patients suffering their initial event fail to survive to become candidate for secondary prevention. Because of the wide spread acceptance of implantable cardioverter defibrillator [ICD] as a method treating the survivals of SCD, attention has turned to primary prevention. Implantable cardioverter-defibrillator [ICD] is highly effective in primary and secondary prevention of SCD due to life threatening ventricular tachycardia [VT]. To register and interpret the results of implantation and follow-up of ICD during the period between 2002-2007 in Ibn Al-Bitar hospital. Sixty patients with standard indications for ICD; data were pooled from patients history, ECG, Echocardiography, Holter, blood investigation and coronary angiography.75% males and 25% females. After implantation, class III anti-arrhythmic drugs [Amiodarone] were stopped, except for patients with a history of supraventricular tachycardia or recurrent VT. Coronary artery disease [CAD] was the most common presentation of patients for whom implantation was done; coronary artery disease [CAD] 43%, dilated cardiomyopathy [DCM] 26%, and hypertrophic obstructive cardiomyopathy [HOCM] 16%. Sixty-three of them had moderate-severe LV dysfunction [LVEF<40%]. Recurrent VT was the most common cause of implantation [76%]. Primary prevention was aimed in [60%] of patients and secondary prevention in 40%. Sixty percent of those with ICD implanted due to primary prevention fulfil MADIT II [Multicenter Automatic Defibrillator Implantation Trial II] criteria. The majority of patients had structural heart disease. Most non-sustained VTs reverted to sinus rhythm by antitachycardia pacing [ATP] therapy from ICD [90%].A11 VF events reverted to sinus rhythm by high energy shock from ICD devices. ICD is highly effective in primary and secondary prevention of life threatening VT/VF

Algoritmos de detecção de taquicardias incorporado e desfibriladores automáticos implantáveis 1)Desfibriladores monocamerais / tachycardias algorithms detectors incorporated to automatic implantable defibrillators 1)Monocameral defibrillators

Diversos algoritmos foram incorporados aos cardioversores-desfibriladores automáticos implantáveis (CDis) para identificar os distúrbios do ritmo ventricular e, sobretudo, para os diferenciar de taquicardias supraventriculares que não necessitam terapia. Esses benefícios também são encontrados nos CDis bicamerias que têm como benefício a detecção atrial acoplada à detecção do ventrículo. O objetivo dos algoritmos é de identificar todas as arritmias ventriculares (sensibilidade de 100 por cento), para que sejam tratadas corretamente. Devem ainda evitar erros de identificação de arritmias supraventriculares (especificidade máxima). Infelizmente, não é possível alcançar 100 por cento de sensibilidade e especificidade. Além disso, todo aumento da especificidade será acompanhado por uma diminuição da sensibilidade. Essa diminuição de especificidade pode conduzir a falha na detecção dos distúrbios do ritmo ventricular, e como consequência, isto é pior que o tratamento inadequado de uma taquicardia sinusal ou supraventricular

Cocaína: toxicidade cardíaca e suporte avançado de vida em cardiologia / Cocaine: cardiac toxicity and advanced cardiac life support

A utilizaçäo de cocaína com propósito recreacional vem se intensificando. A cocaína pode induzir infarto isquêmico e arritmias. Antagonistas de cálcio podem ser usados judiciosamente para diminuir espasmo coronário e profilático na prevençäo da fibrilaçäo ventricular.

Effect of verapamil post-treatment in myocardial reperfusion injury.

Effect of verapamil post-treatment (0.2 mg/kg bolus, followed by 0.01 mg/kg/min infusion) on the functional and metabolic changes of the heart after a brief regional ischemia (20 min) followed by 1 hr of reperfusion was studied in open-chest pentobarbitone anaesthetized dogs. In control dogs 1 hr of reperfusion failed to cause any improvement of depressed myocardial contractility (LVdP/dtmax and LVEDP) caused by 20 min of ischemia, which confirmed the earlier reported phenomenon of 'Stunned Myocardium'. Myocardial ischemia caused a significant loss of high-energy phosphate (HEP) content of the affected myocardium (ATP decreased by 60% and CP decreased by 75% of non-ischemic level). Following 1 hr of reperfusion, myocardial ATP was not replenished, though creatine phosphate became near normal. When verapamil was administered just before reperfusion, it showed a profound beneficial effect on the incidence of fatal reperfusion arrhythmias. At the end of 1 hr of reperfusion in this group, the recovery of the myocardial contractility was incomplete, but a significant replenishment of the myocardial HEP content was observed. Thus verapamil post-treatment can prevent reperfusion-induced myocardial injury but functional recovery may be delayed due to the drug's inherent direct myocardial depressant effect.