Redução da densidade de extrassístoles e dos sintomas relacionados após administração de magnésio por via oral / Successful improvement of frequency and symptoms of premature complexes after oral magnesium administration

FUNDAMENTO: As extrassístoles ventriculares e supraventriculares (EV e ESSV) são frequentes e muitas vezes sintomáticas. O íon magnésio (Mg) desempenha um papel importante na fisiologia do potencial de ação transmembrana celular e do ritmo cardíaco. OBJETIVO: Avaliar se a administração do pidolato de magnésio (PMg) em pacientes com EV e ESSV tem desempenho superior ao uso do placebo (P) na melhora dos sintomas e densidade das extrassístoles (DES). MÉTODOS: Estudo duplo-cego, randomizado, com 60 pacientes sintomáticos consecutivos, com mais de 240/EV ou ESSV ao Holter de 24 horas e selecionados para receber P ou PMg. Para avaliar a melhora da sintomatologia, foi feito um questionário categórico e específico de sintomas relacionados às extrassístoles. Após o tratamento, foi considerada significante uma redução de mais de 70% na DES por hora. A dose do PMg foi de 3,0 g/dia por 30 dias, equivalente a 260 mg do elemento Mg. Nenhum paciente tinha cardiopatia estrutural ou insuficiência renal. RESULTADOS: Dos 60 pacientes estudados, 33 eram do sexo feminino (55%). A faixa etária variou de 16 a 70 anos. No grupo PMg, 76,6% dos pacientes tiveram redução maior que 70%, 10% deles maior que 50% e somente 13,4% tiveram redução menor que 50% na DES. No grupo P, 40% dos pacientes tiveram melhora de apenas 30% na frequência de extrassístoles (p < 0,001). A melhora dos sintomas foi alcançada em 93,3% dos pacientes do grupo PMg, comparada com somente 16,7% do grupo P (p < 0,001). CONCLUSÃO: A suplementação de Mg via oral reduziu a DES, resultando em melhora dos sintomas.

BACKGROUND: Premature ventricular and supraventricular complexes (PVC and PsVC) are frequent and often symptomatic. The magnesium (Mg) ion plays a role in the physiology of cell membranes and cardiac rhythm. OBJECTIVE:We evaluated whether the administration of Mg Pidolate (MgP) in patients with PVC and PsVC is superior to placebo (P) in improving symptoms and arrhythmia frequency. METHODS: Randomized double-blind study with 60 consecutive symptomatic patients with more than 240 PVC or PsVC on 24-hour Holter monitoring who were selected to receive placebo or MgP. To evaluate symptom improvement, a categorical and a specific questionnaire for symptoms related to PVC and PsVC was made. Improvement in premature complex density (PCD) per hour was considered significant if percentage reduction was >70% after treatment. The dose of MgP was 3.0 g/day for 30 days, equivalent to 260mg of Mg element. None of the patients had structural heart disease or renal failure. RESULTS: Of the 60 patients, 33 were female (55%). Ages ranged from 16 to 70 years old. In the MgP group, 76.6% of patients had a PCD reduction >70%, 10% of them >50% and only 13.4% <50%. In the P group, 40% showed slight improvement, <30%, in the premature complexes frequency (p < 0.001). Symptom improvement was achieved in 93.3% of patients in the MgP group, compared with only 16.7% in the P group (p < 0.001). CONCLUSION: Oral Mg supplementation decreases PCD, resulting in symptom improvement.

Influence of patient-controlled i.v. analgesia with opioids on supraventricular arrhythmias after pulmonary resection.

BACKGROUND: Postoperative supraventricular arrhythmias (SVA) are common after pulmonary resection and autonomic imbalance is thought to be one of the triggers. Opioids can increase parasympathetic activity and may balance heightened sympathetic tone after operation. We have examined the effect of postoperative patient-controlled analgesia (PCA) with opioids on postoperative SVA. METHODS: Forty-eight patients were randomly assigned to two groups. The GA group received general anaesthesia PCA and PCA with opioids (fentanyl 6 microg ml(-1) and tramadol 3 mg ml(-1)). The GEA group received combined general/epidural anaesthesia plus patient-controlled epidural analgesia (PCEA). Holter recording was completed for 12 h before operation and 12 and 48 h after operation. The incidence of supraventricular tachycardias (SVT), atrial fibrillation, and supraventricular ectopic beats (SVEBs) was evaluated. RESULTS: The incidence of postoperative SVT was significantly lower in the GA group than in the GEA group (3/22 vs 10/22, P=0.021). The incidence of postoperative SVEBs was not statistically different between the groups, but the frequency of postoperative SVEBs increased less in the GA than the GEA group (7/22 vs 15/22, P=0.016). CONCLUSIONS: PCA with opioids (fentanyl and tramadol) can reduce postoperative SVA after pulmonary resection compared with PCEA with ropivacaine.