Effects of thrombolysis in the evolution of right bundle-branch block complicating an acute anterior myocardial infarction.

INTRODUCTION: There is scant information about the effects of thrombolysis in the evolution of right bundle-branch block (RBBB) in the setting of acute anterior myocardial infarction. The aim of this study has been to analyse these effects and its impact on prognosis. METHODS: We studied 54 patients who presented a RBBB related to an acute anterior myocardial infarction. We defined two groups: those who received thrombolytic treatment and those who did not. We analysed the evolution of RBBB (transience, moment of onset, moment of disappearance) and its relationship with in-hospital mortality.Twenty-one patients (39%) received thrombolytic treatment (groupT) and 33 patients (61%) (group NT) did not. RESULTS: The incidence of late appearance (> 6 h) of RBBB was less frequent in group T compared with group NT (10% vs. 33%, p = 0.04). The incidence of transient block was similar in the two groups (57% vs. 45%, p ns). However, early disappearance of RBBB (in < 6 hours) was more common in group T than in group NT (33% vs. 9%, p = 0.04). Mortality was higher in patients with RBBB present at 24 h after admission) than in those with RBBB resolved in less than 24 hours (in group NT, 55% vs. 8%, p = 0.02 and in group T 50% vs. 0%, p = 0.02, respectively). CONCLUSIONS: Thrombolysis seems to influence the moment of onset and disappearance of RBBB by promoting its early disappearance and avoiding its late appearance. Disappearance of RBBB is associated with a better prognosis.

[Sudden death (III). The causes of sudden death. Problems at the time of establishing and classifying the types of death]. / Muerte súbita (III). Causas de muerte súbita. Problemas a la hora de establecer y clasificar los tipos de muerte.

Sudden cardiac death is one of the main causes of death in Western countries. Identification of possible causes and their intrinsic mechanisms, is directed to achieve a better risk stratification, which permits the obtention of a more effective primary and secondary prevention. In the last two decades, important advances in the field of arrhythmia treatment have been obtained, which could have an important impact on the incidence of sudden death in the highest risk groups. However, the low positive predictive value of the diagnostic tools available nowadays, as well as the high number of patients who have sudden death as the first initial symptom of their disease, represent an important limitation for the primary prevention on the whole of the general population. In this article we review different diseases associated with sudden death, with special focus on the subgroup of patients with higher risk within each disease group, as well as the problems in establishing an accurate definition of sudden death.

[Image of pseudocapture caused by micro-dislodgment of the electrode in a VDD pacemaker]. / Imagen de seudocaptura por microdesplazamiento del electrodo en un marcapasos VDD.

The new AV sequential pacemakers have improved the suitability for the election of the best pacing mode for each patient. The complexity of the systems may mask some dysfunctions. In the presented case, a failure to capture due to micro-dislodgment, may have been missed in a simple pacemaker control, because of the combination of several factors: the presence of normal AV conduction at that moment, the concordance between the pacemaker stimulus and the conducted QRS complex and the similar morphology of the conducted and paced QRS complex.

[The hemodynamic effects of the combination of milrinone in heart failure refractory to treatment with dopamine, dobutamine and/or nitroprusside]. / Efectos hemodinámicos de la asociación de milrinona en la insuficiencia cardíaca refractaria al tratamiento con dopamina, dobutamina y/o nitroprusiato.

INTRODUCTION: Classical treatment of advanced heart failure is mainly based on the intravenous administration of inotropic drugs and vasodilators. Phosphodiesterase-III inhibitors, drugs whose effectiveness is not affected for the beta-receptor downgrading, may be particularly helpful in patients with severe heart failure refractory to conventional treatment with dopamine, dobutamine and/or nitroprusside. PATIENTS AND METHODS: We have analysed the hemodynamic effects of milrinone in 13 patients (11 men, 2 women, mean age 55 +/- 12 years) with advanced heart failure resistant to dopamine, dobutamine and/or nitroprusside. Basally, before milrinone was administered, mean cardiac index and pulmonary capillary wedge pressure were 1.9 +/- 0.4 l/min/m2 and 25 +/- 6 mmHg, respectively. Milrinone was administered intravenously with a initial dose of 50 micrograms/kg over 10 minutes and followed by and infusion of 0.75 micrograms/kg/min over 6 hours. RESULTS: During milrinone administration cardiac index and stroke volume index significantly increased (40% and 28%, respectively) (p < 0.05). Furthermore, systemic and pulmonary vascular resistance indexes significantly decreased (17% and 30%, respectively) (p < 0.05). Mean right atrial pressure and pulmonary capillary wedge pressure also decreased (36% and 20%, respectively), but differences did not reach statistical significance. Milrinone was well tolerated and no patient presented serious side-effects. CONCLUSION: Our results suggest that in patients with advanced heart failure refractory to conventional treatment with dopamine, dobutamine and/or nitroprusside, the addition of milrinone significantly improves parameters of systolic function.