[Isotopic ventriculography in patients with obstructive hypertrophic cardiomyopathy treated with dual chamber stimulation]. / Ventriculografía isotópica en pacientes con miocardiopatía hipertrófica obstructiva tratados con estimulación bicameral.

BACKGROUND: Dual pacing stimulation improves symptoms and reduces intraventricular pressure gradient in obstructive hypertrophic cardiomyopathy. The mechanisms proposed for these effects are a change in ventricular contraction sequence, a paradoxical movement of the interventricular septum and a reduction in ventricular contractility. However, dual chambers pacing stimulation effects on systolic and diastolic function are unknown, and the study of this is the aim of this work. PATIENTS AND METHODS: We performed a radionuclide ventriculography in 10 patients with obstructive hypertrophic cardiomyopathy at 2 days and 1 and 6 months after placing a dual chamber pacemaker. The phase images, ventricular volumes, left ventricular ejection fraction and segmentary contractility were evaluated. Diastolic maximum peak-filling-rate and time to-peak-filling-rate were also studied. RESULTS: In DDD pacing stimulation, parametric phase images show a reversal up-down contraction sequence starting from the apical segment. At 6 months radionuclide ventriculography, a reduction in ejection fraction was found (60.9 +/- 12 vs 73.4 +/- 9.1; p < 0.05) which was attributed to apical, apical-septum and mainly basal-septum segmentary contraction decrease. A paradoxical mid-systolic septum movement was also found during DDD stimulation. No differences on diastolic parameters were noted. CONCLUSION: During dual chamber stimulation, a reversal ventricular contraction sequence, a paradoxical septum movement, hypokinesis of the septal ventricular segments and a reduction on left ventricular ejection fraction was observed.

[Detection of residual ischemia after acute anterior myocardial infarction using Thallium-201 SPECT]. / Detección de isquemia residual tras infarto agudo de miocardio de localización anterior mediante SPECT con talio-201.

OBJECTIVES: To assess the utility of single photon emission computed tomography (SPECT) with Thallium-201 after anterior myocardial infarction at predischarge time in the detection of; a) the prevalence of isotopic redistribution in the infarct area or at a distance; b) the correlation between peri-infarction ischemia and the angiographic state of the infarct-related artery, and c) the correlation between ischemia at a distance and the presence of multivessel disease. MATERIAL AND METHOD: Seventy-three survivors of an uncomplicated anterior myocardial infarction, 67 men and 7 women, with a mean age of 56 +/- 9 years (34-70 range), underwent T1-SPECT after stress test (62 exercise test and 11 pharmacological Dipyridamole test) as well as coronarographic studies before discharge. Peri-infarction ischemia was defined as redistribution presence in the distribution territory of the left anterior descending artery (LAD) and was assessed in a semi-quantitative way scoring both stress and rest images that allowed the calculation of a redistribution index R (Stress Score-Rest Score/Stress Score). Ischemia at a distance was defined as redistribution presence in the territories of circumflex and right coronary arteries as assessed both by visual analysis (VA) and bull's eye polar maps (BE) or by washout imaging (WO). RESULTS: Peri-infarction ischemia (R > 0) was found in 48 (65.7%) patients; 43 with and 5 without significant residual lesions in the LAD and the absence of peri-infarction ischemia (R = 0) was found in 25 (34.3%) patients, 19 with and 6 without significant residual lesions in the LAD. Sensitivity and specificity for multivessel disease detection by ischemia at a distance was 64% and 85% respectively, for VA; 60% and 77% for BE; and 95% and 65% for WO. Combinations of different analytical methods (multiparametric approach) showed a decrease in sensitivity but improved specificity and positive predictive value: 60%, 90% and 75%, respectively, for BE & WO; 44%, 90% and 69% for VA & BE and 60%, 92% and 79% for VA & WO. CONCLUSIONS: TI-SPECT imaging is a useful diagnostic method to detect both peri-infarction ischemia and ischemia at a distance at predischarge time following anterior myocardial infarction. Redistribution presence in the non infarct-area shows a fair sensitivity and a high positive predictive value to detect residual multivessel disease.

[Susac syndrome: clinical and diagnostic approach. A new case report]. / Síndrome de Susac: actitud diagnóstica y terapéutica. Presentación de un nuevo caso.

INTRODUCTION: The Susac syndrome is made up of the clinical triad: encephalopathy, visual and hearing defects. It is caused by microangiopathy of unknown origin affecting the small arteries of the brain, retina and cochlea. It is very uncommon. It mainly affects young women. The course of the illness is usually monophasic and self-limiting. The deficit of visual acuity is caused by occlusion of tributaries of the retinal artery. The auditory defect is bilateral and symmetrical, and particularly affects medium and low frequencies. NMR is of great diagnostic value, showing multiple lesions in the grey and white matter. Our case gives more data regarding the evolution of this condition and the contribution of cerebral SPECT to diagnosis, the results of systemic treatment, use of hyperbaric oxygen and reflections on the physiopathology of the process. CLINICAL CASE: We present the clinical case of a young woman who presented with psychiatric symptoms and migraine followed by clinical encephalopathy and acute/subacute coma. There were also visual and auditory deficits. Other types of systemic disease were ruled out. CONCLUSIONS: Findings on SPECT suggested the presence of a microangiopathic disorder of the brain. The patient responded to systemic treatment with cortico-steroids. The encephalopathy resolved in a few days and two months later she had resumed her former daily activities. Treatment with hyperbaric oxygen definitely reduced visual sequelae.

Development of a middle fossa arachnoid cyst. A theory on its pathogenesis.

The progression of congenital arachnoid cysts has seldom been documented. We report the case of a child who was diagnosed with arrested hydrocephalus at the age of 13 months. Neuroimaging studies performed when the girl was 22 months old showed the appearance of an arachnoid cyst in the right middle fossa, while the previously enlarged ventricles seemed to have decreased in size. To the best of our knowledge, the paradoxical expansion of an arachnoid pouch following a reduction in the size of the ventricular system has not previously been documented. We advance the hypothesis that the development of some cases of arachnoid cyst might be pathogenically related to impaired CSF dynamics associated with pre-existing hydrocephalus. We also briefly review the pertinent literature on the formation and evolution of congenital cerebral arachnoid cysts.

Effect of nonworking heterotopic transplantation on rat heart glycogen metabolism.

To determine whether the contractile work history of cardiac muscle influences its responsiveness to insulin, we examined the effect of insulin infusion on glycogen metabolism in the rat heart 1 wk after transplantation into a nonworking heterotopic infrarenal position. Nonworking heterografts had higher basal glycogen concentrations than did in situ working hearts of the same animals (29.9 +/- 2.7 vs. 23.3 +/- 0.8 mumol/g; P < 0.05), and a smaller fraction of their glycogen synthase enzyme activity was in the physiologically active glycogen synthase I form (8 +/- 2 vs. 22 +/- 3%; P < 0.02). During a 25-min infusion of insulin (1 U/min) and glucose (30 mg.kg-1.min-1), the fractional glycogen synthase I activity of heterografts remained lower than that of in situ hearts (29 +/- 5 vs. 56 +/- 7%; P < 0.02) and heterografts synthesized glycogen more slowly (0.126 +/- 0.07 vs. 0.352 +/- 0.06 mumol.g-1.min-1; P < 0.02). These effects could be duplicated by a 24-h fast, which similarly increased myocardial glycogen concentration (to 32.9 +/- 5.6 mumol/g). These observations suggest that the performance of repetitive contractile work is necessary to maintain the myocardium maximally responsive to insulin. Mechanical unloading increases myocardial glycogen concentration, thereby reducing the magnitude of insulin's stimulation of glycogen synthase and consequently the rate of incorporation of circulating glucose into glycogen.