Síncope único o muy poco frecuente en 104 casos / Single or very isolated syncope in 104 cases

Resumen Introducción: Es frecuente de encontrar personas enviadas para realizar la prueba de Tilt Test (TT), que sufrieron un solo síncope aislado o que ocurre muy ocasionalmente durante su vida. En este trabajo nos preguntamos en qué se diferencian estas personas de las que nunca tienen síncopes. Métodos: Realizamos el examen de TT en 104 pacientes que sufrieron sólo uno o como máximo 5 síncopes por cualquier causa durante su vida. Intentamos explicar cómo actúan los diferentes factores predisponentes para provocar el síncope. Resultados: Encontramos diferencias en factores predisponentes del síncope, entre nuestros pacientes y los controles en factores como: la herencia, la hipermovilidad articular, el encharcamiento venoso durante el TT, la ingesta de alimentos, el uso de fármacos, el estrés y la emoción. Conclusiones: En el síncope único o muy ocasional, deben conjugarse en la persona dos factores. Lo explicamos: Estos pacientes tienen una predisposición orgánica (herencia -hipermovilidad articular- falla en los baroreflejos, algunas enfermedades neurológicas, etc.) a presentar síncopes. Pero los síncopes no ocurrirán a menos que se agregue simultáneamente un factor ambiental, que actúa como un desencadenante (estadía larga de pie, estrés, dolor y emoción, deshidratación, drogas, comida abundante, etc.), es por eso que en estos pacientes los síncopes son tan raros.

Introduction: It is frequent meeting people sent to perform a tilt test suffering from a single or such isolated syncope that occur very occasionally during the patient's life. We ask ourselves how these people differ from those who never have syncopes. Methods: We performed tilt test in 104 patients who suffer a single or maximum 5 syncopes from any cause during their lifetimes. We try to explain how different predisposing factors act to provoke syncope. Results: We found differences between cases and controls in inheritance of syncopes, joint hypermobility, venous pooling during tilt test, food intake, use of drugs, stress and emotion as a trigger for syncope. Conclusions: Patients with single or occasional syncope have an organic predisposition (inheritance - joint hypermobility - failure in the baroreflexes, some neurological diseases, etc.) to present syncopes, but syncopes do not occur unless it is added simultaneously an environmental factor, which acts as a trigger (prolonged standing up - stress, pain and emotion - dehydration - drugs - abundant food, etc.) that is why these episodes are so rare.

[Comparison of the use of isoproterenol or nitroglycerine during the Tilt test]. / Prueba de basculación (Tilt Table Testing): Comparación de dos protocolos: isoproterenol versus nitroglicerina.

BACKGROUND: There is debate about the advantages of different protocols usefulness of tilt test for the diagnosis of vasovagal collapse. AIM: To compare the sensitivity, specificity, adverse reactions, complications and time requirements of two different Tilt test protocols. MATERIAL AND METHODS: A Tilt test using isoproterenol in progressive doses (2 µg for 10 min and 5 µg for 5 min posteriorly was performed in 159 patients aged 9 to 84 years (59 males). Another Tilt test using sublingual nitroglycerine in doses of 0.3 mg was performed in 201 patients aged 8 to 87 years (62 males). Also, 20 healthy volunteers were tested. RESULTS: The positivity rates of the tests using isoproterenol and nitroglycerin were 75.5 and 77.6% respectively (NS). The figures for sensitivity were 98.4 and 99.3% (NS). The figures for specificity were 93.2 and 98.4% (NS). The test using isoproterenol requires 15 more minutes. As adverse reactions, 38% of participants experienced palpitations with isoproterenol and 22% experienced headache with nitroglycerin. CONCLUSIONS: The Tilt test with nitroglycerin is shorter, simpler, painless, with less personnel involved and has the same diagnostic accuracy than the test with isoproterenol.

Prueba de basculación (Tilt Table Testing): Comparación de dos protocolos: isoproterenol versus nitroglicerina / Comparison of the use of isoproterenol or nitroglycerine during the Tilt test

Background: There is debate about the advantages of different protocols usefulness of tilt test for the diagnosis of vasovagal collapse. Aim: To compare the sensitivity, specificity, adverse reactions, complications and time requirements of two different Tilt test protocols. Material and Methods: A Tilt test using isoproterenol in progressive doses (2 μg for 10 min and 5 μg for 5 min posteriorly was performed in 159 patients aged 9 to 84 years (59 males). Another Tilt test using sublingual nitroglycerine in doses of 0.3 mg was performed in 201 patients aged 8 to 87 years (62 males). Also, 20 healthy volunteers were tested. Results: The positivity rates of the tests using isoproterenol and nitroglycerin were 75.5 and 77.6% respectively (NS). The figures for sensitivity were 98.4 and 99.3% (NS). The figures for specificity were 93.2 and 98.4% (NS). The test using isoproterenol requires 15 more minutes. As adverse reactions, 38% of participants experienced palpitations with isoproterenol and 22% experienced headache with nitroglycerin. Conclusions: The Tilt test with nitroglycerin is shorter, simpler, painless, with less personnel involved and has the same diagnostic accuracy than the test with isoproterenol.

[Postural orthostatic tachycardia syndrome (POTS): report of 15 cases]. / Taquicardia postural ortostática en 15 pacientes: disautonomía compleja.

BACKGROUND: Patients with postural orthostatic tachycardia syndrome (POTS) report dizziness, lightheadedness, weakness, blurred vision, and fatigue upon standing. The diagnosis of the syndrome is made when an orthostatic intolerance and tachycardia appear in the standing position. AIM: To report 15 patients with POTS. MATERIAL AND METHODS: Review of Tilt test reports in a period of 15 years. Those reports in which orthostatic postural tachycardia and symptoms compatible with POTS appeared, were selected for analysis. RESULTS: We identified 15 patients (3.1% of all positive Tilt test reports) with compatible signs and symptoms. There was a lag of 8 -10 years between the onset of symptoms and the time of diagnosis. Most patients complained of orthostatic intolerance, dizziness and frequent fainting. Orthostatic tachycardia and symptoms occurred on average after 2.9 and 6.1 minutes, respectively,of staying in the standing position. These patients had a high frequency of family history of syncope orpresyncope (66% frequency) and hyper mobility syndrome (53% prevalence). Only 33% of the patients reported relief of their symptoms after being treated (most of them with fludrocortisone). Most patients that reported little or no relief, did not use medications or were treated for a short period. CONCLUSIONS: POTS syndrome is uncommon but disturbs quality of life of those who suffer it. Its association with hyper mobility syndromes must be investigated.

Thermal threshold: research study on small fiber dysfunction in distal diabetic polyneuropathy.

OBJECTIVE: The most commonly used technique for diagnosis of diabetic neuropathy (DN) is nervous conduction (NC). Our hypothesis is that the use of the thermal threshold (TT) technique to evaluate small fiber damage, which precedes large fiber damage, could enable earlier diagnosis and diminish false negatives. RESEARCH DESIGN AND METHODS: The study involved 70 asymptomatic patients with type 2 diabetes mellitus (T2DM) all being treated with oral hypoglycemic medication, and having negative metabolic control levels with glycosylated hemoglobin A1c greater than 7% and less than 8%. Diabetic neuropathy was their only evident complication. All other complications or other causes of neuropathy were discarded. Their time of evolution was 1 to 48 months since date of diagnosis of diabetes. Both thermal threshold and sensory and motor nervous conduction were determined in upper and lower limbs. RESULTS: Nervous conduction was found normal in 81% and altered in 19% of patients (large fiber neuropathy). Thermal threshold was normal in 57% and altered in 43% of patients (small fiber neuropathy). In those with normal TTs, no case with an altered NC was found (p < 0.001). Patients with altered TTs could have normal (57%) or altered NC (43%). Thus, NC showed a high frequency of false negatives for DN (57% of 30 cases). The frequency of small fiber neuropathy found with the TT test was higher than that of large fiber neuropathy found with the NC test (p < 0.001) and was found at an earlier age. CONCLUSIONS: The TT test demonstrated a higher frequency of neuropathy than the NC test in clinically asymptomatic T2DM patients. We suggest that small fiber should be studied before large fiber function to diagnosis distal and symmetrical DN.

Taquicardia postural ortostática en 15 pacientes: disautonomía compleja / Postural orthostatic tachycardia syndrome (POTS): Report of 15 cases

Background: Patients with postural orthostatic tachycardia syndrome (POTS) report dizziness, lightheadedness, weakness, blurred vision, and fatigue upon standing. The diagnosis of the syndrome is made when an orthostatic intolerance and tachycardia appear in the standing position. Aim: To report 15 patients with POTS. Material and Methods: Review of Tilt test reports in a period of 15 years. Those reports in which orthostatic postural tachycardia and symptoms compatible with POTS appeared, were selected for analysis. Results: We identified 15 patients (3.1% of all positive Tilt test reports) with compatible signs and symptoms. There was a lag of 8 -10 years between the onset of symptoms and the time of diagnosis. Most patients complained of orthostatic intolerance, dizziness and frequent fainting. Orthostatic tachycardia and symptoms occurred on average after 2.9 and 6.1 minutes, respectively,of staying in the standing position. These patients had a high frequency of family history of syncope orpresyncope (66% frequency) and hyper mobility syndrome (53% prevalence). Only 33% of the patients reported relief of their symptoms after being treated (most of them with fludrocortisone). Most patients that reported little or no relief, did not use medications or were treated for a short period. Conclusions: POTS syndrome is uncommon but disturbs quality of life of those who suffer it. Its association with hyper mobility syndromes must be investigated.