Perfil de presión arterial e historia familiar de hipertensión en niños escolares sanos de Santiago de Chile / Blood pressure and family history of hypertension in children from Santiago, Chile

Background: The prevalence of pediatric arterial hypertension (AHT) is approximately 1% to 2%. In the last ten years, mean blood pressure levels (BP) have raised due to obesity and changes in lifestyles. Family history (FH) of AHT is a risk factor to develop AHT inchildren. Aim: To assess blood pressure, cardiovascular risk factors and family history in healthy children of Santiago. Material and methods: Blood pressure, family history of AHT, birth weight(BW), gestational age, puberal stage, blood glucose, serum lipids and ultrasensitive Reactive C Protein (usCRP) were analyzed, using data from a study of early markers of atherosclerosis in children. Results: Data of 112 children aged between 6-12 years was analyzed. Hypertension (BP >percentile 95) was detected in 2.7% and pre hypertension (BP in percentiles 90-95) in 3.6% of thesample. Children with abnormal BP had higher levels of usCRP (p <0.05) and a non significant tendency towards a higher body mass index. All hypertensive and one pre hypertensive children had FH of AHT. Eleven percent of parents, had high blood pressure. In no children, both parents werehypertensive. Children with a family history of hypertension had higher concentrations of total serum cholesterol (p <0.05). Conclusions: The abnormal prevalence of AHT found in this study is comparable to other studies. FH associated to higher levels of BP in children. Children withabnormal BP had a higher subclinical level of inflammation.

Arterioesclerosis subclínica, factores de riesgo cardiovascular clásicos y emergentes en niños obesos chilenos / Subclinical atherosclerosis: classic and emerging cardiovascular risk factors in Chilean obese children

La arteriosclerosis puede comenzar en la niñez y desarrollarse crónicamente dependiendo de la carga de factores de riesgo (FR) cardiovascular. Objetivo: Comparar niños obesos con eutróficos en cuanto a FR clásicos, emergentes (Proteína C Reactiva ultrasensible: PCRus) y arteriosclerosis subclínica, mediante dos nuevas técnicas no invasivas: dilatación mediada por flujo de la arteria braquial (DMF) y grosor de la íntima-media carotídea (IMT). Método: Se estudiaron 26 niños obesos (IMC ³ Pc95) y 57 eutróficos (IMC: Pc10 - Pc85). Se evaluó antropometría, presión arterial (PA), DMF, IMT, y se determinó de PCRus, perfil lipídico y glicemia de ayunas. Resultados: El 50 por ciento fueron mujeres y 41 por ciento prepúberes. Con edad de 9,9 + - 1,6 y 9,8 + - 1,8 años (ns), zIMC: 2,0 + - 0 2 y 1,7 + - 0,6, perímetro de cintura (por ciento Media): 133,5 + - 16 y 100,5 + -1 0 por ciento en obesos y eutróficos respectivamente. Los obesos tuvieron mayor Colesterol Total, CLDL, Triglicéridos, PCRus y menor CHDL (p < 0,005). No hubo diferencia significativa en DMF: 9,03 + - 5,2 por ciento vs 9,3 + - 4,2 por ciento, IMT: 0,49 + - 0,03 vs 0,50 + - 0,03 mm, glicemia ni PA. Conclusión: Este grupo de niños obesos chilenos presenta mayor carga de FR clásicos y nivel de PCRus que los eutróficos, pero no se encontró diferencia significativa en marcadores sustitutos de arteriosclerosis subclínica.

Biomarcadores coronarios y evolución clínica alejada en pacientes con síndromes coronarios agudos sin elevación del segmento ST / Coronary biomarkers and long-term clinical outcome in acute coronary syndrome without ST segment elevation

Background: The use of new biomarkers improved risk stratification for patients with acute coronary syndromes (ACS). Aim: To evaluate the relationship between multiple biomarkers and long-term clinical outcome in ACS without ST segment elevation. Patients and Methods: Consecutive patients presenting with suspected ACS were studied. On admission to the emergency room, serum was obtained to determine highly sensitive C reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), lipoprotein (a) (LPa) and soluble P selectin (sPS). Clinical endpoints were mortality and a composite endpoint of major adverse cardiovascular events (MACE) including death, re-infarction, and angina. Results: Seventy patients, aged 63±13 years, 54 males, were studied. Final diagnosis was unstable angina in 71% and non-ST-segment elevation myocardial infarction in 29%. MACE and mortality rate were 17% and 5.8%, respectively. We found higher plasma levels of hsCRP, ESR and Lp(a) in patients with MACE (p=0.032, p=0.015 and p=0.010, respectively). Plasma levels of hsCRP and ESR were also higher in patients who died during the follow up (p=0.002 y p=0.045, respectively). Conclusion: Plasma levels of inflammatory markers and atherosclerosis biomarkers are associated with a worse long-term clinical outcome in ACS without ST segment elevation. The inclusion of these biomarkers in the routine blood test on admission, could improve risk stratification of patients with ACS in the future.

Insuficiente control de factores de riesgo en prevención secundaria cardiovascular / Prevalence of cardiovascular risk factors among patients suffering vascular events on admission and one year later

Background: International studies show a low compliance with norms for the management of cardiovascular risk factors. Aim: To assess the prevalence of risk factors in patients admitted for a coronary or vascular event and to evaluate the proportion of patients that normalize these factors after one year of follow up. Material and Methods: Three hundred and fifty seven patients aged 64±13 years (264 males), admitted to a University Clinical Hospital for a coronary or vascular event were studied. They were educated about cardiovascular risk factors and followed by their treating physicians for a mean of 11.9±2 months. During this period, smoking habits, body mass index. blood pressure, serum lipid levels, blood glucose and the appearance of new cardiovascular events were registered. Results: One year survival was 96% (all 13 deaths were of cardiac origin). Eighty seven percent of patients were free of major cardiovascular events. At discharge from hospital and at the end of follow up 49% and 44% had a total cholesterol over 200 mg/dl respectively, 9,6% and 20,8% had systolic pressure over 140 mmHg. There was no diastolic hypertension in these patients, 27% and 31% had a body mass index over 25 kg/m2 and 2% smoked (versus 32% before the event). Conclusions: After one year of follow up, the prevalence of risk factors in patients that had suffered a cardiovascular event, continues to be high.

Hipercoagulabilidad en fibrilación auricular y su relación con factores de riesgo para embolia sistémica / Hypercoagulable state in atrial fibrillation and its relationship with risk factors for systemic embolism

Background: Atrial fibrillation is associated to a high risk of systemic embolism and to hypercoagulability. Aim: To evaluate the activation of the coagulation cascade through determinations of the thrombin-antithrombin complex in patients with atrial fibrillation and to correlate this data with the clinical and echocardiographic risk factors for systemic embolism. Patients and Methods: In 53 patients with atrial fibrillation plasma levels of the thrombin-antithrombin complex were determined on admission to a coronary care unit and 30 days later. Using a univariate and multiple regression analysis, the association basal thrombin-antithrombin with the duration of the arrhythmia, age over 70 years, previous use of antiplatelet agents, history of hypertension, mitral valve disease, diabetes, heart failure, previous systemic embolism, left atrial diameter and the presence of spontaneous contrast echo or thrombus in the left atrial appendage, was studied. Results: Basal thrombin-antithrombin values were 40.1ñ69 mg/L (Median 8.34 [3.0-47.5]) compared to 2.7ñ3.3 mg/L in healthy controls (p <0.001). No significant correlation was found between activation of the coagulation cascade and risk factors for systemic embolism. There were no significant differences in thrombin-antithrombin values between patients with chronic or paroxysmal atrial fibrillation (29.5ñ43 mg/L and 49.4ñ83 mg/L respectively). Mean thrombin-antithrombin values in patients under antiplatelet agents were lower than in those without treatment (17.3ñ43 vs 66.8ñ127 mg/L; p=0.018). Conclusions: The activation of the coagulation cascade in patients with atrial fibrillation was confirmed. However, no association of this activation with well known clinical and echocardiographic risk factors for systemic embolism, was found. Previous antiplatelet treatment prevented a higher activation of the coagulation cascade

La hiperuricemia es un marcador del umbral anaeróbico en la insuficiencia cardíaca crónica / Hyperuricemia is a marker for anaerobic threshold in chronic cardiac failure

Background: Patients with chronic cardiac failure often have elevated plasma uric acid levels, that are associated to a dismal prognosis. Aim: To investigate possible metabolic mechanisms to explain elevated uric acid levels in these patients. Patients and methods: Eighteen patients with chronic cardiac failure aged 61 ñ 10 years old, without gout or renal failure and not using high doses of diuretics (equal or less than 80 mg/day furosemide or 50 mg/day hydrochlorothiazide) were studied. Plasma uric acid levels were correlated with anaerobic threshold, maximal oxygen uptake, plasma noradrenaline and creatinine and left ventricular ejection fraction, measured radioisotopically. Results: Mean maximal oxygen uptake was 16.6 ñ 4.2 ml/kg/min. There was a negative correlation between uric acid levels and maximal oxygen uptake or maximal oxygen uptake/body surface area (r=0.521 and -0.533 respectively, p<0.05). Patients with uric acid levels over 7 mg/dl had a lower anaerobic threshold than patients with lower levels (9.81 ñ 2.41 and 13.08 ñ 3.28 ml/kg/min respectively, p<0.05). No significant differences in maximal oxygen uptake were observed in these two groups of patients (15.5 ñ 4.24 and 18.08 ñ 3.86 ml/kg/min respectively). Uric acid levels did not correlate with plasma noradrenaline, creatinine or lefi ventricular ejection fraction. Conclusions: These results suggest that a defect in cellular oxygenation contributes to the elevation of plasma uric acid levels in patients with chronic cardiac failure

Solución GIK en el infarto agudo al miocardio: el resurgimiento de una antigua terapia / Glucose-insulin-K solution for acute myocardial infarction: rebirth of an old form of therapy

La terapia con solución de glucosa insulina y potasio en el infarto o solución GIK fue inicialmente utilizada por Sodi-Pallares. Desde entonces muchos trabajos con esta solución han sido publicados con resultados disímiles. Sin embargo el resultado de un meta-análisis reciente, que incluye sólo trabajos randomizados con dosis adecuadas de GIK, parece confirmar la disminución de la mortalidad asociada a solución GIK. Para comprender mejor los fundamentos y posibles mecanismos de beneficio con el empleo de la solución GIK en el infarto del miocardio, revisaremos primero el metabolismo miocárdico normal y en condiciones de isquemia, luego el daño por reperfusión post infarto y los efectos de la solución GIK en el miocardio. Por último, analizaremos las experiencias clínicas publicadas con esta terapia

Marcapasos bicamerales: resultados inmediatos y alejados / Short and long terms results of dual chamber pacemaker use

Background: Continuous improvement of dual chamber DDD pacemakers, electrode stability and programmed sequential stimulation changed the prognosis of patients implanted with these devices. Aim: To report our experience with the use of dual chamber pacemakers. Material and methods: One hundred seventy six patients (116 male), aged 13 to 91 years old, who received a dual chamber pacemaker implant, are reported. Patients were followed for a mean of 2.6 years. Results: Indications for DDD pacemaker were complete atrioventricular block in 43 percent, sick sinus syndrome in 32 percent, paroxysmal A-V block in 24 percent. All pacemakers were Siemens-Pacesetter and were provided with an automatic sensing and threshold device. J shaped atrium electrodes were used in 78 percent of patients and screw-in electrodes in 22 percent. Post operative complications were displacement of atrial electrode in 8 patients, of ventricular electrode in 6 patients, infection in two patients and a hematoma in one. Chronic parameters, measured after six months, were within expected ranges and allowed a good reprogramming of pacemakers. Long term programming aimed to reduce battery depletion, enhance device performance and improve hemodynamic conditions. Normal sequential stimulation was achieved in 154 patients (87 percent), 14 (85) patients died of cardiovascular disease not related to pacemaker function. Eight patients were in atrial fibrillation and were reprogrammed to VVI and DDI modes. Conclusions: DDD pacemakers are reliable and afford symptomatic relief in a broad spectrum of patients

Déficit de hormona de crecimiento en pacientes con insuficiencia cardíaca crónica / Growth hormone deficiency in patients with chronic cardiac failure

Nine patients, aged 49 to 76 years old, 7 male, were studied. Seven had an idiopathic dilated cardiomyopathy and 2 a coronary heart disease. All had a stable cardiac failure, in functional capacity II or III and were receiving digoxin, furosemide and potassium supplements. Thyroid hormone levels, basal and exercise growth hormone and IGF-1 levels were measured and compared with reference values for American populations. Left ventricular ejection fraction was measured with an isotopic technique and nutritional status using anthropometry and indirect calorimetry. Anthropometric measures, basal and postprandial oxygen consumption were within normal limits. Thyroid hormone levels were normal. During maximal exercise, growth hormone levels were 2.56ñ4.1 ng/ml and IGF-1 levels were 0.56ñ0.61 mU/ml. These values were significantly lower than expected for age and sex. These patients with chronic cardiac failure have lower than normal growth hormone and IGF-1 levels

Fulguración con radiofrecuencia de la vía nodal lenta: experiencia en 30 casos consecutivos / Radiofrequency fulguration of the slow nodal pathway: experience in 30 consecutives cases

Atrioventricular nodal reentry tachycardia (AVNRT) is one of the most mechanisms of paroxysmal supraventricular tachycardia. In these patients tachycardia is maintained due to anterograde conduction through a slow pathway and retrograde conduction to the atrium via a fast pathway. We present here our experience in ablation of the slow pathway. Since January 1993, 30 consecutive patients with AVNRT underwent attempted catheter ablation of the slow pathway. Mean age was 37ñ3.7 years. All patients had symptomatic tachycardia and six had history of syncope. Electrophysiological studies revealed AVNRT in all patients, in addition, 2 patients had a left accesory pathway. Slow pathway ablation was performed with Mansfield 7 F catheter, guided by both fluoroscopic positioning and endocardial signals. A mean of 13 burst were applied. In the 30 patients conduction though the slow pathway was interrupted and thus tachycardia was no longer inductible. Retrograde conduction post ablation was evaluated in 17 of the 30 patients, significant changes were observed in three of them. One patient developed second degree AV block and a permanent pacemaker was implanted. Another patient had recurrence of tachycardia three months post ablation. After a second attempt she is arrhythmia free. Patients have been followed for a mean of 15.7ñ2.5 months and are asymptomatic in the absence of antiarrhythmic therapy

Taquicardia incesante de la unión: características clínicas, electrofisiológicas y rol de la fulguración en 5 casos / Permanent form of junctional tachycardia: clinical and electrophysiological characteristics and fulguration role in 5 cases

The permanent form is a variety of functional reciprocating tachycardia that is refractory to medical treatment. The anterograde arm of the circuit is formed by the His Purkinje bundle and the retrograde conduction is through a slow conduction accesory atrioventricular pathway. We report five patients with this type of arrhythmia, subjected to electrophysiological assessment. Their mean age was 37 years, all suffered from palpitations and several medical treatments had failed. During tachycardia, electrocardiogram had a negative P wave in inferior leads and RP interval was bigger than PR interval. Accesory Pathway were located in the right postero-septal region in three patients, in the left postero-septal region in one and in the left lateral in one. Specific bundle fulguration was succesfully attempted in four patients, in whom arrythmias did not recur without medical treatment

Displasia arritmogénica de ventrículo derecho: opciones de tratamiento durante 12 años de seguimiento en un caso / Arrhythmogenic right ventricular dysplasia: Therapeutic options during 12 years follow up in 1 case

The replacement of muscle by fibrous and adipose tissue leads to arrhythmogenic right ventricular dyaplasia. We report the clinical features and therapeutic options of a 50 years old male with the disease followed during 12 years. The latter included pharmacological therapy, surgical pseudoaneurysmal resection and radiofrequency fulguration of a second arrhythmogenic focus that appeared 10 after the surgical procedure. The patient remained asymptomatic after each therapy, until the disease progressed again. This follow up is one of the longest reported and documents the disease's clinical presentation, evolution and treatment