Duration and clinical outcomes of dual antiplatelet therapy following percutaneous coronary intervention for acute coronary syndrome: A multicentre "real-world practice" registry-based study.

Background: The optimal duration of dual antiplatelet therapy (DAPT) ought to be determined taking into account individual ischaemic or bleeding events risks. To date, studies have provided inconclusive evidence on the effects of prolonged DAPT. We sought to evaluate the long-term outcomes of this strategy following percutaneous revascularization in the context of acute coronary syndrome (ACS). Methods: Retrospectively from four centers in Madrid, we identified 750 consecutive ACS patients, divided in two groups of DAPT duration: <13 months and >13 months, with a mean follow-up of 48 months. Results: Patients with DAPT > 13 months had a higher non-adjusted incidence of Major Adverse Cardiovascular Events (11.6% vs. 17.3%) and new revascularization (3.7% vs. 8.7%). Differences in all-cause death, cardiac death, myocardial infarction, stent thrombosis and stroke were non-significant. There was no difference in the incidence of major bleeding (7.4% vs. 6.3%). Multivariable Cox regression analysis showed that the independent risk predictors of MACE were age (HR: 1.04, 95% CI: 1.02-1.06, p < 0.001) and multivessel disease (HR: 2.29, 95% CI: 1.32-3.95, p = 0.003), whereas the independent protective predictor was normal hemoglobin (HR: 0.88, 95% CI: 0.78-0.98, p = 0.022). Conclusions: In this real-world registry cohort of ACS patients treated with PCI and 1 year of DAPT in Spain, we report a trend of increased rate of MACE and new revascularization not associated with TVR in patients with longer DAPT. Our findings support the need for future randomized controlled trials to confirm or refute these results.

Sympathetic nervous system activation, antivenin administration and cardiovascular manifestations of scorpion envenomation.

We performed two-dimensional echocardiograms and determined plasma norepinephrine levels on admission and at 24h after hospitalization, in 16 children with scorpion envenomation. All patients came from areas where scorpions have been identified as Tityus zulianus and received antivenin at the site of the accident or upon admission. Based on the presence or absence of cardiovascular manifestations, patients were divided into two groups. GROUP A: 10 patients had cardiovascular manifestations of pulmonary edema. Four patients had mild pulmonary edema (Left ventricular ejection fraction: 0.43+/-0.19) and six had moderate to severe pulmonary edema (Ejection fraction: 0.31+/-0.09. p=NS, M+/-SD). Plasma norepinephrine was elevated on admission (1279+/-824) and decreased at 24h in seven of eight patients (474+/-140 pg/ml, p<0.03). GROUP B: Six patients had no cardiovascular manifestations. These patients had normal chest X-rays and normal echocardiograms. Plasma norepinephrine was not elevated (188+/-180 pg/ml). Time interval from the accident to antivenin administration was significantly longer in Group A compared to Group B (4.5+/-3.3 vs 1.2+/-0.4h, p<0.03) and correlated directly with the absolute change in plasma norepinephrine (r=0.76, p<001). Consequently, we strongly recommend very early administration of antivenin in the medical management of scorpion envenomation by T. zulianus.

A modified and unifying neurogenic hypothesis can explain the natural history of chronic Chagas heart disease.

The pathogenesis of chronic Chagas disease still is an unresolved and controversial issue. Parasite persistence and autoimmune responses cannot explain the spectrum of chronic Chagas disease. However, a modified neurogenic hypothesis, concerning the timing and mechanisms responsible for the cardiac parasympathetic damage and for the activation of the sympathetic nervous system and of other neurohormonal systems, unifies cardiac remodelling and neurohormonal activation to explain most of the events of the natural history of Chagas disease.

Valsalva maneuver in chagasic patients with documented past medical history of acute chagasic myocarditis.

BACKGROUND: We studied the heart rate responses to the Valsalva maneuver in eight patients with documented past medical history of acute Chagas' disease. METHODS: Four patients were studied 8-21 months after the acute episode and four, 58-68 months thereafter (age 25+/-8.65 years M+/-S.D.). Seventeen healthy subjects of similar age were included as controls (age 27+/-7.5 years, P=NS). RESULTS: Baseline heart rate was higher in chagasic patients (88+/-15 beats/min) compared to controls (69.8+/-9.8, P=0.001). Maximum heart rate at phase II of the maneuver was also higher (114+/-16.3 vs. 101.5+/-9.9, P=0.02). Minimum heart rate at phase IV was, however, not different (57.4+/-10.4 vs. 63.3+/-7.3 P=NS). The magnitude of the absolute negative change at phase IV was larger in the chagasic patients, although, not different (-50.8+/-13.8 vs. -44+/-13.8, P=NS). The Valsalva index was 1.81+/-0.26 in the chagasic patients and 1.82+/-0.42 in the controls (P=NS). Minimum heart rate at phase IV correlated neither with the baseline heart rate (r=-0.28, P=NS) nor with the Valsalva index (r=-0.40, P=NS). The magnitude of the absolute negative change during phase IV correlated with, both, the baseline heart rate (r=-0.80, P<0.01) and the Valsalva index (r=-0.95, P<0.0001). The higher baseline high rate influenced the magnitude of the negative heart rate change, but not the minimum heart rate reached at phase IV. CONCLUSIONS: Chagasic patients with proven past medical history of acute Chagas' disease had unimpaired heart responses to the Valsalva maneuver.

Effects of metoprolol in chagasic patients with severe congestive heart failure.

BACKGROUND: Beta-blockers are the most effective and promising treatment for congestive heart failure secondary to left ventricular dysfunction and sympathetic activation. METHODS: Since chagasic patients with severe congestive heart failure have left ventricular systolic dysfunction and neurohormonal activation, we administered metoprolol to nine chagasic patients who were in severe congestive heart failure. Metoprolol (5 mg p.o. daily) was uptitrated on a weekly basis. RESULTS: Patients were receiving digitalis, diuretics and angiotensin converting enzyme inhibitors and had left ventricular dilatation (6.77+/-0.89 cm), depressed ejection fraction (0.20+/-0.06), low systolic blood pressure (93+/-11 mm Hg), sinus tachycardia (115+/-17 beats/min) and sympathetic activation 400+/-246 pg/ml). One patient was in New York Heart Association Functional class III and eight patients were in functional class IV. At the end of the fifth week of treatment (metoprolol 25 mg), seven patients were in functional class III and two were in functional class II. Heart rate decreased to 85+/-15 beats/min (P<0.05) and the systolic blood pressure increased to 108+/-18 mm Hg (P<0.01). There were no significant changes in left ventricular ejection fraction. By the end of the tenth week of treatment (metoprolol 50 mg), four patients were now in functional class I and five were in functional class II. Left ventricular ejection fraction increased to 0.27+/-0.05 (P<0.01) and the left ventricular systolic diameter decreased from 6.38+/-0.90 at baseline to 5.89+/-0.59 and 5.76+/-0.96 after 25 and 50 mg of metoprolol treatment, respectively (P<0.04). Plasma norepinephrine decreased non-significantly to 288+/-91 pg/ml. CONCLUSION: Beta-blockers improve the clinical status and the left ventricular function of chagasic patients with severe congestive heart failure.

Epicardial adipose tissue thickness and its association with adiponectin in metabolic syndrome patients from Mérida, Venezuela.

OBJECTIVE: To study the relationship between epicardial adipose tissue (EAT) thickness and plasma levels of adiponectin in Venezuelan patients. SUBJECTS AND METHODS: Thirty-one patients diagnosed with metabolic syndrome (study group) and 27 controls were selected and tested for glycemia, lipids, and adiponectin. EAT thickness, ejection fraction, diastolic function, left ventricular mass (LVM), and left atrial volume (LAV) were determined by transthoracic echocardiography. RESULTS: EAT thickness was greater in metabolic syndrome patients (5.69 ± 1.12 vs. 3.52 ± 0.80 mm; p = 0.0001), correlating positively with body mass index (BMI) (r = 0.661; p = 0.0001); waist circumference (WC) (r = 0.664; p = 0.0001); systolic (SBP) (r = 0.607; p = 0.0001), and diastolic blood pressure (DBP) (r = 0.447; p = 0.0001); insulin (r = 0.505; p = 0.0001); Tg/HDL-C ratio (r = 0.447; p = 0.0001), non-HDL-C (r = 0.353; p = 0.007); LAV (r = 0.432; p = 0.001), and LVM (r = 0.469; p = 0.0001). EAT thickness correlated negatively with adiponectin (r = -0.499; p = 0.0001). CONCLUSION: A significant association exists between EAT thickness and both metabolic syndrome components and adiponectin concentration, a link that might be used as a biomarker for this disease.

[Cut-off point of epicardial adipose tissue thickness for predicting metabolic syndrome in Venezuelan population]. / Punto de corte de espesor de tejido adiposo epicárdico para predecir síndrome metabólico en población venezolana.

OBJECTIVE: To define an echocardiographically-assessed cut-off point for epicardial adipose tissue (EAT) thickness associated to metabolic syndrome (MS) components in Venezuelan subjects. METHODS: Fifty-two subjects aged 20-65 years diagnosed with MS according to International Diabetes Federation criteria and 45 sex- and age-matched controls were selected. Blood glucose and plasma lipids were tested; EAT thickness and left ventricular mass were measured by echocardiography. RESULTS: No significant age and sex differences were found between the two groups. Body weight, body mass index, waist circumference, and systolic and diastolic blood pressure were significantly higher (P=.0001) in the MS group. This group showed significantly higher levels of fasting blood glucose (P=.0001), total cholesterol (P=.002), LDL-C (P=.007), non-HDL-C (P=.0001), triglycerides (P=.0001), Tg-HDL-C ratio (P=.0001), and lower HDL-C levels (P=.0001) as compared to the control group. EAT thickness (P=.0001) and left ventricular mass (P=.017) were significantly higher in the MS group. The ROC curve showed an AUC of 0.852 (P=.0001) with a power of the test of 0.99. A 5-mm EAT thickness showed a sensitivity of 84.62% (95%CI: 71.9-93.1) and a specificity of 71.11% (95%CI: 55.7-83.6) for predicting MS. The odds ratio of this population for experiencing MS due to an EAT ≥ 5 mm was 8.25 (95%CI: 3.15-21.56; P=.0001). CONCLUSION: An EAT value ≥ 5 mm has good sensitivity and specificity for predicting MS in the Venezuelan population.

Muscarinic antibodies and heart rate responses to dynamic exercise and to the Valsalva maneuver in chronic chagasic patients.

We have studied the cardiac chronotropic responses to the Valsalva maneuver and to dynamic exercise of twenty chronic chagasic patients with normal left ventricular function and no segmental wall abnormalities by two-dimensional echocardiogram. The absolute increase in heart rate of the patients (Δ = 21.5 ± 10 bpm, M±SD) during the maneuver was significantly diminished when compared to controls (Δ = 31.30 ± 70, M±SD, p = 0.03). The minimum heart rate (58.24 ± 8.90 vs. 62.80 ± 10, p = 0.68) and the absolute decrease in heart rate at the end of the maneuver (Δ = 38.30 ± 13 vs. Δ = 31.47 ± 17, p = 0.10) were not different from controls. The initial heart rate acceleration during dynamic exercise (Δ = 12 ± 7.55 vs. Δ = 19 ± 7.27, M±SD, p = 0.01) was also diminished, but the heart rate recovery during the first ten seconds was more prominent in the sero-positive patients (Median: 14, Interquartile range: (9.75-17.50 vs. 5(0-8.75, p = 0.001). The serum levels of muscarinic cardiac auto-antibodies were significantly higher in the chagasic patients (Median: 34.58, Interquartile Range: 17-46.5, Optical Density) than in controls (Median: 0, Interquartile Range: 0-22.25, p = 0.001) and correlated significantly and directly (r = 0.68, p = 0.002) with early heart rate recovery during dynamic exercise. The results of this investigation indirectly suggest that, the cardiac muscarinic auto-antibodies may have positive agonist effects on parasympathetic heart rate control of chagasic patients.

Cardiac autonomic control mechanisms in the pathogenesis of chagas' heart disease.

Primary abnormalities of the autonomic nervous system had been postulated as the pathogenic mechanisms of myocardial damage, in patients with Chagas disease. However, recent investigations indicate that these abnormalities are secondary and amenable to treatment with beta-adrenergic blockers. Moreover, muscarinic cardiac autoantibodies appear to enhance parasympathetic activity on the sinus node. Therefore, the purpose of this paper is to analyze how knowledge on Chagas' disease evolved from being initially considered as a primary cardioneuromyopathy to the current status of a congestive cardiomyopathy of parasitic origin.

[Antiadrenergic rescue therapy with amiodarone in children with severe left ventricular dysfunction secondary to scorpion envenomation]. / Terapia de resgate com amiodarona em crianças com grave disfunção ventricular esquerda causada por veneno de escorpião.

BACKGROUND: Children with scorpion envenomation have massive sympathetic activation and variable degrees of left ventricular systolic dysfunction. OBJECTIVE: To evaluate a rescue protocol for children with severe left ventricular dysfunction secondary to scorpion envenomation. METHODS: Four children, after scorpion envenomation, were subjected to a rescue protocol for acute left ventricular dysfunction: Endotracheal intubation and respiratory assistance, electrocardiograms, chest x-Ray, echocardiograms and blood samples for norepinephrine and troponin I serum levels. Samples and echocardiograms were repeated at 12, 24 and 48 hours. Intravenous medications: Dobutamine: 4-6 microg/kg/min. Amiodarone: 3 mg/kg during a 2 hour period. Maintenance: 5 mg/kg/day. Furosemide: 0.5 mg/kg/dose. Diuretics were given when the systemic blood pressure was above percentile fifty. Amiodarone, Dobutamine and Furosemide were administered during the first 48 hours. Beta-adrenergic blockers and angiotensin converting enzyme were given, at 48 hours after admission, once the left ventricular Ejection fraction > 0.35 and the clinical status had improved. RESULTS: On admission, norepinephrine was 1,727.50 +/-794.96 pg/ml, troponin I 24.53 +/- 14.09 ng/ml and left ventricular ejection fraction 0.20 +/- 0.056. At twelve hours, norepinephrine and troponin I serum levels were down to half of the initial values and the ejection fraction increased to 0.32 +/- 0.059. During the next 24 and 48 hours, the ejection fraction rose to 0.46 +/- 0.045, (p<0.01) and norepinephrine and troponin diminished to 526.75 +/- 273.73 (p < 0.02) and 2.20 +/- 2.36 (p<0.02) respectively. CONCLUSION: Amiodarone, by acting as a neuromodulator, is very likely responsible for the early and progressive decrease of serum norepinephrine.

Acutely decompensated systolic heart failure: effects of frequent doses of furosemide vs a single dose plus carvedilol on clinical status, neurohormonal activation and ventricular arrhythmias.

Beta blockers are contraindicated in patients with acutely decompensated heart failure. Current therapeutic strategies increase morbidity and mortality. We have compared the effects of frequent doses of diuretics vs a single dose of diuretics and cautious uptitration of carvedilol. Our results indicate that, although clinical compensation is achieved with both strategies; the effects on neurohormonal activation and ventricular arrhythmias are opposite.

ecto de la dosis de actividad física sobre la presión arterial, índice de masa corporal y circunferencia abdominal en adolescentes

Objetivo: Evaluar en adolescentes si una mayor dosis de actividad física genera mayores beneficios en factores de riesgo cardiovascular como presión arterial (PA), índice de masa corporal (IMC) y circunferencia abdominal (CA). Material y Métodos: En el presente estudio observacional, analítico, de corte transversal se compararon 101 adolescentes de ambos sexos de dos instituciones de educación media, cada una de las cuales y de acuerdo con el programa de la asignatura en educación física tenía diferente dosis de actividad física (AF). En una institución se encontró que el programa tenía una dosis baja (DB) y en la otra, una dosis alta (DA) de AF. A los individuos se les midió PA, IMC y CA. Resultados: No hubo diferencia significativa en relación a la media de PA entre los grupos estudiados, sin embargo en el grupo con DB de AF hubo una mayor prevalencia de PA sistólica (PAS) alta (29% vs 10%, p < 0.014). También en los adolescentes con DB hubo un mayor IMC (22,56 vs 20,87 kg/m2 S.C, p<0.007) y de CA (77,61 vs 73,54 cm, p< 0,009), así como una asociación significativa con mayor frecuencia de sobrepeso y obesidad (15,7% vs 2%, p=0,045) que en aquellos con DA de AF. En el análisis de correlación con el total de los participantes, se observó que la PA diastólica (PAD) tuvo una correlación directa y positiva con el peso, el IMC y la CA. En cambio, la PAS no tuvo correlación con ninguna de estas variables estudiadas. Conclusión: Se concluye que en los adolescentes, una DA de AF se asocia con mayores efectos beneficiosos en factores de riesgo cardiovascular como fueron: menor prevalencia de presión arterial sistólica elevada, menor índice de masa corporal y de circunferencia abdominal. Por lo cual, se considera que los adolescentes debieran practicar una actividad física aeróbica vigorosa con una dosis mayor a la recomendada hasta ahora.

Objective: Assessing in adolescents if a higher dose of physical activity generates higher profits in cardiovascular risk factors such as blood pressure (BP), body mass index (BMI) and waist circumference (WC). Methods: In the present observational, analytical, cross-sectional study, 101 adolescents of both sexes from two institutions of secondary education, each of which, in accordance with the course syllabus in physical education had different doses of physical activity were compared (FA). In an institution found that the program had a low dose (LD) and the other, a high dose (HD) of FA. PA, BMI and WC were measured. Results: There was no significant difference in the mean BP between the groups studied, however in the group with LD of FA there was a higher prevalence of systolic high BP (SBP) (29% vs 10%, p <0.014). Adolescents with LD of FA showed higher BMI (22.56 vs. 20.87 kg/m2 SC, p <0.007) and CA (77.61 vs. 73.54 cm, p <0.009), and a significant association with higher frequency of overweight and obesity (15.7% vs 2%, p = 0.045) than those with HD of FA. In the correlation analysis with the total participants, we observed that the diastolic BP (DBP) had a direct and positive correlation with weight, BMI and CA. In contrast, SBP did not correlate with any of these variables. Conclusions: We conclude that in adolescents, a HD of FA is associated with greater beneficial effects on cardiovascular risk factors as were: lower prevalence of high SBP, lower BMI and WC. Therefore, it is considered that teens should practice a vigorous aerobic physical activity with a higher dose than recommended so far.

Epicardial adipose tissue thickness and its association with adiponectin in metabolic syndrome patients from Mérida, Venezuela / Associação entre a espessura do tecido adiposo epicárdico e a adiponectina em pacientes com síndrome metabólica em Mérida, Venezuela

Objective: To study the relationship between epicardial adipose tissue (EAT) thickness and plasma levels of adiponectin in Venezuelan patients. Subjects and methods: Thirty-one patients diagnosed with metabolic syndrome (study group) and 27 controls were selected and tested for glycemia, lipids, and adiponectin. EAT thickness, ejection fraction, diastolic function, left ventricular mass (LVM), and left atrial volume (LAV) were determined by transthoracic echocardiography. Results: EAT thickness was greater in metabolic syndrome patients (5.69 ± 1.12 vs. 3.52 ± 0.80 mm; p = 0.0001), correlating positively with body mass index (BMI) (r = 0.661; p = 0.0001); waist circumference (WC) (r = 0.664; p = 0.0001); systolic (SBP) (r = 0.607; p = 0.0001), and diastolic blood pressure (DBP) (r = 0.447; p = 0.0001); insulin (r = 0.505; p = 0.0001); Tg/HDL-C ratio (r = 0.447; p = 0.0001), non-HDL-C (r = 0.353; p = 0.007); LAV (r = 0.432; p = 0.001), and LVM (r = 0.469; p = 0.0001). EAT thickness correlated negatively with adiponectin (r = -0.499; p = 0.0001). Conclusion: A significant association exists between EAT thickness and both metabolic syndrome components and adiponectin concentration, a link that might be used as a biomarker for this disease. .

Objetivo: Estudar a relação entre a espessura do tecido adiposo epicárdico (TAE) e os níveis plasmáticos de adiponectina em pacientes venezuelanos. Sujeitos e métodos: Foram selecionados 31 pacientes com diagnóstico de síndrome metabólica (SM) (grupo de estudo) e 27 controles. Foram medidos a glicose, os lipídios e a adiponectina. Foram determinados a espessura do TAE, a fração de ejeção, a função diastólica, a massa ventricular esquerda (MVE) e o volume atrial esquerdo (VAI) pela ecocardiografia transtorácica. Resultados: A espessura do TAE foi maior em pacientes com SM (5,69 ± 1,12 contra 3,52 ± 0,80 mm; p = 0,0001) com uma correlação positiva com o índice de massa corporal (IMC) (r = 0,661; p = 0,0001), circunferência da cintura (CC) (r = 0,664; p = 0,0001), pressão arterial sistólica (PAS) (r = 0,607; p = 0,0001), diastólica (PAD) (r = 0,447; p = 0,0001), insulina (r = 0,505; p = 0,0001), com a relação TG/HDL-C (r = 0,447; p = 0,0001), com o colesterol HDL (r = 0,353; p = 0,007), VAI (r = 0,432; p = 0,001) e MVI (r = 0,469; p = 0,0001). A espessura do TAE se correlacionou negativamente com a adiponectina (r = -0,499; p = 0,0001). Conclusão: Existe uma relação significativa entre a espessura do TAE, os componentes do SM e a concentração plasmática de adiponectina, o que poderia ser utilizado como um biomarcador para essa doença. .

Patterns of left ventricular hypertrophy in essential hypertension: should echocardiography guide the pharmacological treatment?

The experimental design of clinical studies, on the pharmacological treatment of essential hypertension, has ignored a fundamental issue: Hypertensive patients are not a homogenous population. The adaptation of the cardiovascular system to hypertension is structurally and functionally heterogeneous. Recent clinical investigations suggest that this heterogeneity can be minimized by echocardiography. Thus, when the hemodynamic and neurohormonal profiles of untreated hypertensive patients are considered, in the particular context of the cardiac morphologic adaptation to high blood pressure, distinct common denominators emerge. Concentric and eccentric hypertrophy, the two most common patterns of ventricular hypertrophy, are at the extremes of the geometric spectrum. Concentric hypertrophy is characterized by an elliptic left ventricle, normal stroke volume and high peripheral vascular resistance. Its predominant neurohormonal profile includes elevated plasma renin and natriuretic peptide levels. Conversely, most patients with eccentric hypertrophy have a spheric left ventricle, increased stroke volume and low peripheral vascular resistance. Its corresponding neurohormonal profile shows low serum renin and enhanced sympathetic nervous activity. The therapeutic response, to angiotensin II antagonists and to beta-adrenergic blockers, of these two geometric patterns is also different. Concentric hypertrophy is substantially reversed by losartan, whereas, eccentric hypertrophy is refractory to both, losartan and atenolol. These facts raise a relevant question: Should ventricular geometry be considered when deciding which antihypertensive drug is to be prescribed?

Muscarinic antibodies and heart rate responses to dynamic exercise and to the Valsalva maneuver in chronic chagasic patients / Anticorpos muscarínicos e resposta da frequência cardíaca ao exercício dinâmico e a manobra de Valsalva na doença de Chagas crônica

We have studied the cardiac chronotropic responses to the Valsalva maneuver and to dynamic exercise of twenty chronic chagasic patients with normal left ventricular function and no segmental wall abnormalities by two-dimensional echocardiogram. The absolute increase in heart rate of the patients (Δ = 21.5 ± 10 bpm, M±SD) during the maneuver was significantly diminished when compared to controls (Δ = 31.30 ± 70, M±SD, p = 0.03). The minimum heart rate (58.24 ± 8.90 vs. 62.80 ± 10, p = 0.68) and the absolute decrease in heart rate at the end of the maneuver (Δ = 38.30 ± 13 vs. Δ = 31.47 ± 17, p = 0.10) were not different from controls. The initial heart rate acceleration during dynamic exercise (Δ = 12 ± 7.55 vs. Δ = 19 ± 7.27, M±SD, p = 0.01) was also diminished, but the heart rate recovery during the first ten seconds was more prominent in the sero-positive patients (Median: 14, Interquartile range: (9.75-17.50 vs. 5(0-8.75, p = 0.001). The serum levels of muscarinic cardiac auto-antibodies were significantly higher in the chagasic patients (Median: 34.58, Interquartile Range: 17-46.5, Optical Density) than in controls (Median: 0, Interquartile Range: 0-22.25, p = 0.001) and correlated significantly and directly (r = 0.68, p = 0.002) with early heart rate recovery during dynamic exercise. The results of this investigation indirectly suggest that, the cardiac muscarinic auto-antibodies may have positive agonist effects on parasympathetic heart rate control of chagasic patients.

Foram estudadas as respostas cronotrópicas cardíacas à manobra de Valsalva e ao exercício dinâmico de vinte pacientes chagásicos com função ventricular esquerda normal e sem alterações da contractilidade segmentar por ecocardiografia bidimensional. O aumento absoluto da frequência cardíaca dos pacientes (Δ = 21,5 ± 10 bpm, M ± DP) durante a manobra de Valsalva foi significativamente menor quando se comparava ao grupo controle (Δ = 31,30 ± 70, p = 0,03). A frequência cardíaca mínima (58,24 ± 8,90 vs 62,80 ± 10, p = 0,68) e a diminuição da frequência cardíaca absoluta no final da manobra (Δ = 38,30 ± 13 vs Δ = 31,47 ± 17, p = 0,10) não foram diferentes em comparação com o grupo controle. A aceleração inicial da frequência cardíaca durante o exercício dinâmico (Δ = 12 ± 7,55 vs Δ = 19 ± 7,27, p = 0,01) também foi menor, mas a recuperação da frequência cardíaca, durante os primeiros dez segundos, foi maior no grupo sero-positivos [mediana:14 (intervalo interquartil: 9,75-17,50) vs 5 (0 - 8,75), p = 0,001]. Os níveis séricos de auto-anticorpos muscarínicos cardíacos foram significativamente maiores nos pacientes chagásicos do que no grupo controle [(mediana: 34,58 densidade óptica (intervalo interquartil 17 - 46,5) vs (mediana: 0, intervalo interquartil 0 - 22,25) p = 0,001] e a correlação é significativa e direta (r = 0,68, p = 0,002) com o início da recuperação da frequência cardíaca durante o exercício dinâmico. Os resultados desta investigação sugerem que indiretamente, os auto-anticorpos muscarínicos cardíacos, podem ter ação agonista positiva sobre o controle parassimpático da frequência cardíaca dos pacientes chagásicos.

Terapia de resgate com amiodarona em crianças com grave disfunção ventricular esquerda causada por veneno de escorpião / Antiadrenergic rescue therapy with amiodarone in children with severe left ventricular dysfunction secondary to scorpion envenomation / Terapia de rescate con amiodarona en niños con severa disfunción ventricular izquierda ocasionada por veneno de escorpión

Fundamentos: As crianças picadas por escorpião, pressintam ativação maciça do sistema nervoso simpática com vários graus de disfunção sistólica ventricular esquerda. Oobjetivo: Testar um protocolo de resgate em crianças com grave disfunção ventricular esquerda causada por picada de escorpião. Métodos: Quatro crianças após serem picadas por escorpião foram submetidas a: Encubação endotraqueal e suporte respiratório, eletrocardiograma, radiografia de tórax, ecocardiograma e determinação sérica da norepinefrina e troponina I. As análises foram repetidas após 12, 24 e 48 horas. As seguintes medicações intravenosas foram administradas: dobutamina 4-6 μg/kg/min; amiodarona 3 mg/kg durante duas horas, com dose de manutenção de 5 mg/kg/dia; e furosemida 0,5 mg/kg. Amiodarona, dobutamina e furosemida foram administradas durante as primeiras 48 horas. Bloqueadores beta-adrenérgicos e inibidores da enzima conversora da angiotensina foram administrados até 48 após a internação, uma vez que o estado clínico havia melhorado e a fração de ejeção ventricular esquerda encontrava-se acima de 0,35 por cento. Resultados: Na admissão, a dosagem da norepinefrina foi 1.727,50± 794,96 pg/ml, a de troponina I 24,53 ± 14,09 ng/ml e a fração de ejeção do ventrículo esquerdo foi 0,20 ± 0,056. Após 12 horas, os níveis séricos de norepinefrina e de troponina I diminuíram para a metade dos valores iniciais e a fração de ejeção aumentou para 0,32 ± 0,059. Durante as 24 e 48 horas subseqüentes, a fração de ejeção elevou-se para 0,46 ± 0,045 (p<0,01) e a norepinefrina e de troponina I diminuíram para 526,75 ± 273,73 (p< 0,02) e 2,20 ± 2,36 (p<0,02) respectivamente. Conclusão: É bem provável que a amiodarona, ao agir como neuromodulador, seja responsável pela redução rápida e progressiva dos níveis séricos de norepinefrina.

Background: Children with scorpion envenomation have massive sympathetic activation and variable degrees of left ventricular systolic dysfunction. Objective: To evaluate a rescue protocol for children with severe left ventricular dysfunction secondary to scorpion envenomation. Methods: Four children, after scorpion envenomation, were subjected to a rescue protocol for acute left ventricular dysfunction: Endotracheal intubation and respiratory assistance, electrocardiograms, chest x-Ray, echocardiograms and blood samples for norepinephrine and troponin I serum levels. Samples and echocardiograms were repeated at 12, 24 and 48 hours. Intravenous medications: Dobutamine: 4-6 μg/kg/min. Amiodarone: 3 mg/kg during a 2 hour period. Maintenance: 5 mg/kg/day. Furosemide: 0.5 mg/kg/dose. Diuretics were given when the systemic blood pressure was above percentile fifty. Amiodarone, Dobutamine and Furosemide were administered during the first 48 hours. Beta-adrenergic blockers and angiotensin converting enzyme were given, at 48 hours after admission, once the left ventricular Ejection fraction > 0.35 and the clinical status had improved. Results: On admission, norepinephrine was 1,727.50 ±794.96 pg/ml, troponin I 24.53 ± 14.09 ng/ml and left ventricular ejection fraction 0.20 ± 0.056. At twelve hours, norepinephrine and troponin I serum levels were down to half of the initial values and the ejection fraction increased to 0.32 ± 0.059. During the next 24 and 48 hours, the ejection fraction rose to 0.46 ± 0.045, (p<0.01) and norepinephrine and troponin diminished to 526.75 ± 273.73 (p < 0.02) and 2.20 ± 2.36 (p<0.02) respectively. Conclusion: Amiodarone, by acting as a neuromodulator, is very likely responsible for the early and progressive decrease of serum norepinephrine.

Fundamento: Los niños con picaduras de escorpión sufren activación masiva del sistema nervioso simpático con varios grados de disfunción sistólica ventricular izquierda. Objetivo: Probar un protocolo de rescate en niños con disfunción ventricular severa izquierda ocasionada por picadura de escorpión. Métodos: Cuatro niños tras un escorpión picarlas se sometieron a: incubación endotraqueal y soporte respiratorio, electrocardiograma, radiografía de tórax, ecocardiograma y determinación sérica de la norepinefrina y troponina I. Los análisis se repitieron tras 12, 24 y 48 horas. Las siguientes medicaciones intravenosas se administraron: dobutamina 4-6 mcg/kg/min; amiodarona 3 mg/kg durante dos horas, con dosis de mantenimiento de 5 mg/kg/día; y furosemida 0.5 mg/kg. Amiodarona, dobutamina y furosemida se administraron durante las primeras 48 horas. Bloqueante betaadrenergicos e inhibidores de la enzima convertidora de la angiotensina se administraron hasta 48 tras la internación, una vez que el estado clínico había mejorado y la fracción de eyección ventricular izquierda se hallaba superior a un 0,35 por ciento. Resultados: Al ingreso, la dosificación de la norepinefrina fue 1727,50± 794,96 pg/ml, la de troponina I 24,53 ± 14,09 ng/ml y la fracción de eyección del ventrículo izquierdo fue 0,20 ± 0,056. Tras 12 horas, los niveles séricos de norepinefrina y de troponina I disminuyeron para la mitad de los valores iniciales y la fracción de eyección aumentó para 0,32 ± 0,059. Durante las 24 y 48 horas subsiguientes, la fracción de eyección se elevó para 0,46 ± 0,045 (p<0,01) y la norepinefrina y de troponina I se redujeron para 526,75 ± 273,73 (p< 0,02) y 2,20 ± 2,36 (p<0,02) respectivamente. Conclusión: Es bien probable que la amiodarona, al actuar como neuromodulador, sea responsable de la reducción rápida y progresiva de los niveles séricos de norepinefrina.