RESUMEN
It is controversial whether people with vasovagal syncope (VVS) have abnormal autonomic responses at baseline and whether specific diagnostic manoeuvres have a diagnostic value. We investigated whether the pupillary light reflex and cardiac autonomic tests can be used to identify autonomic dysfunction in volunteers with a medical history of VVS. The study groups included 128 healthy volunteers, of whom 31 reported a history of typical VVS. The right pupil was evaluated using an automated, commercial infra-red pupillometer under strict conditions. In addition to miosis and mydriasis kinetics, pupil diameters were measured. Heart rate variability at rest and heart rate changes to standing were quantified with high-resolution electrocardiography and designated software. The demographic and clinical characteristics of both groups were statistically similar. Average constriction velocity (ACV) was significantly higher in VVS patients following a univariate analysis (3.83 ± 0.59 vs. 3.56 ± 0.73 mm/s, p = 0.042) and after correcting for potential confounders (p = 0.049). All other pupillometric and heart rate indices were comparable between groups. Patients with a history of VVS depict pupillary parasympathetic overactivity in response to light stimuli, manifested as increased ACV. The prognostic implications of this finding and the significance of using this simple clinical tool to identify patients who are at risk for developing frequent episodes of VVS or physical injuries following a syncope merits further study.
Asunto(s)
Electrocardiografía , Frecuencia Cardíaca , Corazón , Sistema Nervioso Parasimpático , Valor Predictivo de las Pruebas , Pupila , Reflejo Pupilar , Síncope Vasovagal , Humanos , Síncope Vasovagal/fisiopatología , Síncope Vasovagal/diagnóstico , Masculino , Femenino , Adulto , Reflejo Pupilar/fisiología , Sistema Nervioso Parasimpático/fisiopatología , Pupila/fisiología , Estudios de Casos y Controles , Corazón/inervación , Corazón/fisiopatología , Adulto Joven , Persona de Mediana Edad , Estimulación Luminosa , Sistema Nervioso Autónomo/fisiopatologíaRESUMEN
Vasovagal syncope (VVS) has a high prevalence in the general population and is associated with potential complications. There is limited information on the possible association between venous capacitance (VC) and venous return (VR), important determinants of preload and VVS. Since the tilt test was reported to yield a high rate of false positive results, the aim of this study was to evaluate whether abnormal VC and VR at baseline could predispose individuals to VVS.To this end, 88 young, healthy volunteers were recruited and classified to 26 (29.5%) who experienced typical VVS and 62 (70.5%) who did not. VC and VR were evaluated with a commercial device and plethysmography applied to the elevated legs. Maximum venous outflow (MVO), segmental venous capacitance (SVC) and MVO/SVC ratio were calculated and averaged.No significant differences between MVO (5.0±0.5 vs 5.6±0.8, p>0.05), SVC (6.0±0.5 vs 6.3±0.8, p>0.05) or MVO/SVC ratio (0.83±0.02 vs 0.86±0.03, p>0.05) were observed for the non-VVS and VVS volunteers, respectively. There was a significant association between a higher MVO and SVC values and a larger decrease in diastolic blood pressure with standing, although correlations were weak (R2=0.0582 and 0.0681, respectively).In conclusion, at baseline, VC and VR are not impaired in healthy volunteers with a history of VVS. It remains unknown if similar results would be found in patients with cardiovascular comorbidities. Also, the sensitivity of VC and VR evaluations to identify a predisposition for VVS following physiological provocations merits further study.
Asunto(s)
Síncope Vasovagal/diagnóstico , Venas/fisiopatología , Presión Venosa , Adolescente , Adulto , Anciano , Presión Sanguínea , Estudios Transversales , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Mesa Inclinada , Adulto JovenRESUMEN
OBJECTIVE: Oesophageal atresia (OA) is a major anomaly of varying severity. The complexity of surgical correction highly depends on the gap length of missing oesophagus and the presence of a distal fistula. The aim of this study was to identify antenatal sonographic findings associated with presence of a distal fistula and type of surgical repair METHODS: Prenatal medical records of neonates postnatally diagnosed with OA were reviewed. Sonographic signs of OA (small/absent stomach, polyhydramnios, oesophageal pouch) and the trimester at sign detection were recorded and compared between (1) OA with and without a distal fistula and (2) early one-step versus delayed two-step anastomosis. Multivariate analysis was performed. RESULTS: Overall, 80 cases of OA were included. Absence of a distal fistula was significantly associated with higher rates of small/absent stomach (100% vs 28.6%, P<0.0001), oesophageal pouch (100% vs 24.3%, P<0.0001) and severe polyhydramnios (66.7% vs 22.9%, P=0.006), compared with OA with a distal fistula.Cases requiring a delayed two-step repair had higher rates of small/absent stomach (84.2% vs 16.7%, P>0.0001), severe polyhydramnios (47.4% vs 16.7%, P=0.008) and oesophageal pouch (73.7% vs 18.5%, P<0.0001), compared with those corrected in an early one-step anastomosis.Multivariate logistic regression found small/absent stomach and pouch to be significantly and independently associated with a delayed two-step anastomosis. CONCLUSION: OA without a distal fistula is associated with higher rates of prenatal sonographic signs. Both small/absent stomach and a pouch are independently associated with a delayed two-step anastomosis. These findings may help improve antenatal parental counselling regarding the anticipated surgical repair.
Asunto(s)
Atresia Esofágica/diagnóstico por imagen , Atresia Esofágica/cirugía , Fístula Traqueoesofágica/diagnóstico por imagen , Fístula Traqueoesofágica/cirugía , Ultrasonografía Prenatal/métodos , Anastomosis Quirúrgica , Femenino , Humanos , Embarazo , Diagnóstico Prenatal/métodos , Estudios RetrospectivosRESUMEN
OBJECTIVE: Hypertension is the leading cause of cardiovascular disease and premature death. New methods for early detection of hypertension and its consequences can reduce complications arising from uncontrolled hypertension. Pulse-wave velocity (PWV), a measure of arterial stiffness, has been recognized as a valuable tool in assessing risk for cardiovascular complications, although its use in clinical practice is currently limited. Here we examine whether brachial--ankle PWV (baPWV) and femoral--ankle PWV (faPWV) are elevated in nonhypertensive volunteers, with and without a history of familial hypertension. METHODS: Volunteers were recruited and questioned as to their medical background and family history. Participants were divided into two groups based on history of familial hypertension and were measured for baPWV and faPWV. Carotid--femoral PWV was computed from these measurements. RESULTS: A total of 82 healthy nonhypertensive volunteers (mean age 31.4â±â9.6) were recruited. Among the study cohort, 43.7% had a history of familial hypertension. There were no between-group differences in any other clinical or demographic characteristics. Both baPWV and faPWV were significantly elevated in volunteers with a history of familial hypertension (10.86â±â1.69 vs. 9.68â±â1.52âm/s, Pâ<â0.004, and 7.01â±â1.65 vs. 6.28â±â1.26âm/s, Pâ<â0.028, respectively). CONCLUSION: Volunteers with a history of familial hypertension present with elevated baPWV and faPWV. This is suggestive of increased central and peripheral arterial stiffness in susceptible individuals before the onset of hypertension. Routine measurement of these parameters may allow for early intervention and risk stratification, especially in persons with a history of familial hypertension.
Asunto(s)
Hipertensión , Rigidez Vascular , Adulto , Índice Tobillo Braquial , Arteria Braquial , Humanos , Hipertensión/complicaciones , Hipertensión/genética , Análisis de la Onda del PulsoRESUMEN
It has been suggested that some of the adverse, long-term cardiovascular outcomes of smoking are mediated by impaired autonomic nervous system (ANS) activity. Yet, this association is currently inconclusive. Heart rate variability (HRV) and the deep breathing test (DBT) represent common quantitative markers of ANS activity due to their simplicity and reliability. This large cross-sectional study was designed to assess the effect of active smoking on ANS function as manifested by HRV or DBT abnormalities. Electrocardiograms were recorded at rest for 5 min and during forced metronomic breathing. HRV and DBT were calculated according to accepted standards. Participants were divided into two groups based on current smoking status. The study included 242 healthy volunteers (196 nonsmokers and 46 smokers). There were no significant differences in age, sex, and BMI between groups. Cumulative smoking exposure burden (CSEB) for the study group was 5.3 ± 1.3 pack-years. Comparative analysis of HRV and DBT parameters according to smoking status revealed no significant differences between groups. Significant (p < 0.05), yet weak or moderate correlations (r < 0.7) were found between CSEB and abnormal change in HRV parameters consistent with sympathetic overactivity and decreased parasympathetic tone. In conclusion, smoking for a relatively short period in healthy adults does not seem to lead to significant impairment in ANS function. Yet, the consequences of smoking seem to be amplified when cumulative exposure burden increases.