RESUMEN
OBJECTIVES: This study was a sham-controlled, double-blind, randomized clinical trial to examine the effect of chronic low level tragus stimulation (LLTS) in patients with paroxysmal AF. BACKGROUND: Low-level transcutaneous electrical stimulation of the auricular branch of the vagus nerve at the tragus (LLTS) acutely suppresses atrial fibrillation (AF) in humans, but the chronic effect remains unknown. METHODS: LLTS (20 Hz, 1 mA below the discomfort threshold) was delivered using an ear clip attached to the tragus (active arm) (n = 26) or the ear lobe (sham control arm) (n = 27) for 1 h daily over 6 months. AF burden over 2-week periods was assessed by noninvasive continuous electrocardiogram monitoring at baseline, 3 months, and 6 months. Five-minute electrocardiography and serum were obtained at each visit to measure heart rate variability and inflammatory cytokines, respectively. RESULTS: Baseline characteristics were balanced between the 2 groups. Adherence to the stimulation protocol (≤4 sessions lost per month) was 75% in the active arm and 83% in the control arm (p > 0.05). At 6 months, the median AF burden was 85% lower in the active arm compared with the control arm (ratio of medians: 0.15; 95% confidence interval: 0.03 to 0.65; p = 0.011). Tumor necrosis factor-alpha was significantly decreased by 23% in the active group relative to the control group (ratio of medians: 0.77; 95% confidence interval: 0.63 to 0.94; p = 0.0093). Frequency domain indices of heart rate variability were significantly altered with active versus control stimulation (p < 0.01). No device-related side effects were observed. CONCLUSIONS: Chronic, intermittent LLTS resulted in lower AF burden than did sham control stimulation, supporting its use to treat paroxysmal AF in selected patients. (Transcutaneous Electrical Vagus Nerve Stimulation to Suppress Atrial Fibrillation [TREAT-AF]; NCT02548754).
Asunto(s)
Fibrilación Atrial/terapia , Estimulación Eléctrica Transcutánea del Nervio/métodos , Anciano , Fibrilación Atrial/fisiopatología , Método Doble Ciego , Oído Externo/fisiología , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nervio Vago/fisiologíaRESUMEN
INTRODUCTION: Mineralocorticoid receptor antagonism reduces sudden cardiac death in heart failure, but the underlying mechanism is unclear. Our previous studies indicate that treatment with a mineralocorticoid receptor antagonist prevents adverse ventricular electrophysiological remodeling and reduces ventricular tachyarrhythmia inducibility in the rapid ventricular pacing-induced heart failure model. This study's aim was to determine whether chronic spironolactone treatment prevents formation of local electrical activation delays in the cardiomyopathic ventricle by attenuating inflammatory pathways and myocardial fibrosis. METHODS AND RESULTS: Dogs subjected to rapid ventricular pacing at 220 bpm for 5 weeks in the absence or presence of spironolactone treatment were assessed by echocardiography, electrophysiology study, ventricular fibrosis measurements and inflammatory cytokine mRNA expression analysis. Spironolactone failed to prevent LV systolic dysfunction or chamber enlargement in dogs that underwent rapid ventricular pacing. Spironolactone prevented ventricular electrogram widening after premature stimulation at short coupling intervals, electrogram fractionation, interstitial fibrosis, and inflammatory cytokine (interleukin-6, tumor necrosis factor-α) gene overexpression in ventricular paced dogs with heart failure. CONCLUSIONS: Our findings establish an important link between inflammatory cytokine gene expression, interstitial fibrosis and myocardial electrical activation delays during premature excitation and provide insight into the mechanisms by which mineralocorticoid receptor antagonism may prevent development of an arrhythmogenic ventricular substrate in systolic heart failure.
Asunto(s)
Arritmias Cardíacas/prevención & control , Insuficiencia Cardíaca/tratamiento farmacológico , Ventrículos Cardíacos/fisiopatología , Inflamación/prevención & control , Antagonistas de Receptores de Mineralocorticoides/uso terapéutico , Miocardio/patología , Espironolactona/uso terapéutico , Disfunción Ventricular/prevención & control , Animales , Arritmias Cardíacas/complicaciones , Perros , Fenómenos Electrofisiológicos , Fibrosis/complicaciones , Fibrosis/prevención & control , Insuficiencia Cardíaca/etiología , Inflamación/complicaciones , Disfunción Ventricular/complicacionesAsunto(s)
Reanimación Cardiopulmonar/métodos , Paro Cardíaco Extrahospitalario/terapia , Reanimación Cardiopulmonar/normas , Servicios Médicos de Urgencia/métodos , Servicios Médicos de Urgencia/normas , Humanos , Paro Cardíaco Extrahospitalario/mortalidad , Guías de Práctica Clínica como Asunto , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
Cardiac injury, specifically valvular rupture, must be considered after blunt chest trauma even in previously healthy patients. Isolated mitral regurgitation (MR) and tricuspid regurgitation (TR) due to blunt chest trauma are rare phenomena. More unique is simultaneous complete papillary muscle rupture of the mitral valve (MV) and tricuspid valve (TV) with only four patients being previously reported in the literature. This case describes a patient with complete transection of the posteromedial papillary muscle of the MV with severe MR and a concomitant flail TV with severe TR following a motor vehicular accident. The importance of transthoracic and transesophageal echocardiography in the early evaluation of patients following blunt chest trauma is also highlighted by this case.