RESUMEN

AIMS: The aim of this study was to evaluate the relationship between preoperative left atrial function and recurrence of atrial fibrillation (AF) after mitral valve surgery and Cox Maze procedure in patients with moderate-to-severe rheumatic mitral stenosis (MS) combined with AF, in order to facilitate clinical risk stratification and to guide treatment strategies. METHODS AND RESULTS: Patients with moderate-to-severe rheumatic MS attending Beijing Anzhen Hospital of Capital Medical University from April 2022 to September 2023 were prospectively collected, and all of them underwent transthoracic two-dimensional speckle-tracking echocardiography to assess left atrial structure and function before undergoing mitral valve surgery and Cox Maze procedure and postoperative follow-up. 121 patients were enrolled, of whom 77.69 % (94/121) were female, with a median follow-up time of 9.56 ± 1.83 months, and 48 patients (39.7 %, 48/121) had postoperative recurrence of AF. Preoperative left atrial stiffness index (LASI) [3.76(3.10-5.44) vs. 2.41(1.75-3.33), P < 0.001] and left atrial mechanical dispersion (SD-TPS) (15.84 ± 5.92vs. 11.58 ± 5.96, P = 0.001) were significantly higher in the postoperative AF recurrence group than in the without recurrence group; Multivariable cox regression analysis showed that LASI>3.15 and SD -TPS > 13.2 were associated with independent risk factors for AF recurrence (hazard ratio = 2.957, 95 %CI,1.366-6.399, P = 0.006 and hazard ratio = 2.892, 95 %CI,1.381-6.057, P = 0.005). CONCLUSION: LASI and SD-TPS were effective predictors of postoperative recurrence of AF in patients with moderate-to-severe rheumatic MS, and LASI >3.15 and SD-TPS% >13.2 were independent influences on the recurrence of AF after Cox Maze in this group of patients.

Asunto(s)

Fibrilación Atrial , Función del Atrio Izquierdo , Estenosis de la Válvula Mitral , Recurrencia , Cardiopatía Reumática , Índice de Severidad de la Enfermedad , Humanos , Femenino , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/cirugía , Fibrilación Atrial/diagnóstico por imagen , Estenosis de la Válvula Mitral/cirugía , Estenosis de la Válvula Mitral/fisiopatología , Estenosis de la Válvula Mitral/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Cardiopatía Reumática/cirugía , Cardiopatía Reumática/fisiopatología , Cardiopatía Reumática/complicaciones , Cardiopatía Reumática/diagnóstico por imagen , Función del Atrio Izquierdo/fisiología , Estudios de Seguimiento , Estudios Prospectivos , Atrios Cardíacos/fisiopatología , Atrios Cardíacos/diagnóstico por imagen , Adulto , Valor Predictivo de las Pruebas , Ecocardiografía/métodos

RESUMEN

In recent years, research on ventilating tunnels has become increasingly important. However, the impact of external disturbances on ventilating systems has been largely ignored. To address this issue of frequent airflow fluctuations caused by external perturbations, which cannot be fully compensated using conventional control methods, this study proposes a perturbation-compensated ventilation control approach. A disturbance compensator is developed by incorporating the tunnel's airflow velocity and the number of jet fan start-stop events as input parameters. By compensating for external disturbances, the disturbance to the system is reduced. The Simulink model of the tunnel controller was used for simulation experiments. The compensator demonstrated good tracking results in comparison experiments with different disturbances. The ventilation approach based on disturbance compensator is capable of regulating the fluctuation of CO concentration within a justifiable range compared to using PID control and ADRC. This not only improves the stability of the entire control system but also significantly prolongs the service life of the jet fan by reducing the frequency of start-stop cycles.