The importance of using mouthguards as well as their low acceptance rate have been demonstrated. The aim of this study was to investigate the influence of customized mouthguards on hemodynamics.. This randomized crossover study used data from 13 subjects (23.5±1.4 years). The cardiopulmonary and metabolic parameters were observed during ergometer tests without mouthguard (control) in comparison to two types of mouthguards (with and normal without breathing channels). Maximum ventilation was significantly decreased with the normal mouthguard (113.3±30.00 l ∙ min−1) in contrast to the mouthguard with breathing channels (122.5±22.9 l ∙ min−1) and control (121.9±30.8 l ∙ min−1). Also the inspiration time was longer when using the normal mouthguard (0.70±0.11 s) compared to the mouthguard with breathing channels (0.63±0.11 s) and control (Co 0.64±0.10 s). Lactate was also increased under the influence of the mouthguard with breathing channels (10.72±1.4 mmol ∙ l−1) compared to the control (9.40±1.77 mmol ∙ l−1) and the normal mouthguard (9.02±1.67 mmol ∙ l−1). In addition, stroke volume kinetics (p=0.048) and maximum heart rates (p=0.01) show changes. Despite equal levels of oxygen uptake and performances under all three conditions, the use of mouthguards showed differences in cardiopulmonary parameters. The use of mouthguards during exercise does not affect physical performance and can be recommended for injury prevention.

Purpose There is evidence of both the preventive effects and poor acceptance of mouthguards. There are various effects on performance depending on the type of mouthguard model. Hemodynamic responses to wearing a mouthguard have not been described. The aim of this study was to investigate the effects of self-adapted mouthguards with breathing channels (SAMGvent). Methods In this randomized crossover study, 17 healthy, active subjects (age 25.12 ± 2.19 years) underwent body plethysmography and performed two incremental exertion tests wearing a (SAMGvent) and not wearing (CON) a mouthguard. Blood lactate, spirometrics, and thoracic impedance were measured during these maximum exercise tests. Results The mean values using a SAMGvent revealed significantly greater airway resistance compared to CON (0.53 ± 0.16 kPa·L−1 vs. 0.35 ± 0.10 kPa·L−1, respectively; p = < 0.01). At maximum load, ventilation with SAMGvent was less than CON (118.4 ± 28.17 L min−1 vs. 128.2 ± 32.16 L min−1, respectively; p = < 0.01). At submaximal loads, blood lactate responses with SAMGvent were higher than CON (8.68 ± 2.20 mmol·L−1 vs. 7.89 ± 1.65 mmol·L−1, respectively; p < 0.01). Maximum performance with a SAMGvent was 265.9 ± 59.9 W, and without a mouthguard was 272.9 ± 60.8 W (p < 0.01). Maximum stroke volume was higher using a SAMGvent than without using a mouthguard (138.4 ± 29.9 mL vs. 130.2 ± 21.2 mL, respectively; p < 0.01). Conclusion Use of a self-adapted mouthguard led to increased metabolic effort and a significant reduction in ventilation parameters. Unchanged oxygen uptake may be the result of cardiopulmonary compensation and increased breathing efforts, which slightly affects performance. These results and the obvious preventive effects of mouthguards support their use in sports.

Postinfarction ventricular septal defect (pVSD) due to acute myocardial infarction complicated by cardiogenic shock (CS) is associated with high mortality. The aim of this study was to determine the outcome of primary surgical repair of pVSD in patients with CS and examine whether it is influenced by the use of mechanical circulatory support (MCS) devices. Between October 1994 and April 2016, primary surgical repair of pVSD complicated by CS was performed in 53 patients. Thirty‐six (68%) were implanted pre‐operatively with an intra‐aortic balloon pump (IABP), 4 (8%) with extracorporeal life support (ECLS), and 13 (24%) received no MCS device. Prospectively collected demographic and perioperative data were analyzed retrospectively. All‐cause, 30‐day mortality rates were analyzed and multivariate analysis was performed to differentiate independent risk factors. No pre‐operatively implanted MCS device was able to improve 30‐day survival, whereas pre‐operatively implanted ECLS tended to have a positive effect (P = .106). The post‐operative need for a MCS device or escalation of MCS invasiveness (IABP upgrade to ECLS) was associated with a higher 30‐day mortality (P = .001) compared with patients without any MCS device or those with pre‐operatively implanted MCS devices. An independent risk factor for 30‐day mortality was the interval between acute myocardial infarction and surgery <7 days (OR 5.895, CI 1.615‐21.515; P = .007). Pre‐operative implantation of ECLS for CS tends to improve the outcome of early primary surgical pVSD repair. The need for a post‐operative MCS device is associated with a worse 30‐day survival after early primary surgical pVSD repair.