Objective To compare the predicted and actual maximal heart rate (HRmax) values in the cardiopulmonary exercise test (CPET).Methods We retrospectively investigated 1,060 patients who underwent a CPET between January 2016 and April 2020 at our institution’s cardiopulmonary rehabilitation center. The following patients were included: those aged >20 years, those tested with a treadmill, and those who underwent symptom-limited maximum exercise testing— reaching ≥85% of the predicted HRmax (62% if taking beta-blockers) and highest respiratory exchange ratio ≥1.1. Ultimately, 827 patients were included in this study. Data on diagnosis, history of taking beta-blockers, age, body mass index (BMI), and CPET parameters were collected. Subgroup analysis was performed according to age, betablockers, BMI (low <18.5 kg/m2, normal, and high ≥25 kg/m2), and risk classification.Results There was a significant difference between the actual HRmax and the predicted value (p<0.001). Betablocker administration resulted in a significant difference in the actual HRmax (p<0.001). There were significant differences in the moderate-to-high-risk and low-risk groups and the normal BMI and high BMI groups (p<0.001). There was no significant difference between the elderly and younger groups. We suggest new formulae for HRmax of cardiopulmonary patients: estimated HRmax=183-0.76×age (the beta-blocker group) and etimated HRmax=210-0.91×age (the non-beta-blocker group).Conclusion Age-predicted HRmax was significantly different from the actual HRmax of patients with cardiopulmonary disease, especially in the beta-blocker group. For participants with high BMI and moderate-tosevere risk, the actual HRmax was significantly lower than the predicted HRmax.

Rationale: Videofluoroscopic swallowing study (VFSS) is a noninvasive radiographic procedure that examines the oral, pharyngeal, and cervical esophageal stages of swallowing. Tracheoesophageal fistula (TEF) is difficult to diagnose depending on its size and location. However, how VFSS can be of benefit in the diagnosis of TEF has not been reported yet. Patient concerns: A 64-year-old man who had been tracheostomized post spinal tumor resection surgery at the cervical level 1 to 2, had his tracheostomy tube removed approximately 25 years ago. After decannulation, he reported coughing while swallowing food, foreign sensation in the neck and repeated bouts of pneumonia ever since. Diagnosis: VFSS revealed, for the first time, acquired TEF after tracheostomy decannulation as the cause of repetitive aspiration pneumonia. Intervention: VFSS was performed in this case. Outcomes: In the background of suspected TEF based on VFSS results, the patient underwent a computed tomography scan of the chest and airway in the prone position, followed by bronchoscopy, which confirmed the existence of a TEF. He then underwent primary closure of the fistula. The patient had an uneventful recovery and is currently symptom-free 10 months after the surgery. Lessons: This case alerts clinicians to the possibility of TEF as a diagnosis when the aspirate leaks from the upper esophagus and through the posterior wall of trachea in the esophageal phase of VFSS.

Rationale: An abdominal pseudohernia is a protrusion of the abdominal wall that there is no actual muscular disruption. This report presents a case in which abdominal muscle activities were accurately and quantitatively measured using ultrasonography (US) and surface electromyography in a patient with abdominal pseudohernia. Patient concerns: A 62-year-old man presented with a marked protrusion on the left abdomen with increasing abdominal pressure. Diagnoses: First, the thickness of the abdominal muscle was measured with US while the patient constantly blew the positive expiratory pressure device. When the force was applied to the abdomen, the mean thickness of the muscle layer on the lesion site was found to be thinner. Second, the activities of the abdominal muscles were measured using surface electromyography by attaching electrodes to 8 channels at the same time. When the same pressure was applied on both sides of the abdomen, more recruitment occurred to compensate for muscle weakness at the lesion site. Through the previous 2 tests, the decrease in muscle activity in the lesion area could be quantitatively evaluated. Third, the denervation of the muscle was confirmed using US-guided needle electromyography. Interventions: The patient in this case was wearing an abdominal binder. In addition, he had been training his abdominal muscles through McGill exercise and breathing exercises such as with a positive expiratory pressure device. Outcomes: The patient was able to understand his symptoms. A follow-up test will be performed to see if there is any improvement. Lessons: By using these outstanding assessment methods, proper diagnosis and rehabilitation treatment strategies can be developed.