Introduction : Physical exercise in patients with pulmonary hypertension (PH) can improve their physical capabilities and quality of life. However, the safety of exercise protocols has not been established due to difficulties in predicting large increases in pulmonary artery pressure (PAP) during exercise. Therefore, in this study, we identified clinical indicators predicting deterioration of pulmonary circulation caused by physical exercise to establish the medical safety of exercises in patients with PH.
Methods : A total of 27 patients with mild PH who were admitted to our hospital for right heart catheterization (RHC) were included in this study. We collected the hemodynamic data derived from RHC during cardiopulmonary exercise testing (CPX). Muscle strength (grip and knee extension), physical performance (Short Physical Performance Battery ; SPPB), and body composition were also measured on admission. We divided the patients into two groups : those with a steeper increase in mean PAP (mPAP) to cardiac output [CO] increase (mPAP-CO slope of ≥3.0 ; exercise PH group) and those without (mPAP-CO slope of ＜3.0 ; non-exercise PH group). We used chi-square and Mann–Whitney U tests to characterize the groups and logistic regression analysis to reveal significant between-group differences after adjusting the data for patient age.
Results : We found no significant difference in disease type, treatment, or SPPB score between the groups. However, patients were significantly older in the exercise PH group. Results of the age-adjusted logistic regression analysis showed that significant predictors of steeply increasing mPAP during exercise were minute ventilation (VE) (odds ratio, 7.93 ; 95% CI, 1.94–87.06), VE/carbon dioxide output (VCO) (odds ratio, 1.18 ; 95% CI, 1.02–1.42), systolic pulmonary arterial pressure (sPAP) (odds ratio, 1.35 ; 95% CI, 1.06–2.23), and respiratory exchange ratio (R) (odds ratio, 3.28 ; 95% CI, 1.33–11.01).
Conclusion : Increased sPAP at rest predicted a steep increase in mPAP with CPX. Inadequate vascular reverse remodeling of the pulmonary artery in patients with PH stiffens the artery ; therefore, PAP increases more with exercise in response to an increase in arterial blood flow. Increased VE and VE/VCO or decreased R at rest suggested steeply increasing PAP during exercise in patients with PH.

A 77-year-old man was admitted to our hospital with persistent watery diarrhea. Computed tomography revealed widespread intestinal inflammation, suggesting infectious enteritis. Symptoms did not improve after initiation of empiric levofloxacin which was further broadened to meropenem and fosfomycin and he developed toxic megacolon. After a detailed inquiry, we confirmed the history of sexual activity in a brothel several months before the onset. Suspecting fulminant amoebic colitis, metronidazole was started, and the symptoms improved markedly. Additional tests revealed a definite diagnosis of amoebic colitis. After that, he was discharged from the hospital without recurrence of colitis.
Even in the elderly, amoebic colitis should be considered one of differential diagnosis of enteritis. In addition, in fulminant amoebic colitis, conservative treatment may be effective, as our case. However, surgery should be considered immediately in those who fail to respond to medical management or if the complication such as perforation develops.