Is Age-Predicted Maximal Heart Rate Applicable in Patients With Heart or Lung Disease?

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.

Comparision of the Clinical Results in Photorefractive Keratectomy with that in Laser In Situ Keratomileusis for Correction of Moderate Myopia

We have performed photorefractive keratectomy(PRK) and Laser In situ keratomileusis(LASIK) to compare the clinical results of PRK with that of LASIK in moderate myopes retrospectively. Of 70 eyes who were between -4.0 diopter and -8.0 diopter, there were 40 eyes, 33 patients treated by PRK and 30 eyes, 23 patients treated by LASIK. Follow-up evaluations were done at 1, 2, 3, 6, 9 months and uncorrected visual acuity, best corrected visual acuity, spherical equivalent, corneal haze, complications were analized. The postoperative uncorrected visual acuity was 0.72, 0.86, 0.86, 0.91, 0.85 in PRK and 0.86, 0.86, 0.83, 0.85, 0.82 in LASIK and the best corrected visual acuity was 0.94, 0.97, 0.97, 0.99 0.97 in PRK and 0.96, 0.97, 0.97, 0.97, 0.96 in LASIK respectively. Although the postoperative refractions within +/-1 diopter of emmetropia were 32.5% in PRK and 76.7% in LASIK and statistically significantly different between the two groups at 1 months(P0.05) from 2 months. The average corneal haze was not significant(P>0.05) from 2 months. The average corneal haze was decreased from Grade 1.66 to Grade 0.48 in PRK at 1, 6 months but in LASIK, the corneal haze was low grade of Grade 0.35 from 1 month. The complications of PRK were irregular astigmatisms in 2 eyes and that of LASIK, the corneal haze was low irregular astigmatisms in 2 eyes and that of LASIK were interface particles in 3 eyes, irregular astigmatisms in 3 eyes. The clinical results of PRK and LASIK were satisfactory and the two technical methods were effective for correction of moderate myopes.

Gas Injection and Simple Pars Plana Vitrecomy in Submacular hemorrhage without using t-PA

Surgical methods using retinotomy, intravitreal or subretinal tissue plasminogen activator(tPA) injection and so on have been introduced in diffuse subretinal hemorrahage involving submacular area. We present our experience of improvement of vision in an 50-year old woman with submacualr hemorrgage, treated with 0.6cc expanding sulfur hexafluoride gas(SF6) injetion intravitreally and face-dwon positioning resulting in the movement of subacular hemorrhage to the inferior direction and intravitreal space, and simple pars plana vitrectomy of breakthrough vitreous hemorrhage.