Development and validation of equation for cardiorespiratory fitness in patients with heart failure with preserved ejection fraction

Background/Aims@#Cardiorespiratory fitness (CRF), as measured by maximal oxygen consumption (VO2max), is an important independent predictive factor of cardiovascular outcomes in patients with heart failure (HF). However, it is unclear whether conventional equations for estimating CRF are applicable to patients with HF with preserved ejection fraction (HFpEF). @*Methods@#This study included 521 patients with HFpEF (EF ≥ 50%) whose CRF was directly measured by cardiopulmonary exercise test using a treadmill. We developed a new equation (Kor-HFpEF) for half of the patients in the HFpEF cohort (group A, n = 253) and validated it for the remaining half (group B, n = 268). The accuracy of the Kor-HFpEF equation was compared to that of the other equations in the validation group. @*Results@#In the total HFpEF cohort, the directly measured VO2max was significantly overestimated by the FRIEND and ACSM equations (p < 0.001) and underestimated by the FRIEND-HF equation (p <0.001) (direct 21.2 ± 5.9 mL/kg/min; FRIEND 29.1 ± 11.8 mL/kg/min; ACSM 32.5 ± 13.4 mL/kg/min; FRIEND-HF 14.1 ± 4.9 mL/kg/min). However, the VO2max estimated by the Kor-HFpEF equation (21.3 ± 4.6 mL/kg/min) was similar to the directly measured VO2max (21.7 ± 5.9 mL/kg/min, p = 0.124), whereas the VO2max estimated by the other three equations was still significantly different from the directly measured VO2max in group B (all p < 0.001). @*Conclusions@#Traditional equations used to estimate VO2max were not applicable to patients with HFpEF. We developed and validated a new Kor-HFpEF equation for these patients, which had a high accuracy.

Successful Endovascular Therapy for Bilateral Popliteal Thrombotic Occlusions / 대한내과학회지

The popliteal artery is a relatively short vascular structure, but acute occlusion can decrease blood flow into the lower extremities and cause subsequent critical limb ischemia, amputation, and even mortality. Further, peripheral artery disease patients frequently have combined cardio-cerebrovascular disease. Here, we report a rare case of sudden bilateral thrombotic total occlusion in the popliteal arteries of a patient with dilated cardiomyopathy and left ventricular thrombi. This patient has been successfully managed by endovascular therapy and subsequent intra-arterial thrombolytic therapy.

The Comparison of Blood Pressure and Heart Rate Changes with Extubation of the Endotracheal Tube and the Laryngeal Mask Airway / 대한마취과학회지

When the endotracheal tube is removed, blood pressure elevates and heart rate increases. In order to evaluate the hemodynamic changes after removal of a new developed device-laryngeal mask airway, we measured the change of the systolic & diastolic blood pressure and heart rate of 120 patients undergoing general anesthesia. The results were elevation of blood pressure and heart rate after extubation or removal on both groups immediately. But the degree of changes were 18.7+/-1.6% in the endotracheal tube groups and 12.3+/-1.4% in the laryngeal mask airway groups in systolic blood pressure respectively. Therefore the degree of changes of the laryngeal mask airway groups was significantly small (p<0.05). The comparison of the change of diastolic blood pressure was not significant. The degree of the change in heart rate was 19.6+/-2.8% in the endotracheal tube groups and 9.2+/-2.2% in the laryngeal mask airway groups. Therefore the degree of the ehange in blood pressure and heart rate of the laryngeal mask airway groups was significantly small (p<0.05).