RESUMO
Cardiopulmonary exercise testing (CPET) was limited to peak oxygen consumption analysis (VO2peak), and now the ventilation/carbon dioxide production (VE/VCO2) slope is recognized as having independent prognostic value. Unlike VO2peak, the VE/VCO2 slope does not require maximal effort, making it more feasible. There is no consensus on how to measure the VE/VCO2 slope; therefore, we assessed whether different methods affect its value. This is a retrospective study assessing sociodemographic data, left ventricular ejection fraction, CPET parameters, and indications of patients referred for CPET. The VE/VCO2 slope was measured to the first ventilatory threshold (VT1-slope), secondary threshold (VT2-slope), and included all test data (full-slope). Of the 697 CPETs analyzed, 308 reached VT2. All VE/VCO2 slopes increased with age, regardless of test indications. In patients not reaching VT2, the VT1-slope was 32 vs. 36 (p < 0.001) for the full-slope; in those surpassing VT2, the VT1-slope was 29 vs. 33 (p < 0.001) for the VT2-slope and 37 (all p < 0.001) for the full-slope. The mean difference between the submaximal and full-slopes was ±4 units, sufficient to reclassify patients from low to high risk for heart failure or pulmonary hypertension. We conclude that the method used for determining the VE/VCO2 slope greatly influences the result, the significant variations limiting its prognostic value. The calculation method must be standardized to improve its prognostic value.
RESUMO
OBJECTIVE: To evaluate the role of peak atrial longitudinal strain (PALS) through speckle tracking 2D echocardiography for the assessment of structural and functional left atrial (LA) remodeling in a type 2 diabetes mellitus (T2DM) population. METHODOLOGY: We conducted a cross-sectional study during a 9-month period. T2DM adults aged 18 and above were included. The variables assessed during the study include age and gender of participants, diabetes characteristics, cardiovascular risk factors, clinical anthropometric and hemodynamic parameters, standard echocardiographic parameters, volume-derived LA functions, and 2D PALS. RESULTS: We included a total of 102 patients. The mean age was 58 ± 11.7 years, and the M/F sex ratio was 1:1.5. Coexistent arterial hypertension (HTN) was observed in more than half (59.8%) of the population sample. Mean 2D PALS was 29.2 ± 8.9% with 58.8% (95% CI: 50.0-68.6) of subjects having a reduced LA strain (ie,<32%). Reservoir and pump functions were the most altered LA volumetric phasic functions. Mean indexed LA maximal volume was 22.2 ± 6.8 mL/m2 . There was a significant association between abnormal PALS and age, Body mass index (BMI), indexed LA volume, E/E' ratio, LA active ejection fraction (pump function), and LA expansion index (reservoir function). CONCLUSION: Left atrial remodeling is a recurrent condition in adult T2DM Cameroonians. The reservoir and pump LA functions were the most affected. Assessment of LA global strain allows early detection of LA remodeling with comparison to LA size standard analyses. Age, BMI, indexed LA volume, E/E' ratio, and reservoir and pump LA functions were associated to 2D LA global strain impairment.
