Phasic ECG voltage changes or electrical alternans is a well-described ECG changes seen in the pericardial effusion and cardiac tamponade. Popular as once believed, this ECG features are no longer considered pathognomonic for pericardial effusion and cardiac tamponade. Electric alternans is observed in pneumothorax especially left-sided pneumothorax. This is a case of a 41-year-old man who presented with chest pain and breathlessness to the emergency department. Assessment in the emergency unit revealed an obvious distress man with a respiratory rate of 60 breaths/min with cyanosis There were generalised rhonchi and prolonged expiratory breath sound appreciated. Chest X-ray (CXR) was done and diagnosed to have left tension pneumothorax. Initial electrocardiogram (ECG) showed electrical alternans in all leads. He was intubated for respiratory distress followed by chest tube insertion. His initial ECG findings resolved after treatment of the tension pneumothorax. Doctors need to evaluate the cardiac findings along with respiratory findings.
Leaf respiration in the dark (Rdark ) is often measured at a single time during the day, with hot-acclimation lowering Rdark at a common measuring temperature. However, it is unclear whether the diel cycle influences the extent of thermal acclimation of Rdark , or how temperature and time of day interact to influence respiratory metabolites. To examine these issues, we grew rice under 25°C : 20°C, 30°C : 25°C and 40°C : 35°C day : night cycles, measuring Rdark and changes in metabolites at five time points spanning a single 24-h period. Rdark differed among the treatments and with time of day. However, there was no significant interaction between time and growth temperature, indicating that the diel cycle does not alter thermal acclimation of Rdark . Amino acids were highly responsive to the diel cycle and growth temperature, and many were negatively correlated with carbohydrates and with organic acids of the tricarboxylic acid (TCA) cycle. Organic TCA intermediates were significantly altered by the diel cycle irrespective of growth temperature, which we attributed to light-dependent regulatory control of TCA enzyme activities. Collectively, our study shows that environmental disruption of the balance between respiratory substrate supply and demand is corrected for by shifts in TCA-dependent metabolites.