LA function can be affected in a variety of adult diseases which can be measured with cardiac ultrasound. However, accurate image acquisition and analysis is not always easy using conventional echocardiography techniques. Speckle tracking echocardiography is a new non-Doppler technique that can determine all important LA function parameters (volume and deformation) from one image. The technique is easier, more reliable and more sensitive in detecting atrium dysfunction compared to conventional techniques. New information on the clinical relevance of LA volume and deformation analysis is constantly emerging in adult medicine. Several neonatal diseases are associated with LA dysfunction. For the preterm infant, LA dysfunction is predominantly caused by the presence of a ductus arteriosus. The ductus arteriosus is a fetal vessel that connects the aorta and pulmonary artery, and supposed to close soon after birth. Persistence of a ductus arteriosus (PDA) is found in over half of all extremely preterm infants, and typically leads to a shunt of blood into the pulmonary circulation, flooding the lungs and left heart, and predisposing to death, brain injury and chronic lung disease of prematurity. Treatment for a PDA is administration of non-steroidal anti-inflammatory drugs. This treatment is not always successful (i.e. the PDA does not close) and associated with significant short and long term side effects. Careful selection of patients who might benefit from this treatment is thus warranted. Like the adult situation, conventional ultrasound parameters are not sensitive enough in detecting LA dysfunction. Additional or alternative parameters are needed to help differentiate between normal developmental changes and true LA dysfunction. The aim of this study is to assess the feasibility and reliability of speckle tracking derived LA volume and deformation parameters, and determine reference values for preterm infants. We would also like to asses which parameter is best associated with LA dysfunction and successful PDA treatment. To answer these questions, we will perform 2 standardised cardiac ultrasounds about 10 days apart in a group of very preterm infants with and without a PDA. Images will be analysed using conventional techniques and speckle tracking analysis, and according to the presence of clinical signs of LA dysfunction. In a secondary analysis, we will explore which parameter is best associated with successful NSAID treatment. Finding a better diagnostic tool to help select candidates for potential harmful treatments will improve outcomes for a highly-compromised group of infants. Reducing harm in preterm infants will reflect in improved outcomes throughout childhood and have its merits extended well into adulthood.
The left atrium (LA) is one of the four chambers of the heart. Its primary roles are to act as a holding chamber for blood returning from the lungs and to act as a pump to transport blood to the left ventricle of the heart, after which the blood flows to the body.