Turner syndrome also increases the risk of aortic dissection, by aortic root dilatation. Finally, in an attempt to offset decreased blood pressure, ventricular dilatation and myocardial dysfunction occur. This can cause dilatation and weakening of the walls of the ascending aorta. Some patients may, however, develop narrowing (stenosis) or dilatation at the previous coarctation site. Sometimes, in the presence of ventricular disease associated with dilatation, EDV may vary. Gastroesophageal reflux (GERD) occurs after pneumatic dilatation in some patients. The most common acquired TR is due to right ventricular dilatation. Radioisotopes can differentiate between passive dilatation and obstruction. Liver abscesses may be seen even without dilatation of intrahepatic bile ducts. P waves (known as "P mitrale") indicate left-atrial abnormality - e.g. dilatation or hypertrophy. Some variants of pyloroplasty are Pyloric dilatation and pyloromyotomy, which are less invasive. In contrast to false labour, true labor is accompanied by cervical dilatation and effacement. Partograph includes several labour vitals including cervix dilatation of the mother. Treatment may include behavior therapy such as graduated exposure therapy and gradual vaginal dilatation. An increase in EDV could counterbalance LV dilatation and impaired contraction.