Haribabu
Vydehi Institute of Medical Sciences and Research Center, India
Title: To study the efficacy of right ventricular isovolumic acceleration by 2d-Echo in evaluating post operative outcomes in tetrology of fallot
Biography
Biography: Haribabu
Abstract
Aim:-Tetralogy of fallot(TOF) is a most common cyanotic congenital heart disease encountered in clinical practice. Right ventricular function is an important determinant of post operative outcomes in these patients. Cardiac Magnetic Resonance Imaging is a gold standard in evaluating right ventricular function. However this technique is expensive, has limited availability, and requires significant expertise to acquire and interpret. Hence we would like to use 2D-Echo which is easily available. Most of the parameters used in 2D-Echo in evaluating right ventricular function are load dependent except for isovolumic acceleration (IVA) and myocardial performance index(MPI). Hence in view of lack of data on Isovolumic acceleration on pre-operative evaluation in Congenital Heart Disease, we used this parameter in evaluating the post-operative outcomes in (TOF). Isovolumic acceleration is a ratio of peak velocity during isovolumic contraction and time to peak.
Methods:-Sixty three consecutive TOF patients planned for intracardiac repair referred for pre-operative Echocardiographic evaluation were studied. Their mean age was 9+/-3 years. All patients were in sinus rhythm with stable hemodynamic condition during Echocardiographic examination. Doppler tissue imaging technique was used to determine IVA. Recordings were made at a sweep speed of 50 to 100mm/s. Values are presented as means of 3 consecutive beats. The sample volume of 6mm. From the basal right ventricular free wall IVA was measured. These patients were followed up with IVA for 2 weeks and at 1 month. We correlated preoperative IVA to length of ICU stay and 30 day mortality using chi-square test. A P value of <0.005 was considered significant.
Results:-Sixty three TOF patients were divided into four groups based on IVA values. Group 1 consisted of 19 patients who had IVA > 2.2m/s2 were used as controls. Group 2 consisted 12 patients who had IVA between 1.5 and 2.2m/s2. Group 3 consisted of 17 patients who had IVA between 1 and 1.5m/s2. Group 4 consisted of 15 patients who had IVA <1m/s2. Each group was further subdivided based on length of ICU stay and mortality. Group 1 and group 2 had no mortality nor the postoperative ICU stay was more than a week. In group 3, twelve had ICU stay for more than a week and three died in hospital. Group 4, thirteen patients had ICU stay for more than 1 week and 11 died in hospital.
Conclusion:-Our studied showed there is a significant association of pre-operative IVA to post operative outcomes in TOF patients and those patients whose IVA values < 1m/s2 had high 30 day mortality with significant P values < 0.0001. Hence IVA can be used as a prognostic marker in TOF patients who are planned for intra-cardiac repair.
