Role of speckle tracking derived strain and strain rate in evaluating the right ventricular functions pre and post balloon pulmonary valvulopalsty

Abstract

Summary I n congenital heart disease assessment of right ventricular function remains challenging.Global function and the role of regional differences during the progression of myocardial dysfunction needs to be defined, so the present study was performed to study the effect of pulmonary stenosis on RV speckle tracking derived Indices and compare them to the usual 2D parameters. The study included 160 patients, 100 with moderate or severe pulmonary stenosis who were referred for balloon pulmonary valvuloplasty to Ain Shams university hospital and 60 control subjects referred to perform echocardiography in Ain shams university echocardiography unit from January 2012 to July 2013. All the patients included in the study performed full echocardiographic examination and speckle tracking analysis before BPV and three months after BPV. The patients included 52 females (52 %) and 48 males (48 %) with a median age of 1.5 years (range from 2 months to 60 years). The fractional area change increased after successful BPV, the mean FAC before BPV was 33.6 % ±8.78 %which increased to 42.2% ± 9% after BPV. The peak pressure gradient across the PV dropped from 80.8 ± 22.9 mm Hg to 26.9 ± 8.9 mm Hg after BPV. The RV longitudinal dimension decreased after successful BPV from 36.1 mm ± 8.8 mm to 32.6 ± 8.3 mm. The RV transverse dimension decreased after BPV from 21.5± 5.7 mm to 19.9 ± 5.6 mm. The TAPSE increased after BPV from 1.68 ± 0.42 cm to 1.95 ± 0.32 cm. The RV wall thickness decreased after BPV from 5.2 mm ± 1.6 mm to 4.06 ± 1.3 mm. The pressure gradient across the PV obtained by catheter pull back decreased after successful BPV from 78.1 ± 22 mmHg to 18.4 ± 6.75 mmHg. Out of 100 patients 96 % (96 patients) were properly analyzed by the STE software where only 4 patients were rejected by the software and were not analyzed. The segmental and global RV strain increased after BPV, theglobal RV strain increased after BPV from -19.8 ± 4.74 % to -24.37 ± 3.57 %, this increase was statistically significant with a P value of < 0.0001. The segmental and global right ventricular strain rate increasedafter BPV,theglobal RV strain rate increased after BPV from -2.41 ± 0.66 % to -3.85 ± 0.51 %, this increase was statistically significant with a P value of < 0.0001. The time to peak systolic strain was shorter in all the segments after BPV. 93% (n=56) of the control subjects were properly analyzed by the STE software where 6.7% (4 controls) of the control subjects were rejected by the software. The FAC was higher among control subjects as compared to patients with PS where it was 41.3 ± 5.9 % among controls versus 33.6 ± 8.78 % among PS patients; this difference was statistically significant with a P value < 0.0001 TAPSE was higher in control subjects as compared to patients with PS where it measured 1.68 ± 0.42 cm in patients with PS as compared to 2.1 ± 0.33 cm in control subjects; this difference was statistically significant with a P value of < 0.0001. The RV wall was thicker in patients with PS where it measured 5.2 ± 1.6 mm in patients with PS as compared to 3.5 ± 0.6 mm in control subjects; this difference was statistically significant with a P value of < 0.0001. The FAC in patients after BPV was slightly higher than control subjects, where it measured 42.2 ± 9 % in patients versus 41.3 ± 5.9 % in controls; the difference was not statistically significant.