The purpose of this study was to assess M-mode echocardiographic criteria for pulmonary artery hypertension in patients with intracardiac shunts, and to observe any signs not previously described.
Forty-seven consecutive cardiac cathetherised patients with routine M-mode echocardiogram done were reviewed. Twenty-six patients had atrial septal defect, nine had ventricular septal defect (VSD), four had patent ductus arteriosus (PDA), five had Eisenmenger syndrome and three had combined VSD and PDA.
Fifteen of 20 patients with pulmonary artery mean pressure (PAMP) of more than 50 mmHg demonstrated diminished a-dip (p < 0.001), reduced e-f slope (p < 0.01) and increased b-e slope to > 380 mm/sec (p < 0.01). The presence of systolic flutter or mid-systolic notch, or both was not observed in patients with normal PAMP, but was noted in all of the 20 patients with raised pressure(> 50 mmHg).
This study confirms the limitation of M-mode echocardiographic features in the evaluation of pulmonary artery hypertension in patients with intracardiac shunt, though clinically useful.