Background: Flattening of the interventricular septum (D-shaped Septum) detected during echocardiographic examination is correlated with significant right ventricular (RV) overload. There are no reports of this finding with cardiac gated SPECT imaging. We report an observational study correlating this finding with the presence of RV overload.
Method: Retrospectively we compared eight cases with flattening of the interventricular septum on cardiac gated SPECT imaging of which echocardiographic correlations and clinical data were available for the presence of RV overload.
Results: All patients but one had pulmonary hypertension ranging from 42 to 52 mmHg measured by echocardiographic doppler studies. Except one all patients had reasons for RV overload (chronic obstructive pulmonary disease in three, history of atrial septal defect in three, pulmonary embolism in one and obstructive sleep apnea in one). Septal flattening present on gated SPECT images was seen in 50% of the cases by echocardiography. Other signs of RV overload (RV enlargement, RV hypertrophy) were observed by echocardiography in five patients and by the gated SPECT in seven patients.
Conclusion: The presence of interventricular septal flattening on gated SPECT studies correlates with right ventricular overload and should be routinely assessed during interpretation of gated SPECT studies.
We suggest that more attention should be given to the shape of the interventricular septum during interpretation of gated SPECT studies and the term of septal flattening should be routinely used and reported similar to echocardiographic descriptions of the septum in patients with suspected RV overload.
Mohammad-Reza Movahed, None.