A 55 yrs old male was admitted with a 3 week history of acute onset anasarca. Past medical history was significant for COPD and HTN. Medications included lisinopril and lasix. Admission EKG showed right atrial enlargement and right ventricular hypertrophy. Myocardial perfusion imaging with stress testing was ordered to rule out myocardial ischemia.

Images at rest and stress did not show any reversible defects to suggest presence of dipyridamole induced ischemia. Flat interventricular septum and a D shaped left ventricle were noted, along with dilated and hypertrophied right ventricle. Normal left ventricular wall motion was seen along with ejection fraction of 70%. The gated images also show right ventricular hypokinesis.

Patient subsequently underwent agitated saline echocardiogram, which was negative for intracardiac shunt, and catheterization showed pulmonary HTN with a PASP of 58mm Hg.

This case demonstrates findings with myocardial perfusion imaging – RV hypertrophy, D shaped left ventricle / septal flattening with a fixed defect mimicking scar – that suggest the presence of Pulmonary HTN. The finding of abnormal tracer uptake in the septum, at both rest and stress (fixed defect), typically would be defined as scar. However, this same finding was recently described in a single case report (1) in association with pulmonary hypertension; although the mechanism is not defined, it may be related to acute RV pressure overload compromising septal blood flow throughout the cardiac cycle, resulting in a “fixed” defect, which has been described in a canine model previously (2).

1) Maeder et al, Kard Medizin 2007;10: 113-14
2) Gibbons et al, Am J Physiol Heart Circ Physiol 2006; 290: H2432-8

This case was compiled by Joseph Vollink PA, MEDVAMC