Myocardial perfusion SPECT in the diagnosis of apical hypertrophic cardiomyopathy.
BACKGROUND
Apical hypertrophy cardiomyopathy (ACM) is a rare condition characterized by asymmetric myocardial hypertrophy of the apex of the left ventricle. When two-dimensional echocardiography is limited by a poor acoustic window, patients are often referred for MRI. Our hypothesis is that a cheaper and more widely available diagnostic modality like myocardial perfusion single photon emission computed tomography (SPECT) may be helpful in the diagnosis of ACM.


OBJECTIVE
The purpose of this prospective study was to define the characteristics of rest and stress SPECT studies in patients with known ACM, and whether SPECT may be helpful in the diagnosis of ACM.


METHODS
Adult patients with ACM were enrolled in the study. Diagnosis was made with 2-D echo. A rest and exercise or dipyridamole stress SPECT study was performed in all patients with Tc-99m sestamibi.


RESULTS
We enrolled 20 patients (mean age 60 +/- 16 years), 9 were female, with ACM. SPECT at rest revealed in 15 patients (75%) an increased apical tracer uptake, a spade-like deformity of the left ventricular chamber, and the "Solar Polar" map pattern consistent with ACM. The sensitivity, specificity, positive predictive value, and negative predictive value of SPECT for detecting ACM were 75%, 100%, 100%, and 80%, respectively.


CONCLUSIONS
Three-fourths of adult patients with ACM showed, on myocardial perfusion SPECT, characteristic findings which were not seen in age-matched control subjects, such as a significant increased apical tracer uptake, a spade-like deformity of the left ventricle, and the "Solar Polar" map. Nuclear physicians should be aware of these SPECT findings because many ACM patients may first end up in the nuclear labs due to their markedly abnormal ECG for exclusion of obstructive coronary artery disease.
Cianciulli
Tomás F
TF
Division of Cardiology, Hospital of the Government of the City of Buenos Aires Dr. Cosme Argerich, C1155AHB, Buenos Aires, Argentina. tcianciulli@fibertel.com.ar
Saccheri
María C
MC
Masoli
Osvaldo H
OH
Redruello
Marcela F
MF
Lax
Jorge A
JA
Morita
Luis A
LA
Gagliardi
Juan A
JA
Dorelle
Adriana N
AN
Prezioso
Horacio A
HA
Vidal
Luis A
LA
D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*