The prognostic significance of typical perfusion defects on vasodilator stress myocardial perfusion SPECT in patients with left bundle branch block or right ventricular apical pacing.
OBJECTIVE
Left bundle branch block (LBBB) and ventricular pacing may induce typical artefacts that appear as perfusion defects in myocardial perfusion single photon emission computed tomography (MPS). We assessed the prognosis of patients with LBBB or right ventricular apical (RVA) pacing who had chest pain and an MPS with only abnormal activation-related defects (AARD).


METHODS
All patients with LBBB or ventricular pacing referred for vasodilator stress MPS between April 2002 and January 2006 were analyzed. AARD were defined as small, nontransmural, fixed defects and small reversible defects in well-defined regions always accompanied with concomitant wall motion abnormalities.


RESULTS
Ninety-seven patients were included, with a mean follow-up period of 3+/-1.3 years. MPS showed AARD in 57 and it was completely normal in 40 patients. No significant difference in cumulative cardiac event-free follow-up was observed between patients with AARD (93%) and normal MPS (85%). The average annual cardiac event rate was not significantly different between the groups (1.7 and 4.3% per year, respectively). No difference was found between patients with LBBB and RVA pacing.


CONCLUSIONS
Patients with chest pain and LBBB or RVA pacing who show AARD on MPS have a comparable prognosis as patients with abnormal activation and a normal MPS. This justifies MPS for risk stratification of patients with chest pain and LBBB or RVA pacing.
Ten Cate
Tim J F
TJ
Department of Nuclear Medicine, St. Antonius Hospital, Nieuwegein, The Netherlands. timtencate@yahoo.com
Kelder
Johannes C
JC
Bogaard
Margot D
MD
Van Hemel
Norbert M
NM
Fred Verzijlbergen
Johan
J
D000241:Adenosine / Q000494:pharmacology; D000368:Aged; D016477:Artifacts; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D002637:Chest Pain / Q000000981:diagnostic imaging; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D055414:Myocardial Perfusion Imaging; D011379:Prognosis; D012189:Retrospective Studies; D013312:Stress, Physiological / Q000187:drug effects; D015899:Tomography, Emission-Computed, Single-Photon; D014664:Vasodilation / Q000187:drug effects
D000241:Adenosine