[Assessment of myocardial perfusion and function in victims of scorpion envenomation using gated-SPECT].
BACKGROUND
Cardiogenic shock and acute pulmonary edema are the major causes of death of patients with scorpion envenomation, whose pathophysiological mechanism remains controversial.


OBJECTIVE
To investigate the correlation between myocardial perfusion abnormalities and left ventricular contractile function in victims of scorpion envenomation.


METHODS
Fifteen patients underwent ECG-gated myocardial perfusion scintigraphy (gated SPECT) within 72 hours of, and 15 days after scorpion envenomation. Images were analyzed by means of a semi-quantitative visual perfusion score (0 = normal, 4 = absent) and motion score (0 = normal, 4 = akinesia), using the 17-segment model. Summed perfusion (SPS) and summed motion (SMS) scores were calculated for each patient. Ejection fraction (LVEF) was calculated by a commercially available software.


RESULTS
At baseline, 12 out of the 15 patients presented abnormal myocardial perfusion and contractility. Mean values of SPS, SMS and LVEF were 12.5 A+/- 7.3, 17.0 A+/- 12.8, and 44.6 A+/- 16.0%, respectively. A positive correlation between SPS and SMS (r = 0.68; p = 0.005) and negative correlation between SPS and LVEF (r = -0.75; p = 0.0021) were found. The follow-up studies showed recovery of global contractility (LVEF of 68.9 A+/- 9.5, p = 0.0002), segmental contractility (SMS of 2.6 A+/- 3.1, p = 0.0009) and perfusion (SPS of 3.7 A+/- 3.3, p = 0.0003). Improvement of LVEF correlated positively with improvement of SPS (r = 0.72; p = 0.0035).


CONCLUSIONS
Myocardial perfusion abnormalities are common in scorpion envenomation and correlate topographically with the contractile dysfunction. Recovery of contractility correlates with reversibility of perfusion defects. These findings suggest the participation of myocardial perfusion abnormalities in the pathophysiology of this form of acute ventricular failure.
Figueiredo
Alexandre Baldini de
AB
Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto, USP, São Paulo, SP, Brasil.
Cupo
Palmira
P
Pintya
Antônio O
AO
Caligaris
Fábio
F
Marin-Neto
José A
JA
Hering
Sylvia E
SE
Simões
Marcus Vinicius
MV
D000818:Animals; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000139:chemically induced / Q000000981:diagnostic imaging*; D055414:Myocardial Perfusion Imaging; D011446:Prospective Studies; D065008:Scorpion Stings / Q000150:complications*; D012605:Scorpions; D018487:Ventricular Dysfunction, Left / Q000139:chemically induced / Q000000981:diagnostic imaging*