Acute left ventricular dysfunction of severe scorpion envenomation is related to myocardial perfusion disturbance.
BACKGROUND
Scorpion envenomation (SE) may present severe cardiac dysfunction with acute pulmonary edema and cardiogenic shock. The pathophysiology of this acute heart failure is still controversial. We aimed at assessing the contribution of the myocardial ischemia to the left ventricular dysfunction in SE by using 99mTc-Sestamibi myocardial perfusion scintigraphy (MPS).


METHODS
Twelve children (7 males, 1-12 years old) presenting severe Tityus serrulatus envenomation were prospectively submitted to MPS within 72 h (acute) and 15 days (follow-up) after the event. MPS images were interpreted using a visual semi-quantitative uptake score (0 = normal, 4 = absent). Echocardiography was used for the assessment of left ventricular (LV) ejection fraction (EF) and regional wall motion (WM) by using a semi-quantitative score (0 = normal, 4 = akinesia). A 16-segment LV model was used.


RESULTS
Initial echocardiography showed marked WM abnormalities with a mean score of 31.4+/-13.9, and a reduced EF (36+/-16%). All patients exhibited myocardial perfusion (MP) defects. The mean MP uptake score was 14.6+/-7.8. A significant topographic association between MP and WM changes was obtained (p<0.0001, Fischer exact test). A positive correlation was obtained between the summed WM and MP scores (R=0.68, p=0.016). Follow-up evaluation showed a significant improvement of LVEF (65+/-10%) and WM score (3.9+/-4.2), parallel to the normalization of MP.


CONCLUSIONS
These observations strongly support the participation of transitory myocardial ischemia in the mechanism of the acute cardiac dysfunction caused by severe scorpion envenoming. Micro vascular spasm related to the catecholamine over stimulation may be the pathophysiologic link triggering the myocardial perfusion disturbance in this syndrome.
Cupo
Palmira
P
Pediatrics Division, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil. pcupo@fmrp.usp.br
Figueiredo
Alexandre B
AB
Filho
Antonio P
AP
Pintya
Antonio O
AO
Tavares Júnior
Gerson A
GA
Caligaris
Fábio
F
Marin-Neto
José A
JA
Hering
Sylvia E
SE
Simões
Marcus V
MV
D000208:Acute Disease; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D017202:Myocardial Ischemia / Q000139:chemically induced* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011654:Pulmonary Edema / Q000139:chemically induced / Q000628:therapy; D011877:Radionuclide Imaging; D012604:Scorpion Venoms / Q000506:poisoning*; D001098:Spider Bites / Q000150:complications*; D016896:Treatment Outcome; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy
D012604:Scorpion Venoms