ABSTRACT
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.
Subject(s)
Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography , Myocardial Ischemia/diagnostic imaging , Myocardial Perfusion Imaging , Scorpion Stings/complications , Ventricular Dysfunction, Left/diagnostic imaging , Animals , Child , Female , Humans , Male , Myocardial Contraction , Myocardial Ischemia/chemically induced , Prospective Studies , Scorpions , Ventricular Dysfunction, Left/chemically inducedABSTRACT
FUNDAMENTO: O choque cardiogênico e o edema agudo de pulmão são as principais causas de óbito em pacientes com escorpionismo, cujo mecanismo fisiopatológico ainda é controverso. OBJETIVOS: Investigar a correlação entre os distúrbios da perfusão miocárdica e a função contrátil do ventrículo esquerdo, em vítimas de escorpionismo. MÉTODOS: Quinze pacientes submeteram-se à cintilografia de perfusão miocárdica sincronizada com ECG (Gated SPECT), dentro de 72 horas e 15 dias após o acidente escorpiônico. As imagens foram analisadas visualmente por escore semiquantitativo de perfusão (0 = normal, 4 = ausente) e mobilidade (0 = normal, 4 = acinético), utilizando modelo de 17 segmentos. Para cada paciente foram calculados escores somados de perfusão (ESP) e mobilidade (ESM). A fração de ejeção (FEVE) foi calculada por software comercialmente disponível. RESULTADOS: Na avaliação inicial, 12 dos 15 pacientes apresentaram alterações da contratilidade e da perfusão miocárdica. O ESP foi de 12,5 ± 7,3, o ESM de 17,0 ± 12, 8 e a FEVE de 44,6 ± 16,0 por cento. Houve correlação positiva entre o ESP e o ESM (r = 0,68; p = 0,005) e negativa entre o ESP e a FEVE (r = -0,75; p = 0,0021). Os estudos de seguimento mostraram recuperação da contratilidade global (FEVE de 68,9 ± 9,5, p = 0,0002), segmentar (ESM 2,6 ± 3,1, p = 0,0009) e da perfusão (ESP 3,7 ± 3,3, p = 0,0003). A melhora da FEVE correlacionou-se positivamente com a melhora do ESP (r = 0,72; p = 0,0035). CONCLUSÕES: Alterações perfusionais miocárdicas são comuns no envenenamento escorpiônico e correlacionam-se topograficamente com a disfunção contrátil. A recuperação da contratilidade correlaciona-se com a reversibilidade dos defeitos perfusionais. Estes achados sugerem a participação de alterações perfusionais miocárdicas na fisiopatologia desta forma de insuficiência ventricular aguda. (Arq Bras Cardiol 2010;94(4): 444-451)
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 ± 7.3, 17.0 ± 12.8, and 44.6 ± 16.0 percent, 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 ± 9.5, p = 0.0002), segmental contractility (SMS of 2.6 ± 3.1, p = 0.0009) and perfusion (SPS of 3.7 ± 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. (Arq Bras Cardiol 2010;94(4): 418-425)
Subject(s)
Animals , Child , Female , Humans , Male , Spider Bites/complications , Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography , Myocardial Perfusion Imaging , Myocardial Ischemia , Ventricular Dysfunction, Left , Myocardial Contraction , Myocardial Ischemia/chemically induced , Prospective Studies , Scorpions , Ventricular Dysfunction, Left/chemically inducedABSTRACT
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.
Subject(s)
Myocardial Ischemia/chemically induced , Scorpion Venoms/poisoning , Spider Bites/complications , Ventricular Dysfunction, Left/chemically induced , Ventricular Dysfunction, Left/physiopathology , Acute Disease , Child , Child, Preschool , Female , Humans , Infant , Male , Myocardial Ischemia/diagnostic imaging , Prospective Studies , Pulmonary Edema/chemically induced , Pulmonary Edema/therapy , Radionuclide Imaging , Treatment Outcome , Ultrasonography , Ventricular Dysfunction, Left/diagnostic imaging , Ventricular Dysfunction, Left/therapyABSTRACT
Em 17 cardiopatas chagásicos crônicos com disritmia ventricular detectada clínicamente, procedeu-se ao registro eletrocardiográfico contínuo, em três derivaçöes clássicas, durante 15 minutos, em condiçöes padronizadas de repouso, posiçäo supina, fase pós-prandial. A análise das características morfológicas e quantitativas dos distúrbios de ritmo verificadas nesse período permitiu evidenciar que os critérios diagnsoticos de parassistolia ventricular nunca foram completamente atendidos em qualquer dos pacientes estudados pela ausência de relaçöes matemáticas definidas entre os intervalos interectópicos. Entretanto, a presença de intervalo de acoplamento variáveis torna possível a caracterizaçäo de ritmo ventricular parassistólico em 9 casos. Em 4 deles, a concomitância de complexos de fusäo foi considerada suficiente para dar o caráter de provável a esse tipo de disritmia. Em dois pacientes, mais de uma morfologia de origem ventricular exibia comportamento compatível com provável parassistolia múltipla. Säo discutidas as dificuldades inerentes aos métodos de detecçäo de parassistolia ventricular, b aseados em traçados eletrocardiográficos longos. Além disso, especula-se que a possibilidade de esse distúrbio de ritmo ser freqüente na cardiopatia chagásica e depender de mecanismo eletrofisiológico provalvelmente decorrente de automatismo ventricular exacerbado, torna-o potencialmente possível de abordagem terapêutica diferenciada, no contexto do tratamento da cardiopatia chagásica crônica
