Mosche Gueron

The cardiovascular system after scorpion envenomation. A review

Scorpion envenomation is a common medical problem and life hazard in many countries of the world. Scientific investigations have addressed the interrelationship between the stimulatory effects of the venom on the autonomic nervous system and adrenals and the subsequent effects of released transmitters on the cardiovascular system. A number of clinical cardiovascular syndromes may dominate the initial clinical presentation after envenomation: the syndromes usually vary with the age of the victim, the size of the offender and the season. Central nervous system dysfunction is seen in children but rarely observed in adults; if accompanied by severe hypertension the clinical picture is consistent with acute hypertensive encephalopathy. Heart failure, pulmonary edema or a shock-like syndrome has been observed in 25% and hypertension in 30% to 77% of our patients. The electrocardiographic abnormalities recorded in the majority of the patients after envenomation include an acute myocardial infarction-like pattern. Rhythm disturbances are frequent but conduction abnormalities are rare. Echocardiographic, radionuclide and experimental hemodynamic observations have provided evidence that heart failure and pulmonary edema after envenomation are multifactorial with diminished systolic performance following the initially increased left ventricular contractility and decreased ventricular diastolic compliance. Clinical laboratory data reporting increased catecholamine metabolite excretion and elevated plasma renin and aldosterone are consistent with the stimulatory effects of the venom on the autonomic nervous system. Treatment, including our experience with vasodilators and calcium channel blockers, is reviewed.

Respiratory failure in children following envenomation by the scorpion Leiurus quinquestriatus: Hemodynamic and neurological aspects

Nine children, hospitalized for severe respiratory failure following scorpion envenomation, were a part of a group of 61 youngsters and infants admitted to the Pediatric Intensive Care Unit of the Soroka Medical Center, Beer-Sheva during the years 1983-87 because of scorpion venom intoxication. Four out of the nine had cardiogenic shock, three had severe systemic hypertension and one had severe airway obstruction. All nine patients had central nervous system manifestations, including lethargy, confusion and agitation (three cases), and markedly reduced level of consciousness (six cases). Hemodynamic studies performed in two patients showed high pressure (cardiogenic) pulmonary edema. Seven patients recovered completely, one died and another one was left severely handicapped. Hydralazine i.v. showed a remarkable effect on the systemic blood pressure and central nervous system disturbances in addition to mechanical ventilation. Based on our own experience and previous clinical and experimental studies, the possible pathogenetic mechanisms underlying the respiratory and central nervous system dysfunction following scorpion sting are discussed.

Interleukin-6 release following scorpion sting in children

Interleukin-6 levels were measured in the serum of ten children following severe scorpion envenomation. Measurements were taken on arrival, at the emergency room, and 12 and 24 hr after arrival. Interleukin-6 was markedly elevated in the serum of eight out of ten children on arrival. Interleukin-6 levels gradually decreased toward normal values on 12 and 24 hr measurements, but remained above control levels on all measurements. These results imply that signs and symptoms following scorpion envenomation may in part be explained by release of cytokines. Human and experimental animal studies are required in order to verify the assumption that interleukin-6 and other cytokines are involved in the pathogenesis of scorpion envenomation.

Acute pancreatitis in children following envenomation by the yellow scorpion Leiurus quinquestriatus

Plasma immunoreactive cationic trypsin (ICT), which is a specific and highly sensitive indicator of pancreatic injury, was measured in 14 children with signs of systemic envenomation following a sting by the scorpion Leiurus quinquestriatus. High ICT levels were found in 13 children (93%), indicating that acute pancreatitis is a common complication of envenomation by this scorpion. The pancreatitis may account for the abdominal pain and vomiting commonly seen in scorpion envenomation and may also contribute to the agitation and discomfort noted in young children.

Myocardial injury without heart failure following envenomation by the scorpion Leiurus quinquestriatus in children

The enzymatic activity of creatine kinase-MB isoenzyme (CK-MB), a sensitive and specific marker of myocardial damage, was measured in 32 children following scorpion envenomation. CK-MB activity, total creatine phosphokinase (CPK) and serum glutamine oxalacetic transaminase (SGOT) levels were examined for relationship with electrocardiographic (ECG) results and the clinical state of the children. Twenty-seven out of the 32 children had signs of systemic intoxication (symptomatic cases), while the other five children had only local signs (asymptomatic cases). Thirteen out of the 27 symptomatic children had enzymatic myocardial involvement characterized by high total CPK level, elevated CK-MB level and a CK-MB/CK ratio exceeding 6%. Six of these 13 children had ECG changes consistent with myocardial damage, and only one child had clinical signs of myocardial injury. None of the asymptomatic children, nor five healthy control children, had any evidence of myocardial damage as judged by CK-MB levels, clinical signs and ECG. Our study suggests that CK-MB activity is specific and highly sensitive in detecting myocardial damage in children following scorpion envenomation, and appears superior to ECG and clinical parameters. We speculate that the myocardial lesions are too small to cause heart failure in most cases, but they may account for the cardiovascular changes frequently seen in scorpion envenomation.

Left anterior descending artery length in left and right coronary artery dominance

BackgroundCoronary stenosis of the left anterior descending artery (LAD) is respected by cardiologists because of its negative influence on morbidity and mortality. An important anatomical consideration is the length of the LAD. ObjectiveTo investigate the relationship between length of LAD and coronary dominance. DesignRetrospective comparison of 100 consecutive angiograms with left coronary dominance with 100 consecutive angiograms with right coronary dominance. The relationship between the length of the LAD and coronary dominance was analyzed. MethodsWe retrospectively compared 100 consecutive angiograms with left coronary dominance (the posterior descending artery being supplied by the circumflex artery) with 100 consecutive angiograms with right coronary dominance (the posterior descending artery being supplied by the right coronary artery). LADs were categorized into three types: type A, LAD terminating before the cardiac apex; type B, LAD reaching the apex but not supplying the inferoapical segment of the left ventricle; and type C, LAD wrapping around the apex and supplying the inferoapical segment. LAD typing was also analyzed in relation to gender. ResultsIt was found that the LAD wrapped around the apex in 87% of cases of left coronary dominance but only in 47% of patients with right coronary dominance, and that the long LADs were more frequently seen in women than in men, irrespective of coronary dominance. ConclusionsWe found that the LAD in left coronary dominance is usually long and wraps around the apex, and believe that angiographic interventions in such cases have important clinical significance.

Left ventricular performance in patients with atrial septal defect: evaluation with noninvasive methods.

Eighteen patients with an atrial septal defect (Group I) and 45 patients whose defect had been repaired (Group II) were studied with echocardiography and systolic time Intervals. All patients In Group I had an increased right ventricular diameter (mean 24.5 mm/m2) that showed a direct linear relation to the size of the shunt (Qp/Qs ratio). In Group II the right ventricular diameter was significantly smaller (mean 15.6 mm/m2) (P < 0.001). The left ventricular diameter measured less than the mean normal value in 13 of the 18 patients in Group I (mean 23.2 mm/m2) and was significantly larger in the 45 in Group II (mean 27.7 mm/m2) (P < 0.001). n nComparison of systolic time intervals in Groups I and II showed that patients in the former group had shorter mean left ventricular ejection time index (LVETI) (407.9 versus 420.8 msec, P < 0.05), a longer mean preejection period index (PEPI) (140.9 versus 126.7 msec, P < 0.001) and a higher mean ratio of preejection period to ejection time (PEP/LVET) (0.39 versus 0.33, P < 0.001). A direct linear relation existed between both the preejection period index and the PEP/LVET ratio and the size of the shunt (Qp/Qs) in Group I. In three patients the abnormal systolic time intervals were consistent with mildly diminished left ventricular performance preoperatively but promptly returned to normal postoperatively. However, echocardiographic assessment revealed that left ventricular wall contractility was normal or hyperdynamic in all cases. n nThe mildly diminished overall left ventricular performance as shown by systolic time intervals appears to be related to the volume overload of the right ventricle and to the concomitantly diminished volume of the left ventricle rather than to any impairment of myocardial contractility. After closure of the defect the size of the ventricle and its performance return to normal.

Atypical ventricular tachycardia and alternating Osborn waves induced by spontaneous mild hypothermia

SummaryA one-month-old infant developed atypical ventricular tachycardia, complete right bundle branch black, and alternating 2:1 Osborn waves during spontaneous mild hypothermia; 10 h after rewarming, the electrocardiogram was normal.

Viral myocarditis simulating dilated cardiomyopathy in early childhood: evaluation by serial echocardiography.

Left ventricular dimensions and function were assessed by serial M mode and cross sectional echocardiography in ten infants and young children with heart muscle disease characterised by left ventricular dilatation and impaired systolic function presenting in congestive heart failure, severe respiratory distress, or both. The patients were followed for 8-60 months after their initial admission. The aetiology was probably viral in all cases. One patient died three weeks after diagnosis. Left ventricular size and function returned to normal in only one child; however, various degrees of improvement were found in seven others who were symptom free at follow up. This study demonstrates that serial echocardiography adequately defines this disease in infants and young children and that invasive evaluation is seldom required. Furthermore, it emphasises the fact that even in symptom free children an echocardiographic picture that is indistinguishable from dilated cardiomyopathy may persist; such patients required continued follow up.

Anomalous origin of the left main coronary artery from the ascending aorta above the "non-facing" sinus of Valsalva

We describe a patient with an unusual coronary anatomic variant in which the main stem of the left coronary artery originates from the ascending aorta just above the “non-facing” aortic sinus of Valsalva.