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.