Cardiac tamponade in Russell viper (Daboia russelii) bite: case report with brief review

Kounis syndrome following an anaphylactic reaction to antivenom in a patient with Russell's viper (Daboia russelii) bite: A case report

Kounis syndrome is the occurrence of acute coronary syndrome associated with mast cell and platelet activation in the setting of allergic or anaphylactic insults. Kounis syndrome has been previously reported following snake envenoming rarely, with or without antivenom therapy. We report a case of inferolateral ST elevation myocardial infarction 32 hours from a confirmed Russell's viper bite. He also had an anaphylactic reaction soon after antivenom. The absence of underlying atheromatous coronary artery disease during subsequent cardiac imaging was suggestive of a diagnosis of a type I variant of Kounis syndrome. Chest pain completely resolved by day 6 following initiation of standard treatment for acute coronary syndrome. Concurrence of allergic features and acute coronary syndrome in a snakebite patient following antivenom therapy should alert clinicians to the possibility of Kounis syndrome, which should be diagnosed with a high degree of clinical suspicion.

Russell's Viper Envenomation-Associated Addisonian Crisis

Snakebite envenomation is an important public health problem in tropical countries. We report a case of bilateral adrenal hemorrhage in a 28-y-old man with Russell's viper bite that occurred in the Sathyamangalam forest range in the Indian state of Tamil Nadu. In this case, a combination of early bite recognition, hospital-based supportive care, corticosteroid therapy, and timely administration of polyvalent antivenom resulted in a favorable clinical outcome.

Reversible atrial fibrillation following Crotalinae envenomation

Background

Cardiotoxicity is a documented complication of Crotalinae envenomation. Reported cardiac complications following snake envenomation have included acute myocardial infarction, electrocardiogram abnormalities and arrhythmias. Few reports exist describing arrhythmia induced by viper envenomation and to our knowledge none describe arrhythmia induced by Crotalinae envenomation. This report concerns the first known case of atrial fibrillation precipitated by rattlesnake bite.

Case presentation

A 73-year-old Caucasian man with a past medical history of hypertension, hyperlipidemia, type 1 diabetes mellitus, and a baseline first-degree atrioventricular block presented to the emergency department following a rattlesnake bite to his left lower leg. He developed pain and swelling in his left leg two-hour post-envenomation and subsequently received four vials of Crotalidae polyvalent immune fab (ovine). At three-hour post-envenomation following transfer to the intensive care unit, an electrocardiogram revealed new-onset atrial fibrillation. An amiodarone drip was started and the patient successfully converted to normal sinus rhythm approximately six hours after he was found to be in atrial fibrillation. A transthoracic echocardiogram revealed mild concentric left ventricular hypertrophy and an ejection fraction of 72%. He was discharged the following day with no hematological abnormalities and a baseline first-degree atrioventricular block.

Conclusion

This is the first documented case of reversible atrial fibrillation precipitated by Crotalinae envenomation. In patients with pertinent risk factors for developing atrial fibrillation, physicians should be aware of the potential for this arrhythmia. Direct toxic effects of venom or structural and electrophysiological cardiovascular abnormalities may predispose snakebite patients to arrhythmia, warranting extended and attentive cardiac monitoring.

A fatal outcome due to pulmonary hemorrhage following Russell's viper bite

Russell's viper (RV) envenomation causes local effects, coagulopathy, thrombosis, rhabdomyolysis, acute kidney injury, and neurological manifestations. Although coagulopathy and endothelial destruction causing local and mucosal surface bleeding is known, isolated severe pulmonary hemorrhage is not commonly reported. We report a previously healthy 18-year-old male who had bilateral severe pulmonary hemorrhages, which resulted in a fatal outcome following RV bite. This diagnosis was supported by persistent alveolar shadows, with minimum improvement despite hemodialysis without heparin, mixed acidosis and endotracheal tube bleeding. Other bleeding manifestations were absent. Polyvalent antivenom was administered in lieu of prolonged whole blood clotting time. Thrombocytopenia and mildly deranged clotting parameters were noted. Pulmonary hemorrhages were significant enough to require transfusion. This case highlights the importance of suspecting pulmonary hemorrhages in patients with alveolar shadows and desaturation following RV bite despite the absence of other bleeding manifestations in light of failure of optimum therapy including hemodialysis.

Sinus node dysfunction complicating viper bite

Viper venom toxicities comprise mainly bleeding disorders and nephrotoxicity. Cardiotoxicity is a rare manifestation of viper bite. We describe the case of a previously healthy 35-year-old man who developed coagulopathy and sinus node dysfunction following a viper bite. Electrocardiography showed sinus arrest and junctional escape rhythm. This is the first account of sinus node dysfunction caused by a viper bite.

Synergistically acting PLA₂: peptide hemorrhagic complex from Daboia russelii venom

Snake venoms are complex mixture of enzymatic and non-enzymatic proteins. Non-covalent protein-protein interaction leads to protein complexes, which bring about enhanced pharmacological injuries by their synergistic action. Here we report identification and characterization of a new Daboia russelii hemorrhagic complex I (DR-HC-I) containing phospholipase A₂ (PLA₂) and non-enzymatic peptide. DR-HC-I was isolated from the venom of D. russelii by CM-Shepadex-C25 and gel permeation chromatography. Individual components were purified and identified by RP-HPL chromatography, mass spectrometry and N-terminal amino acid sequencing. DR-HC-I complex was lethal to mice with the LD₅₀ dose of 0.7 mg/kg body weight with hemorrhagic and neurotoxic properties. DR-HC-I complex consists of non-hemorrhagic PLA₂ and neurotoxic non-enzymatic peptide. The non-enzymatic peptide quenched the intrinsic fluorescence of PLA₂ in a dose dependent manner, signifying the synergistic interaction between two proteins. PLA₂ and peptide toxin in a 5:2 M ratio induced skin hemorrhage in mice with MHD 20 μg. However, addition of ANS (1-Anilino-8-naphthalene sulfonate) to DR-HC-I complex inhibited skin hemorrhagic effect and also synergic interaction. But there was no impact on PLA₂ due to this synergistic interaction, and indirect hemolytic or plasma re-calcification activity. However, the synergistic interaction of PLA₂ and non-enzymatic peptide contributes to the enhanced venom-induced hemorrhage and toxicity of Daboia russellii venom.

Purification, characterization, and chemical modification of neurotoxic peptide from Daboia russelii snake venom of India

Comprehensive knowledge of venom composition is very important for effective management of snake envenomation and antivenom preparation. Daboia russelii venom from the eastern region of India is the most neurotoxic among the four venom samples investigated. From the eastern D. russelii venom sample, neurotoxic peptide has been purified by combined method of ion exchange gel permeation chromatography and reversed phase high performance liquid chromatography. Molecular weight of Daboia neurotoxin III (DNTx-III) found to be 6,849 Da (as measured on matrix-assisted laser desorption/ionisation-time of flight mass spectrometer), and N-terminal amino acid sequences is I K C F I T P D U T S Q A. Approximate LD50 dosage was 0.24 mg/kg body weight. It produced concentration- and time-dependent inhibition of indirectly stimulated twitches of Rana hexadactyla sciatic nerve gastrocnemius muscle preparations. Chemical modification of DNTx-III tryptophan residue(s) reduced the twitch height inhibition property of toxin, signifying the importance of tryptophan residues for the neurotoxic function. This type of neurotoxic peptide is unique to east Indian regional D. russelii venom.

Acute myocardial infarction following a possible direct intravenous bite of Russell's viper (Daboia russelli)

BACKGROUND

Russell's viper (Daboia russelli) bites lead to high morbidity and mortality in South Asia. Although variety of clinical manifestations is reported in viper bite victims, myocardial ischemic events are rare.

CASE PRESENTATION

We report a unique case of inferior wall ST elevation myocardial infarction due to a Russell's viper bite over a vein with possible direct intravenous envenoming, in a young male with no past history or family history suggestive of ischemic cardiac disease, from Sri Lanka. In addition, the possible mechanisms of myocardial ischemia in snake bite victims are also briefly discussed.

CONCLUSION

Importance of the awareness of physicians on the rare, yet fatal manifestations of snake envenoming is highlighted.