Adenosine-induced coronary vasospasm following drug-eluting stent implantation

Torsades de pointes and myocardial infarction following reversal of supraventricular tachycardia with adenosine: a case report

Adenosine is an antiarrhythmic drug that slows conduction through the atrioventricular node and acts as a coronary blood vessel dilator. This case report highlights two unusual life-threatening events following the use of adenosine to revert supraventricular tachycardia in a structurally normal heart: non-sustained polymorphic ventricular tachycardia and myocardial infarction. A 46-year-old woman presented to the emergency department with a two-hour history of palpitations and was diagnosed with supraventricular tachycardia. Vagal maneuvers were ineffective, and after intravenous adenosine administration, the patient presented with chest pain and hypotension. The rhythm degenerated into non-sustained polymorphic ventricular tachycardia and spontaneously reverted to sinus rhythm with ST elevation in lead aVR and ST depression in the inferior and anterolateral leads. The patient spontaneously recovered within a few minutes. Despite successful arrhythmia reversal, the patient was admitted to the intensive care unit because of an infarction without obstructive atherosclerosis. This report aims to alert emergency physicians about the potential complications associated with supraventricular tachycardia and its reversal with adenosine.

Development of elastic artificial vessels with a digital pulse flow system to investigate the risk of restenosis and vasospasm

The postoperative risk of stenosis is a complex issue, with risk factors including the status of human umbilical vein endothelial cells, the shear stress of dynamic blood flow, and blood physiology. Current research would benefit from in vitro models that can mimic the microenvironment of living vessels, to study the response of endothelial cells to stent placement. In this study, we constructed a digital pulse flow system based on a group of programmable solenoid valves, to mimic dynamic blood flows in the left coronary artery. Elastic artificial vessels, with internally cultured endothelial cells, were used to simulate vessel function and physiology. Based on this novel platform, we systematically explored cell proliferation and function in artificial vessels implanted with bare metal stents or drug-eluting stents, using unstented vessels as controls, under static and pulse flow conditions. The results indicate that the natural shear stresses of dynamic blood flow actually benefit endothelial cell attachment and proliferation. And drug-eluting stents showed stronger inhibition of cell proliferation than bare metal stents, but had a more negative effect on the synthesis of nitric oxide synthase (NOS), suggesting that drug elution might reduce the postoperative risk of restenosis, while increasing the risk of vasospasm. The results suggest that stent evaluation should include both the risk of restenosis and the effect on endothelial cells. Our simulation establishes a realistic in vitro model for pathological studies of restenosis and vasospasm, shows potential for evaluation of new stent designs, and could help develop individualised therapies for patients with atherosclerosis.