Prescription Medications

Heart Attack Damage Control

Background: A heart attack is not a simple event. It involves anoccluded (blocked) blood vessel or vessels in the heart muscle. Thisblockage results in oxygen deprivation which in turn stimulates the productionof a protein called vascular endothelial growth factor (VEGF). In the longrun, VEGF production is good because it promotes the growth of new blood vesselsthat can makea detouraround the blockagebut in the short run,VEGF causes vessels to leak andthat results in fluid buildup and tissuedamagein the heart muscle.

Study: Research in mice demonstrated that it is possible to limit theleaky effect of VEGF by blocking an enzyme called Src kinase. (The article inthe Journal of Clinical Investigation poetically referred to Src as a"myocardial shark"). Mice genetically deficient in Src or normal micetreated with pharmacological Src inhibitors showed minimal vascularpermeability, edema and platelet microthrombi following a heart attack. Thesemice exhibited not only dramatically reduced infarct volume early on, but also adecrease in fibrosis and mortality months after the injury. Importantly, asingle dose of an Src inhibitor given up to 6 hours after injury still providedcardiac protection.

Comment: All of this suggests that care must be exercised in the clinicaluse of VEGF to promote the growth of new blood vessels in the heart. And it alsosuggeststhat blockading Src may reduce tissue injury followingaheart attackand perhaps after similar events elsewhere in the body.Nowto go from mice to men.

Barbara K. Hecht,Ph.D.
Frederick Hecht, M.D.
Medical Editors, MedicineNet.com

Related Links

• VEGF
• Angiogenesis
• Heart Attack Warning Signs
• Heart Attack Symptoms - Different In Women!
• Heart Attack Pathology (interactive graphics showing clogged arteries)
• Heart Attack (main article)

Heart Attack Therapy Prevents Long-Term Damage

MONDAY, March 15 (HealthDayNews) -- A new way to treat heart attacks, aimed at inhibiting the leakage of fluid from the blood vessels of the heart, may prevent long-term damage and save more lives, a new study finds.