Vulnerable plaques, inflammation and newer imaging modalities.

Currently, inflammation is considered to be the central player in the pathogenesis of atherosclerosis. It leads to the formation of multiple plaques in the arterial beds including coronary vasculature. Recent studies using the latest imaging techniques have shown that in patients with acute coronary syndromes (ACS) multiple plaques are ruptured and have thrombus formation on them. Various factors make these plaques unstable, these include structural components of plaque like thin fibrous cap, high lipid content of the plaque core and inflammation, both localized and generalized. It has been shown that most of the ACS are caused by plaques causing non-critical stenosis as seen on traditional X-ray angiography. Also, the phenomenon of remodelling makes angiography a poor technique for plaque visualization. Hence newer modalities are required to identify these "vulnerable plaques". Intravascular ultrasound (IVUS), thermography and Magnetic Resonance Imaging (MRI) are a few such promising techniques. Here we review the invasive and non-invasive modalities that can be helpful in the identification of these plaques before they become unstable and cause ACS, and also the available therapies to stabilize these plaques.

Brain natriuretic peptide in diagnosis and treatment of heart failure.

Currently we are in the midst of a chronic disease epidemic of congestive heart failure (CHF) worldwide. This epidemic is marked by a rapid rise in prevalent cases over the past decade that is due in part to the aging population and improved survival in patients with other cardiovascular conditions. At present there are 5 million Americans with congestive heart failure, with nearly 500000 new cases every year. To provide cost-effective treatment for patients with congestive heart failure, rapid and accurate differentiation of congestive heart failure from other causes of dyspnea must be accomplished. Although echocardiography is considered the gold standard for the detection of left ventricular dysfunction, it is expensive, is not always easily accessible, and may not always reflect an acute condition. B-type natriuretic peptide (BNP) is a cardiac neurohormone specifically secreted from the cardiac ventricles as a response to ventricular volume expansion, pressure overload, and resultant increased wall tension. BNP can be used in the diagnosis of CHF. However, the present American College of Cardiology/American Heart Association practice guidelines (2001) for the evaluation and management of CHF state that the role of blood BNP in the identification of patients with CHF remains to be fully clarified. We have discussed the role of BNP in the diagnosis and management of CHF.