Acute Coronary and Acute Aortic Syndromes

Extrinsic compression of coronary and pulmonary vasculature

Coronary artery disease from atherosclerosis induced stenosis remains the leading cause of acute coronary syndrome (ACS) and death worldwide, however extrinsic compression of coronary arteries from adjacent anatomical and pathological structures is an infrequent but important diagnosis to be aware of, especially given the nonspecific symptoms of chest pain that mimic angina in patients with pulmonary hypertension (PHT) and congenital heart disease. Non-invasive CT angiography is an invaluable diagnostic tool for detection of coronary artery compression, pulmonary artery dilatation and pulmonary vascular compression. Although established guidelines are not available for management of left main coronary artery (LMCA) compression syndrome, percutaneous coronary intervention and stent implantation remain a feasible option for the treatment, specifically for patients with a high surgical risk. Treatment of pulmonary vein or artery compression is more varied and determined by etiology. This review article is focused on detailed discussion of extrinsic compression of coronary arteries, mainly the LMCA and brief discussion on pulmonary vasculature compression by surrounding anatomical and pathological entities, with focus on pathophysiology, clinical features, complications and role of imaging in its diagnosis and management.

[Sudden chest pain and lower abdominal pain : The usual suspects]

CLINICAL PROBLEM

Sudden chest pain and sudden abdominal pain are among the most common reasons that lead patients to the emergency room. The heterogeneous field of possible, sometimes serious diagnoses requires a structured and rapid interdisciplinary clarification in order to be able to promptly provide patients with an adequate therapy.

STANDARD RADIOLOGICAL PROCEDURES

Knowing the "usual suspects" of sudden chest and abdominal pain enables the radiologist to quickly select the appropriate imaging method that allows a diagnosis to be made without delay. In addition to pain localization and character, age, gender, any previous illnesses and laboratory results are taken into account in the differential diagnosis.

METHODICAL INNOVATION AND EVALUATION

The technical state of computer tomography (CT) now ensures that most diagnoses can be clarified due to its excellent spatial and temporal resolution. In the abdomen, however, ultrasound should continue to be used at least for primary evaluation. Only if there is a further need for abdominal imaging afterwards is CT indicated for clarification. Magnetic resonance imaging is rarely used in the emergency setting of abdominal pain except to avoid radiation exposure in children or pregnant women.

RECOMMENDATION FOR THE PRACTICE

Knowledge of the usual diagnoses that cause sudden chest or abdominal pain, as well as knowledge of the appropriate examination procedures and classic radiological signs are essential to avoid errors and delays in the emergency diagnosis of sudden chest and abdominal pain.

Detailed structural assessment of healthy interventricular septum in the presence of remodeling infarct in the free wall - A finite element model

Purpose

Computational modelling may improve the fundamental understanding of various mechanisms of diseases more particularly related to clinical challenges. In this study the effect of remodeling infarct presence in the left ventricle on the interventricular septal wall is studied using the finite element methods.

Methods

In this study, two rat heart (one model with healthy myocardium and one model with remodeling free wall and healthy septal wall) with magnetic resonance imaging data was gathered to reconstruct three-dimensional (3D) rat heart models. 3D data points from Segment® were imported into SolidEdge® for creation of 3D rat heart models. Abaqus® was used for finite element modeling.

Results

The strain in the healthy interventricular septum of the infarcted left ventricle wall increased when compared to the healthy interventricular septum in the healthy left ventricle. Similarly, the average stress in the healthy left ventricle was observed to have increased on the healthy the interventricular septum where the free wall is subjected to remodeling infarct. When comparing the infarcted models to the healthy model, it was found that the average strain had greatly increased by up to 50.0 %.

Conclusions

The remodeling infarct in the left ventricle has an impact on the healthy interventricular septal wall. Even though the interventricular septal wall was modelled as healthy, it was observed that it has undergone considerable changes in stresses and strains in circumferential and longitudinal direction. The observed changes in myocardial stresses and strains may result in poor global functioning of the heart.