Prosthetic valve thrombosis (PVT) is a rare but serious complication of valve replacement, most often encountered with mechanical prostheses. The significant morbidity and mortality associated with this condition warrants rapid diagnostic evaluation. However, diagnosis can be challenging, mainly because of variable clinical presentations and the degree of valvular obstruction. Cinefluoroscopy (for mechanical valves) and transthoracic and transoesophageal echocardiography represent the main diagnostic procedures.

Although surgical treatment is usually preferred in cases of obstructive PVT, optimal treatment remains controversial. The different therapeutic modalities available for PVT (heparin treatment, fibrinolysis, surgery) will be largely influenced by the presence of valvular obstruction, by valve location (left- or right-sided), and by clinical status. Hence, treatment of an obstructive left-sided PVT will differ from that of non-obstructive or right-sided PVT. The purpose of this article is to review the physiopathology, diagnosis and treatment of PVT and to provide recommendations for management.

### Mechanical valve thrombosis

The incidence of obstructive PVT for mechanical valves varies between 0.3–1.3% patient years.1 Thromboembolic complications, including systemic emboli, are more frequent and occur at a rate of 0.7–6% patient years. Non-obstructive PVT is a relatively frequent finding in the postoperative period,2 with a reported incidence as high as 10% in recent transoesophageal echocardiography (TOE) studies. Although these are usually small non-obstructive thrombi, they underline the necessity of optimal anticoagulation in the postoperative period. According to a series of surgical interventions for PVT, the first postoperative year is marked by a 24% incidence of thrombosis, with a stable incidence between the second to fourth years of approximately 15%, with a subsequent decrease thereafter.3

### Bioprosthetic valve thrombosis

Thrombosis of a bioprosthetic valve4 is a rare occurrence when compared to mechanical prostheses. Bioprosthetic PVT is usually diagnosed in the early postoperative period, when endothelialisation of the suture zone is not yet complete. Hence, this has led …

/pdf/thrombosis-of-prosthetic-heart-valves-diagnosis-and-5863rcqm5e.pdf

Thrombosis of prosthetic heart valves: diagnosis and therapeutic considerations

Thin-walled microvessels in human coronary atherosclerotic plaques show incomplete endothelial junctions: relevance of compromised structural integrity for intraplaque microvascular leakage

Primary tumors of the heart are uncommon in the fetus and neonate Nevertheless, the widespread use of new imaging techniques has contributed significantly to earlier diagnosis, treatment, and thus improved survival The clinical findings, imaging studies, pathology, and outcome of 224 fetuses and neonates with cardiac tumors collected from the literature are evaluated and discussed Most tumors are benign, and of these rhabdomyoma is the most common, followed by teratoma, fibroma, oncocytic cardiomyopathy, vascular tumors, and myxoma Malignant and metastatic tumors are described but are rare Murmurs, arrhythmias, cyanosis, respiratory distress, and cardiac failure are the main presenting signs of cardiac tumors in the perinatal period Disturbances in hemodynamic function are correlated with the size and location of the tumor Cardiac vascular tumors have the best outcome, whereas malignant tumors have the worst The purpose of this review is to concentrate on the fetus and neonate in an attempt to determine the various ways cardiac tumors differ clinically and morphologically in this age group from those occurring in older children and adults and to show that certain types of tumors have a better prognosis than others

Fetal and Neonatal Cardiac Tumors

Mathematical and numerical modelling of the cardiovascular system is a research topic that has attracted remarkable interest from the mathematical community because of its intrinsic mathematical difficulty and the increasing impact of cardiovascular diseases worldwide. In this review article we will address the two principal components of the cardiovascular system: arterial circulation and heart function. We will systematically describe all aspects of the problem, ranging from data imaging acquisition, stating the basic physical principles, analysing the associated mathematical models that comprise PDE and ODE systems, proposing sound and efficient numerical methods for their approximation, and simulating both benchmark problems and clinically inspired problems. Mathematical modelling itself imposes tremendous challenges, due to the amazing complexity of the cardiocirculatory system, the multiscale nature of the physiological processes involved, and the need to devise computational methods that are stable, reliable and efficient. Critical issues involve filtering the data, identifying the parameters of mathematical models, devising optimal treatments and accounting for uncertainties. For this reason, we will devote the last part of the paper to control and inverse problems, including parameter estimation, uncertainty quantification and the development of reduced-order models that are of paramount importance when solving problems with high complexity, which would otherwise be out of reach.

The cardiovascular system: Mathematical modelling, numerical algorithms and clinical applications *

Cocaine is the second commonest illicit drug used and the most frequent cause of drug related deaths. Its use is associated with both acute and chronic complications that may involve any system, the most common being the cardiovascular system. Cocaine misuse has a major effect in young adult drug users with resulting loss of productivity and undue morbidity with cocaine related cardiac and cerebrovascular effects. Many cocaine users have little or no idea of the risks associated with its use. Patients, health care professionals, and the public should be educated about the dangers and the considerable risks of cocaine use. This review concentrates on the cardiovascular effects of cocaine and their management.

https://pmj.bmj.com/content/postgradmedj/81/959/568.full.pdf

Cocaine and the heart

https://www.annalsthoracicsurgery.org/article/S0003-4975(01)03588-3/pdf

Dynamic analysis of the aortic valve using a finite element model

https://www.annalsthoracicsurgery.org/article/S0003-4975(03)01518-2/pdf

Further insights into normal aortic valve function: role of a compliant aortic root on leaflet opening and valve orifice area

Objective: To use finite element modelling to look at the impact of lumen shape and vessel geometry on stress distribution in a vessel.

Methods: A finite element model of an atherosclerotic plaque in a coronary artery was created and a non-linear analysis with Ogden strain energy function was done. The three most common shapes seen in an artery with an eccentric plaque—namely an elliptical lumen inside a circular vessel (A), a circular lumen inside an elliptical vessel, typical of a vessel with positive remodelling (B), and a circular lumen inside a circular vessel (C)—were modelled with and without lipid. Stress was analysed in the region of the fibrous cap separating the lumen from the plaque and the region of maximum stress along the circumference of the lumen was noted.

Results: In a normal circular shaped coronary artery, the haemodynamic stresses were uniformly distributed all around the circle. However, if the circle was changed to an ellipse, the stresses were redistributed along the major axis and dropped substantially along the minor axis. The stresses in a positively remodelled vessel (B) were significantly greater than in A and C, by almost 100%. Moreover, the haemodynamic stresses increased significantly towards the major axis or the shoulder in A and B, due to lumen shape and vessel geometry alone, even in the absence of lipid in the model. The stresses also had a direct relation with the thickness of the lipid pool and an inverse relation with cap thickness and lumen stenosis.

Conclusions: The increased vulnerability of the shoulder region of a plaque and a remodelled coronary artery are due, apart from other factors, to increased biomechanical stresses as a result of lumen shape and vessel geometry.

https://heart.bmj.com/content/heartjnl/91/11/1459.full.pdf

Influence of lumen shape and vessel geometry on plaque stresses: possible role in the increased vulnerability of a remodelled vessel and the “shoulder” of a plaque

Blunt abdominal trauma resulting in urinothorax from a missed uretero-pelvic junction avulsion: case report.

A 60-year-old man with triple-vessel coronary artery disease was admitted for coronary artery bypass grafting. An endarterectomy of the left anterior descending coronary artery was needed to achieve revascularization. The endarterectomized plaque was subjected to light and electron microscopic examination, including immunohistochemistry for smooth muscle actin and macrophage marker CD 68. The images (Figure 1 through Figure …

Komarakshi R. Balakrishnan

Papers

Dynamic analysis of the aortic valve using a finite element model

Further insights into normal aortic valve function: role of a compliant aortic root on leaflet opening and valve orifice area

Influence of lumen shape and vessel geometry on plaque stresses: possible role in the increased vulnerability of a remodelled vessel and the “shoulder” of a plaque

Blunt abdominal trauma resulting in urinothorax from a missed uretero-pelvic junction avulsion: case report.

Role of Inflammation in Atherosclerosis Immunohistochemical and Electron Microscopic Images of a Coronary Endarterectomy Specimen