Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

579 results found
Article

Unroofed coronary sinus

An unroofed coronary sinus is a rare variant of atrial septal defect (ASD). The atrial wall between the coronary sinus and left atrium is either partially or completely absent, resulting in a left-to-right shunt. It is associated with persistent left-sided SVC and heterotaxy syndromes. Clinica...
Article

Upper lobe pulmonary venous diversion

Upper lobe pulmonary venous diversion (cephalisation) reflects elevation of left atrial pressure and can occur with pulmonary edema. It produces stag-antler's sign on a frontal chest x-ray. The normal left atrial pressure is 5-10 mmHg. An elevation of left atrial pressure to 10-15 mmHg will res...
Article

Vagoglossopharyngeal neuralgia

Vagoglossopharyngeal neuralgia is an uncommon presentation of glossopharyngeal neuralgia where the typical symptoms of pain are associated with cardiac symptoms including arrhythmias, asystole, and syncope. It is believed to be due to complex interconnections between the nervus intermedius, the...
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Valsalva maneuver

The Valsalva maneuver is the forced expiration of air against a closed airway, resulting in increased intra-abdominal, intrathoracic and pharyngeal pressure. It can be performed against a closed glottis or by one closing the mouth and pinching the nose while forcibly exhaling. It is commonly us...
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Valvular heart disease

Valvular heart diseases, or cardiac valvulopathies, describe any acquired or congenital disease affecting one or more of the four cardiac valves. This is a general index article that classifies cardiac valvulopathies depending on which valve(s) is affected 1. See individual articles for in-dept...
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Vein of Marshall

The vein of Marshall, oblique vein of Marshall or the oblique vein of the left atrium is a small vein that descends on and drains the posterior wall of the left atrium. It drains directly into the coronary sinus at the same end as the great cardiac vein, marking the origin of the sinus. It repr...
Article

Venae cordis minimae

The venae cordis minimae (singular: vena cordis minima), meaning "smallest cardiac veins", also known as thebesian veins (as these are eponymous, they are sometimes capitalized as Thebesian veins) are a small group of valveless myocardial coronary veins within the walls of each of the four cardi...
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Ventricular assist device

Ventricular assist devices (VAD) are a mechanical circulatory support device, which is providing an effective therapy for a significant number of patients with advanced heart failure. There are mostly left VADs, although right VADs are also implanted.  Device elements inflow cannulas  electri...
Article

Ventricular fibrillation

The diagnosis of ventricular fibrillation (VF) refers to a cardiac arrythmia where disorganized electrical activity within the heart causes uncoordinated contraction of the ventricular myocardium. The heart is subsequently unable to pump blood normally to the body, leading to cardiac arrest. VF ...
Article

Ventricular interdependence

Ventricular interdependence (or ventricular coupling) is a phenomenon whereby the function of one ventricle is altered by changes in the filling of the other ventricle. This leads to increase in volume of one ventricle associated with a decreased volume in the opposite ventricle 1. This conditi...
Article

Ventricular septal defect

Ventricular septal defects (VSD) represent defects in the interventricular septum that allow a hemodynamic communication between the right and left ventricles. It typically results in a left-to-right shunt. Epidemiology They represent one of the most common congenital cardiac anomalies and may...
Article

Vulnerable plaque

Vulnerable or high-risk plaque refers to coronary artery atherosclerotic lesions with features associated with future acute coronary events, independent of luminal stenosis. Clinical presentation The relevant clinical sequelae of vulnerable plaque are acute coronary syndromes, which present as...
Article

Walking man sign (chest x-ray)

The walking man sign is seen on a lateral chest radiograph and is a sign of left atrial enlargement. It results from posterior displacement of the left main bronchus such that it no longer overlaps the right bronchus. The left and right bronchus thus appear as an inverted 'V', mimicking the legs...
Article

Wall motion score index (echocardiography)

Calculation of the left ventricular wall motion score index (WMSI) with transthoracic echocardiography allows the semi-quantification of left ventricular ejection fraction (LVEF). Calculation of the LVEF with a WMSI demonstrates stronger agreement with measures obtained by cardiac MRI, the gold ...
Article

Watchman device

Watchman device is a permanent left atrial appendage closure device, which is percutaneously implanted to prevent embolization of thrombus from the appendage into the systemic circulation in cases atrial fibrillation. It is used when there is contraindication to anticoagulation or high risk of l...
Article

Waterston shunt

A Waterston shunt is a form of palliative surgery performed in patients with tetralogy of Fallot prior to the ability to repair the defect. It consists of a shunt formed between the ascending aorta and the right pulmonary artery. This does not relieve the right ventricular outflow obstruction, ...
Article

Wellens syndrome

Wellens syndrome (also referred to as LAD coronary T-wave syndrome) refers to an ECG pattern specific for critical stenosis of the proximal left anterior descending artery. The anomalies described occur in patients with recent anginal chest pain, and do not have chest pain when the ECG is record...
Article

Wells criteria for pulmonary embolism

The Wells criteria for pulmonary embolism is a risk stratification score and clinical decision rule to estimate the probability for acute pulmonary embolism (PE) in patients in which history and examination suggests acute PE is a diagnostic possibility. It provides a pre-test probability which, ...
Article

White coat effect

The white coat effect (WCE), not to be confused with white coat hypertension, is a measure of change that is commonly defined as the difference between in-clinic and out-of-clinic blood pressure readings 1,2.  Alternatively, the white coat effect can be defined as the increase in the arterial b...
Article

Williams syndrome

Williams syndrome (WS) is characterized by some or all of the following features: craniofacial dysmorphism (e.g. elfin facies) oral abnormalities short stature (50% of cases) mild to moderate intellectual disability  supravalvular aortic stenosis 2 pulmonary artery stenosis 3 renal insuff...
Article

Wolff-Parkinson-White syndrome

The Wolff-Parkinson-White syndrome describes paroxysmal tachydysrhythmias in the presence of a specific accessory pathway which allows direct electrical connection between the atria and ventricles, which usually exclusively occurs via the atrioventricular (AV) node. The accessory pathway is usua...

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