Microvascular obstruction (MVO), also known as no reflow phenomenon, is an established complication encountered in coronary angioplasty for prolonged acute myocardial infarction.
The phenomenon results from obstruction of the myocardial microcirculation, which is composed of vessel...
Coronary MR angiography (coronary MRA) is a developing approach to imaging the coronary arteries.
Advantages of coronary MRA include avoidance of the intravenous iodinated contrast and ionizing radiation used in coronary CT angiography and conventional angiography.
A disadvantage of coronary M...
The coronary sinus is the major coronary vein. It returns the majority of the left ventricular blood flow to the right atrium.
The coronary sinus courses along the posterior wall of the left atrium into the left atrioventricular groove. It normally drains into the right atrium. T...
The coronary veins return deoxygenated blood from the myocardium back to the right atrium. Most venous blood returns via the coronary sinus. Coronary venous anatomy is highly variable, but is generally comprised of 3 groups of veins:
cardiac veins which drain into the coronary sinus:
A coumadin ridge, also called warfarin ridge or left lateral ridge, is a band-like embryological remnant in the left atrium between the left superior pulmonary vein and the left atrial appendage. It is considered an anatomical variant.
The ridge is formed by the coalition of the left superior ...
The crista terminalis is a smooth muscular ridge in the superior aspect of right atrium. It represents the junction between the sinus venosus and the heart. It divides the pectinate muscle origin and the right atrial appendages in the right atrium.
Its identification is significant in the deter...
Chest CT is a computed tomography examination of the thoracic cavity performed for a variety of reasons, from suspected cancer to penetrating chest trauma.
A CT chest can be performed with or without IV contrast and when IV contrast is given, the timing of the contrast delivery can make a massi...
A number of entities can present as cyanotic congenital heart disease. These can be divided into those with increased or decreased pulmonary vascularity (pulmonary plethora):
increased pulmonary vascularity
total anomalous pulmonary venous return (TAPVR) (types I and II)
transposition of the ...
D-SPECT represents the next step in the evolution of SPECT technology and is based on a unique acquisition geometry. It has nine arrays of cadmium zinc telluride (CZT) detectors, each of which rotates around its central axis with programmable angular rotation 1. The detectors are very compact al...
Deductive echocardiography is a step-by-step approach in diagnosing and differentiating congenital heart disease.
position of heart
Delayed myocardial enhancement, as seen on cardiac MRI, occurs when gadolinium contrast material seeps into fibrotic or necrotic myocardial tissue. It is due to a number of aetiologies, and has variable appearances.
subendocardial enhancement indicates an ischaemic aetiology
Delayed myocardial enhancement can occur in cardiac MR assessment due to a number of causes.
myocardial ischaemia: typically subendocardial and follows a vascular territory 1
nonischaemic dilated cardiomyopathy
Atrial situs refers to the relative position of cardiac atria in relation to abdominal viscera and the midline.
Identification of atrial situs is an important initial step in the antenatal and postnatal diagnosis of cardiac structural and situs anomalies.
Dextrocardia is a congenital cardiac malrotation in which the heart is situated on the right side of the body (dextroversion) with the apex pointing to the right.
Dextrocardia is believed to occur in approximately 1 in 12,000 people 2.
There are two main types of dextr...
Diagonal branches of the left anterior descending coronary artery supply blood flow to the anterior and anterolateral walls of the left ventricle.
Diastolic pseudogating appears as periodic bright and dark signal in arteries such as the aorta as one progresses through a series of images. Synchronization of the cardiac cycle and the pulse sequence results in high signal in the artery during diastole when blood is relatively stationary and l...
A small cardiothoracic ratio (CTR) as defined as <42%/0.42 when assessed on a PA chest radiograph, and can be due to number of entities:
adrenal insufficiency, e.g. Addison disease
asthmatic paroxysm ...
Dilated cardiomyopathy (DCM) is defined as left ventricular chamber dilation with decreased systolic function (FEVG <40%). There may also be right ventricular dysfunction. Causes are related to intrinsic myocardial damage.
There are dilated, thin-walled, poorly contracting ventricles...
Double-density sign is seen on frontal chest radiograph in the presence of left atrial enlargement, and occurs when the right side of the left atrium pushes behind the right cardiac shadow, indenting the adjacent lung and forming its own distinct silhouette 1-3.
If large enough, the left atriu...
The double density sign, also sometimes clumsily referred to as the hotter spot within hot area sign, is a bone scan sign of an osteoid osteoma.
It refers to a central focus of intense uptake (the nidus) within a surrounding lower, but nonetheless increased uptake, rim.
Double oblique is a type of multiplanar reconstruction used in cardiac cross-sectional imaging. It is useful for an accurate assessment of the ascending aorta and aortic annulus, and is particularly useful for pre- and post-procedure evaluation of a transcatheter aortic valve replacement (TAVR)....
Double outlet left ventricle (DOLV) is an extremely rare congenital cardiac anomaly where both the aorta and pulmonary trunk arise from the anatomical left ventricle. It is usually classified as a conotruncal anomaly and is often associated with a ventricular septal defect with normal continuity...
Double outlet right ventricle (DORV) is a congenital cardiac anomaly where both the aorta and pulmonary trunk arise from the morphologically right ventricle. It is reported to account for ~2% of congenital cardiac defects 1. It is usually classed as a conotruncal anomaly. There is almost always ...
The double switch procedure is a surgical technique used to repair congenitally corrected transposition of the great arteries (L-TGA), which is a cardiovascular anomaly with atrioventricular and ventriculoarterial discordance.
The procedure consists of any of the following surgical combinations...
Down syndrome (or trisomy 21) is the most common trisomy and also the commonest chromosomal disorder. It is a major cause of intellectual disability, and also has numerous multi-system manifestations.
According to the world health organisation (WHO), the approximate worldwide inci...
Dressler syndrome (DS) is a delayed immune-mediated or secondary pericarditis developing weeks to months after a myocardial infarction (MI).
Dressler syndrome is not to be confused with pericarditis epistenocardica (which is seen earlier in the post-MI period) and is considered a r...
Drug and toxin induced pulmonary hypertension is one of the causes of pulmonary arterial hypertension. It falls under group 1.3 under the Dana point classification system of pulmonary hypertension.
A wide range of difference drugs have been associated with developing pulmonary hyper...
The ductus arteriosum (or arteriosus) is the thick short conduit for blood to bypass the non-ventilated lungs in the fetus. It is located between and connects the proximal left pulmonary artery and the undersurface of the aortic arch distal to the origin of the last branch of the arch, at the ao...
The Duke criteria are a set of clinical criteria set forward for the diagnosis of infective endocarditis
For diagnosis the requirement is:
2 major and 1 minor criteria or
1 major and 3 minor criteria or
5 minor criteria
positive blood cultures for infective endocarditis
Dysphagia megalatriensis, also known as cardiovascular dysphagia or cardiac dysphagia, is an impairment of swallowing due to oesophageal compression from a dilated left atrium.
Presentation is generally with mild dysphagia, although a minority of patients will have dysph...
The earth-heart sign is a newly recognised sign of cardiac compromise that may be seen on chest radiographs of patients with tension pneumomediastinum.
The substantial pressure exerted on the heart by the air trapped in mediastinum with subsequent impairment of central venous return and obstruc...
Ebstein anomaly is an uncommon congenital cardiac anomaly, characterised by a variable developmental anomaly of the tricuspid valve.
The anomaly accounts for only ~0.5% of congenital cardiac defects 6-7, although it is the most common cause of congenital tricuspid regurgitation. T...
Echogenic intracardiac focus (EIF) is a relatively common sonographic observation that may be present on an antenatal ultrasound scan.
They are thought to be present in ~4-5% of karyotypically normal fetuses. They may be more common in the Asian population 5.
Ectopia cordis is an extremely rare congenital malformation where the heart is located partially or totally outside the thoracic cavity. The four main ectopic positions are::
adjacent to the thorax: ~60 %
The estimated ...
Egg-on-a-string sign, also referred as egg on its side, refers to the cardiomediastinal silhouette seen in transposition of the great arteries (TGA).
The heart appears globular due to an abnormal convexity of the right atrial border and left atrial enlargement and therefore appears like an egg...
Eisenmenger complex is a specific subset of Eisenmenger syndrome, and consists of:
ventricular septal defect (VSD)
severe pulmonary arterial hypertension resulting in
shunt reversal and cyanosis
The Elliott et al classification system of cardiomyopathies is one of the cardiomyopathy classification systems. This was published by the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases. This places emphasis on phenotypic classification 1-2.
Endocardial fibroelastosis (EFE) is a rare cardiac condition which is classically described in the paediatric population (typically first two years). It is one of the causes for infants to present with unexplained heart failure.
The condition results from increasing amounts of fibro...
An enlarged/dilated azygos vein may result from a number of physiological as well as pathological causes. The enlarged azygos vein may be seen as a widened right paratracheal/paraspinal stripe on a frontal chest radiograph.
Causes for dilatation
There are a number of physiological causes for e...
The differential of an enlarged pulmonary trunk/main pulmonary artery on chest radiography includes:
may appear prominent in young patients especially women
rotation of the heart
left lower lobe collapse
pulmonary arterial hyp...
Eosinophilic endocarditis (or Loeffler endocarditis) is one of the cardiac manifestations of idiopathic hypereosinophilic syndrome. It also considered a form of cardiomyopathy.
It has a variable prognosis but can sometimes be fatal 4.
History and etymology
It is named after Wilhelm...
Epicardial (pericardial) fat pads are normal structures that lie in the cardiophrenic, more so on the right. Unsurprisingly, they are more prominent in obese patients.
They can be affected by fat necrosis (see: epipericardial fat necrosis).
Epicardial lipomatosis or epicaridal lipomatous hypertrophy is a form of cardiac lipomatosis and is characterised by accumulation of non-encapsulated mature adipose tissue in the epicardial space due to hyperplasia of lipocytes. Its exact aetiology is not well known, but it may be associated wit...
Epicardial pacing wires allow rapid commencement of atrial and/or ventricular pacing in the event of a perioperative cardiac arrhythmia that has the potential to cause significant haemodynamic compromise.
They are usually inserted during open heart surgery, and especially in those with congenit...
The Eustachian valve (also known as the "valve of the inferior vena cava") is a ridge of variable thickness in the inferior right atrium. It is a remnant of a fetal structure that directed incoming oxygenated blood to the foramen ovale and away from the right atrium.
Incomplete regression of ...
Fetal atrial fibrillation is a type of fetal tachyarrhythmia and usually has atrial rate of 400 beat per minute and a completely irregular ventricular rhythm.
Antanatal ultrasound - echocardiography
The artial contractions are usually too faint to be detected by M Mode ...
Fetal atrial flutter is the second most common fetal tachyarrhythmia and can account for up to 30% of such cases 1-2.
As with other tachyarrthymias it is often detected in the 3rd trimester.
It has a typical atrial rate of 300-600 beats per minute (bpm)...
Fetal bradyarrhythmia refers to an abnormally low fetal heart rate (less than 100-110 beats per minute 3,7) as well as being irregular, i.e. irregular fetal bradycardia.
A fetal bradyarrhythmia can fall in to several types which include
fetal partial atrioventricular block (PAVB)
Fetal bradycardia refers to an abnormally low fetal heart rate, a potentially ominous finding. A sustained first trimester heart rate below 100 beats per minute (bpm) is generally considered bradycardic. The average fetal heart rate changes during pregnancy, however, and some consider the lower ...
Fetal cardiac tumours refer to primary cardiac tumours that can present in the in utero population.
Fetal cardiac tumours are rare; the prevalence, reported from autopsy studies of patients of all ages, varies from 0.0017-0.28 % 2.
Known cardiac tumour types that pres...
Fetal cardio-thoracic (C/T) circumference ratio is parameter than can be used in assessment of fetal cardiac and thoracic/chest wall anomalies. It is essentially the ratio of the cardiac circumference of the thoracic circumference and may be easily measured on ultrasound/fetal echocardiography. ...
Fetal cardiomegaly (FC) essentially refers to an enlarged fetal heart. It is variably defined with some sources stating the cut off as a fetal cardio-thoracic circumference above two standard deviations 7.
It can arise from a number of situations which include
congenital cardiac an...
Fetal cardiomyopathy refers to a very rare situation where a cardiomyopathy occurs in utero. It is often a diagnosis of exclusion where by definition there is an absence of an underlying congenital cardiac morphological anomaly.
The estimated incidence is variable with the high en...
Fetal congenital complete heart block (CAVB) is a rare cardiac conduction abnormality which is associated with high morbidity and mortality. It is considered the commonest of fetal bradyarrhymias.
The estimated prevalence of complete heart block in newborns is at ~1 in 20,000.
A standard fetal echocardiogram consists of several specific views which can be obtained to optimise visualisation of different structures and anomalies. They include:
abdominal situs view
four chamber view
left ventricular outflow tract view (or a five-chamber view)
Fetal pericardial effusions (FPE) occur when there is an accumulation of pericardial fluid in utero. In order to be considered as abnormal, is it generally accepted that the pericardial fluid thickness should be greater than 2 mm.
The estimated incidence is at ~ 2% of pregnancies ...
Fetal pericardial teratomas are rare pericardial teratomas that present in utero. They are an uncommon primary cardiac tumour occurring in a fetus.
It is a type of germ cell tumour and arises from multipotential cells derived from all three germinal layers. In contrast to ovarian ter...
Fetal premature atrial contractions (FPAC's) are a type of extrasystoles that can be occasionally detected in fetal heart monitoring. They along with fetal premature ventricular contractions (PVC's) account for the majority of in utero rhythm disturbances 3.
They may arise from...
Fetal premature ventricular contractions (FPVC) are a type ectopic ventricular contractions detected in utero. They are a type of extrasystoles.
Premature ventricular contractions are often followed by a compensatory pause due to the refractory state of the conduction system; the next conducted...
Fetal right ventricular (RV) enlargement is an infrequently encountered situation in antenatal imaging.
The right ventricle is a dominant ventricle in in utero life. RV enlargement can occur with a number cardiac as well as non cardiac anomalies
hypoplastic left heart syndr...
A fetal sinus bradycardia is a sub type of fetal bradycardia where the fetal heart rate is abnormally slow ( less than 100 beat per minute) but runs at the regular rate with sinus rhythm.
congenital long QT syndrome 1
maternal anti Ro antibodies 2-3
Fetal supraventricular tachycardia (SVT) is considered the most common type of fetal tachyarrhythmia and can accounts for 60-90% of such cases.
It has a typical ventricular rate of ~230-280 beats per minute (bpm) 1 and isoften associated with an accessory AV conduction pathway....
Fetal tachyarrhythmia refers to an irregular increase in fetal heart rate.
Depending on its exact definition, the prevalance rate is thought to be around 0.5-1% of pregnancies.
Many cases tend to be discovered in the 3rd trimester.
Fetal tachycardia is an abnormal increase in the fetal heart rate. It is variably defined as a heart rate above 160-180 beats per minute (bpm) and typically ranges between 170-220 bpm (higher rates can occur with tachyarrhythmias).
The estimated prevalence is ~0.4-1% of pregnancie...
The following lesions may resemble a figure of eight (sometimes referred to as snowman shaped):
supracardiac variety of total anomalous pulmonary venous return 1
pituitary macroadenoma with suprasellar extension 2
intraspinal neurofibroma with extraspinal extension through neural foramina
The Fontan procedure is a repair surgical strategy for congenital cardiac anomalies. It is not usually used in isolation, but in combination with other repair procedures in a staged manner in an attempt to correct the underlying cardiac pathology.
The procedure attempts to bypass the...
The foramen ovale (or ovalis) is the opening in the interatrial septum in the fetal heart that allows blood to bypass the right ventricle and non-ventilated lungs, shunted from the right atrium to the left atrium. Specifically it represents the opening between the upper and lower portions of the...
The fossa ovale (or ovalis) is the small oval depression in the interatrial septum at the site of the closed foramen ovale, which closes once fetal circulation ceases in the first few minutes of postnatal life. It represents the overlapping primary and secondary septa of the interatrial septum. ...
The four chamber cardiac view is an important and routinely performed view in both fetal echocardiography as well as on a standard second trimester anatomy scan.
The four chamber view can only detect some of the congenital cardiac anomalies (~64% according to one study 2) ...
Fractional flow reserve (FFR) is a technique to evaluate the haemodynamic relevance of coronary artery stenoses. Due to recent technical advances, besides conventional invasive coronary angiography, FFR can also be computed based on noninvasive coronary computed tomography angiography (CTCA).
The Glenn shunt, also known as Glenn procedure, is a palliative surgical procedure for a variety of cyanotic congenital heart diseases.
In this procedure, the systemic venous return is re-directed to the pulmonary circulation, bypassing the right heart 1-3.
It can be used in a varie...
The great cardiac vein (GCV) runs in the anterior interventricular groove and drains the anterior aspect of the heart where it is the venous complement of the left anterior descending artery. It is the main tributary of the coronary sinus.
It begins on the anterior surface of th...
Cardiac involvement in haemochromatosis typically occurs with primary haemochromatosis, as the organ is usually spared in the secondary form of the disease.
Cardiac involvement occurs in approximately 15-20% of the patients with haemochromatosis.
Haemopericardium refers to the presence of blood within the pericardial cavity, i.e. a sanguineous pericardial effusion. If enough blood enters the pericardial cavity, then a potentially fatal cardiac tamponade can occur.
There is a very long list of causes 1,4 but some o...
The heart is a hollow, muscular organ of the middle mediastinum, designed to pump oxygenated blood around the systemic circulation and de-oxygenated blood around the pulmonary circulation
The heart has a somewhat conical form and is enclosed by pericardium. It is positioned poste...
There are four heart chambers, the right atrium, left atrium, right ventricle and left ventricle. These receive blood from the body and lungs, and contract to transmit blood to the lungs for oxygenation and to the body for use in metabolism.
It is best to list the four chambers in order of the ...
This is a basic article for medical students and other non-radiologists
Heart failure is a syndrome of cardiac ventricular dysfunction, where the heart is unable to pump sufficiently to meet the body's blood flow requirements.
Although it is useful to divide the signs an...
Heyde syndrome is an association between aortic valve stenosis and gastrointestinal haemorrhage.
The aetiology of the gastrointestinal bleeding in this setting is uncertain, but it is thought to be related to intestinal angiodysplasia. The strength of this association independent of age-related...
Hibernating myocardium is myocardial tissue that has reduced contractility due to poor perfusion, but remains viable. It is important as hibernating myocardium can recover normal contractility with revascularisation.
Hibernating myocardium is most commonly seen in the setting of chr...
High output cardiac failure refers to a state of cardiac failure that is associated with a higher than normal cardiac output which is still not sufficient for body tissue demands.
Patients can present with a number of symptoms of varying degrees which include tachycardia,...
Cardiovascular manifestations are seen with increased frequency in the HIV/AIDS adult population, and include:
dilated cardiomyopathy (prevalence 8-30%)
endocarditis: either infective or non-bacterial thrombotic (marantic) which is associated with malignancy or HIV wasti...
Hypertrophic cardiomyopathy (HCM) is a type of cardiomyopathy and is the leading cause of sudden death (from arrhythmias) in infants, teenagers and young adults.
There is no gender predilection and has a prevalence of around 0.3-0.5% in the general population 4.
Hypoplastic left heart syndrome (HLHS) is a cyanotic congenital cardiac anomaly where affected individuals can have profound cyanosis and cardiac failure.
It is one of the commonest causes for a neonate to present with congestive cardiac failure and the 4th most frequent cardiac anomaly to mani...
Idiopathic dilated cardiomyopathy is a subtype of dilated cardiomyopathy. It is a type of non ischaemic cardiomyopathy where no underlying cause can be found.
This form of cardiomyopathy may account for up to 50% of all dilated cardiomyopathies 4. Patients usually ranging around 2...
Idiopathic hypereosinophilic syndrome (IHES) is a leukoproliferative disorder and refers to a situation when there is an unexplained prolonged eosinophilia with associated organ system dysfunction. The condition can affect several organ systems which includes:
heart: cardiac involvement in idio...
Idiopathic pulmonary arterial hypertension is uncommon, representing only a tiny fraction of all cases of pulmonary arterial hypertension, which has a very long list of secondary causes (see causes of pulmonary arterial hypertension).
Older terms for this entity include primary pul...
Implantable loop recorders, also known as insertable cardiac monitors, are small insertable devices that continuously monitor and record cardiac rhythms. They are placed subcutaneously and used for the evaluation of patients with recurrent unexplained episodes of palpitations or syncope. They sh...
Increased cardiothoracic ratio describes widening of the cardiac silhouette on a chest radiograph. This is only of use when making assessment of a PA chest x-ray since the AP chest x-ray causes artefactual magnification of the heart and the cardiothoracic ratio is altered.
Infective endocarditis is defined as infection of the endocardium. It commonly affects the valve leaflets and chordae tendineae, as well as prosthetic valves and implanted devices.
Infective endocarditis has an estimated general prevalence of 3 to 9 cases per 100,000 persons. Intr...
The inferior aortic recess is one of the pericardial recesses forming a small space within the pericardium, which arises from the transverse pericardial sinus between the ascending aorta and the left atrium. It extends inferiorly to the level of the aortic valve.
It may mimic mediastinal lympha...
The inferior interventricular artery (also known as the posterior interventricular artery or posterior descending artery, PDA) is an artery that extends along the inferior interventricular sulcus. The artery supplies the posterior third of the interventricular septum through posterior septal per...
The inferior mediastinum is the box-shaped space in the mediastinum below the transthoracic plane of Ludwig between the wedge-shaped superior mediastinum above and the diaphragm and inferior thoracic aperture below. There are no physical structures that divide the superior and inferior mediastin...
The heart has extrinsic and intrinsic innervation, which allows the heart to continue beating if the nerve supply to the heart is disrupted (e.g. in cardiac transplant).
The heart receives innervation from both the superficial and deep cardiac plexuses, which have both parasympathetic (from vag...