Radiological examination of the temporal artery with ultrasound yields a halo sign.

Contrast-enhanced brain MRI and CT is generally negative in this disorder.

Recent studies have shown that 3T MRI using super high resolution imaging and contrast injection can non-invasively diagnose this disorder with high specificity and sensitivity.

The gold standard for diagnosing temporal arteritis is biopsy, which involves removing a small part of the vessel under local anesthesia and examining it microscopically for giant cells infiltrating the tissue. Since the blood vessels are involved in a patchy pattern, there may be unaffected areas on the vessel and the biopsy might have been taken from these parts. Unilateral biopsy of a 1.5–3 cm length is 85-90% sensitive (1 cm is the minimum). A negative result does not definitively rule out the diagnosis. Characterised as intimal hyperplasia and medial granulomatous inflammation with elastic lamina fragmentation with a CD 4+ predominant T cell infiltrate, currently biopsy is only considered confirmatory for the clinical diagnosis, or one of the diagnostic criteria.

A study by McKhann et al. compared the neurocognitive outcome of people with coronary artery disease (CAD) to heart-healthy controls (people with no cardiac risk factors). People with CAD were subdivided into treatment with CABG, OPCAB and non-surgical medical management. The three groups with CAD all performed significantly lower at baseline than the heart-healthy controls. All groups improved by 3 months, and there were minimal intrasubject changes from 3 to 12 months. No consistent difference between the CABG and off-pump patients was observed. The authors concluded patients with long-standing coronary artery disease have some degree of cognitive dysfunction secondary to cerebrovascular disease before surgery; there is no evidence the cognitive test performance of bypass surgery patients differed from similar control groups with coronary artery disease over a 12-month follow-up period. A related study by Selnes et al. concluded patients with coronary artery bypass grafting did not differ from a comparable nonsurgical control group with coronary artery disease 1 or 3 years after baseline examination. This finding suggests that late cognitive decline after coronary artery bypass grafting previously reported by Newman et al. may not be specific to the use of cardiopulmonary bypass, but may also occur in patients with very similar risk factors for cardiovascular and cerebrovascular disease.

Three tests are useful in confirming the presence and severity of Horner syndrome:

- Cocaine drop test: Cocaine eyedrops block the reuptake of post-ganglionic norepinephrine resulting in the dilation of a normal pupil from retention of norepinephrine in the synapse. However, in Horner's syndrome the lack of norepinephrine in the synaptic cleft causes mydriatic failure. A more recently introduced approach that is more dependable and obviates the difficulties in obtaining cocaine is to apply the alpha-agonist apraclonidine to both eyes and observe the increased mydriatic effect (due to hypersensitivity) on the affected side of Horner syndrome (the opposite effect to what the cocaine test would produce in the presence of Horner's).

- Paredrine test: This test helps to localize the cause of the miosis. If the third order neuron (the last of three neurons in the pathway which ultimately discharges norepinephrine into the synaptic cleft) is intact, then the amphetamine causes neurotransmitter vesicle release, thus releasing norepinephrine into the synaptic cleft and resulting in robust mydriasis of the affected pupil. If the lesion itself is of the third order neuron, then the amphetamine will have no effect and the pupil remains constricted. There is no pharmacological test to differentiate between a first and second order neuron lesion.

- Dilation lag test

It is important to distinguish the ptosis caused by Horner's syndrome from the ptosis caused by a lesion to the oculomotor nerve. In the former, the ptosis occurs with a constricted pupil (due to a loss of sympathetics to the eye), whereas in the latter, the ptosis occurs with a dilated pupil (due to a loss of innervation to the sphincter pupillae). In a clinical setting, these two ptoses are fairly easy to distinguish. In addition to the blown pupil in a CNIII (oculomotor nerve) lesion, this ptosis is much more severe, occasionally occluding the whole eye. The ptosis of Horner syndrome can be quite mild or barely noticeable (partial ptosis).

When anisocoria occurs and the examiner is unsure whether the abnormal pupil is the constricted or dilated one, if a one-sided ptosis is present then the abnormally sized pupil can be presumed to be on the side of the ptosis.

A study by Newman et al. at Duke University Medical Center published in the "New England Journal of Medicine" (NEJM) showed an increased incidence of cognitive decline after coronary artery bypass surgery (CABG), both immediately (53 percent at discharge from hospital) and over time (36 percent six weeks, 24 percent at six months, and 42 percent at five years). This study shows an association of neurocognitive decline with CABG, but does not show causation; the study lacks a control group and is considered level II-3 evidence. Also, the statistical calculation of cognitive decline has been demonstrated as the least reliable due to practice effects, measurement error and the regression to the mean phenomenon.

Subsequent studies have compared "on-pump" CABG to off-pump coronary artery bypass (OPCAB)—essentially establishing controls to compare the incidence of neurocognitive decline in CABG with and without the use of CPB. A small study (60 patients total, 30 in each treatment arm) by Zamvar et al. demonstrated neurocognitive impairment at both 1 week and 10 weeks postoperatively. A larger study (281 patients total) by Van Dijk et al. showed CABG surgery without cardiopulmonary bypass improved cognitive outcomes 3 months after the procedure, but the effects were limited and became negligible at 12 months. Furthermore, the Van Dijk study showed no difference between the on-pump and off-pump groups in quality of life, stroke rate, or all-cause mortality at 3 and 12 months. A study by Jenson et al. published in Circulation found no significant difference in the incidence of cognitive dysfunction 3 months after either OPCAB or conventional on-pump CABG.

Given the above evidence, there is high incidence of neurocognitive deficit post bypass surgery, but the deficits are transient with no permanent neurological impairment. Controlled "on-pump" versus "off-pump" cardiac surgery has only been studied in the setting of CABG and is not necessarily generalizable to other types of cardiac surgery. Recent advancements in transcatheter and percutaneous valve replacement may soon allow comparison of other types of cardiac surgery with and without CPB.

The most common causes in young children are birth trauma and a type of cancer called neuroblastoma. The cause of about a third of cases in children is unknown.

This is based on MRI scan, magnetic resonance angiography and CT scan. A cerebral digital subtraction angiography (DSA) enhances visualization of the fistula.

- CT scans classically show an enlarged superior ophthalmic vein, cavernous sinus enlargement ipsilateral (same side) as the abnormality and possibly diffuse enlargement of all the extraocular muscles resulting from venous engorgement.

- Selective arteriography is used to evaluate arteriovenous fistulas.

- High resolution digital subtraction angiography may help in classifying CCF into dural and direct type and thus formulate a strategy to treat it either by a balloon or coil or both with or without preservation of parent ipsilateral carotid artery.

The gold standard for measuring endothelial function is angiography with acetylcholine injection. Previously, this was not done outside of research because of the invasive and complex nature of the procedure. As mentioned above, the use of acetylcholine injections to test vasodilation is now safely used for procedures where arterial catheterization is employed (this method is less frequently used though, so overall acetylcholine is not used very often in this way).

A noninvasive method to measure endothelial dysfunction is % Flow Mediated Dilation (FMD) as measured by Brachial Artery Ultrasound Imaging (BAUI). Current measurements of endothelial function via FMD vary due to technical and physiological factors. For example, FMD is largely affected by hormones, especially for women. FMD values can differ for the same woman if she is in different phases of her menstrual cycle during the time of measurement. When using this technique on people who suffer from things like heart failure, renal failure, or hypertension, their increased sympathetic tone can often falsify the results. Furthermore, a negative correlation between percent flow mediated dilation and baseline artery size is recognised as a fundamental scaling problem, leading to biased estimates of endothelial function. For research on FMD an ANCOVA approach to adjusting FMD for variation in baseline diameter is more appropriate. Another challenge of FMD is variability across centers and the requirement of highly qualified technicians to perform the procedure.

A non-invasive, FDA-approved device for measuring endothelial function that works by measuring Reactive Hyperemia Index (RHI) is Itamar Medical's EndoPAT™. It has shown an 80% sensitivity and 86% specificity to diagnose coronary artery disease when compared against the gold standard, acetylcholine angiogram. This results suggests that this peripheral test reflects the physiology of the coronary endothelium. Endopat has been tested in several clinical trials at multiple centers (including major cohort studies such as the Framingham Heart Study, the Heart SCORE study, and the Gutenberg Health Study). The results from clinical trials have shown that EndoPAT™ is useful for risk evaluation, stratification and prognosis of getting major cardiovascular events (MACE).

Since NO maintains low tone and high compliance of the small arteries at rest a reduction of age-dependent small artery compliance is a marker for endothelial dysfunction that is associated with both functional and structural changes in the microcirculation that are predictive of subsequent morbid events Small artery compliance or stiffness can be assessed simply and at rest and can be distinguished from large artery stiffness by use of pulsewave analysis with the CV Profilor.

Stent implantation has been correlated with impaired endothelial function in several studies. According to Mischie et al., sirolimus eluting stent implantation induces a higher rate of endothelial dysfunction compared to bare metal stents. This is problematic because stents have been used to treat many diseases related to endothelial dysfunction, including coronary artery disease. Sirolimus eluting stents were previously used because they showed very low rates of in-stent restenosis but further investigation showed that they often impair endothelial dysfunction in humans and worsen conditions. Therefore, now the commonly used drug is iopromide-paclitaxel because it showed low rates of in-stent restenosis and thrombosis and it does not worsen the person's health condition.

A physical examination will demonstrate many of the features listed above.

Blood tests

- Complete blood count may reveal normocytic anemia and eventually thrombocytosis.

- Erythrocyte sedimentation rate will be elevated.

- C-reactive protein will be elevated.

- Liver function tests may show evidence of hepatic inflammation and low serum albumin levels.

Other optional tests include:

- Electrocardiogram may show evidence of ventricular dysfunction or, occasionally, arrhythmia due to myocarditis.

- Echocardiogram may show subtle coronary artery changes or, later, true aneurysms.

- Ultrasound or computerized tomography may show hydrops (enlargement) of the gallbladder.

- Urinalysis may show white blood cells and protein in the urine (pyuria and proteinuria) without evidence of bacterial growth.

- Lumbar puncture may show evidence of aseptic meningitis.

- Angiography was historically used to detect coronary artery aneurysms, and remains the gold standard for their detection, but is rarely used today unless coronary artery aneurysms have already been detected by echocardiography.

- Temporal artery biopsy

Patients who are diagnosed with AAOCA at or before age 30 years are eligible for this study. They should have otherwise normal heart or only minor defects such as Atrial septal defect, Ventricular septal defect, Patent ductus arteriosus, bicuspid aortic valve, mild pulmonary stenosis etc.

Patients who have other major heart problems that require operations are currently not included in this Cohort study. Any other problems with coronary arteries are also not included.

Turner syndrome may be diagnosed by amniocentesis or chorionic villus sampling during pregnancy.

Usually, fetuses with Turner syndrome can be identified by abnormal ultrasound findings ("i.e.", heart defect, kidney abnormality, cystic hygroma, ascites). In a study of 19 European registries, 67.2% of prenatally diagnosed cases of Turner Syndrome were detected by abnormalities on ultrasound. 69.1% of cases had one anomaly present, and 30.9% had two or more anomalies.

An increased risk of Turner syndrome may also be indicated by abnormal triple or quadruple maternal serum screen. The fetuses diagnosed through positive maternal serum screening are more often found to

have a mosaic karyotype than those diagnosed based on ultrasonographic abnormalities, and

conversely, those with mosaic karyotypes are less likely to have associated ultrasound abnormalities.

Wellens' syndrome is an electrocardiographic manifestation of critical proximal left anterior descending (LAD) coronary artery stenosis in patients with unstable angina. It is characterized by symmetrical, often deep (>2 mm), T wave inversions in the anterior precordial leads. A less common variant is biphasic T wave inversions in the same leads.

First described by Hein J. J. Wellens and colleagues in 1982 in a subgroup of patients with unstable angina, it does not seem to be rare, appearing in 18% of patients in his original study. A subsequent prospective study identified this syndrome in 14% of patients at presentation and 60% of patients within the first 24 hours.

The presence of Wellens' syndrome carries significant diagnostic and prognostic value. All patients in the De Zwann's study with characteristic findings had more than 50% stenosis of the left anterior descending artery (mean = 85% stenosis) with complete or near-complete occlusion in 59%. In the original Wellens' study group, 75% of those with the typical syndrome manifestations had an anterior myocardial infarction. Sensitivity and specificity for significant (more or equal to 70%) stenosis of the LAD artery was found to be 69% and 89%, respectively, with a positive predictive value of 86%.

Wellens' sign has also been seen as a rare presentation of Takotsubo cardiomyopathy or stress cardiomyopathy.

Kawasaki disease can only be diagnosed clinically (i.e., by medical signs and symptoms). No specific laboratory test exists for this condition. It is difficult to establish the diagnosis, especially early in the course of the illness, and frequently children are not diagnosed until they have seen several health-care providers. Many other serious illnesses can cause similar symptoms, and must be considered in the differential diagnosis, including scarlet fever, toxic shock syndrome, juvenile idiopathic arthritis, and childhood mercury poisoning (infantile acrodynia).

Classically, five days of fever plus four of five diagnostic criteria must be met to establish the diagnosis. The criteria are:

1. erythema of the lips or oral cavity or cracking of the lips

2. rash on the trunk

3. swelling or erythema of the hands or feet

4. red eyes (conjunctival injection)

5. swollen lymph node in the neck of at least 15 mm

Many children, especially infants, eventually diagnosed with Kawasaki disease, do not exhibit all of the above criteria. In fact, many experts now recommend treating for Kawasaki disease even if only three days of fever have passed and at least three diagnostic criteria are present, especially if other tests reveal abnormalities consistent with Kawasaki disease. In addition, the diagnosis can be made purely by the detection of coronary artery aneurysms in the proper clinical setting.

Turner syndrome can be diagnosed postnatally at any age. Often, it is diagnosed at birth due to heart problems, an unusually wide neck or swelling of the hands and feet. However, it is also common for it to go undiagnosed for several years, typically until the girl reaches the age of puberty/adolescence and she fails to develop properly (the changes associated with puberty do not occur). In childhood, a short stature can be indicative of Turner syndrome.

A test called a karyotype, also known as a chromosome analysis, analyzes the chromosomal composition of the individual. This is the test of choice to diagnose Turner syndrome.

The mainstay of treatment for CCF is endovascular therapy. This may be transarterial (mostly in the case of direct CCF) or transvenous (most commonly in indirect CCF). Occasionally, more direct approaches, such as direct transorbital puncture of the cavernous sinus or cannulation of the draining superior orbital vein are used when conventional approaches are not possible. Spontaneous resolution of indirect fistulae has been reported but is uncommon. Staged manual compression of the ipsilateral carotid has been reported to assist with spontaneous closure in selected cases.

Direct CCF may be treated by occlusion of the affected cavernous sinus (coils, balloon, liquid agents), or by reconstruction of the damaged internal carotid artery (stent, coils or liquid agents).

Indirect CCF may be treated by occlusion of the affected cavernous sinus with coils, liquid agents or a combination of both.

The diagnosis of renal artery stenosis can use many techniques to determine if the condition is present, a clinical prediction rule is available to guide diagnosis.

Among the diagnostic techniques are:

- Doppler ultrasound study of the kidneys

- refractory hypertension

- auscultation (with stethoscope) - bruit ("rushing" sound)

- captopril challenge test

- captopril test dose effect on the differential renal function as measured by MAG3 scan.

- renal artery arteriogram.

The Registry has been enrolling new patients from participating institutions that are member of the Congenital Heart Surgeons' Society. Hospitals from across North America continue to join the study group and enroll patients. Over 140 patients with AAOCA have been enrolled by June 2011, making it the largest cohort ever assembled of this anomaly.

Vessel restenosis is typically detected by angiography, but can also be detected by duplex ultrasound and other imaging techniques.

The most important initial investigation is computed tomography of the brain, which is very sensitive for subarachnoid hemorrhage. If this is normal, a lumbar puncture is performed, as a small proportion of SAH is missed on CT and can still be detected as xanthochromia.

If both investigations are normal, the specific description of the headache and the presence of other abnormalities may prompt further tests, usually involving magnetic resonance imaging (MRI). Magnetic resonance angiography (MRA) may be useful in identifying problems with the arteries (such as dissection), and magnetic resonance venography (MRV) identifies venous thrombosis. It is not usually necessary to proceed to cerebral angiography, a more precise but invasive investigation of the brain's blood vessels, if MRA and MRV are normal.

Upon suspicion of PAD, the first-line study is the ankle–brachial index (ABI). When the blood pressure readings in the ankles is lower than that in the arms, blockages in the arteries which provide blood from the heart to the ankle are suspected. Normal ABI range of 1.00 to 1.40.The patient is diagnosed with PAD when the ABI is ≤ 0.90 . ABI values of 0.91 to 0.99 are considered "borderline" and values >1.40 indicate noncompressible arteries. PAD is graded as mild to moderate if the ABI is between 0.41 and 0.90, and an ABI less than 0.40 is suggestive of severe PAD. These relative categories have prognostic value.

In people with suspected PAD but normal resting ABIs, exercise testing of ABI can be done. A base line ABI is obtained prior to exercise. The patient is then asked to exercise (usually patients are made to walk on a treadmill at a constant speed) until claudication pain occurs (or a maximum of 5 minutes), following which the ankle pressure is again measured. A decrease in ABI of 15%-20% would be diagnostic of PAD.

It is possible for conditions which stiffen the vessel walls (such as calcifications that occur in the setting of long term diabetes) to produce false negatives usually, but not always, indicated by abnormally high ABIs (> 1.40). Such results and suspicions merit further investigation and higher level studies.

If ABIs are abnormal the next step is generally a lower limb doppler ultrasound examination to look at site and extent of atherosclerosis. Other imaging can be performed by angiography, where a catheter is inserted into the common femoral artery and selectively guided to the artery in question. While injecting a radiodense contrast agent an X-ray is taken. Any flow limiting stenoses found in the x-ray can be identified and treated by atherectomy, angioplasty or stenting. Contrast angiography is the most readily available and widely used imaging technique.

Modern multislice computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography.

Magnetic resonance angiography (MRA) is a noninvasive diagnostic procedure that uses a combination of a large magnet, radio frequencies, and a computer to produce detailed images to provide pictures of blood vessels inside the body. The advantages of MRA include its safety and ability to provide high-resolution three-dimensional (3D) imaging of the entire abdomen, pelvis and lower extremities in one sitting.

70% of patients with carotid arterial dissection are between the ages of 35 and 50, with a mean age of 47 years.

Diagnosis can be based on a physical exam, blood test, EKG and the results of these tests (among other exams).

In the first stage of restenosis, administering anti-platelet drugs (called IIb/IIIa inhibitors) immediately after surgery greatly reduces the chance of a thrombosis occurring.

Drug-eluting stents are now being trialled in Europe, Canada and the USA, as well as in Asia-Pacific. These stents are coated with pharmaceuticals that inhibit tissue growth and thus reduce the risk of restenosis from scar-tissue and cell proliferation.

There has been some success with these new stents in reducing the occurrence of restenosis, with clinical studies showing an incidence rate of 5% or lower.

It is not clear if screening for disease is useful as it has not been properly studied.