Trifascicular block is a problem with the electrical conduction of the heart, specifically the three fascicles of the bundle branches that carry electrical signals from the atrioventricular node to the ventricles. The three fascicles are one in the right bundle branch, and two in the left bundle branch the left anterior fascicle and the left posterior fascicle. A block at any of these levels can cause an abnormality to show on an electrocardiogram
The most literal meaning of trifascicular block is complete heart block: all three fascicles are blocked. A second, and clinically distinct, definition of trifascicular block is a circumstance in which right bundle branch block (RBBB) and left bundle branch block occur in the same patient, but at distinct points in time. For example, a patient that is found to have a RBBB one day and a LBBB another can be said to have "alternating bundle branch blocks". In this context, because all three fascicles show evidence of block at different points in time, the term trifascicular block is often used. Finally, the third meaning of trifascicular block refers to a specific finding on an electrocardiogram in which bifascicular block is observed in a patient with a prolonged PR interval (first degree AV block). The treatment of trifascicular block is highly dependent on which clinical entity (one of the three above) is being described. Diagnosis
An electrophysiology study of the conduction system can help discern the severity of conduction system disease.
Causes of Metamorphopsia
Metamorphopsia can be a symptom of a number of eye disorders involving the retina or macula. Some of these conditions include the following:

Age-related macular degeneration
Epiretinal membrane and vitreomacular traction
Posterior vitreous detachment
Macular hole

Diagnosis
Tests used for diagnosis of Metamorphopsia mostly make use of subjective assessments of how a person views regular patterns. Many of these tests have a poor ability to accurately diagnose or identify a person with the disease (i.e.,poor sensitivity). The use of assessments such as a psychophysical test called preferential hyperacuity perimetry, which assesses a person’s ability to any misalignments of visual objects, may permit a more sensitive diagnosis of Metamorphopsia. Treatment and Prognosis
Metamorphopsia is a symptom of several common retinal and macular diseases, therefore treating the underlying disorder can improve symptoms. For people who have conditions such as Epiretinal membrane (ERM), Macular Holes and Retinal Detachment, decreased metamorphopsia is associated with an increase in visual acuity. Quantitative evaluation of metamorphopsia is an important step in understanding visual functions of individuals with macular disorders and is an essential tool for physicians in evaluating treatment results. Types
Dry (non-exudative, > 80%)—deposition of yellowish extracellular material in and between Bruchs membrane and retinal pigment epithelium (“drusen”) with gradual loss in vision.Wet (exudative, 10–15%)—rapid loss of vision due to bleeding secondary to choroidal neovascularization. Etymology
Gk, meta + morphe, form, opsis, sight

See also
Dysmorphopsia
Hallucination


== References ==