Ring block Health Dictionary

Drugs used to slow the response to epinephrine (released by the adrenal medulla), usually to attempt controlling high blood pressure... beta blockers

An abnormality of the conduction of electrical impulses through the ventricles of the HEART, resulting in delayed depolarisation of the ventricular muscle. The electrocardiograph (see ELECTROCARDIOGRAM (ECG)) shows characteristic widening of the QRS complexes. Abnormalities of the right and left bundle branches cause delayed contraction of the right and left ventricles respectively.... bundle branch block

See ANAESTHESIA – Local anaesthetics.... nerve block

A disorder that occurs in the transmission of impulses between the atria (upper chambers) and ventricles (lower chambers) of the heart. A blocking of the normal route of electrical conduction through the ventricles not responding to initiation of the beat by the atria. Beats are missed with possible blackouts.

Causes: myocardial infarction, atherosclerosis, coronary thrombosis or other heart disorder.

Symptoms: slow feeble heart beats down to 36 beats per minute with fainting and collapse, breathlessness, Stoke Adams syndrome.

Treatment. Intensive care. Until the doctor comes: 1-5 drops Oil of Camphor in honey on the tongue or taken in a liquid if patient is able to drink. Freely inhale the oil. On recovery: Motherwort tea, freely. OR, Formula of tinctures: Lily of the Valley 2; Cactus 1; Motherwort 2. Mix. Dose – 30-60 drops in water thrice daily. A fitted pace-maker may be necessary.

Spartiol. 20 drops thrice daily. (Klein) ... heart block

Calcium-channel blockers inhibit the inward ?ow of calcium through the specialised slow channels of cardiac and arterial smooth-muscle cells. By thus relaxing the smooth muscle, they have important applications in the treatment of HYPERTENSION and ANGINA PECTORIS. Various types of calcium-channel blockers are available in the United Kingdom; these di?er in their sites of action, leading to notable di?erences in their therapeutic effects. All the drugs are rapidly and completely absorbed, but extensive ?rst-pass metabolism in the liver reduces bioavailability to around one-?fth. Their hypotensive e?ect is additive with that of beta blockers (see BETA-ADRENOCEPTOR-BLOCKING DRUGS); the two should, therefore, be used together with great caution – if at all. Calcium-channel blockers are particularly useful when beta blockers are contraindicated, for example in asthmatics. However, they should be prescribed for hypertension only when THIAZIDES and beta blockers have failed, are contraindicated or not tolerated.

Verapamil, the longest-available, is used to treat angina and hypertension. It is the only calcium-channel blocker e?ective against cardiac ARRHYTHMIA and it is the drug of choice in terminating supraventricular tachycardia. It may precipitate heart failure, and cause HYPOTENSION at high doses. Nifedipine and diltiazem act more on the vessels and less on the myocardium than verapamil; they have no antiarrhythmic activity. They are used in the prophylaxis and treatment of angina, and in hypertension. Nicardipine and similar drugs act mainly on the vessels, but are valuable in the treatment of hypertension and angina. Important di?erences exist between di?erent calcium-channel blockers so their use must be carefully assessed. They should not be stopped suddenty, as this may precipitate angina. (See also HEART, DISEASES OF.)... calcium-channel blockers

Inability to express true feelings or thoughts, usually as a result of emotional or mental conflict. In Freudian- based psychotherapies, blocking is regarded as originating from repression of painful emotions in early life. A very specific form of thought blocking occurs in schizophrenia: trains of thought are persistently interrupted involuntarily to

be replaced by unrelated new ones.

(See also psychotherapy.)... blocking

Also called adrenoceptor-blocking agents or alpha blockers, these drugs stop the stimulation of alpha-adrenergic receptors at the nerve endings of the SYMPATHETIC NERVOUS SYSTEM by HORMONES with ADRENALINE-like characteristics. The drugs dilate the arteries, causing a fall in blood pressure, so they are used to treat HYPERTENSION and also benign enlargement of the PROSTATE GLAND. Examples of this group of drugs are doxazosin, indoramin, phentolamine and prazosin. The drugs should be used with caution as some may cause a severe drop in blood pressure when ?rst taken.... alpha adrenergic blockers

The continued occupation of a hospital bed by a patient who is ?t to be discharged but requires further care in a nursing home or in a community setting that cannot be arranged because of lack of suitable facilities and/or funding. Bed-blocking has become a common phenomenon in the NHS, particularly in the winter.

The result is that patients who need inpatient care cannot always be admitted. The term ‘bedblockers’ is derogatory and should not be used.... bed-blocking

Also called beta blockers, these drugs interrupt the transmission of neuronal messages via the body’s adrenergic receptor sites. In the HEART these are called beta1 (cardioselective) receptors. Another type – beta2 (non-cardioselective) receptors – is sited in the airways, blood vessels, and organs such as the eye, liver and pancreas. Cardioselective beta blockers act primarily on beta1 receptors, whereas non-cardioselective drugs act on both varieties, beta1 and beta2. (The neurotransmissions interrupted at the beta-receptor sites through the body by the beta blockers are initiated in the ADRENAL GLANDS: this is why these drugs are sometimes described as beta-adrenergic-blocking agents.)

They work by blocking the stimulation of beta adrenergic receptors by the neurotransmitters adrenaline and noradrenaline, which are produced at the nerve endings of that part of the SYMPATHETIC NERVOUS SYSTEM – the autonomous (involuntary) network

– which facilitates the body’s reaction to anxiety, stress and exercise – the ‘fear and ?ight’ response.

Beta1 blockers reduce the frequency and force of the heartbeat; beta2 blockers prevent vasodilation (increase in the diameter of blood vessels), thus in?uencing the patient’s blood pressure. Beta1 blockers also affect blood pressure, but the mechanism of their action is unclear. They can reduce to normal an abnormally fast heart rate so the power of the heart can be concomitantly controlled: this reduces the oxygen requirements of the heart with an advantageous knock-on e?ect on the respiratory system. These are valuable therapeutic effects in patients with ANGINA or who have had a myocardial infarction (heart attack – see HEART, DISEASES OF), or who suffer from HYPERTENSION. Beta2 blockers reduce tremors in muscles elsewhere in the body which are a feature of anxiety or the result of thyrotoxicosis (an overactive thyroid gland – see under THYROID GLAND, DISEASES OF). Noncardioselective blockers also reduce the abnormal pressure caused by the increase in the ?uid in the eyeball that characterises GLAUCOMA.

Many beta-blocking drugs are now available; minor therapeutic di?erences between them may in?uence the choice of a drug for a particular patient. Among the common drugs are:

Primarily cardioselective	Non-cardioselective
Acebutolol	Labetalol
Atenolol	Nadolol
Betaxolol	Oxprenolol
Celiprolol	Propanolol
Metoprolol	Timolol

These powerful drugs have various side-effects and should be prescribed and monitored with care. In particular, people who suffer from asthma, bronchitis or other respiratory problems may develop breathing diffculties. Long-term treatment with beta blockers should not be suddenly stopped, as this may precipitate a severe recurrence of the patient’s symptoms – including, possibly, a sharp rise in blood pressure. Gradual withdrawal of medication should mitigate untoward effects.... beta-adrenoceptor-blocking drugs

Reserving money to be spent for a particular service, such as grants to local authorities.... ring-fencing

Due to many causes from catarrh to infection. May be associated with sinus headache and nasal congestion.

Alternatives. Teas. Plantain leaves, Nasturtium leaves, Marigold flowers (Calendula), Thyme. Tablets/capsules. Garlic, Goldenseal, Iceland Moss.

Tinctures. Formula. Echinacea 2; Goldenseal 1. Mix. 30-60 drops in water thrice daily. Practitioner. Ephedra.

Topical. Decongestants. Olbas oil. Oils of Aromatherapy: Eucalyptus, Garlic, Thyme. Supplementation. Vitamins A, C.

Bedtime: 2-3 Garlic capsules. ... blocked-up nose

In clinical practice, the transmission of impulses at the NEUROMUSCULAR JUNCTION may be blocked to paralyse temporarily a patient for a surgical procedure, or to assist treatment on the intensive care unit. There are two main types of drug, both of which competitively block the ACETYLCHOLINE receptors on the motor end plates. (1) Depolarising neuromuscular blocking agents: these act by ?rst producing stimulation at the receptor, and then by blocking it. There are characteristic muscle fasciculations before the rapid onset of paralysis which is of short duration (less than ?ve minutes with the commonly used drug, suxamethonium). The drug is removed from the receptor by the enzyme, CHOLINESTERASE.

(2) Non-depolarising neuromuscular blocking agents: these drugs occupy the receptor and prevent acetylcholine from becoming attached to it. However, in su?ciently high concentrations, acetylcholine will compete with the drug and dislodge it from the receptor; the e?ect of these drugs is reversed by giving an anticholinesterase, which allows the amount of acetylcholine at the neuromuscular junction to build up. These drugs have varying durations of action, but all are slower in onset and of longer duration than the depolarisers.... neuromuscular blockade

A group of drugs used to treat hypertension (high blood pressure) and urinary symptoms due to enlargement of the prostate gland. Alpha-blockers are also used to treat urinary retention caused by an enlarged prostate gland (see prostate, enlarged). Side effects of the drugs may include dizziness and fatigue due to a sudden drop in blood pressure, nausea, dry mouth, and drowsiness.... alpha-blocker drugs

See nasal congestion; nasal obstruction.... blocked nose

A type of nerve block, in which a local anaesthetic is injected into the lower part of the spinal canal.

Caudal block may be used for obstetric and gynaecological procedures.... caudal block

A type of nerve block used to provide pain relief for a forceps delivery.

A local anaesthetic (see anaesthesia, local) is injected into either side of the vagina near the pudendal nerve.... pudendal block

(alpha-adrenergic blocker) a drug that prevents the stimulation of alpha *adrenoceptors at the nerve endings of the sympathetic nervous system by noradrenaline and adrenaline: it therefore causes relaxation of smooth muscle, including widening of arteries (vasodilatation) and a drop in blood pressure. Alpha blockers include *doxazosin, *phentolamine, *phenoxybenzamine, *indoramin, *prazosin, *alfuzosin, and *tamsulosin.... alpha blocker

see retraction ring. [L. Bandl (1842–92), German obstetrician]... bandl’s ring

n. any interruption of physiological or mental function, brought about intentionally (as part of a therapeutic procedure) or by disease. See also heart block; nerve block.... block

A group of drugs, also known as beta-adrenergic blocking agents, prescribed principally to treat heart and circulatory disorders such as angina and hypertension. Beta-blockers block the effects of the sympathetic nervous system, which releases adrenaline (epinephrine) and noradrenaline (norepinephrine) at nerve endings that are known as beta receptors.

There are 2 types of beta receptor: beta 1 and beta 2. Beta 1 receptors are present in the heart and blood vessels, and beta 2 in the lungs. Some betablockers (such as acebutolol, atenolol, and metoprolol) are termed cardioselective and, because they act mostly on beta 1 receptors, are used mainly to treat heart disease such as angina, hypertension, and cardiac arrhythmia. The drugs are sometimes given after a myocardial infarction (heart attack) to reduce the likelihood of further damage to the heart muscle.

Other types of beta-blocker, such as oxprenolol, propranolol, and timolol, may be given to prevent migraine attacks by acting on blood vessels in the head; reduce the physical symptoms of anxiety; or control the symptoms of thyrotoxicosis. Beta-blocker drugs such as timolol are sometimes given in the

form of eye drops to treat glaucoma and work by lowering the fluid pressure in the eyeball.

Beta-blockers may reduce an individual’s capacity for strenuous exercise. The drugs may worsen the symptoms of asthma, bronchitis, or other forms of lung disease. They may also reduce the flow of blood to the limbs, causing cold hands and feet. In addition, sleep disturbance and depression can be side effects of beta-blockers.... beta-blocker drugs

(beta-adrenergic receptor blocker) a drug that prevents stimulation of the beta *adrenoceptors at the nerve endings of the sympathetic nervous system. Blockade of ?1 receptors causes a decrease in heart rate and force; blockade of ?2 receptors causes constriction of the airways and the arteries. Beta blockers include *acebutolol, *atenolol, *bisoprolol, *oxprenolol, *propranolol, and *sotalol; they are used to control abnormal heart rhythms, to treat angina, and to reduce high blood pressure (although they are no longer regarded by some experts as the first choice of drug for treating hypertension in the absence of heart disease, being less effective than newer antihypertensive drugs). Beta blockers that block both ?1 and ?2 receptor sites cause constriction of air passages in the lungs, and these drugs should not be used in patients with asthma and bronchospasm. Other beta blockers are relatively selective for the heart (cardioselective) and are less likely to constrict the airways. Some beta blockers (e.g. *carteolol, *levobunolol, and *timolol) reduce the production of aqueous humour and therefore the pressure inside the eye; they are taken as eye drops in the treatment of *glaucoma.... beta blocker

(calcium antagonist) a drug that inhibits the influx of calcium ions into cardiac and smooth-muscle cells; it therefore reduces the strength of heart-muscle contraction, reduces conduction of impulses in the heart, and causes *vasodilatation. Calcium-channel blockers, which include *amlodipine, *diltiazem, *nicardipine, *nifedipine, and *verapamil, are used to treat angina and high blood pressure.... calcium-channel blocker

a ring designed to be inserted into the peripheral tissue of the cornea in order to alter the curvature of the corneal surface. It is undergoing trials to assess its ability to correct errors of refraction. In myopia (short-sightedness), for example, the ring would be required to stretch the corneal tissue peripherally and thus flatten the central corneal curvature in order to correct the myopia.... corneal ring

a deposit of iron in the form of a ring in the epithelium of the cornea, which is seen, for example, around the base of the ‘cone’ of the cornea in *keratoconus. It is best visualized using cobalt blue light. [B. Fleischer (1848–1904), German physician]... fleischer ring

a watertight adherent ring placed around an intestinal *stoma and incorporating a flange to which a disposable plastic bag could be attached. It was the forerunner of modern disposable stoma bags.... hollister ring

(inferior alveolar nerve block) a type of injection to anaesthetize the inferior *dental nerve. Inferior dental block is routinely performed to allow dental procedures to be carried out on the lower teeth on one side of the mouth.... inferior dental block

a brownish-yellow ring in the outer rim of the cornea of the eye. It is a deposit of copper granules and is diagnostic of *Wilson’s disease. When well developed it can be seen by unaided observation, but faint Kayser-Fleischer rings may only be detected by specialized *slit-lamp ophthalmological examination. [B. Kayser (1869–1954), German ophthalmologist; B. Fleischer (1848–1904), German physician]... kayser–fleischer ring

a type of squint (convergent *strabismus) that results from the use of the convergence mechanism to block or dampen down *nystagmus in an attempt to improve visual acuity.... nystagmus block syndrome

n. (in anatomy) see annulus.... ring

a ringlike constriction in the lower part of the gullet (oesophagus). The cause is unclear. Patients may be asymptomatic or experience episodic difficulty in swallowing. Diagnosis is made at gastroscopy or *barium swallow. Antisecretory agents and endoscopic balloon dilatation are reserved for symptomatic patients. [R. Schatzki (20th century), German-born US physician]... schatzki ring

a sudden halting of the flow of thought, usually manifested as an interruption to speech lasting for a few seconds or more; when speech resumes, it is often on an unrelated subject. Thought block is a common symptom in severe mental illness but may also arise in the context of *psychosis, severe anxiety, or depression.... thought block

a depression in the uterine wall marking the junction between the actively contracting muscle fibres of the upper segment of the uterus and the muscle fibres of the lower segment. This depression is not always visible and is normal. In obstructed labour (e.g. contracted pelvis or malposition of the fetus resulting in shoulder presentation), the muscle fibres of the upper segment become shorter and thicker; the muscle fibres of the lower segment, on the other hand, become elongated and thinner. The junction between the two becomes more distinct as it rises into the abdomen from the pelvis. This abnormal ring is known as Bandl’s ring and is a sign of impending rupture of the lower segment of the uterus, which becomes progressively thinner as Bandl’s ring rises upwards. Immediate action to relieve the obstruction is then necessary, usually in the form of Caesarean section.... retraction ring

the ring of lymphoid tissue formed by the *tonsils. [H. W. G. von Waldeyer (1836–1921), German anatomist]... waldeyer’s ring

a ringlike opacity on the posterior vitreous surface, arising as a result of a posterior *vitreous detachment. It is seen as a ring-shaped *floater.... weiss ring