When the sinus rate falls below the discharge rate of the AV node, this becomes the dominant pacemaker, and the result is called a junctional escape beat. If the rate from both the SA and AV node fall below the discharge rate of ventricular pacemaker cells, a ventricular escape beat ensues.An escape beat is a form of cardiac arrhythmia, in this case known as an ectopic beat. It can be considered a form of ectopic pacemaker activity that is unveiled by lack of other pacemakers to stimulate the ventricles. Ventricular pacemaker cells discharge at a slower rate than the SA or AV node. While the SA node typically initiates a rate of 70 beats per minute (BPM), the atrioventricular node (AV node) is usually only capable of generating a rhythm at 40-60 BPM or less. Ventricular contraction rate is thus reduced by 15-40 beats per minute.If there are only one or two ectopic beats, they are considered escape beats. If this causes a semi-normal rhythm to arise it is considered an idioventricular rhythm.The escape arrhythmia is a compensatory mechanism that indicates a serious underlying problem with the SA node or conduction system (commonly due to heart attack or medication side effect), and because of its low rate, it can cause a drop in blood pressure and syncope. Diagnosis
An electrocardiogram can be used to identify a ventricular escape beat. The QRS portion of the electrocardiogram represents the ventricular depolarisation; in normal circumstances the QRS complex forms a sharp sudden peak.
Clobazam, sold under the brand names Frisium, Onfi and others, is a benzodiazepine class medication that was patented in 1968. Clobazam was first synthesized in 1966 and first published in 1969. Clobazam was originally marketed as an anxioselective anxiolytic since 1970, and an anticonvulsant since 1984. The primary drug-development goal was to provide greater anxiolytic, anti-obsessive efficacy with fewer benzodiazepine-related side effects. Medical uses
Clobazam is used for its anxiolytic effect, and as an adjunctive therapy in epilepsy. As an adjunctive therapy in epilepsy, it is used in patients who have not responded to first-line drugs and in children who are refractory to first-line drugs. It is unclear if there are any benefits to clobazam over other seizure medications for children with Rolandic epilepsy or other epileptic syndromes. It is not recommended for use in children between the ages of six months and three years, unless there is a compelling need. In addition to epilepsy and severe anxiety, clobazam is also approved as a short-term (2–4 weeks) adjunctive agent in schizophrenia and other psychotic disorders to manage anxiety or agitation.Clobazam is sometimes used for refractory epilepsies. However, long-term prophylactic treatment of epilepsy may have considerable drawbacks, most importantly decreased antiepileptic effects due to drug tolerance which may render long-term therapy less effective. Other antiepileptic drugs may therefore be preferred for the long-term management of epilepsy. Furthermore, benzodiazepines may have the drawback, particularly after long-term use, of causing rebound seizures upon abrupt or over-rapid discontinuation of therapy forming part of the benzodiazepine withdrawal syndrome.