Concept
Supraventricular tachycardia
Related concepts (24)
Sinus rhythm
A sinus rhythm is any cardiac rhythm in which depolarisation of the cardiac muscle begins at the sinus node. It is necessary, but not sufficient, for normal electrical activity within the heart. On the electrocardiogram (ECG), a sinus rhythm is characterised by the presence of P waves that are normal in morphology.
Ebstein's anomaly
Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced downwards towards the apex of the right ventricle of the heart. It is classified as a critical congenital heart defect accounting for less than 1% of all congenital heart defects presenting in around 1 per 200,000 live births. Ebstein's anomaly usually presents with a systolic murmur (sometimes diastolic) and frequently with a gallop rhythm. The annulus of the valve is still in the normal position.
Re-entry ventricular arrhythmia
Re-entry ventricular arrhythmia is a type of paroxysmal tachycardia occurring in the ventricle where the cause of the arrhythmia is due to the electric signal not completing the normal circuit, but rather an alternative circuit looping back upon itself. There develops a self-perpetuating rapid and abnormal activation. ("Circus Movement" is another term for this.) Conditions necessary for re-entry include a combination of unidirectional block and slowed conduction.
Ectopic pacemaker
An ectopic pacemaker, also known as ectopic focus or ectopic foci, is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart. It is thus a cardiac pacemaker that is ectopic, producing an ectopic beat. Acute occurrence is usually non-life-threatening, but chronic occurrence can progress into tachycardia, bradycardia or ventricular fibrillation. In a normal heart beat rhythm, the SA node usually suppresses the ectopic pacemaker activity due to the higher impulse rate of the SA node.