MedGen

A type of supraventricular tachycardia in which the atria are the principal site of electrophysiologic disturbance. [from HPO]

Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum. [from HPO]

An anomaly of the intra-atrial or intraventricular septum. [from HPO]

Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both. [from HPO]

Pattern of blood flow in the heart that deviates from the normal circuit of the circulatory system from the left side of the heart to the right. [from HPO]

The PR (or PQ) interval is the time required for an electrical impulse to travel from the atrial myocardium adjacent to the sinus node through the atrioventricular node (AVN) to the Purkinje fibers. Delayed conduction results in prolongation of the PR interval and subsequent risk of atrial fibrillation (summary by Holm et al., 2010). The PR interval has a substantial heritable component, with heritability estimates ranging between 30 and 50%. The PR interval is considered an intermediate phenotype for atrial fibrillation, as alterations in atrial action potential duration and in atrioventricular conduction influence both PR interval and atrial fibrillation risk (summary by Pfeufer et al., 2010). [from OMIM]