- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. (PMID:11407343)
- Shortened PR interval (HP:0005165): Reduced time for the PR interval (beginning of the P wave to the beginning of the QRS complex). In adults, normal values are 120 to 200 ms long. Evidence: PCS. (PMID:11407343)
- Wolff-Parkinson-White syndrome (HP:0001716): A disorder of the cardiac conduction system of the heart characterized by ventricular preexcitation due to the presence of an abnormal accessory atrioventricular electrical conduction pathway. Evidence: PCS. Frequency: 35/35. (PMID:11748095;PMID:11407343)
- Childhood onset (HP:0011463): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 3/3. (PMID:11748095)
- Young adult onset (HP:0011462): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. (PMID:11407343)
- Ventricular preexcitation with multiple accessory pathways (HP:0006684): A form of ventricular preexcitation due to the presence of multiple accessory pathways for cardiac conduction. Evidence: PCS. Frequency: 2/8. (PMID:11407343)
- Ventricular preexcitation (HP:0004309): An abnormality in which the cardiac ventricles depolarize too early as a result of an abnormality of cardiac conduction pathways such as an accessory pathway. Evidence: PCS. Frequency: 27/27. (PMID:11748095;PMID:11407343)
- Atrial flutter (HP:0004749): A type of atrial arrhythmia characterized by atrial rates of between 240 and 400 beats per minute and some degree of atrioventricular node conduction block. Typically, the ventricular rate is half the atrial rate. In the EKG; atrial flutter waves are observed as sawtooth-like atrial activity. Pathophysiologically, atrial flutter is a form of atrial reentry in which there is a premature electrical impulse creates a self-propagating circuit. Evidence: PCS. Frequency: 2/3. (PMID:11748095)
- Palpitations (HP:0001962): A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia. Evidence: PCS. (PMID:11407343)
- Paroxysmal atrial fibrillation (HP:0004757): Episodes of atrial fibrillation that typically last for several hours up to one day and terminate spontaneously. Evidence: PCS. Frequency: 15/34. (PMID:11748095;PMID:11407343)
- Prolonged QRS complex (HP:0006677): Increased time for the complex comprised of the Q wave, R wave, and S wave as measured by the electrocardiogram (EKG).. In adults, normal values are 0.06 - 0.10 sec. Evidence: PCS. (PMID:11407343)
- Syncope (HP:0001279): A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion. Evidence: PCS. Frequency: 14/26. (PMID:11748095;PMID:11407343)
- Autosomal dominant inheritance (HP:0000006): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:11407343)
- Sudden cardiac death (HP:0001645): The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset). Evidence: PCS. Frequency: 6/31. (PMID:11407343)
These phenotypes are associated with the disease Wolff-Parkinson-White syndrome (OMIM:194200).