Related Experiment Video
Updated: May 20, 2026
11:07
High-resolution Optical Mapping of the Mouse Sino-atrial Node
Published on: December 2, 2016
[Cardiac sinus node dysfunction due to a new mutation of the SCN5A gene].
J-B Selly1, B Boumahni, A Edmar
1Service de réanimation néonatale et pédiatrique, CHU groupe hospitalier Sud, avenue du Président François-Mitterand, 97410 Saint-Pierre, Réunion. bernardselly@hotmail.com
Summary
A child with chikungunya virus infection experienced bradycardia due to sinus node dysfunction. Genetic analysis revealed compound heterozygous SCN5A mutations, leading to pacemaker insertion years later.
Area of Science:
- Pediatric Cardiology
- Infectious Diseases
- Clinical Genetics
Background:
- Viral infections can precipitate cardiac events in susceptible individuals.
- Sinus node dysfunction (SD) is a significant cause of bradycardia in children.
- The SCN5A gene is crucial for cardiac electrical function.
Observation:
- A 10-year-old child presented with bradycardia during chikungunya infection.
- Previous unexplained bradycardia episodes were noted.
- Cardiac investigations confirmed sinus node dysfunction.
Findings:
- Genetic screening identified compound heterozygous mutations in the SCN5A gene (p.Ala735Val and p.Asp1792Asn missense mutants).
- These SCN5A mutations are associated with cardiac sinus node dysfunction.
- Electrophysiological study revealed atrial flutter, necessitating pacemaker insertion.
Implications:
- This case highlights the potential for viral infections to unmask underlying genetic cardiac conditions.
- SCN5A mutations can lead to severe sinus node dysfunction and arrhythmias.
- Early genetic diagnosis and long-term monitoring are crucial for managing pediatric cardiac conditions.
Related Concept Videos
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the...
01:28Mechanism of Cardiac Arrhythmias
Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.
01:30Cardiomyopathy II: Dilated Cardiomyopathy
Dilated cardiomyopathy, or DCM, is a progressive myocardial disorder characterized by ventricular chamber dilation and contractile dysfunction.EtiologyVarious factors can cause DCM, including hypertension and heavy alcohol intake, which contribute to the weakening and enlargement of the heart muscle. Viral infections, such as Coxsackievirus B, adenoviruses, and influenza, can lead to DCM by causing inflammation and damage to heart tissue. Certain chemotherapeutic agents, including daunorubicin,...
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy
Restrictive cardiomyopathy (RCM) is a rare heart muscle disease characterized by impaired ventricular filling due to stiffened ventricular walls, leading to significant diastolic dysfunction.EtiologyRestrictive cardiomyopathy can arise from both inherited and acquired diseases, many of which are systemic. It is categorized into four main types: infiltrative, storage, non-infiltrative, and endomyocardial diseases.Infiltrative diseases, such as amyloidosis, lead to RCM by depositing amyloid...
01:25Cardiomyopathy I: Introduction and Classification
Cardiomyopathy, or CMP, is a group of diseases affecting the myocardial structure, impairing its ability to pump blood effectively. This condition can lead to arrhythmias, heart failure, or sudden cardiac death.Cardiomyopathies are classified into primary and secondary categories:Primary Cardiomyopathy refers to conditions involving only the heart muscle that are often idiopathic (of unknown cause) or genetic. They primarily affect the myocardium without the involvement of other systemic...
01:29Heart Failure II: Pathophysiology
Systolic Heart Failure and Compensatory MechanismsSystolic heart failure (also termed HFrEF, Heart Failure with Reduced Ejection Fraction) is the most prevalent type of heart filure. It results in a decreased volume of blood being pumped from the ventricle. The aortic arch and carotid sinuses have baroreceptors that detect reduced blood pressure, triggering the sympathetic nervous system (SNS) to release epinephrine and norepinephrine. Initially, this response aims to boost heart rate and...