Familial fibrillation

Familial Atrial Fibrillation Overview

• Definition: Familial Atrial Fibrillation (AFib) is an inherited heart condition characterized by uncoordinated electrical activity in the heart.

• Terminology:

  • Familial: Inherited from family.

  • Atrial: Referring to the upper chambers of the heart.

  • Fibrillation: Disorganized electrical signals causing irregular heartbeats.

Risk Factors

• Ancestry Influence: Individuals of European ancestry have a higher likelihood of developing AFib.

  • Risk Increase: Each 10% of European ancestry increases AFib risk by 13%.

Historical Context

• First Mention: Documented by William Osler in 1783 as "rebellious palpitation."

Diagnosis of AFib

• Initial Diagnosis:

  • EKG (Electrocardiogram): Quick 5-minute test for detecting AFib.

• Follow-up Tests:

  • Holter Monitor: Long-term heart rhythm monitoring.

  • Cardiac MRI: Detailed imaging of heart structure.

  • Echocardiogram: Evaluates heart function and structure.

Genetic Factors

• Inheritance Patterns:

  • Majority of mutations are autosomal dominant; one mutation is X-linked.

• Common Mutation:

  • KCNQ1 Gene: Encodes alpha subunit of cardiac potassium ion channel affecting heart depolarization and repolarization.

  • Effects of Mutation: Shortens action potential and increases pore numbers in the potassium channel.

Genetic Testing for AFib

• Testing Considerations:

  • Generally performed if individual is young or has family history of AFib.

  • Evaluation may include full panel testing for common mutations or genome sequencing.

Treatment Options

• Heart Rate Management:

  • Digoxin: Strengthens heart contractions and helps regulate heart rhythm.

• Heart Rhythm Stabilization:

  • Procainamide: Treats fast or irregular heartbeats, stabilizes rhythm.

• Blood Thinners:

  • Warfarin: Prevents blood clots and reduces clot formation risk.

• Procedures:

  • Electrical Cardioversion: Restores normal heart rhythm using electrical shocks.

Lifestyle Modifications

• Dietary Recommendations:

  • Emphasis on a balanced diet with vegetables, lean proteins (fish, chicken, turkey), and healthy fats (olive and avocado oil).

• Exercise: Regular heart-focused exercises can help manage heart rate.

• Alcohol Consumption: Limiting alcohol intake is advised.

Research Insights

• Study Focus: Examined a family with a history of AFib and the role of NPPA mutation on hormone and ion regulation in the heart.

  • NPPA Role: Regulates blood volume and ion concentrations influencing cardiac action potentials.

  • Findings: Elevated levels of A and P in some family members correlated with AFib occurrences, suggesting genetic implications.

Typical Age of Onset

• Typical onset age ranges from mid-70s to 80s, but can also be seen in teens and twenties due to genetic factors.

Questions Addressed

• Genes Associated with AFib: Many genes are involved, predominantly located on chromosome 11, with 5-6 key genes identified with related mutations.