What is Progressive Cardiac Conduction Defect (PCCD)?
Progressive Cardiac Conduction Defect (PCCD), also known as Lev-Lenegre’s Syndrome, is a rare heart condition characterised by a gradual slowing of the heart’s electrical impulses. Over time, this slowing leads to heart block, where the electrical signals fail to properly conduct from the atria (upper chambers of the heart) to the ventricles (lower chambers).
PCCD can progress at varying rates, and the severity of heart block and associated risks differ among individuals.
How PCCD Affects the Heart
In people with Progressive Cardiac Conduction Defect, the slow conduction of electrical impulses can cause arrhythmias. These irregular heartbeats can be either too slow (known as bradycardia or asystole) or too fast (tachycardia) due to improper regulation in certain parts of the heart.
Recent studies suggest that PCCD may be linked to sodium channel mutations, similar to those found in individuals with Brugada syndrome. These mutations can disrupt normal heart rhythm and increase the risk of serious complications.
Symptoms of PCCD
- Dizziness
- Blackouts or fainting episodes
- In severe cases, cardiac arrest may occur.
Signs of Progressive Cardiac Conduction Defect
Physical signs of PCCD are generally not apparent unless the heart block is present. In such cases, a healthcare provider may notice a slow pulse during a physical exam.
Diagnosis of PCCD
To diagnose Progressive Cardiac Conduction Defect, several tests may be used:
- Electrocardiogram (ECG): A standard ECG can detect abnormalities in the heart’s electrical activity.
- Holter Monitoring: Continuous monitoring of the heart’s rhythm over 24 to 48 hours may reveal irregularities not seen on a standard ECG.
- Electrophysiological (EP) Study: This test can help doctors determine the exact nature of the electrical conduction issue.
- Genetic Testing: If PCCD is suspected to be linked to a sodium channel mutation, genetic tests can be used to identify the mutation in the affected individual and potentially in their family members.
Management and Treatment Options for PCCD
Treatment for Progressive Cardiac Conduction Defect primarily involves managing the risk of dangerous heart rhythms:
- Pacemaker Implantation: Most individuals with PCCD will need a pacemaker to prevent bradycardia.
- Anti-Arrhythmic Medications: In addition to a pacemaker, some patients may require medications to control tachycardia.
- Implantable Cardioverter Defibrillator (ICD): For individuals at risk of life-threatening arrhythmias, an ICD may be recommended instead of a pacemaker. An ICD can detect and correct abnormal heart rhythms.
Why Medication Alone Isn’t Enough
For most patients with PCCD, medications alone are insufficient to manage the condition. A pacemaker or ICD is typically necessary to prevent serious complications such as heart failure or sudden cardiac death.
