Progressive cardiac conduction defect (PCCD)

Progressive cardiac conduction defect (PCCD) (also known as Lev-Lenegre’s Syndrome) is a rare condition. In people with PCCD, the heart’s electrical impulses are conducted very slowly and this results in the gradual development over time of heart block. Heart block is a failure of the heart’s electrical impulse to conduct properly from the top chambers (the atria) to the bottom chambers (the ventricles). The severity of the condition and its associated risk can vary.

PCCD can cause arrhythmias – either because the heart’s rhythm is too sluggish (bradycardia and asystole), or because of rapid rhythm disturbances (tachycardia) arising from parts of the heart that have escaped normal regulation. In some people PCCD has been associated with sodium channel mutations that cause changes in the channel similar to those found in people with Brugada syndrome.

Symptoms

Dizziness and blackouts are the usual symptoms, cardiac arrest may also occur.

Signs

There are no physical signs usually except if there is heart block when the doctor may feel a slow pulse.

Diagnosis

The ECG abnormalities may be detected either on a standard ECG or with Holter monitoring. An electrophysiological (EP) study may also help the doctor make a diagnosis. If a sodium channel mutation is identified in affected members of a family then it may also be found in other relatives.

Management

If you have PCCD you will probably need to have a pacemaker fitted in order to stop dangerous bradycardia from occurring. This may not prevent tachycardias from occurring so you may also need to take anti-arrhythmic drugs. Some people may need to have an ICD fitted instead of a pacemaker. Medication alone does not help.