A third-degree AV block is a serious type of heart rhythm disorder where the electrical signal between the upper chambers of the heart and the lower chambers is completely interrupted.
What exactly happens in a third-degree AV block?
The heart works like a pump whose beat is controlled by electrical impulses. These impulses start in the sinoatrial node, travel through the AV node (short for "atrioventricular node"), and reach the ventricles. Normally, this system keeps the heart beating steadily and in a coordinated way.
In a third-degree AV block, also called a complete AV block, the connection between the upper chambers (atria) and the lower chambers (ventricles) is completely blocked. The electrical signals from the atria can no longer reach the ventricles. As a result, the ventricles beat in their own rhythm, which is usually much slower. The atria and ventricles then work completely independently of each other.
Symptoms and possible consequences
A complete AV block can cause quite different symptoms. Some people only notice occasional dizziness or mild weakness, while others experience more pronounced symptoms. Common signs include strong fatigue, fainting episodes, or a noticeably slow pulse. In some cases, sudden loss of consciousness can occur because the brain is not receiving enough blood for a short time.
The consequences of a third-degree AV block can be serious. When the heart beats too slowly, it can no longer supply the body with enough oxygen. The risk of complications such as heart failure, falls, or even sudden cardiac death is increased. Older people or those with additional heart conditions are particularly at risk.
Causes: why does a complete AV block develop?
A third-degree AV block can develop due to various changes in the heart. Often, there is age-related calcification or damage to the electrical conduction system. Heart attacks, inflammation, certain medications, or congenital conditions can also be triggers. In rare cases, heart surgery or a severe infection may be the cause.
Is this serious, and what happens now?
A complete AV block is a dangerous heart rhythm disorder that needs treatment in most cases. Many people wonder after the diagnosis: how dangerous is this? The answer is that without treatment, there is a high risk of further fainting episodes or even life-threatening complications. However, if the AV block is identified and treated in time, the outlook is good in the vast majority of cases.
The diagnosis can be unsettling. Common questions include: "Could I suddenly collapse?" or "What will daily life look like with this diagnosis?" These worries are completely understandable. The good news is that with the right treatment, the risk of serious consequences can be significantly reduced.
Treatment options for third-degree AV block
The most important and most common treatment is the implantation of a pacemaker. This small device takes over the job of sending electrical impulses to the ventricles, ensuring a regular heartbeat. The pacemaker is usually fitted under local anaesthetic and prevents the heart from beating too slowly.
After a pacemaker is fitted, a normal life is possible again in most cases. Symptoms such as dizziness or fainting generally disappear quickly. Regular check-ups with a cardiologist are important to monitor how the device is working and to spot any potential problems early.
Sometimes a third-degree AV block can be temporary, for example triggered by medication or an acute inflammation. In such cases, it may be enough to treat the underlying cause. However, if the block persists, a pacemaker is almost always necessary.
Living with the diagnosis
Many people feel anxious about the idea of relying on a pacemaker. Most, however, quickly get used to the small device and can live their daily lives with very few restrictions. Sport, travel, and social activities are still possible with only a few exceptions. Modern pacemakers are very reliable and are checked regularly.
It is important to seek medical help straight away if you notice new or unusual symptoms such as dizziness, fainting, or a strong palpitation. Even after a pacemaker is fitted, the heart should be monitored regularly.
A third-degree AV block is a serious but very treatable heart rhythm disorder. With modern medicine and the right treatment, quality of life can be maintained in the vast majority of cases.
