A heart block is actually one of the results that doctors may derive from tests such as an ECG or electrocardiogram or an echo cardio stress test. It may be caused by certain conditions that may affect the electrical system of the heart. Heart blocks may occur in the different levels of electrical conduction system of the heart.

Heart Block Causes

Electrical pulses to the heart usually signal it to beat, these electrical impulses usually travel through pathways that go from the heart's upper chambers through the atrioventricular node and then through the heart's lower chambers. Along this route, the electrical impulses may move along a slender cluster of fibers known as the "bundle of His". This cluster divides into two branches- the right and the left bundles with one each for the heart's ventricles.

When one or both of these branches of heart fibers are damaged, such as during a heart attack, the electrical pulses that go through them may be compromised and may prevent the heart from beating normally. This can lead to the heart beat slowing down or blocked and the ventricles may no longer work in perfect coordination with one another.

Heart block can be caused by a number of things, with a heart attack just one among them. Weakened heart muscles can also lead to a heart block in some people. High blood pressure may also cause heart block as well as a heart abnormality that may already be present at birth. Heart block can also be caused by scar tissue that may develop in the heart after surgery. A viral or bacterial infection that affects the heart muscle can also cause heart block.

Heart Block Symptoms

In most cases, a heart block may not show any obvious symptoms. Some cases where people born with the condition may not even feel any symptoms of heart block for years. But in some people, symptoms of heart block that do occur may include fainting, dizziness, as well as a slow heart rate.