Answer
The abnormal cords or bridges of myocardium that extend from the atrium to the ventricle, bypassing the normal atrioventricular (AV) node and other parts of the conduction system, can lead to a condition known as **atrioventricular (AV) reentrant tachycardia** or **atrioventricular reentrant rhythms**. This condition can significantly affect the cardiac rhythm and lead to irregular and rapid heartbeats. Here's how this abnormality can impact cardiac rhythm:
1. **Formation of Reentrant Circuit:** In a normal heart, the AV node serves as a gatekeeper, allowing only specific electrical impulses to pass from the atria to the ventricles. When abnormal cords or bridges of myocardium are present, they create additional pathways for electrical signals to travel directly from the atria to the ventricles. This can create a reentrant circuit, where electrical signals can loop back and re-enter the AV node or bypass the normal conduction pathway.
2. **Reentry Loops:** The presence of these extra pathways can create reentry loops, in which electrical impulses continuously circulate between the atria and ventricles. This can lead to rapid and chaotic electrical activity in the heart.
3. **Atrioventricular Reentrant Tachycardia:** The reentrant circuits can cause the heart to beat abnormally fast, resulting in tachycardia. Atrioventricular reentrant tachycardia is characterized by rapid heart rates, often ranging from 150 to 250 beats per minute. The abnormal electrical signals can overwhelm the normal heart rate control mechanisms, leading to sustained periods of rapid heartbeat.
4. **Symptoms:** Patients with AV reentrant tachycardia may experience palpitations, dizziness, lightheadedness, shortness of breath, and even fainting. The rapid and irregular heartbeat can disrupt normal blood flow and oxygen delivery to the body's organs and tissues.
5. **Management:** AV reentrant tachycardia can often be managed through medical interventions, such as medications that regulate heart rate and rhythm. In some cases, procedures like catheter ablation might be recommended to selectively eliminate the abnormal conduction pathways and restore normal heart rhythm.
In summary, the presence of abnormal cords or bridges of myocardium that create additional pathways for electrical signals in the heart can lead to the formation of reentrant circuits and atrioventricular reentrant tachycardia. This condition disrupts the normal coordination of electrical signals between the atria and ventricles, resulting in rapid and irregular heartbeats that can cause various symptoms and potential complications.
Work Step by Step
The abnormal cords or bridges of myocardium that extend from the atrium to the ventricle, bypassing the normal atrioventricular (AV) node and other parts of the conduction system, can lead to a condition known as **atrioventricular (AV) reentrant tachycardia** or **atrioventricular reentrant rhythms**. This condition can significantly affect the cardiac rhythm and lead to irregular and rapid heartbeats. Here's how this abnormality can impact cardiac rhythm:
1. **Formation of Reentrant Circuit:** In a normal heart, the AV node serves as a gatekeeper, allowing only specific electrical impulses to pass from the atria to the ventricles. When abnormal cords or bridges of myocardium are present, they create additional pathways for electrical signals to travel directly from the atria to the ventricles. This can create a reentrant circuit, where electrical signals can loop back and re-enter the AV node or bypass the normal conduction pathway.
2. **Reentry Loops:** The presence of these extra pathways can create reentry loops, in which electrical impulses continuously circulate between the atria and ventricles. This can lead to rapid and chaotic electrical activity in the heart.
3. **Atrioventricular Reentrant Tachycardia:** The reentrant circuits can cause the heart to beat abnormally fast, resulting in tachycardia. Atrioventricular reentrant tachycardia is characterized by rapid heart rates, often ranging from 150 to 250 beats per minute. The abnormal electrical signals can overwhelm the normal heart rate control mechanisms, leading to sustained periods of rapid heartbeat.
4. **Symptoms:** Patients with AV reentrant tachycardia may experience palpitations, dizziness, lightheadedness, shortness of breath, and even fainting. The rapid and irregular heartbeat can disrupt normal blood flow and oxygen delivery to the body's organs and tissues.
5. **Management:** AV reentrant tachycardia can often be managed through medical interventions, such as medications that regulate heart rate and rhythm. In some cases, procedures like catheter ablation might be recommended to selectively eliminate the abnormal conduction pathways and restore normal heart rhythm.
In summary, the presence of abnormal cords or bridges of myocardium that create additional pathways for electrical signals in the heart can lead to the formation of reentrant circuits and atrioventricular reentrant tachycardia. This condition disrupts the normal coordination of electrical signals between the atria and ventricles, resulting in rapid and irregular heartbeats that can cause various symptoms and potential complications.
