Tuesday, September 9, 2014


The ventricles are the heart's two lower chambers. They fill with blood from the top chambers of the heart (atria) and send it to the lungs and through the aorta to be circulated throughout the body. Tachycardia is a heart rate of greater than 100 beats per minute. A normal heart rate is 60 to 100 beats per minute at rest. Ventricular tachycardia is a regular, faster-than-normal heart rate that begins in the heart's lower chambers. In most patients with ventricular tachycardia the rate is in the range of 170 beats per minute or more.

Most often, ventricular tachycardia is caused by other heart problems such as coronary artery disease, high blood pressure, an enlarged heart (cardiomyopathy) or heart valve disease. It also can develop after a heart attack (myocardial infarction) or after heart surgery because of scar tissue that forms on the heart.

VT can develop in people who do not have heart disease, but this is less commonly the case. In these individuals, the condition can be caused by certain medications, an imbalance in electrolytes (the minerals that regulate heart rhythm), excessive caffeine or alcohol consumption, recreational drugs or exercise, or certain genetically transmitted conditions. In others, it occurs in the absence of heart disease or any other clearly identified causes.

What is atrial fibrillation?
Atrial fibrillation (AF or AFib) is the most common irregular heart rhythm that starts in the atria. Instead of the SA node (sinus node) directing the electrical rhythm, many different impulses rapidly fire at once, causing a very fast, chaotic rhythm in the atria. Because the electrical impulses are so fast and chaotic, the atria cannot contract and/or squeeze blood effectively into the ventricle.

Instead of the impulse traveling in an orderly fashion through the heart, many impulses begin at the same time and spread through the atria, competing for a chance to travel through the AV node. The AV node limits the number of impulses that travel to the ventricles, but many impulses get through in a fast and disorganized manner. The ventricles contract irregularly, leading to a rapid and irregular heartbeat. The rate of impulses in the atria can range from 300 to 600 beats per minute.

There is no one “cause” of atrial fibrillation, although it is associated with many conditions, including:
Hypertension (high blood pressure)
Coronary artery disease
Heart valve disease
After heart surgery
Chronic lung disease
Heart failure
Congenital heart disease
Pulmonary embolism


Know more about VT:

Know more about AF:

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