User:Mr. Ibrahem/AV nodal reentrant tachycardia

AV-nodal reentrant tachycardia (AVNRT) is a type of abnormal fast heart rhythm. Symptom may include episodes of palpitations, neck pounding, lightheadedness, shortness of breath, increased urination, and chest discomfort. Onset is generally sudden. Complications may include a heart attack in those with preexisting coronary artery disease.

It is generally not associated with underlying heart disease. The underlying mechanism is believed to involve two pathways in the atrioventricular (AV) node that conduct at different speeds. Diagnosis is supported by an electrocardiogram (ECG) showing a regular heart rate of 140 to 280 beats per minute and a narrow QRS complex. The P waves are generally not visible as they occur within the QRS complex.

Treatment is with specific physical maneuvers, medications, or electrical cardioversion. Medications used may include adenosine or diltiazem. The initial recommended dose for cardioversion is 50 to 100J. Frequent attacks may be treated with radiofrequency ablation. If this is not an option beta blockers or diltiazem may be used long term. Outcomes are generally good.

AV nodal reentrant tachycardia represents about 60% of cases of paroxysmal supraventricular tachycardia (SVT). Onset is most often in people between 14 to 50 years old. Women are affected twice as often as men. The underlying mechanism was first descripted in 1973 by Denes.