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Tachycardia: Difference between revisions
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→Atrial Flutter
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===Atrial Flutter=== | ===Atrial Flutter=== | ||
====Pathophysiology:==== | ====Pathophysiology:==== | ||
Atrial flutter (AFT) is the most common type of atrial tachycardia | Atrial flutter (AFT) is the most common type of atrial tachycardia. The typical atrial flutter is dependent of the cavotricuspid isthmus. The isthmus between the caval vein and tricuspid is an area of slow conduction. Due to this slow conduction counterclockwise re-entry around the tricuspid annulus can exist. This re-entry produces a typical arrhythmia with activates the atria at a frequency between 250-350 beats per minute. If the re-entry circuit moves counterclockwise a typical AFT is produced. If the re-entry circuit moves clockwise, a atypical AFT is seen. The causes and risk are comparable with atrial fibrillation. | ||
====Clinical diagnosis:==== | ====Clinical diagnosis:==== | ||
An AFT is usually paroxysmal and is diagnosed on the ECG by it typical sawtooth pattern and atrial frequency. An AFT has a frequency of 300 bpm, which conducts to the ventricles in 2:1, 3:1 or 4:1 manner. The P-wave morphology has a sawtooth like appearance and in a typical AFT has a negative vector in the inferior leads. The first part of the P-wave is fast, the second path slow. In a atypical AFT the inferior leads have a positive vector. | An AFT is usually paroxysmal, with a sudden onset, and is diagnosed on the ECG by it typical sawtooth pattern and atrial frequency. Patients experience complaints of palpitations, dyspneu, fatigue or chest pain. An AFT has a frequency of 300 bpm, which conducts to the ventricles in 2:1, 3:1 or 4:1 manner. The P-wave morphology has a sawtooth like appearance and in a typical AFT has a negative vector in the inferior leads. The first part of the P-wave is fast, the second path slow. In a atypical AFT the inferior leads have a positive vector. Atrial fibrillation is a common finding in patients with an atrial flutter (up to 35%). | ||
====Management:==== | ====Management:==== | ||
In a acute episode a patient with an AFT requires cardioversion. This can be achieved with anti-arrhythmic drugs or electrical cardioversion. Vagal manoeuvres increase the AV-block on the ECG and demonstrate the AFT more clearly | In a acute episode a patient with an AFT requires cardioversion. This can be achieved with anti-arrhythmic drugs or electrical cardioversion. Vagal manoeuvres increase the AV-block on the ECG and demonstrate the AFT more clearly. Anti-arrhythmic drugs are not effective in the acute setting and have the risk of pro-arrhythmic effects. Patients with AFT require anti-coagulation as in atrial fibrillation according to the CHADSVASc score. DC cardioversion is an effective methods to cardiovert AFT, especcily in patients with heart failure or hemodinamic instability. AFT are amendable to catheter ablation and this is the treatment of choice in AFT. This is a very succesfull procedure, with few complications in the hands of an experiences electrophysiologist. If patients are not eligible for ablation, anti-arrhythmic drugs can be started. However they are of limited efficacy and class IC drugs not be administered because of atrial slowing can result in 1:1 AV conduction. | ||
===Atrial Fibrillation=== | ===Atrial Fibrillation=== | ||