Related Subjects:
|Wolff-Parkinson White syndrome (WPW) AVRT
|Lown Ganong Levine Syndrome AVRT
|Supraventricular Tachycardia (SVT)
|Atrioventricular Nodal Reentrant Tachycardia AVNRT
|Atrial Flutter
|Atrial Fibrillation
|Sinus Tachycardia
|Sinus Arrhythmia
|Multifocal Atrial Tachycardia
|Resuscitation - Adult Tachycardia Algorithm
Important: Class I and III drugs should not be given until the rate has been controlled by Digoxin, beta-blockers or calcium blockers. This is because they slow the flutter rate and this can lead to 1:1 conduction. Due to a reentrant circuit which produces typical atrial flutter has led to the development of catheter ablation techniques that can prevent recurrence in >90% of cases
About
- Atrial arrhythmia rate 280-350/min
- Always suspect when the rate is 150/min
Aetiology
- Atrial flutter is a macro reentrant atrial arrhythmia
- Usual rate of 280-350/min usually involving the right atrium
ECG
- Sawtooth appearance atrial rate 300
- 1:1 AV Block Rate Ventricular rate 300/min but AV node blocks such rates though an accessory pathway may allow it.
- 2:1 AV Block Rate Ventricular rate 150/min
- 3:1 AV Block rate Ventricular rate 100/min
- 4:1 AV Block Rate Ventricular rate 75/min
- Carotid sinus massage or Adenosine increases AV block and shows flutter waves
Now it is divided into Type I and II
- Type I is due to a macro reentrant tachycardia
- Type II no one is sure about the mechanism of type II
ECG Appearance
Causes
- Idiopathic, Pulmonary embolism, Atrial septal defect, IHD
- Hypertension, Cardiomyopathy
- COPD, Post Cardiac surgery, Pericarditis
Clinical
- None, palpitations, breathlessness, Heart failure, Hypotension
Investigations
- FBC, U&E, TFT's, CRP, CXR. Troponin and BNP may be useful.
- ECG: A Flutter should be suspected in all tachyarrhythmias with a ventricular rate of 150/min as it may well be underlying Aflutter with 2:1 AV block. Carotid sinus massage or Adenosine may increase AV block and show flutter waves
- Echocardiogram: assess LV function, valves, pericardium
Management
- Synchronised DC cardioversion is the best treatment to restore sinus rhythm rapidly if the patient is unwell.
- Digoxin increases AV block and slows ventricular rate.
- Amiodarone may restore SR and reduce the
frequency of Flutter.
- Usually associated with a single re-entrant pathway in the right atrium which makes it amenable to cure by catheter ablation techniques
- Adenosine may be useful to cause some degree of AV block and allow the flutter saw tooth waves to be more evident but does not stop the arrhythmia unlike a re-entrant SVT
- Anticoagulation: The evidence and data for thromboembolism with pure atrial flutter are lacking. However, many patients would be anticoagulated but the risks of embolism are less than with AF.
- Flecainide alone slows the flutter but can cause 1:1 conduction - see below
References