12- channel ECG
Diagnosis is almost always possible with the help of the ECG (Mewis 2004). A regular ventricular rhythm of 140 beats/min with a normal QRS complex is always suspicious for atrial flutter (Wolff 2020).
Typical in atrial flutter is the presence of a:
- Sawtooth-shaped deformation due to
- negative P- waves in II, III and aVF at "counter- clock- wise" (see "Pathophysiology") with a frequency of 220 - 270 beats / min.
- positive P- waves in II, III, aVF and V1 in "reverse typical atrial flutter" (see "Pathophysiology"), also with a frequency of 220 - 270 beats / min (Herold 2020 / Pinger 2019).
However, the typical sawtooth-shaped deformation may often not be apparent in a 2: 1 transition. In this case, a carotid pressure test is recommended (this leads to a temporary AV block) (Wolff 2020).
Type I (see classification):
- negative flutter waves in II, III, aVF are possible
- positive flutter wave in V1 possible
Type II (see classification):
- The typical morphology of P- waves is not found here (Stierle 2017). In most cases, an AV- block of II degree with 2: 1 or 3: 1 conduction occurs, which leads to a lowering of the ventricular frequency. The frequency of the ventricles in this case is about 140 beats / min.However, there is always a risk of 1: 1 conduction with threatening ventricular tachycardia (Herold 2020).
Transesophageal echocardiography (TEE).
If atrial flutter persists for more than 48 h, thrombus exclusion by TEE is required. Patients on permanent anticoagulation are excluded (Kraemer 2018).