Obligatory medical device diagnostics.
- Electrocardiogram (ECG; recording of the electrical activity of the heart muscle).
- [Strictly regular atrial actions: regular, sawtooth P waves with a frequency of 250-400/min.
- Narrow QRS complexes
- AV nodal block and conduction in a 4:1 or 2:1 ratio, rarely alternating.
- Atrial flutter with regular AV conduction (usually 2:1): narrow ventricular complex (QRS width ≤ 120 ms) = narrow complex tachycardia; atrial flutter with variable AV conduction (“variable block”): irregular narrow complex tachycardia]
- Transesophageal echocardiography (TEE; ultrasound examination of the heart using an ultrasound probe inserted into the esophagus) – before performing cardioversion (restoring normal heart rhythm) to rule out thrombi (blood clots) in the atrium
Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics and obligatory medical device diagnostics – for differential diagnostic clarification.
- Long-term ECG (ECG applied over 24 hours) – for more accurate assessment of cardiac function within the day, event recorder if necessary.