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Palpitations - sudden rapid pulse - 1-channel ECG with Apple Watch 4
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A 62-year-old healthy man notices a sudden inner restlessness from physical rest. Consequently, he palpates a very rapid pulse. There is no definite trigger.
However, he already knows this heart palpitations from his previous history. On the one hand the palpitations always start suddenly, on the other hand they stop just as suddenly (on-off, like a light switch). The episodes occur 1-2 times a year and so far he can successfully end them by vagal or mechanical maneuvers with ice water or headstand. A documentation with a 12-lead ECG has not been done yet.
Current symptoms of running heart palpitations
- inner restlessness
- No drowsiness
- physically resilient
Smartphone 1-channel ECG - Apple Watch 4
What do I see:
- electrical heart rate 170 bpm
- regular chamber actions
- narrow chamber complexes
- no safe P wave, possible immediately after QRS complex
Suspected diagnosis by the cardiologist
- Highly suspected AV nodal re-entrant tachycardia (AVNRT).
Anamnesis criteria from the previous history
- sudden onset and cessation of tachycardia
- ended several times by mechanical and vagal maneuvers
ECG - criteria of typical AVNRT
- narrow QRS complexes
- regular QRS complexes
- No P wave or P wave detectable immediately after QRS complex
Acute therapy of AVNRT
Mechanical maneuver
- Headstand (original image)
- leads to termination of the arrhythmia with sinus rhythm
Technical notes
At very high heart rates, the P wave is often difficult to delineate. However, complete blockade of the AV node using adenosine can make the P wave visible.
The analysis mode of the Apple Watch only allows the diagnosis "possible atrial fibrillation" up to a heart rate of 120 bpm. Incidentally, the same also applies at a heart rate of below 50 bpm. In short, the Apple Watch is only suitable for the diagnosis of "possible atrial fibrillation" in a heart rate range of 50-120 bpm. Consequently, strictly speaking, the above case may have been pseudoregular fast atrial fibrillation. However, this is unlikely due to the responsiveness of the arrhythmia to a vagal maneuver with prompt termination of the tachycardia. At most, atrial fibrillation responds to vagal maneuvers with a transient slowing of the heart rate, almost never with complete termination.
Brief Description AV Nodal Reentry Tachycardia (AVNRT).
AVNRT is a basically "benign" cardiac arrhythmia, which typically begins and ends suddenly. This form of tachycardia can occur for the first time at any age.
In fact, you can often terminate AVNRT by vagal maneuvers (e.g., eye bulb pressure, pressure on a carotid artery, Valsalva press maneuver, ice water). However, you should really only perform a headstand if you are truly proficient in it. Consequently, the use of vagal maneuvers must always be discussed with a cardiologist before being performed for the first time.
AVNRT can lead to shortness of breath, increased urinary output ("urinary flooding") and poor performance if it lasts for several hours. For this reason, critical circulatory weakness with pulmonary edema may occur with concomitant other cardiovascular diseases, such as heart failure and coronary artery disease.
Consequently, if the AVNRT persists or the tachycardia cannot be terminated by vagal or mechanical maneuvers, then you must seek medical attention. If you are well, you can go immediately to a cardiologist or an emergency department. In case of doubt, and always in case of symptoms such as shortness of breath and dizziness, you should call the emergency medical services on 112.
AVNRT can typically be terminated by intravenous administration of adenosine (Adrekarâ"‡). In addition, this also allows diagnostic differentiation of atrial flutter with regular conduction.
Moreover, we can treat and thus "cure" AVNRT by catheter ablation. In addition, the procedure has few complications and is highly effective with success rates > 95%. Medicinal recurrence prophylaxis is not very effective and not recommended.
Cardiopraxis - Cardiologists in Düsseldorf & Meerbusch
