Exercise-Induced Arrhythmia or Munchausen Syndrome in a Marathon Runner?

Abstract

A 36-year-old professional marathon runner reported sudden irregular palpitations occurring during competitions, with heart rates (HR) up to 230 bpm recorded on a sports HR monitor (HRM) over 4 years. These episodes subsided upon the cessation of exercise. Electrocardiograms, echocardiography, and cardiac magnetic resonance imaging results were borderline for athlete's heart. Because an electrophysiology study and standard exercise tests provoked no arrhythmia, doctors suspected Munchausen syndrome. Ultimately, an exercise test that simulated the physical effort of a competition provoked tachyarrhythmia consistent with the HRM readings. This case demonstrates the diagnostic difficulties related to exercise-induced arrhythmia and the diagnostic usefulness of sports HRMs.

Keywords: Munchausen syndrome; arrhythmia; artifacts; athlete’s heart; endurance running; exertion rhythm disorders; heart rate monitor; tachycardia.

Figure 1

HR recordings on the athlete’s HRM (Suunto Smartwatch 9 Peak with Suunto Smart Heart Rate Belt) during two different marathon runs (A,B) and a 10 km run (C). In (A,B), HR spikes (red peaks) up to about 219 bpm receded after the athlete stopped for a short period. Panel (B) additionally shows the running pace in black; the five sharp “down-spikes” in black indicate momentary stops by the runner during the competition. Panel (C) shows apparently similar changes in the runner’s HR values during a 10 km competition (158–210 bpm), but these are simple artifacts; these disturbances resolved after the HRM belt’s battery was replaced.

Figure 2

The athlete following an exercise test on a treadmill, wearing the ECG apparatus (BTL Flexi 12 ECG; (A) and his heart rate monitor, including the Suunto Smart Heart Rate Belt (B) and Smartwatch Suunto 9 Peak (C). Only the attachment strap and electrodes of the ECG apparatus are visible because they are attached to the athlete’s back.

Figure 3

The athlete’s heart rhythm during an exercise test (A), including ECG printouts illustrating tachyarrhythmia paroxysms during the test (B,C). A brief supraventricular tachycardia paroxysm of several seconds was recorded at 187 bpm ((A), arrow 1, and (B)) and again at 230 bpm ((A), arrow 2, and (C)) on both devices simultaneously.

Figure 4

Procedure for managing suspected arrhythmias based on indications by different types of heart rate monitors according to Gajda et al. [26]. Abbreviations: HRM—heart rate monitor, PPG-S—photoplethysmography sensors, ECG-S—electrocardiography sensors, ECG—electrocardiography, TTE—transthoracic echocardiography, ETT—exercise tolerance test, MRI—magnetic resonance imaging, EPS—intracardiac electrophysiology study.