55 year-old male amateur athlete with palpitations during bike rides

The case

Description

• This male amateur athlete (55 years, BMI 23.15 kg/m2) presented with palpitations during bike rides
• He described a rapid increase in heart rate up to 210 bpm, documented by his training monitor, associated with a feeling of loss of performance.
• The patient has a history of mitral regurgitation secondary to a mitral valve prolapse of the posterior leaflet, for which he underwent mitral valve reconstruction one year ago.
• The patient used to exercise 3 times per week for 2 to 4 hours per session (skiing and biking). Currently he is not on any medication.
• A recently performed 24-hour ambulatory ECG revealed some premature ventricular beats.
• A transthoracic echocardiography showed mildly dilated atria and ventricles, a normal left ventricular ejection fraction and a good mitral valve function without relevant regurgitation.
• The family history includes a sudden cardiac death of a brother at the age of 57 years.
• A cardiopulmonary exercise test was performed for further investigation.

Test findings

• The 9-plot analysis documented an above-average exercise capacity with 278 Watt (135 % predicted), and a peak VO₂ of 38 ml/min/kg (120 % predicted) (Panel 3).
• The O₂ pulse (VO₂/heart rate) (Panel 2) increased to above average values with a sudden drop at the end of the test. VO₂ increased parallel to the work load with a sudden drop at the end of the test (Panel 3).
• Exercise ECG revealed a sudden increase in heart rate at the end of the test but no exercise-induced ischemia. Blood pressure increased gradually from 130/80 mmHg at rest to 195/80 mmHg at peak exercise.
• There were no pathologic findings with regard to respiratory efficiency (VE/V_CO2 slope, Panel 4), P_ETCO₂ progress (Panel 9), breathing reserve (Panel 8) and resting pulmonary function test.
  
  

ECG during exercise