68 year-old female patient with exertional dyspnoea

The case

A 68-year-old female patient (BMI 20.8 kg/m2) complained of exertional dyspnoea:

• She had a history of composite graft replacement of the aortic root because of a bicuspid aortic valve with a dilated annulus 9 months ago.
• A DDD pacemaker was implanted due to postoperative atrioventricular (AV) block.
• A cardiopulmonary exercise test was performed on a treadmill using the modified Bruce protocol.

SPIROMETRY

9 PANEL PLOT OF THE CARDIOPULMONARY EXERCISE TEST

KEY PANELS

EXERCISE ECG

Test findings

The resting spirometry showed a FVC of 3.6 l (116% predicted), a FEV1 of 2.4 l (89% predicted), and a FEV1/FVC of 65%. Estimated maximum voluntary ventilation (MVV, FEV1*40) was 96 l.

Cardiorespiratory fitness was normal with a peak VO₂ of 20.5 ml/min/kg (5.9 MET, 106 % predicted) (Panel 3).

Blood pressure increased from 130/90 mmHg to 160/105 mmHg at peak exercise. Maximum respiratory exchange ratio was 1.04 (Panel 8). The patient was exhausted at the end of the test (Borg 18/20) and complained of exertional dyspnoea.

Maximum ventilation was 69 l (Panel 1). Breathing reserve ((1-VE_max/MVV)*100) was 27% (Panel 8). Respiratory efficiency, determined by the VE/VCO₂ slope was 38 (Panel 4). Peak P_ETCO₂ was 29 mmHg (Panel 9). The O₂ pulse (VO₂/heart rate) increased to 15.8 ml (199% of predicted, Panel 2). At the end of the test, a sudden drop in oxygen uptake (Panel 3) was detected.