56 year-old male amateur athlete with transient ischemic attack during mountain race

The case

Description

• A male amateur athlete (56 years, BMI 22.8 kg/m2) suffered a transient ischemic attack during a mountain race.
• He now complained of a reduced exercise capacity after a period of no exercise training.
• Prior to the event, the patient exercised 5 times per week for 1 to 2 hours per session, cross-country skiing during winter and running and cycling during summer, and participated in official competitions.
• He had a history of arterial hypertension which was treated with an ACE-Inhibitor.
• Family history was negative for cardiovascular disease.
• The electrocardiogram showed a normal sinus rhythm, 65 beats per min, without depolarisation or repolarisation abnormalities.
• A transthoracic echocardiography showed concentric left ventricular remodeling with normal systolic function and first degree diastolic dysfunction, mildly dilated atria, without relevant valvular dysfunction nor pulmonary hypertension.
• Transoesophageal echocardiography revealed neither thrombi nor persistent foramen ovale.
• Seven days Holter monitoring revealed no atrial fibrillation.

A cardiopulmonary exercise test was performed for the following questions:

1. Determination of exercise capacity.
2. Blood pressure response during exercise.
3. Heart rate kinetics and exercise-related arrhythmias.
4. Exercise-related pulmonary hypertension (ventilation-perfusion mismatch)
5. Determination of training zones based on ventilator thresholds to guide re-uptake of exercise training.

Test findings

• The resting spirometry showed a FVC of 4.5 l (99% predicted), a FEV1 of 3.8 l (106% predicted), and a FEV1/FVC of 85%. Estimated maximum voluntary ventilation (MVV, FEV1*40) was 152 l.
• A standard ramp protocol for athletic individuals was chosen. The test started with 3 min rest (R), followed by 3 min constant load at 100 watt, followed by a ramp (30 watt/min) (T) until exhaustion, ending with a 4 min recovery period at 50 watt (R) (Panel 3).
• Exercise capacity was above average with 316 Watt (4.3 Watt/kg, 189 % predicted), and a peak VO2 of 45.8 ml/min/kg (13.1 MET, 146 % predicted) (Panel 3).
• Blood pressure increased from 130/75 mmHg to 200/95 mmHg at peak exercise.
• Heart rate increased from 79 beats per min to 148 beats per min (90% predicted).
• Heart rate recovery in the first min after exercise was 22 beats (Panel 2).
• No arrhythmias or ST depressions occurred.
• Maximum rate pressure product was 29600 mmHg/min.
• Maximum respiratory exchange ratio was 1.22 (Panel 8).
• The patient was exhausted at the end of the test (Borg 19/20).
• Maximum ventilation was 135 l (Panel 1)
• Breathing reserve ((1-VEmax/MVV)*100) was 11% (Panel 8).
• Respiratory efficiency, determined by the VE/VCO2 slope was 25 (Panel 4).
• Peak PETCO2 was 42 mmHg (Panel 9).
• The O2 pulse (VO2/heart rate) increased to 22.6 ml (170% of predicted, Panel 2).
• The VO2/work rate slope was 8.8 ml/min/watt (Panel 3).
• The first ventilatory threshold (anaerobic threshold, AT) could be determined in Panel 6 (increase in EqO2) and Panel 9 (increase in PETO2), but not in Panel 5.
• The second ventilatory threshold (respiratory compensation point, RCP) could be determined in Panel 6 (increase in EqCO2), and Panel 9 (decrease in PETCO2), and could be confirmed in Panel 4 (increase in VE/VCO2 slope).

Spirometry

9 Panel Plot of the Cardiopulmonary Exercise Test