August 18, 2021/Pulmonary/Case Study

Case Study: Invasive Cardiopulmonary Exercise Testing Helps Uncover True Cause of Dyspnea

Ruling out a common diagnosis and identifying an elusive condition

21-PUL-2223308_Fig3B 650×450-hero

By Adriano Tonelli, MD, and Anthony Cucci, MD

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Presentation

An obese 51-year-old man with obstructive sleep apnea presented with progressive dyspnea for one year. Extensive evaluations revealed mild restriction on pulmonary function tests with normal diffusing capacity for carbon monoxide and normal lung parenchyma on a CT of the chest. An echocardiogram showed normal left and right ventricular systolic function. A right heart catheterization noted postcapillary pulmonary hypertension (PH) (pulmonary artery wedge pressure [PAWP] of 25 mm Hg). The patient was treated with diuretics without clinical improvement.

Management

The patient underwent invasive cardiopulmonary exercise testing, given the persistent dyspnea with minimal activities. During the test we noted the presence of postcapillary PH with an end-expiratory PAWP of 26 mm Hg. We suspected a high intrathoracic pressure given obesity and pronounced respiratory oscillation with positional changes of his pulmonary pressures. Esophageal manometry revealed an end-expiration supine pressure of 18 mm Hg (Figure 1), hence the adjusted PAWP was normal at 8 mm Hg. In addition, the PAWP/cardiac output slope was normal (< 2 Wood units) during the exercise test and therefore not supportive of postcapillary PH with activities.

Figure 1. End-expiratory PAWP (A) and intrathoracic pressures (B) in supine position.

Maximum exercise showed a mildly decreased peak oxygen consumption at 78% of predicted with normal anaerobic threshold. The flow-volume loops during exercise revealed inspiratory and expiratory flattening suspicious for an airway pathology (Figure 2).

Figure 2. Flow-volume loops at rest (red line) and during exercise (other colors). Figure shows inspiratory and expiratory flow flattening with exercise.

We performed flexible laryngoscopy during exercise and noted a right vocal cord paralysis with redundant arytenoid tissue that reduced the glottis. The patient was able to exercise better while on continuous positive airway pressure (CPAP) adjusted to his intrathoracic pressure, with better glottis opening during flexible laryngoscopy.

A dynamic CT of the chest showed no significant tracheal stenosis or tracheobronchomalacia. However, a bronchoscopy revealed a right arytenoid fold that almost completely occluded the airway under deep respiration (Figure 3), with evidence of severe expiratory dynamic airway collapse (Figure 4) that extended to the segmental bronchial level.

Figure 3. Flexible laryngoscopy during exercise (A) and bronchoscopy evaluation (B [inhalation], C [exhalation]). Figures show right vocal cord paralysis, redundant right arytenoid fold with narrowing/occlusion of the glottis.

Advertisement

Figure 4. Bronchoscopy showing expiratory dynamic airway collapse (A [inspiration], B [exhalation]).

Implications

This case illustrates the value of an adequate hemodynamic evaluation in patients with PH. An increase in intrathoracic pressure is directly transmitted to the pulmonary vessels leading to a high PAWP and the inadequate diagnosis of postcapillary PH, as in this case. This change in diagnosis was supported by the lack of clinical response and worsening of renal function when the patient was treated with diuresis. A careful recording of flow-volume loops allowed us to detect the flattening of inspiratory and expiratory flows. This abnormal finding was further explored with flexible laryngoscopy and then bronchoscopy, leading to the final diagnosis of exercise-induced laryngeal obstruction with expiratory dynamic airway collapse.

Adriano Tonelli, MD, is staff in the Department of Pulmonary Medicine within Cleveland Clinic’s Respiratory Institute. Anthony Cucci, MD, is staff in the Department of Critical Care Medicine within Cleveland Clinic’s Respiratory Institute.

Advertisement

Related Articles

POCUS
November 16, 2022/Pulmonary/Case Study
Case Study: Point of Care Ultrasound to Guide Complex Hemodynamic Management

A recent case illustrates how timely and appropriate use of POCUS can provide benefits at all stages of the care path

CT of chest
November 2, 2022/Pulmonary/Case Study
Case Report: Pulmonary Hypertension in a Patient with IgG4-Related Disease

An inability to obtain a biopsy of the patient’s hilar lymphadenopathy due to severe PAH and severe hypoxemia made diagnosis verification challenging

Sarcoidosis
July 12, 2022/Pulmonary/Case Study
Case Study: Pulmonary Sarcoidosis

A multidisciplinary approach to treatment can be beneficial since other organs in addition to the lungs can be affected by the systemic disease

chest examination
April 21, 2022/Pulmonary/Case Study
Dyspnea, Wheezing and Cough: A Case Study

This case illustrates the importance of looking at the bigger picture when considering a patient’s respiratory symptoms.

21-PUL-2311233 Comples Case Immunology Fernandez_CQD
September 20, 2021/Pulmonary/Case Study
Case Report: Common Variable Immunodeficiency and Lung Disease

Multidisciplinary treatment of rare and complex immunodeficiencies

650&#215;450-Chronic-thromboembolic-pulmonary-hypertension
February 2, 2021/Pulmonary/Case Study
Expert CTEPH Centers Provide Valuable Diagnostic and Therapeutic Skill

Pulmonary endarterectomy improves outcomes for many patients

650&#215;450-vape-CT-chest-coronal
November 1, 2019/Pulmonary/Case Study
A Closer Look at Vaping-Associated Lung Injury: What You Can Do for Your Patients

Physicians present a case study, discuss clinical guidelines and the value of a multidisciplinary approach

650&#215;450-Bacteria
August 19, 2019/Pulmonary/Case Study
Phage Therapy for Multidrug Resistant Bacterial Infections

Cleveland Clinic experience with a lung transplant patient

Ad