Examkin

Question

Difficulty: MediumPulmonary and Critical Care

A 45-year-old woman is evaluated in the outpatient clinic for a 6-month history of progressive exertional dyspnea and fatigue. She has no history of smoking, cardiac disease, or venous thromboembolism. Vital signs are within normal limits. Physical examination reveals a loud pulmonic component of the second heart sound (P2) and a right ventricular heave. Lungs are clear to auscultation bilaterally. Electrocardiography shows right axis deviation and right ventricular hypertrophy. Pulmonary function tests are normal. A chest radiograph reveals enlarged central pulmonary arteries. Arrange the following diagnostic modalities in the most appropriate chronological sequence for the evaluation of this patient's suspected condition.

  1. 1Perform transthoracic echocardiography
  2. 2Obtain a ventilation-perfusion (V/Q) scan
  3. 3Perform right heart catheterization
  4. 4Conduct acute pulmonary vasoreactivity testing

Answer

The correct sequence of diagnostic steps is: Transthoracic echocardiography, followed by a ventilation-perfusion (V/Q) scan, then right heart catheterization, and finally acute pulmonary vasoreactivity testing.
The evaluation of suspected pulmonary hypertension follows a strict stepwise approach to minimize invasive testing and identify curable causes. The patient's clinical presentation strongly suggests pulmonary hypertension. The first step is noninvasive screening with transthoracic echocardiography to identify structural abnormalities and estimate pressures. Next, a ventilation-perfusion (V/Q) scan is performed to screen for CTEPH. If the V/Q scan does not indicate CTEPH, invasive right heart catheterization is required to definitively diagnose Group 1 pulmonary arterial hypertension. Finally, during catheterization, acute vasoreactivity testing is performed to identify candidates for calcium channel blocker therapy.

Step-by-Step Solution

1
Establish the initial probability of pulmonary hypertension noninvasively.
Transthoracic echocardiography is performed.
Echocardiography evaluates right ventricular function and estimates pulmonary artery systolic pressure, serving as the safest initial screening test.
2
Screen for chronic thromboembolic pulmonary hypertension (CTEPH).
A ventilation-perfusion (V/Q) scan is obtained.
Once pulmonary hypertension is suspected and left heart or intrinsic lung diseases are ruled out, CTEPH must be evaluated because it is a surgically treatable etiology.
3
Confirm the diagnosis of pulmonary arterial hypertension (PAH) directly.
Right heart catheterization is performed.
Invasive measurement is required to definitively confirm PAH (mean pulmonary artery pressure greater than 20 mm Hg at rest) and to guide further management.
4
Determine eligibility for targeted medical therapy.
Acute pulmonary vasoreactivity testing is conducted.
Performed during right heart catheterization, this identifies patients with PAH who may benefit from high-dose calcium channel blocker therapy.

Key Concept

Diagnostic algorithm for pulmonary hypertension
Rate this question

Topics

Pulmonary and Critical Care

More questions from this topic