Review Question - QID 217646

This older man with an extensive smoking history presenting with worsening exertional dyspnea, jugular venous distention, distant heart sounds, hepatomegaly, and significant lower extremity swelling with an electrocardiogram (ECG) demonstrating right heart strain most likely has right heart failure due to pulmonary hypertension from untreated chronic obstructive pulmonary disease (COPD), also known as cor pulmonale.

Pulmonary hypertension (PH) can be defined as a mean pulmonary artery pressure (PAP) ≥ 20 mmHg. An abnormally elevated mean PAP can occur due to numerous etiologies including left heart disease, pulmonary disease, chronic thromboembolic disease, sarcoidosis, or primary pulmonary arterial hypertension (PAH). In patients with PH, the right ventricle (RV) will experience increased afterload which, over enough time, will lead to maladaptive compensatory ventricular remodeling in the form of RV hypertrophy and ultimately right heart failure. Patients with PH typically present with exertional dyspnea, chest pain, fatigue, syncope, and a prominent P2 on cardiac auscultation. On ECG, findings of right axis deviation indicate compensatory right ventricular hypertrophy. The diagnosis can be confirmed with a right heart catheterization demonstrating mean PAP ≥ 20 mmHg. Management may include continuous long-term oxygen therapy in addition to treatment aimed at the underlying cause of PH (e.g., inhaled bronchodilators for COPD).

Cassady et al. review the pathophysiology, presentation, diagnosis, and management of chronic right heart failure in patients with PH. Of note, the authors explain how RV hypertrophy in response to increased afterload eventually leads to right heart failure. Briefly, RV hypertrophy eventually reaches a point in which the muscle tissue oxygen demand exceeds the supply, leading to significant tissue hypoxia which, in turn, leads to a cascade of detrimental effects on the tissue.

Figure/Illustration A is an ECG demonstrating right axis deviation as shown by a negative R wave in lead I (black arrow) and positive R waves in leads II, III, and aVF (red arrows).

Incorrect Answers:
Answer 1: Coin lesion on chest radiograph describes a pulmonary nodule that is concerning for lung cancer. Although this patient has an extensive smoking history which places him at high risk for developing lung cancer, he does not report any other symptoms concerning for malignancy such as unintended weight loss, hemoptysis, or night sweats.

Answer 2: Increased pericardial fluid on echocardiogram is concerning for cardiac tamponade, which would present with Beck triad (hypotension, jugular venous distention, and muffled heart sounds). Additionally, ECG in patients with cardiac tamponade would show electrical alternans and decreased QRS voltages, rather than right axis deviation. Although the distant heart sounds found in this patient can be confused with the muffled heart sounds classically associated with cardiac tamponade, this patient's findings are due to an increased distance of the heart from the chest wall rather than excess pericardial fluid.

Answer 3: Left ventricular ejection fraction < 35% is indicative of heart failure with reduced ejection fraction (HFrEF), also referred to as systolic heart failure, and presents with signs of left-sided heart failure such as cold extremities, pulmonary edema, orthopnea, and paroxysmal nocturnal dyspnea. This is in contrast to signs of right heart failure which include jugular venous distention, ascites, and lower extremity edema.

Answer 5: Right coronary artery (RCA) 100% occlusion causes ST-elevation myocardial ischemia (STEMI), leading to right ventricular ischemia and subsequent right heart failure which presents with chest pain, exertional dyspnea, jugular venous distention, and lower extremity edema. On ECG, RCA STEMIs result in ST elevations in leads II, III, and aVF unlike in this patient's ECG.

Bullet Summary:
Patients with long-standing COPD are at risk for developing pulmonary hypertension, defined as a mean PAP ≥ 20 mmHg, which can lead to cor pulmonale or right heart failure due to pulmonary disease.