CHAPTER 11: ECHOCARDIOGRAPHIC ASSESSMENT IN PULMONARY HYPERTENSION AND RIGHT HEART FAILURE

INTRODUCTION

The assessment of the right heart presents many challenges due to its unique anatomy and physiology.¹ In spite of these limitations, echocardiography remains the principal imaging method employed to assess patients with known or suspected right heart disease, especially in the acute setting. While other imaging techniques such as cardiac CT and MRI have provided additional tools to evaluate cardiac anatomy and function, they currently play a secondary role in most clinical settings. MRI is playing a larger role in the assessment of right ventricular size and function, especially in the congenital heart disease population.

The use of echocardiography is a class 1 indication for the evaluation of many clinical scenarios in which right heart disease is suspected.² In the recently revised appropriate use criteria for echocardiography,³ echocardiography is deemed appropriate in a variety of such clinical scenarios.

In this chapter, we will demonstrate the utility of echocardiography in the assessment of acute right heart failure/pulmonary hypertension in a patient with pulmonary embolism and in a patient with chronic pulmonary hypertension and chronic right heart failure.

SECTION 1: ACUTE PULMONARY EMBOLISM/ACUTE PULMONARY HYPERTENSION

CLINICAL CASE PRESENTATION

A 73-year-old white man with a past medical history of coronary artery disease, status post 4-vessel coronary bypass surgery in 1997, Type 2 diabetes mellitus, hypertension, and diverticular disease presented to our hospital with a chief complaint of "shortness of breath." For 2 weeks, he had been complaining of dyspnea on exertion (DOE), a nonproductive cough, and chest heaviness that had progressively worsened. In the emergency department, he was hypoxic (requiring oxygen via a non-rebreather mask), tachycardic, and hypotensive with a systolic blood pressure (SBP) in the 80s that did not respond to intravenous (IV) fluids.

On examination, he was obese and appeared quite uncomfortable, only able to speak 4 to 5 words at a time. His cardiac exam showed significant tachycardia, a normal S₁ and S₂ with a prominent P₂ at the left sternal border at the 4th intercostal space and a right parasternal heave. Pulmonary examination revealed that he had decreased breath sounds at the bases bilaterally with poor chest expansion during inspiration. Extremity exam was significant for unilateral left lower leg 1+ pitting edema. Otherwise, the rest of the physical exam was unremarkable.

Laboratory results were significant for brain natriuretic peptide (BNP) 3382, troponin 5.3, and an arterial blood gas (ABG) of pH 7.2, PCO₂ 30, PO₂ 104, and HCO₃ 11 on 100% oxygen. An electrocardiogram (ECG) showed an S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III (Figure 11-1-1). A transthoracic echocardiogram (TTE) showed a large thrombus in the pulmonary arterial trunk that extended into the pulmonary arteries (PA) (Figure 11-1-2). ...