A 64-year-old man comes to the emergency department due to palpitations and progressive shortness of breath over the past several weeks. The patient says that he develops "a choking sensation accompanied by a dry cough" every time he lies down. He has had no chest pain, sputum production, lightheadedness, or syncope. His other medical conditions include hypertension for the past 20 years and medication nonadherence. He also has a 35-pack-year smoking history. The patient's father died of a heart attack at age 70, and his mother suffered from asthma. Blood pressure is 182/105 mm Hg and pulse is 120/min and irregularly irregular. Lung examination reveals bibasilar crackles. There is 2+ pitting edema of the lower extremities. Bedside echocardiography shows a normal-sized left ventricle with wall hypertrophy, left ventricular ejection fraction of 55%, and no significant mitral or aortic valve disease. Which of the following is most likely responsible for this patient's symptoms?

Question

A 64-year-old man comes to the emergency department due to palpitations and progressive shortness of breath over the past several weeks.  The patient says that he develops "a choking sensation accompanied by a dry cough" every time he lies down.  He has had no chest pain, sputum production, lightheadedness, or syncope.  His other medical conditions include hypertension for the past 20 years and medication nonadherence.  He also has a 35-pack-year smoking history.  The patient's father died of a heart attack at age 70, and his mother suffered from asthma.  Blood pressure is 182/105 mm Hg and pulse is 120/min and irregularly irregular.  Lung examination reveals bibasilar crackles.  There is 2+ pitting edema of the lower extremities.  Bedside echocardiography shows a normal-sized left ventricle with wall hypertrophy, left ventricular ejection fraction of 55%, and no significant mitral or aortic valve disease.  Which of the following is most likely responsible for this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d2f0_6744_bc81_592861de1963_MD0003_00 This patient's progressive dyspnea, orthopnea, bibasilar lung crackles, and lower extremity edema are classic for decompensated heart failure. Echocardiography shows a normal left ventricular (LV) ejection fraction (ie, >50%), consistent with heart failure with preserved ejection fraction (HFpEF). HFpEF results from diastolic dysfunction (ie, impaired relaxation with decreased compliance) that leads to elevated LV diastolic filling pressure and reduced cardiac output. Concentric hypertrophy due to chronic hypertension is usually the primary contributor, causing a normal-sized LV cavity with thickened walls. Obesity and sedentary lifestyle are also often strong contributors, in part through their association with hypertension but also via systemic inflammation that leads to microvascular myocardial ischemia and deposition of interstitial collagen. decreased compliance Atrial fibrillation, which is likely present in this patient with palpitations and an irregularly irregular pulse, is a common precipitant of an acute exacerbation of HFpEF. Due to impaired diastolic filling at baseline, patients with HFpEF are highly sensitive to the loss of atrial kick that occurs with atrial fibrillation. (Choice A) Cor pulmonale refers to right ventricular failure resulting from pulmonary pathology that leads to pulmonary hypertension (eg, chronic obstructive pulmonary disease [COPD], pulmonary embolism). Pulmonary edema is not present with isolated right ventricular failure; this patient's bibasilar crackles and orthopnea suggest LV failure. (Choice C) High-output heart failure involves increased cardiac output in response to a condition causing reduced systemic vascular resistance (eg, arterial venous fistula, hyperthyroidism). Echocardiography typically shows dilation of both the right ventricle and left ventricle as they accommodate the high flow state. (Choice D) Coronary artery disease (CAD) is often present in patients with HFpEF; it likely does not significantly contribute to the pathogenesis of the disease but it may worsen the clinical manifestations (eg, precipitate heart failure exacerbation). Ischemic heart disease due to CAD most commonly leads to systolic dysfunction and heart failure with reduced ejection fraction. (Choice E) Small airway bronchoconstriction due to asthma or COPD would not explain this patient's evidence of left-sided heart failure (eg, lung crackles, orthopnea). Educational objective: Heart failure with preserved ejection fraction results from impaired diastolic relaxation (ie, diastolic dysfunction) in the setting of a normal left ventricular (LV) ejection fraction (ie, >50%). Concentric LV hypertrophy due to chronic hypertension is usually the primary contributor. Patients develop typical heart failure symptoms (eg, dyspnea, orthopnea, lower extremity edema) resulting from elevated LV diastolic filling pressure and reduced cardiac output. References: Clinical practice. Diastolic heart failure. (http://www.ncbi.nlm.nih.gov/pubmed/15356307) 2013 ACCF/AHA guideline for the management of heart failure: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on practice guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/23741057)

A 64-Year-Old Man Comes to the Emergency Department Due to Palpitations