Approach to Heart Failure Introduction Heart failure (HF) is a pathophysiological state in which abnormality of cardiac function is responsible for failure of the heart to pump blood at a rate commensurate with the requirements of the metabolizing tissues. The cardinal manifestations of HF are dyspnea and fatigue resulting in exercise intolerance and fluid retention and leading to pulmonary congestion and peripheral edema. Prevalence HF is increasing in prevalence, resulting in what some have termed an epidemic. Nearly 6.5 million adults in the United States are estimated to have HF, and every year, 960,000 are newly diagnosed. An estimated 23 million people are affected by HF worldwide, with the prevalence of symptomatic HF ranging between 0.4-2.0%. HF is more prevalent in men and with increasing age. Importance HF causes more deaths than all forms of cancer combined. The 5-year mortality rate for a patient diagnosed with HF is 50%. Pathophysiology HF with preserved ejection fraction (HFpEF) is defined as ejection fraction (EF) > 50% with evidence of elevated LV filling pressure and represents about half of HF cases with the remaining half being HF with reduced ejection fraction (HFrEF), wherein EF < 40%. The diagnosis of HFpEF can be challenging because symptoms are nonspecific and can be seen with other noncardiac conditions. TTE remains the principal diagnostic tool. The use of invasive hemodynamic testing and evaluation of coronary arteries is often advocated to reliably diagnose HFpEF. Less common diseases, including restrictive cardiomyopathies that result in HFpEF, can be evaluated by CMR. In a recent study, use of stress CMR diagnosed new significant pathology in 27% of patients with HFpEF. Left vs. Right Heart Failure Left HF refers to the signs and symptoms of elevated pressure and congestion in the pulmonary veins and capillaries, as well as low systemic cardiac output. Right HF refers to the signs and symptoms of elevated pressure and congestion of the systemic veins and capillaries, as characterized by jugular vein engorgement and hepatic congestion. Systolic vs. Diastolic Heart Failure In systolic dysfunction, the left ventricle appears large, dilated, and eccentrically hypertrophied, and the cardiac output is limited by impaired systolic EF. In diastolic dysfunction, the left ventricle typically appears thickened, with a normal to small cavity in which filling is limited because of abnormal left ventricular compliance. Treatment The recently updated American College of Cardiology/American Heart Association Heart Failure Guidelines (2017) provide detailed information regarding the management and prevention of HF. Imaging/Assessment Techniques Different techniques are available to evaluate patients with HF; underlying clinical circumstances determine which test is most appropriate. Electrocardiogram An electrocardiogram (EKG) is used to detect many myocardial abnormalities, such as arrhythmias, previous MI, or ventricular hypertrophy. A normal EKG indicates HF from structural heart disease is unlikely, but its positive predictive value is low. Chest Radiograph Chest radiography (CXR) is used to evaluate the overall cardiac size and to check for signs of HF, such as pulmonary vascular congestion, pulmonary edema, &/or pleural effusions. CXR is also used to exclude other causes of dyspnea (cardiovascular pericardial calcifications, coronary calcifications, noncardiac pneumonia, lung carcinoma, etc.). Although echocardiography has largely replaced CXR as a method to determine heart dimensions and function, radiography is often used to monitor acutely ill patients and their responses to therapy. In patients with decompensated HF, CXR may show cephalization of pulmonary blood flow, interstitial or alveolar edema, effusions, and increased vascular pedicle width. Clearing of these findings on follow-up CXR is indicative of a response to therapy. Echocardiography 2D transthoracic echocardiography and Doppler US are strongly recommended as a 1st-line technique for imaging patients with new-onset HF. It provides extensive information about the etiology and severity of HF as it can accurately assess chamber dimensions, ventricular function, valvular stenosis or regurgitation, and systolic/diastolic function (filling pressures and patterns). Four-chamber dilatation suggests a nonischemic etiology, whereas regional wall motion abnormalities may suggest an ischemic etiology. Other diagnoses may present with classic findings. For example, cardiac amyloidosis may present with biventricular thickening, small chamber size, restrictive physiology, and “sparkling” echogenicity. Similarly, hypertrophic cardiomyopathy can present with systolic anterior motion of the mitral valve, outflow tract obstruction, and asymmetric septal hypertrophy. Serial echocardiography is reasonable in patients with ST-segment elevation MI (STEMI) to reevaluate cardiac function during recovery when results are utilized to guide therapy (class 2a, level C recommendation). Single-Photon Emission Computed Tomography Single-photon emission computed tomography (SPECT) is not primarily used to determine left ventricular systolic function unless the relevant parameters are quantified from a myocardial perfusion assessment. Gated SPECT improves accuracy and provides information on LV volumes, LVEF, and motion abnormalities. SPECT can also be used for evaluation of myocardial ischemia. Radionuclide Ventriculography Radionuclide ventriculography (RNV) is a planar technique useful for assessment of volumes in patients with significant wall motion abnormalities or distorted geography. Though used less often, currently RNV is an alternative to evaluate cardiac function. Quantitative assessments are reproducible, and serial measurements have been used to track efficacy of therapies in patients with HF. Computed Tomography CT can provide an accurate assessment of cardiac structure and function, though it is slightly less accurate than MR. CT has very high spatial resolution and is particularly useful for noninvasive evaluation of the coronary arteries. Coronary CTA can be used to exclude ischemic etiology in new-onset HF. One advantage of CT over echocardiography is the ability to detect pericardial calcification, as may be seen with constrictive pericarditis. CT is often used to exclude other etiologies for dyspnea, such as pulmonary embolism. Only gold members can continue reading. 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Approach to Heart Failure Introduction Heart failure (HF) is a pathophysiological state in which abnormality of cardiac function is responsible for failure of the heart to pump blood at a rate commensurate with the requirements of the metabolizing tissues. The cardinal manifestations of HF are dyspnea and fatigue resulting in exercise intolerance and fluid retention and leading to pulmonary congestion and peripheral edema. Prevalence HF is increasing in prevalence, resulting in what some have termed an epidemic. Nearly 6.5 million adults in the United States are estimated to have HF, and every year, 960,000 are newly diagnosed. An estimated 23 million people are affected by HF worldwide, with the prevalence of symptomatic HF ranging between 0.4-2.0%. HF is more prevalent in men and with increasing age. Importance HF causes more deaths than all forms of cancer combined. The 5-year mortality rate for a patient diagnosed with HF is 50%. Pathophysiology HF with preserved ejection fraction (HFpEF) is defined as ejection fraction (EF) > 50% with evidence of elevated LV filling pressure and represents about half of HF cases with the remaining half being HF with reduced ejection fraction (HFrEF), wherein EF < 40%. The diagnosis of HFpEF can be challenging because symptoms are nonspecific and can be seen with other noncardiac conditions. TTE remains the principal diagnostic tool. The use of invasive hemodynamic testing and evaluation of coronary arteries is often advocated to reliably diagnose HFpEF. Less common diseases, including restrictive cardiomyopathies that result in HFpEF, can be evaluated by CMR. In a recent study, use of stress CMR diagnosed new significant pathology in 27% of patients with HFpEF. Left vs. Right Heart Failure Left HF refers to the signs and symptoms of elevated pressure and congestion in the pulmonary veins and capillaries, as well as low systemic cardiac output. Right HF refers to the signs and symptoms of elevated pressure and congestion of the systemic veins and capillaries, as characterized by jugular vein engorgement and hepatic congestion. Systolic vs. Diastolic Heart Failure In systolic dysfunction, the left ventricle appears large, dilated, and eccentrically hypertrophied, and the cardiac output is limited by impaired systolic EF. In diastolic dysfunction, the left ventricle typically appears thickened, with a normal to small cavity in which filling is limited because of abnormal left ventricular compliance. Treatment The recently updated American College of Cardiology/American Heart Association Heart Failure Guidelines (2017) provide detailed information regarding the management and prevention of HF. Imaging/Assessment Techniques Different techniques are available to evaluate patients with HF; underlying clinical circumstances determine which test is most appropriate. Electrocardiogram An electrocardiogram (EKG) is used to detect many myocardial abnormalities, such as arrhythmias, previous MI, or ventricular hypertrophy. A normal EKG indicates HF from structural heart disease is unlikely, but its positive predictive value is low. Chest Radiograph Chest radiography (CXR) is used to evaluate the overall cardiac size and to check for signs of HF, such as pulmonary vascular congestion, pulmonary edema, &/or pleural effusions. CXR is also used to exclude other causes of dyspnea (cardiovascular pericardial calcifications, coronary calcifications, noncardiac pneumonia, lung carcinoma, etc.). Although echocardiography has largely replaced CXR as a method to determine heart dimensions and function, radiography is often used to monitor acutely ill patients and their responses to therapy. In patients with decompensated HF, CXR may show cephalization of pulmonary blood flow, interstitial or alveolar edema, effusions, and increased vascular pedicle width. Clearing of these findings on follow-up CXR is indicative of a response to therapy. Echocardiography 2D transthoracic echocardiography and Doppler US are strongly recommended as a 1st-line technique for imaging patients with new-onset HF. It provides extensive information about the etiology and severity of HF as it can accurately assess chamber dimensions, ventricular function, valvular stenosis or regurgitation, and systolic/diastolic function (filling pressures and patterns). Four-chamber dilatation suggests a nonischemic etiology, whereas regional wall motion abnormalities may suggest an ischemic etiology. Other diagnoses may present with classic findings. For example, cardiac amyloidosis may present with biventricular thickening, small chamber size, restrictive physiology, and “sparkling” echogenicity. Similarly, hypertrophic cardiomyopathy can present with systolic anterior motion of the mitral valve, outflow tract obstruction, and asymmetric septal hypertrophy. Serial echocardiography is reasonable in patients with ST-segment elevation MI (STEMI) to reevaluate cardiac function during recovery when results are utilized to guide therapy (class 2a, level C recommendation). Single-Photon Emission Computed Tomography Single-photon emission computed tomography (SPECT) is not primarily used to determine left ventricular systolic function unless the relevant parameters are quantified from a myocardial perfusion assessment. Gated SPECT improves accuracy and provides information on LV volumes, LVEF, and motion abnormalities. SPECT can also be used for evaluation of myocardial ischemia. Radionuclide Ventriculography Radionuclide ventriculography (RNV) is a planar technique useful for assessment of volumes in patients with significant wall motion abnormalities or distorted geography. Though used less often, currently RNV is an alternative to evaluate cardiac function. Quantitative assessments are reproducible, and serial measurements have been used to track efficacy of therapies in patients with HF. Computed Tomography CT can provide an accurate assessment of cardiac structure and function, though it is slightly less accurate than MR. CT has very high spatial resolution and is particularly useful for noninvasive evaluation of the coronary arteries. Coronary CTA can be used to exclude ischemic etiology in new-onset HF. One advantage of CT over echocardiography is the ability to detect pericardial calcification, as may be seen with constrictive pericarditis. CT is often used to exclude other etiologies for dyspnea, such as pulmonary embolism. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related posts: page 2: CORONARY ARTERY DISEASE 7: CONGENITAL HEART DISEASE Approach to Venous Disease INDEX Ischemia Imaging With CT-FFR Stay updated, free articles. Join our Telegram channel Join Tags: CT and MR in Cardiology Apr 6, 2020 | Posted by admin in CARDIOVASCULAR IMAGING | Comments Off on Approach to Heart Failure Full access? Get Clinical Tree
