Chapter 10
Congestive Heart Failure (Case 5)
Sameer Bashey MD and Michael Kim MD
Case: The patient is a 68-year-old woman with a past medical history of hypertension and rheumatoid arthritis. Her hypertension has been well controlled over the past few years with hydrochlorothiazide. She now presents to your office stating she’s become progressively short of breath over the past few months, most notably with exertion. Initially she felt she was simply “out of shape,” as these symptoms began upon starting an exercise regimen now that she’s retired. However, over the past few months her symptoms have continued to worsen despite regular exercise. She reports having no other associated symptoms and denies chest pain, nausea, vomiting, or palpitations. When not exerting herself, she feels she is at her usual state of health and is enjoying the extra time she has to catch up on several of her interests.
On physical examination, you note a mildly diminished carotid upstroke, nondisplaced point of maximal impact, and a normal jugular venous pressure (JVP). You also note a grade 3/6 systolic murmur most notable at the apex and 1+ pitting edema in the lower extremities bilaterally.
Differential Diagnosis
Aortic stenosis | Dilated cardiomyopathy | Ischemic cardiomyopathy |
Mitral regurgitation | Hypertrophic cardiomyopathy | Pulmonary hypertension |
Diastolic dysfunction | Restrictive cardiomyopathy |
Speaking Intelligently
When encountering a patient presenting with shortness of breath, first try to understand what the patient is actually experiencing, as the sensation of shortness of breath can encompass a range of symptoms including difficulty with air movement, dyspnea despite adequate air movement, and generalized fatigue. These and other associated symptoms may help narrow the differential diagnosis specifically to pulmonary, cardiac, musculoskeletal, or psychiatric causes. In patients with symptoms consistent with heart failure, the next step is to determine the presence of heart failure, the underlying etiology, and the severity for both medical management and prognosis. Finally, it important to bear in mind that effective treatment of chronic heart failure requires a multimodal approach encompassing patient education, coordination of care with nurses and other midlevel providers, and a stepwise implementation of medical and device therapies aimed at improving patient morbidity and mortality.
PATIENT CARE
Clinical Thinking
History
• As 50% to 75% of systolic heart failure cases are secondary to ischemia, assessing CAD risk factors to form a pretest probability is an important first step in establishing a diagnosis. Ischemic cardiomyopathy is not only the most common cause of heart failure but is also somewhat reversible in a minority of patients with large proportions of “hibernating” myocardium secondary to chronic ischemia. Age is another important factor to help inform a differential diagnosis. Aortic stenosis, mitral regurgitation, and diastolic dysfunction increase with age and are oftentimes pathophysiologically related via increased pressure and thus workload, leading to various structural changes.
• Regardless of the etiology, patients with left-sided heart failure will predominantly present with symptoms of exercise intolerance secondary to shortness of breath, fatigue, orthopnea, or paroxysmal nocturnal dyspnea.
Physical Examination
• Evidence of extracardiac manifestations of systemic disorders should also be evaluated.
Tests for Consideration
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| Clinical Entities | Medical Knowledge |
Aortic Stenosis (AS) | |
Pφ | In industrialized countries, degenerative calcification of a congenital bicuspid valve and degenerative calcification of an anatomically normal trileaflet valve represent the two most common causes of AS. Worldwide, rheumatic disease is the most common etiology. Degenerative calcification is characterized by a process of lipid accumulation and inflammation, leading to calcification. |
Patients most commonly present with decreased exercise tolerance and dyspnea on exertion. In more advanced disease, exertional chest pain, syncope, and symptoms of heart failure may be present and portend a poor outcome without intervention. Physical examination may be notable for a weak and delayed carotid upstroke (parvus et tardus), a mid- to late-peaking systolic murmur heard best in the right second intercostal space, or clinical signs of heart failure. | |
Dx | TTE provides the most information by determining leaflet morphology and severity of AS by aortic valve area calculations, as well as evidence of any LV dysfunction. ECG and chest radiograph may demonstrate left ventricular hypertrophy (LVH) and an enlarged cardiac silhouette. |
Tx | Treatment is primarily limited to valve replacement in symptomatic patients with severe AS. These patients have a life expectancy of 1 year without intervention, but this is markedly improved with valve replacement. In mild to moderate AS, medical therapy is limited to symptomatic treatment, as no therapy directly targeting progression of AS has been shown to be effective. Anginal symptoms may be relieved by β-blockers, calcium channel blockers, nitrates, or revascularization, while pulmonary congestion can be improved with use of diuretics. Transcatheter aortic valve implantation (TAVI) is an exciting potential new therapy for patients with severe aortic stenosis who are at high risk for mortality or serious morbidity with aortic valve replacement (AVR) or those considered too high risk to have AVR (extreme risk). This technology has been approved in Europe and is currently being investigated in randomized controlled trials in the United States. See Cecil Essentials 8. |
Mitral Regurgitation (MR) | |
Pφ | Insufficiency of the mitral valve (MV) can occur acutely or chronically. Acutely, as may occur following MI or endocarditis, an increase in left atrial pressure can lead to acute pulmonary edema. Chronically, MR is most commonly seen secondary to MV prolapse, prior ischemia, or heart failure in the United States and Europe. Worldwide, rheumatic heart disease is the most common etiology. Compensatory dilation of the heart in long-standing MR can progress to heart failure. |
As with AS, patients typically present with a progressive limitation in exercise tolerance. With acute MR, symptoms of ischemic chest pain or endocarditis may be noted. In advanced cases, patients may also present with palpitations secondary to new-onset atrial fibrillation from left atrial dilation. On exam, a laterally displaced point of maximal impact, a diminished S1, or a wide splitting of S2 may be noted along with a holosystolic murmur over the apex radiating to the left axilla. | |
Dx | TTE is used both for diagnosing MR and for determining medical and surgical management. The cause of MR can be determined by looking for evidence of secondary causes including prior evidence of ischemia, heart failure, or a primary disorder of the MV apparatus including the leaflets, annulus, chordae tendineae, and papillary muscles. Severity of MR is assessed by measuring regurgitant volumes and orifice area, as well as degree of LV compensation by assessment of LV size and function. |
Tx | As with AS, treatment for MR is primarily limited to surgical intervention given the absence of medical therapies to limit progression of disease. Determining the appropriate time to intervene can be difficult, and surgery is generally performed in patients with severe MR before deterioration of LV function. MV repair is generally preferred over MV replacement to avoid the need for anticoagulation. Symptomatic treatment consisting of arterial vasodilators (nitroprusside, hydralazine) can improve symptoms in acute MR but have limited use chronically in nonoperative candidates. See Cecil Essentials 8. |
Ischemic Cardiomyopathy | |
Pφ | Ischemic cardiomyopathy describes the impairment in LV function resulting from CAD. Most commonly, this occurs following MI secondary to infarction of tissue that is no longer contractile. Less commonly, coronary disease may result in hibernating myocardium, tissue that is functionally reduced secondary to chronic ischemia that may be partially reversible with revascularization. |
Patients typically present with symptoms of heart failure including dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, and lower extremity swelling. Additionally, patients may have multiple risk factors for CAD, a history of prior MI, or ongoing anginal symptoms. Exam findings are nonspecific for heart failure and may include an elevated JVP, displaced PMI, S3 gallop, pulmonary congestion, pulsatile liver, and lower extremity edema. | |
Dx | An ECG with significant Q waves, ST changes, or T-wave inversions can provide evidence of prior ischemic injury. On echocardiography, regional wall motion abnormalities are indicative of prior MI or hibernating myocardium. Further testing is aimed at one of two goals: (1) an evaluation for CAD by either coronary angiography or stress testing, and (2) in patients with known or newly diagnosed CAD, an evaluation for hibernating myocardium by nuclear stress testing, dobutamine echocardiography, or positron emission tomography imaging. |
Tx | There is significant overlap in the benefit of many medical therapies for CAD and ischemic cardiomyopathy. Medical therapies providing mortality benefit include angiotensin-converting enzyme (ACE) inhibitors, which slow progression by inhibiting ventricular remodeling, as well as β-blockers, which lessen mortality by reducing malignant ventricular arrhythmias. To improve pulmonary congestion, furosemide (lasix) and long-acting nitrates can be used. Finally, patients found to have a significant proportion of viable myocardium can consider revascularization and subsequent reevaluation of LV function. Those with advanced heart failure (NYHA Class III–IV) may benefit from several additional medical therapies. Digoxin has been shown to reduce hospitalization for congestive heart failure, while spironolactone has a mortality benefit. Additionally, implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden cardiac death reduce mortality associated with ventricular arrhythmias, while cardiac resynchronization therapy or biventricular pacing may be used to improve symptoms and functional status in patients with prolonged QRS. Finally, cardiac transplantation may be considered in certain circumstances. See Cecil Essentials 6. |
Pφ | Functional abnormality characterized by an abnormality in active relaxation in early diastole combined with passive stiffness leading to elevated LV filling pressures. A variety of cardiac diseases cause diastolic dysfunction, including ischemia, chronic hypertension, AS, and hypertrophic cardiomyopathy (HCM). |
TP | Many patients with diastolic dysfunction are asymptomatic or have mild exercise intolerance. In contrast, those with diastolic heart failure have symptoms and physical exam findings indistinguishable from those of systolic heart failure. Similarly, patients may not tolerate atrial fibrillation or episodes of tachycardia well because of further impaired LV filling in diastole. |
Dx | A diagnosis is made by noting clinical signs and symptoms of heart failure in the absence of impaired systolic function on echocardiography. Additional echocardiographic parameters include E/a ratios, pulmonary vein blood flow velocity, and tissue Doppler imaging. Brain natriuretic peptide concentration, though nonspecific, is also likely to be elevated. |
Tx | While there are no specific treatments for diastolic heart failure, patients generally have additional cardiac comorbidities to guide therapeutic intervention. Those with LVH may benefit preferentially from ACE inhibitors through regression of LVH. Symptomatic patients may benefit from β-blockers or calcium channel blockers by increasing diastolic filling time as well as diuretics if fluid overloaded. See Cecil Essentials 6. |
Dilated Cardiomyopathy | |
Pφ | Dilated cardiomyopathies are a group of disorders characterized predominantly by systolic heart failure secondary to intrinsic myocardial disease. End-stage heart failure secondary to hypertension, CAD, or valvular disease is generally excluded from this classification. While approximately 50% of cases are idiopathic, known precipitants include various infectious etiologies (viral myocarditis, HIV, Chagas disease, Lyme disease), peripartum cardiomyopathy, connective tissue diseases, and toxicity from drugs or medications. |
TP | Given the breadth of systemic disorders underlying dilated cardiomyopathies, clinical presentation varies widely. The presence of heart failure symptoms in younger patients or those without CAD risk factors or valvular disease may provide a clue. A careful history and physical exam with attention to comorbid diseases and environmental factors are required. |
An echocardiogram showing impaired systolic function in the absence of another etiology requires further evaluation. In addition to evaluating for CAD, testing is directed at identifying the underlying etiology and may include laboratory or imaging studies for evidence of infectious, rheumatologic, or endocrine diseases. Occasionally, an endomyocardial biopsy is required. | |
Tx | In addition to treating the underlying cause, treatment guidelines are similar to those in ischemic heart disease and include use of β-blockers, ACE inhibitors, diuretics, and ICD placement as indicated. However, as several etiologies are reversible, judicious use of device therapies is required. See Cecil Essentials 11. |
Hypertrophic Cardiomyopathy | |
Pφ | Similar to dilated cardiomyopathies, HCMs are diseases of intrinsic myocardial tissue and exclude hypertrophy secondary to hypertension or valvular disease. Between 60% and 70% of cases are secondary to one of many mutations in genes encoding contractile proteins within the sarcomere and are expressed in an autosomal-dominant pattern of inheritance with a high degree of penetrance. Ventricular arrhythmias leading to sudden cardiac death (SCD) are caused by myocyte disarray, fibrosis, and ischemia secondary to obstruction of the LV outflow tract. |
TP | Clinical presentation is highly variable and does not correlate well with severity of outflow obstruction. Many patients are asymptomatic or have mildly limited exercise tolerance that advances with age. Others can present with ischemic chest pain or syncope related to outflow obstruction as well as SCD secondary to ventricular arrhythmias. |
Dx | Symptomatic patients require more aggressive evaluation, as they are at increased risk for SCD. ECG can show dramatically increased voltage, prominent Q-waves, or deep T-wave inversions. Echocardiography is used to evaluate LV wall thickness as well as severity of outlet obstruction. Additional testing to identify patients at high risk for SCD requiring ICD placement includes a Holter monitor for nonsustained ventricular tachycardia and a stress test to evaluate for an abnormal BP response. |
Asymptomatic patients without high-risk features (nonsustained ventricular tachycardia [NSVT] on Holter, syncope, family history of SCD, abnormal BP response on stress, or LVH > 30 mm) can be followed annually without need for further therapy. Those with two or more high-risk features or prior cardiac arrest require ICD placement. Additionally, β-blockers can improve palpitations secondary to premature ventricular beats or NSVT. First-degree relatives of patients with HCM also require periodic evaluation. See Cecil Essentials 11. | |
Restrictive Cardiomyopathy | |
Pφ | Restrictive cardiomyopathies are characterized by impaired ventricular filling secondary to a variety of disease states affecting the myocardial substrate. These diseases can be classified as infiltrative (amyloidosis, sarcoidosis), storage (hemochromatosis, Fabry disease), endomyocardial, and noninfiltrative (idiopathic, familial) diseases. Constrictive pericarditis, while also impairing ventricular filling, is not included within this classification, as it occurs secondary to a pericardial effusion rather than as an intrinsic myopathy. |
TP | Clinical presentations are varied relating to other systemic manifestations of the underlying etiology. Clinical signs or symptoms of heart failure in the absence of typical risk factors should prompt further investigation. |
Dx | An ECG with low voltage in the precordial leads may provide an early clue. Systolic heart failure is confirmed by echocardiography, although no other structural abnormality is generally present. An endomyocardial biopsy is considered the reference standard, though cardiac magnetic resonance imaging is also helpful in establishing a diagnosis. |
Tx | Treatment is similar to that for other etiologies of systolic heart failure, including ACE inhibitors, β-blockers, diuretics, digoxin, spironolactone, and device therapies for advanced heart failure. See Cecil Essentials 11. |
Pulmonary Hypertension (PH) | |
Pφ | Defined by elevated pulmonary arterial pressures eventually leading to right heart failure, PH is classified according to etiology by World Health Organization (WHO) Group 1–5 designation corresponding to idiopathic, left heart, intrinsic pulmonary, chronic thromboembolic, or inflammatory diseases. |
Presenting symptoms are nonspecific and consist of exertional dyspnea, lethargy, and fatigue. With disease progression and right heart failure, angina, syncope, and peripheral edema are noted. On exam, a loud P2, widely split S2, peripheral edema, elevated JVP, and evidence of any secondary causes may be evident. | |
Dx | Chest radiograph may show enlargement of the central vasculature, a diminished retrosternal air space on lateral view, and a prominent right heart border. ECG signs of right ventricular strain include right axis deviation, R/S wave ratio less than 1 in V1, increased P amplitude in lead II, and right bundle branch block. Diagnostic testing specifically directed to evaluate PH begins with an echocardiogram, where a pulmonary artery systolic pressures estimation is higher than 40 mm Hg or is suggestive of PH, especially with evidence of structural changes in the right heart. Finally, right heart catheterization is the reference standard for diagnosis and evaluation for response to vasodilator therapy. |
Tx | Aside from treating the underlying cause, multiple indications for treatment exist. Patients with idiopathic PH or chronic thromboembolic disease should be anticoagulated to prevent intrapulmonary thrombus formation. Those with resting hypoxemia should receive supplemental oxygen to prevent hypoxic vasoconstriction that may worsen PH and progression of right heart failure. Finally, symptomatic patients may benefit from diuretics for fluid overload and pulmonary vasodilators if found to improve pressures on right heart catheterization. See Cecil Essentials 13, 19. |
