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“Doctor, I’m short of breath: is this heart failure?” Dyspnea is the most common presenting symptom of heart failure (HF). Mr. Roberts and Dr. Rajda review the utility of various clinical tools for diagnosing HF in patients presenting with dyspnea. Derek J. Roberts, BSc (Pharm); and Miroslaw Rajda, MD, FRCPC eart failure (HF) is a clinical diagnosis requiring integration of risk factors for HF, signs and symptoms and other objective data. Breathlessness (dyspnea) is the most common presenting symptom of HF. However, dyspnea is also commonly present in diseases such as: • chronic obstructive pulmonary disease (COPD), • obesity, • nephrotic syndrome and • cirrhosis, • among others. H Ken’s Dyspnea Ken, 65, has a history of hypertension and previous ST-segment elevation MI. He presents to his FP with a nocturnal cough and increasing dyspnea with exertion over the last three weeks. Four days ago, he also began experiencing difficulty breathing when lying flat. Ken’s physical examination displays bilateral lower extremity edema and elevated jugular venous pressure (JVP). Auscultation reveals a third heart sound (S3), but no pulmonary rales. For more on Ken, turn to page 32. Risk factors and comorbidities for HF Each patient presenting with dyspnea should be investigated for risk factors or comorbidities that predispose to development of HF. Findings that should increase suspicion of HF in patients presenting with dyspnea can be found in Table 1. fluid from gravity dependent areas after lying down. Orthopnea can be functionally defined as breathlessness beginning less than or equal to one minute after lying supine. The severity can be quantified ©by the number of pillows utilized by the patients to relieve their breathlessness. Specific symptoms for HF However, it is important tonldifferentiate from oad, w o d n Symptoms that are common but non-specific to habit pillow use, casa many patients e regularly use sers sonal us u HF include: multiple pillows. d rise for per utho Paroxysmal • fatigue, nocturnal dyspnea (PND) shares a A . d copy ite e l b i g h n i o • dyspnea, similar pathophysiologic mechanism with orthops r se p int a u r p d e d • weight gain, oris nea and is characterized by breathlessness that typan th viewand , y • abdominal ically occurs four hours after the onset of sleep or Unaufullness/bloating a l disp • reduced exercise tolerance. lying supine. After awakening from sleep, patients Symptoms that are more specific for HF include: sit up or even walk around for 10 minutes to 30 • orthopnea and minutes to get relief and they often have a wheeze • paroxysmal nocturnal dyspnea (PND)1-3. and a cough. Orthopnea occurs as a result of an increase in venous return after redistribution of interstitial n o i t u ib r t s i lD a i c r me t h g i r Copym o o f t o N rC o e l r Sa Perspectives in Cardiology / October 2006 29 Heart Failure Table 1 Risk factors and predisposing conditions for development of HF • • • • • • • • • • • • Coronary artery disease Previous MI Hypertension Valvular heart disease Elevated JVP JVP is an estimate of right atrial pressure that is useful in the diagnosis and management of patients with HF. An elevated JVP (> 3 cm above the level of the sternal angle) is a specific but insensitive marker that increases the likelihood of HF approximately five fold (sensitivity 39% and specificity is 94%).1-2 Alcohol/cardiotoxins Family history of dilated cardiomyopathy Positive abdominojugular reflex Age A positive abdominojugular reflex makes the diagnosis of HF six times more likely.2 Thus, examination of the neck veins in conjunction with abdominojugular reflex is one of the best clinical tools for determining the fluid status in patients with dyspnea (sensitivity and specificity is around 80%). Renal dysfunction Diabetes Congenital heart anomalies Obesity Other causes HF: Heart Failure Sensitive and specific physical signs for HF The physical signs of HF depend on whether it is right, left, or biventricular cardiac dysfunction. In predominant left-sided HF, only a third heart sound (S3) and pulmonary rales should be present. Common signs of HF include: • elevated neck veins/jugular venous pressure (JVP), • a positive abdominojugular reflex, • pulmonary rales, or • pleural effusion, • presence of S3, • tachycardia, • ascites and • lower extremity edema. About the authors... Mr. Roberts is a Medical Student, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia. Dr. Rajda is an Assistant Professor of Medicine, Division of Cardiology, Department of Medicine, Dalhousie University, Halifax, Nova Scotia. 30 Perspectives in Cardiology / October 2006 S3 The presence of S3 is extremely specific for HF (specificity is 99%).4 However, many clinicians may have trouble detecting its presence. The optimal way to appreciate the S3 is to place the patient in the left lateral decubitus position and, lightly using the bell of the stethoscope, listen at the apex for an early, low-pitched, rumbling diastolic sound. Lower extremity edema Lower extremity edema has a sensitivity and specificity of approximately 67% for HF.2 However, it can also occur in patients who: • have been sitting or standing in one position for a long period of time, • have varicose veins or • are taking certain medications, such as dihydropyridine calcium channel blockers (e.g., nifedipine). Pulmonary rales Rales are very specific for HF.2 However, they are also very insensitive and their absence does not indicate that the patient is not in HF.1-2 Heart Failure Therefore, in contrast to JVP and orthopnea/PND, the absence of pulmonary rales tells you little about the fluid status in patients with dyspnea. he most commonly reported finding on chest radiographs in patients with HF is cardiomegaly as decided by cardiothoracic ratio T Diagnostic tests for HF Chest radiography The chest radiograph plays an essential role in the routine investigation of patients with suspected HF.3 The most commonly reported finding on chest radiographs in patients with HF is cardiomegaly as decided by cardiothoracic ratio. A ratio > 0.5 is considered abnormal. Other findings include: • vascular redistribution, • peri-bronchial cuffing and • pleural effusions. However, one in five patients presenting to the ED with acute HF will have a negative chest X-ray. Chest radiography also provides valuable information about non-cardiac causes of dyspnea. ECG The 12 lead electrocardiographic tracing is abnormal in most patients with HF, although there are no specific features diagnostic of HF. Common abnormalities include: • Q waves, • abnormalities in the T wave and ST segment, • left ventricular hypertrophy, • bundle branch block and • atrial fibrillation. The combination of a normal chest X-ray and electrocardiographic tracing makes a cardiac cause of dyspnea unlikely. B-type natriuretic peptide testing in patients with dyspnea B-type natriuretic peptide (BNP) is a peptide hormone produced by the ventricular myocardium in response to ventricular fluid overload such as that which occurs in HF. Multiple clinical trials have found that in patients presenting to the ED with dyspnea, BNP testing is cost-effective and the higher the level of BNP, the greater the chance and severity of HF.4-6 These studies also found that low levels of BNP rule out the diagnosis of HF.4,6 Processes such as pulmonary embolism, cor pulmonale and acute coronary syndromes may cause ventricular stretch and lead to mild-tomoderate BNP secretion. As a result, a moderately elevated BNP needs to be interpreted in light of the patient's clinical presentation. Referring for an ECHO The echocardiogram (ECHO) is a paramount diagnostic test for HF. ECHO can accurately determine: • left ventricular size, • systolic and diastolic function, • ejection fraction, • valvular abnormalities and • other abnormalities which can result in HF. A transthoracic ECHO should be performed in all patients with suspected HF.3 Perspectives in Cardiology / October 2006 31 Heart Failure Back to Ken Ken exhibits many signs that are highly specific to HF including: • an elevated JVP, • orthopnea and • the presence of an S3. Therefore, his primary care physician started him on a regimen of HF medications and referred him to a cardiologist for further investigation. The cardiologist sent Ken for an echocardiogram, which revealed a dilated left ventricle with an ejection fraction of 19%. Summary Now I have a story to tell my grandchildren. All patients presenting with dyspnea should have: • a careful history taken, including HF risk factors, • a physical examination, • a chest X-ray and ECG, • BNP testing should be performed (if available) • a transthoracic echocardiogram. PCard References 1. Butman SM, Ewy GA, Standen JR, et al: Bedside cardiovascular examination in patients with severe chronic heart failure: Importance of rest or inducible jugular venous distension. J Am Coll Cardiol 1993; 22(4):968-74. 2. Wang CS, FitzGerald JM, Schulzer M, et al: Does this dyspneic patient in the emergency department have congestive heart failure? JAMA 2005; 294(15):1944-56. 3. Arnold JMO, Liu P, Demers C, et al: Canadian Cardiovascular Society consensus conference recommendations on heart failure 2006: Diagnosis and management. Can J Cardiol 2006; 22(1):23-45. 4. Mueller C, Laule-Kilian K, Schindler C, et al: Cost-effectiveness of Btype natriuretic peptide testing in patients with acute dyspnea. Arch Intern Med 2006; 166(10):1081-7. 5. Maisel AS, Krishnaswamy P, Nowak RM, et al: Rapid measurement of B-type natriuretic peptide in the emergency diagnosis of heart failure. N Engl J Med 2002; 347(3):161-7. 6. Dao Q, Krishnaswamy P, Kazanegra R, et al: Utility of B-type natriuretic peptide in the diagnosis of congestive heart failure in an urgent-care setting. J Am Coll Cardiol 2001; 37(2):379-85. 32 Perspectives in Cardiology / October 2006 A wish can teach a sick child that anything is possible. Even the future. To make your donation or find out more visit www.makeawish.ca or call us at 1-888-822-9474. Share the power of a wish®