NU608 Heart Failure PDF

1 Heart Failure  general term used to when pumping ability of heart is impaired. Used to describe several types of cardiac dysfunction that result in inadequate perfusion of tissues ~1% of Americans over the age of 65 have heart failure 20% of hospitalizations for pa...

1 Heart Failure  general term used to when pumping ability of heart is impaired. Used to describe several types of cardiac dysfunction that result in inadequate perfusion of tissues ~1% of Americans over the age of 65 have heart failure 20% of hospitalizations for patients 65 or older is d/t heart failure Congestive heart failure (CHF) is heart failure accompanied by congestion of body tissues. Heart failure that is complicated by pulmonary or systemic venous congestion. 2  Not only do older persons experience an age-related decrease in LV diastolic relaxation and early LV diastolic filling, they are more likely to have LV diastolic dysfunction because they have an increased prevalence of hypertension, myocardial ischemia due to CAD, LV hypertrophy due to hypertension, valvular aortic stenosis, hypertrophic cardiomyopathy, and other cardiac disorders. In older persons, the increased stiffness of the LV and prolonged LV relaxation time impair LV early diastolic filling and cause higher LV end- diastolic pressures at rest and during exercise. Topic Slide 3 Causes of heart failure are varied and may also result from non-cardiac etiologies. Can be due to Impaired cardiac function as seen in: Myocardial disease  MI, cardiomyopathies, myocarditis Valvular heart disease (both stenotic and regurgitant disease can progress to failure) Can be due to Excess work demands as seen in: Increased pressure work  systemic hypertension, pulmonary hypertension, coarctation of aorta Increased volume work  arterio-venous (Ava) shunts, excessive administration of IVF Increased perfusion work  anemia, thyrotoxicosis 4 Please read slide 5  In patients with normal LV systolic function but abnormal LV diastolic function, myocardial hypertrophy, ischemia, or fibrosis causes slow or incomplete LV filling at normal left atrial pressures. Left atrial pressure rises to increase LV filling, resulting in pulmonary and systemic venous congestion. The development of AF (the prevalence of which increases with age) may also cause a decrease in cardiac output and the development of pulmonary and systemic venous congestion, because of the loss of left atrial contribution to LV late diastolic filling and reduced diastolic filling time due to a rapid ventricular rate. Topic Slide 6  Please read slide Topic Slide 7  LV failure with transudation of fluid into the alveoli causes moist rales, which are heard over the lung bases posteriorly. Congestion of bronchial mucosa causes rhonchi and wheezes. During acute pulmonary edema, coarse, bubbling rales and wheezes are heard over the lung fields. Signs of pleural effusion may occur with LV or RV failure. RV failure may cause an enlarged, tender liver and ascites. Compression of the liver causes the hepatojugular reflux sign. Pressure applied to the middle of the abdomen can cause abdominal jugular reflux sign. A pulsating liver indicates tricuspid regurgitation. Most persons with HF have cardiomegaly. However, HF may develop in persons with AMI or other conditions before the heart has had a chance to enlarge. Heart murmurs due to valvular heart disease may become faint or absent because of a low cardiac output. Older persons, especially women, without HF have higher B-type natriuretic peptide (BNP) levels than younger persons. There is no significant difference in BNP levels between older women with HF and those without HF. BNP levels do not help distinguish older persons with HF with abnormal LVEF from those with normal LVEF, although the former group tends to have higher BNP levels. The use of BNP levels in the evaluation of acute HF does not aid in the treatment of older persons. Topic Slide 8 Flow map of right and left heart failure 9 Right heart failure Failure of right heart to pump blood forward into the pulmonary circulation Leading to accumulation or damming back of blood in the systemic venous side Increase in right atrial, RV end-diastolic and systemic venous pressure Causes: Conditions that restrict blood flow into lungs Stenosis or regurgitation of tricuspid or pulmonic valves Cardiomyopathy Persistent left-sided failure  a failing left ventricle would cause blood to back up in the left atrium And, then to the pulmonary circuit, right ventricle and right atrium *** the main cause of right heart failure is left heart failure**** Acute or chronic pulmonary disease  Pneumonia, pulmonary emboli, pulmonary hypertension (referred to as cor pulmonale) 10 Manifestations of heart failure are often separated into forward and backward effects, with the right and left side of the heart as the starting point. Forward effects are considered downstream from the failing myocardium. Backward effects are considered upstream from the failing mhyocardium Backward effects of right heart failure: Increased venous pooling of blood Edema of hands and feet Ascites Jugular vein distension Hepatomegaly and splenomegaly Forward effects of right heart failure: Decreased pulmonary blood flow Decreased blood oxygenation Fatigue Decreased systemic blood pressure (d/t decreased left heart filling d/t the decreased pulmonary blood flow) 11 Left sided failure Failure of left heart to move blood from the pulmonary circulation into the systemic circulation Leading to a decrease in cardiac output Increase in left atrial & left ventricular end-diastolic pressures Congestion in the pulmonary circulation Associated conditions: Acute myocardial infarction Stenosis or regurgitation of mitral/aortic valves Rapid infusion of IVF or blood 12 Manifestations depend on extent & type of dysfunction when it develops. They reflect the effects of impaired pumping ability of the heart, decreased renal blood flow, and activation of the sympathetic compensatory mechanisms. Forward effects of left heart failure Decreased systemic blood pressure Fatigue Increased heart rate Decreased urine output Backward effects of left heart failure Increased pulmonary congestion (especially when lying down) Dyspnea (difficulty breathing) Right heart failure if condition worsens 13 High output failure  despite adequate blood volume & normal or elevated myocardial contractility, the heart increases its output but the body’s needs are still not met. Causes: Anemia  in attempts to increase O2 carrying capacity there is increase in heart rate and stroke volume; the workload of the heart increases but unless anemia is corrected the body’s needs will still not be met. Sepsis  systemic vasodilation causes hypotension and the workload of the heart increase in attempts to increase cardiac output Hyperthyroidism  increase levels of thyroxine, increases BMR significantly Beriberi (thiamine deficiency) seen alcoholics, impairs cellular metabolism in the tissues 14 Unfortunately…time for another one (this one covering module 7 & 8  15