Heart Failure Patho.docx

1. Discuss the pathophysiological mechanisms that can lead to heart failure. Congestive heart failure is a common chronic condition in the United States. According to the Center for Disease and Control Prevention (CDC, 2019), HF is a serious condition, effecting 6.5 million people a year in the United States. In 2017, HF accounted for 1 in 8 deaths. Risk factors for heart failure include both underlying medical conditions and lifestyle behavior. In heart failure, cardiac output is decreased, resulting in the heart inability to perfuse tissues. Heart failure primarily effect the left ventricle, and can be diastolic (HFpEF) or systolic (HFrEF) heart failure. According to Metra and Teerlink (2017), the pathophysiology of HFrEF is progressive. Risk factors leads to cardiac injuries that over time myocardial dysfunction. Initially, this may be asymptomatic. However, overtime, this symptom increases to end stage heart failure. Some risk factors that Metra et al. mentioned were exposure to cardiotoxic agents (such as alcohol and drugs, cancer treatment, and radiation). Cardiac injuries and myocardial dysfunction results in loss of left ventricular remodeling. This occurred when loss of “myocyte cells and increased myocardial strain cause eccentric hypertrophy of the remaining myocytes, both directly and through neurohormonal activation, leading to fibrosis, progressive left ventricular dilatation, a change in the shape of the left ventricle from elliptical to spherical, and, often, functional mitral regurgitation” (Metra & Teerlink, 2017, p. 1982). Left ventricular remodeling lead to need for the heart to increase oxygen consumption and thus decrease cardiac output. This ultimately lead to hemodynamic reaction, renal reaction, and neurohormonal activation involving multiple pathways and systems. This study source was downloaded by from CourseH on :47:56 GMT -05:00 This study resource was shared via CourseH McCance et al. (2019) noted that HFpEF or diastolic HF occur in 50% of cases. The risk factors for HFpEF include diabetes, valvular disease, hypertension induced myocardial hypertension and myocardial ischemia causing ventricle remodeling. The heart is unable to relax due to ventricular stiffness resulting in higher diastolic pressures. These changes lead to impaired left ventricular filling resulting in increased left ventricle end-diastolic pressure at rest or with exertion. This is transmitted through atrial and pulmonary venous system, thus reducing lung compliance. 2. Differentiate between systolic and diastolic heart dysfunction Systolic and diastolic heart dysfunctions are two types of left heart failure or congestive heart failure. Systolic heart failure is heart failure with reduced ejection fraction, HFrEF. Diastolic heart failure is heart failure with preserved ejection fraction, HFpEF. According to McCance et al. (2019), systolic heart failure is more common in male than female. The ejection fraction is decrease, less than 40%. The size of the left ventricle is increased, with left ventricular hypertrophy on ECG possible. On auscultation, S3 gallop is possible. In addition, pulmonary congestion with cardiomegaly is noted on chest X ray. In contrast, diastolic heart failure is pulmonary congestion with normal stoke volume and cardiac output. HFpEF is more common in female then male. It accounts for 50% of left heart failure. The EF is preserved. Left ventricle size is decreased, with probable chance of left ventricular hypertrophy. S4 sound is auscultated and on chest x ray there is pulmonary congestion, however, without cardiomegaly. 3. Discuss the causes of the patient’s shortness of breath, awakening in the middle of the night and the need to prop herself up on three pillows. Include pathophysiological mechanisms that causes each of these signs and symptoms.