HEART FAILURE CARE CASE STUDY

Heart Failure Care Case Study

Heart Failure Care Case Study

Introduction

Heart failure is a clinical syndrome characterized by systemic perfusion inadequate to meet the body's metabolic demands as a result of impaired cardiac pump function. This may be further subdivided into systolic or diastolic heart failure. In systolic heart failure, there is reduced cardiac contractility, whereas in diastolic heart failure there is impaired cardiac relaxation and abnormal ventricular filling.

The most common cause of heart failure is left ventricular systolic dysfunction (about 60% of patients). In this category, most cases are a result of end-stage coronary artery disease, either with a history of myocardial infarction(s) or chronically underperfused, yet viable, myocardium. In many patients, both processes are present simultaneously. Other common causes of left ventricular systolic dysfunction include idiopathic dilated cardiomyopathy, valvular heart disease, hypertensive heart disease, toxin-induced cardiomyopathies (e.g., doxorubicin, herceptin, alcohol), and congenital heart disease (Kerwin, 2000, pp. 1221).

Right ventricular systolic dysfunction is usually a consequence of left ventricular systolic dysfunction. It may also develop as a result of right ventricular infarction, pulmonary hypertension, chronic severe tricuspid regurgitation, or arrhythmogenic right ventricular dysplasia. A less common cause of heart failure is high-output failure caused by thyrotoxicosis, arteriovenous fistulae, Paget's disease, pregnancy, or severe chronic anemia.

Diastolic left ventricular dysfunction (impaired relaxation) usually is related to chronic hypertension or ischemic heart disease. Other causes include restrictive, infiltrative, and hypertrophic cardiomyopathies. Inadequate filling of the right ventricle may result from pericardial constriction or cardiac tamponade(Sogaard, 2001pp. 173).

With continuous neurohormonal stimulation, the left ventricle undergoes remodeling consisting of left ventricular dilation and hypertrophy, such that stroke volume is increased without an actual increase in ejection fraction. This is achieved by myocyte hypertrophy and elongation.

Left ventricular chamber dilation causes increased wall tension, worsens subendocardial myocardial perfusion, and may provoke ischemia in patients with coronary atherosclerosis. Furthermore, left ventricular chamber dilation may cause separation of the mitral leaflets and mitral regurgitation, leading to pulmonary congestion. Enhanced neurohormonal stimulation of the myocardium also causes apoptosis or programmed cell death, worsening of ventricular contractility, and death(Yu, 2002, pp. 438).

In diastolic dysfunction, the primary abnormality is impaired left ventricular relaxation, causing high diastolic pressures and poor filling of the ventricles. To increase diastolic filling, left atrial pressure increases until it exceeds the hydrostatic and oncotic pressures in the pulmonary capillaries and pulmonary edema ensues(Brecker, 2007, pp. 1308). As a result, patients are often symptomatic with exertion when increased heart rate reduces left ventricular filling time and circulating catecholamines worsen diastolic dysfunction.

Effect Of Depression On Heart Failure

In Left ventricular heart failure patients, the prevalence of major depression - i.e., the full clinical picture of major depression - develops in 14-26%. However, single depressive symptoms can be detected in 24-85% of ventricular heart failure patients. All together, depressive symptoms in ventricular heart failure patients are common, but due to different assessment methods, sample sizes and selection criteria the range of prevalence rates is rather wide(Brecker, 2007, pp. ...