Treatment of Pathophysiological Cases - Case Study Example

Download file to see previous pages Edema is a symptom of excessive fluid in the interstitium resulting from several deregulatory mechanisms and one of these is impaired venous return. In general, the opposing effects of vascular hydrostatic pressure and plasma colloid osmotic pressure are the major factors that govern the movement of fluid between vascular and interstitial spaces. Normally the exit of fluid into the interstitium from the arteriolar end of the microcirculation is nearly balanced by inflow at the venular end; a small residuum of excess interstitial fluid is drained by the lymphatics. Either increased capillary pressure or diminished colloid osmotic pressure can result in increased interstitial fluid.
Congestive heart failure is a syndrome where the heart has an inherent dysfunction, or pathology causing it to be unable to pump efficiently, thus causing the signs and symptoms which include dyspnea, fatigue edema, and rales. In this disease, there is initial left ventricular dysfunction, which may be the result of left ventricular remodeling. This may then lead to functional mitral regurgitation, with overloading of the ventricles because it now has to pump against a higher pressure, and the dysfunction of the atrium, the fibrillation, does not help to push the cardiac volume forward, instead retaining much of the volume because there is no electrical impulse that travels throughout the myocardium that is enough to trigger a contraction. This may then lead to pulmonary congestion, and the symptom of dyspnea because of the fluid accumulation that is hindering the lungs from expanding to its full capacity.   According to Harrison the mechanical burdens that are engendered by LV remodeling can be expected to lead to decreased forward cardiac output, increased LV dilation (stretch), and increased hemodynamic overloading, all of which are sufficient to contribute to the progression of HF. The peripheral edema comes from chronic passive congestion due to the right-sided failure that results from the initial left-sided heart failure due to the transmission of pressure overload and volume overload. In heart disease, edema primarily results from elevated RA pressures or associated peripheral venous disease. Right heart failure most commonly results from left heart failure, pulmonary disease, or RV dysfunction and tricuspid regurgitation, or constrictive pericarditis.
The patient was also noted to have irregular pulses and is a known case of atrial fibrillation. Atrial fibrillation (AF) is caused by multiple reentrant waveforms within the atria, which bombard the atrioventricular (AV) node, commonly leading to a tachycardia that is irregularly irregular. The rate at which atrial fibrillation causes a ventricular contraction is dependent upon the refractory state of the AV node. There is a loss of atrial contraction and its contribution to ventricular filling, also referred to as loss of atrial kick. In addition, this loss of contraction can lead to stagnation of blood in the atrium and can promote thrombus formation. Patients may be at risk for embolization when atrial fibrillation converts to sinus rhythm as organized atrial contractions can now cause the dislodging or fragmentation of the atrial thrombus into the systemic circulation. The symptoms of atrial fibrillation include an irregular heartbeat transmitted peripherally as irregular pulses and is most often tachycardic at 110-140 beats per minute, and rarely exceeding 160 beats per minute. ...Download file to see next pagesRead More