Pathophsyology left ventricular failure

1. Keren Shay Pathophysiology of left ventricular failure

2. Heart failure definition A state in which the heart cannot provide sufficient cardiac output to satisfy the metabolic needs of the body, Because of problem with the structure or function of the heart impairs. It is common end point for many diseases of cardiovascular system, is caused by any condition which reduces the efficiency of the myocardium or heart muscle, through damage or overloading. There are many different ways to categorize heart failure, including: the side of the heart involved (left heart failure against right heart failure or both). Left heart failure compromises aortic flow to the body and brain. Right heart failure compromises pulmonic flow to the lungs.

3. Left ventricular failure Left ventricular failure is a life-threatening condition. The left side of the heart receives blood rich in oxygen from the lungs and pumps it to the remainder of the body. As the ability to pump blood forward from the left side of the heart is decreased, the remainder of the body does not receive enough oxygen especially when exercising, this results in fatigue. causes congestion of the pulmonary vasculature, and so the symptoms are predominantly respiratory in nature Alternative name: Congestive left heart failure

4. etiology Drinking too much alcohol Heart attack Heart muscle infections High blood pressure -volume overload: high output status -pressure overload: systemic hypertension, outflow obstruction Hypothyroidism Leaking or narrow heart valves Any other disease that damages the heart muscle Poor left-side heart function due to prior heart attacks

5. The pathophysiology of l.v.f Over time left sided failure increases in workload will produce changes to the heart itself: - Neuhormonal : sympathetic activity,vasopressin . -Cellular changes-program cell death(apoptosis),increase amount of fibrous tissue. -Hemodynamic -Reduced contractility, or force of contraction, due to overloading of the ventricle , as the ventricle is loaded with blood to the point where heart muscle contraction becomes less efficient, this is due to reduced ability to cross-link actin and myosin filaments in over-stretched heart muscle. -A reduced stroke volume, as a result of a failure of systole, diastole or both. Increased end systolic volume is usually caused by reduced contractility. Decreased end diastolic volume results from impaired ventricular filling – as occurs when the compliance of the ventricle falls

6. -Hypertrophy (an increase in physical size) of the myocardium, caused by the terminally differentiated heart muscle fibres increasing in size in an attempt to improve contractility This may contribute to the increased stiffness and decreased ability to relax during diastole. -The general effect is one of reduced cardiac output and increased strain on the heart. This increases the risk of cardiac arrest Symptoms Cough (produces frothy or blood-tinged mucus) Decreased urine production Difficulty lying down; need to sleep with the head elevated to avoid shortness of breath Fatigue, weakness, faintness Irregular or rapid pulse Sensation of feeling the heartbeat (palpitations) Shortness of breath Waking up due to shortness of breath (paroxysmal nocturnal dyspnea ) Weight gain from fluid retention

7. Signs Left-sided failure Common respiratory signs are tachypnea (increased ''rate'' of breathing) and increased ''work'' of breathing (non-specific signs of respiratory distress). Rales or crackles, heard initially in the lung bases, and when severe, throughout the lung fields suggest the development of pulmonary edema (fluid in the alveoli). Cyanosis which suggests severe hypoxemia, is a late sign of extremely severe pulmonary edema. Additional signs indicating left ventricular failure include a laterally displaced apex beat, may be heard as a marker of increased blood flow, or increased intra-cardiac pressure. Heart murmurs may indicate the presence of valvular heart disease, either as a cause or as a result of the heart failure

8. Heart failure diagnosis Echocardiography- is commonly used to support a clinical diagnosis of heart failure, uses ultrasound to determine the stroke volume, end diastolic volume. Chest X-rays- are frequently used to aid in the this may show visible enlargement of the heart,in left ventricular failure, there may be evidence of vascular redistribution, cuffing of the areas around the bronchi, and interstitial edema. electrocardiogram (ECG)- is used to identify ischemic heart disease, right and left ventricular hypertrophy, and presence of conduction delay or abnormalities. Blood test-An elevated B-type natriuretic peptide (BNP) is a specific test indicative of heart failure, BNP can be used to differentiate between causes of dyspnea due to heart failure

9. medication Treatment of congestive heart failure consists of a combination of non-drug and drug strategies. Lifestyle changes include the f ollowing: Stay active as possible under limitations set by a doctor Schedule relaxation and rest periods throughout the day Avoid excessive fluid intake Do not drink alcohol Keep a diary of daily weight Medication: Digoxin – helps the heart beat more efficiently to reduce the symptoms of CHF. It may also help to control certain abnormal heart rhythms. Beta blockers – slow the heart down and reduce the risk of abnormal heart rhythms. Verapamil – is a calcium channel blocker that is especially useful in the treatment of diastolic CHF.

10. refrances http://www.news-medical.net/health/Heart-Failure-Diagnosis.aspx http://www.news-medical.net/health/Heart-Failure-Pathophysiology.aspx http://health.nytimes.com/health/guides/disease/left-sided-heart-failure/overview.html http://www.powershow.com/view/4455b-YTg4N/Heart_Failure_flash_ppt_presentation http://www.ehealthhut.com/health_information_articleview.php?art_ID=38 Thank u