Insuficiencia Cardiaca Obstetricia 2007

Insuficiencia cardiaca

Dr. Ricardo Armisen Y ICBM Facultad de Medicina Universidad de Chile

Referencias •Harrison, Principles of Internal Medicine, 2007 •Porth, Pathophisiology, 2006 •Lilly, Pathophysiology of Heart Disease: A Collaborative Project of Medical Students and Faculty, 2007 •Ashley & Niebahuer, Cardiology Explained, 2004

Heart Failure ¥ Function of the heart Ð Move deoxygenated blood from the venous system through the right heart into the pulmonary circulation Ð Move the oxygenated blood from the pulmonary circulation through the left heart into the arterial system ¥ Right and left heart must maintain an equal output to function properly

Right Heart Failure ¥ Represents failure of the right heart to pump blood forward into the pulmonary circulation Ð Blood backs up in the systemic circulation ¥ Causes peripheral edema and congestion of the abdominal organs

3

4 2 1

¥ Acute myocardial infarction ¥ Hypertension ¥ Degenerative conditions of the heart muscle known collectively as cardiomyopathies ¥ Excessive work demands (hypermetabolic states) ¥ Volume overload (renal failure)

3

4 2 1

Maintenance of Cardiac Reserve in Heat Failure ¥ Compensatory or adaptive mechanisms Ð Frank-Starling mechanism Ð Activation of neurohumoral influences such as the sympathetic nervous system Ð The renin-angiotensin-aldosterone mechanism Ð Natriuretic peptides Ð Locally-produced vasoactive substances Ð Myocardial hypertrophy and remodeling

Causes of Right-Sided Heart Failure ¥ Conditions that restrict blood flow into the lungs ¥ Stenosis or regurgitation of the tricuspid or pulmonic valves ¥ Right ventricular infarction ¥ Cardiomyopathy ¥ Persistent left-sided failure ¥ Acute or chronic pulmonary disease (cor pulmonale)

Manifestations of Heart Failure ¥ Physiologic effects of the impaired pumping ability of the heart ¥ Decreased renal blood flow ¥ Activation of the sympathetic compensatory mechanisms

Signs and Symptoms of Heart Failure ¥ Fluid retention and edema ¥ Shortness of breath ¥ Fatigue and limited exercise tolerance ¥ Cyanosis ¥ Cachexia and malnutrition ¥ Distention of the jugular veins in right-sided failure ¥ Diaphoresis and tachycardia

Acute Pulmonary Edema ¥ Capillary fluid moves into the alveoli, causes lung stiffness, makes lung expansion more difficult, and impairs the gas exchange function of the lung ¥ With the decreased ability of the lungs to oxygenate the blood, the hemoglobin leaves the pulmonary circulation without being fully oxygenated Ð Results in shortness of breath and cyanosis

P = T/r T is wall tension P is the intraluminal pressure r is vessel radius

T = P × r/wall thickness