Congestive Cardiac Failure Excerpt CSOC

• Heart failure illustration:

The difficulty in diagnosing hypertrophic cardiomyopathy. . 2021. https://pcna.net/the-difficulty-indiagnosing-hypertrophic-cardiomyopathy/. Accessed Jul 21, 2023.

Summarized as an imbalance in Starlings forces or an imbalance in the degree of end-diastolic fiber stretch proportional to the systolic mechanical work expended in the ensuing contraction

Pathophysiology

Or basically like a rubber band, the more it is stretched, the greater the releasing velocity

Depression of Ventricular function

Stretching of myocardial fibers (STARLING’S LAW)

Ventricular dilatation

Left Ventricle Failure

• Ischemic Heart Disease

• Valvular Heart Disease

• Pericardial Restriction

• Myocarditis

Right Ventricle Failure

• Right Side Valvular Disease

• Right Side Myocardial Disease

• Cor Pulmonale

• Pulmonary Hypertension

Compensation Mechanisms Activation

Tachycardia

Etiology

• Coronary artery disease-chronic, post MI

• HTN

• Chronic Valvular heart disease (especially aorta and mitral disease)

• Acute Infection viral myocarditis

• Dysrhythmias

• Alcohol-chronic

• Long standing Diabetes

Concept Of Preload And Afterload

Preload

• The amount of blood the heart must pump with each beat

• Determined by:

• Venous return to heart

• Accompanying stretch of the muscle fibers

• Increasing preload → increased stroke volume in normal heart

• Increasing preload → impaired heart → decreased SV→ Blood is trapped → chamber enlargement

Afterload

• The pressure that must be overcome for the heart to pump blood into the arterial system

• Dependent on the systemic vascular resistance

• With increased afterload, the heart muscles must work harder to overcome the constricted vascular bed → chamber enlargement

• Increasing the afterload will eventually decrease the cardiac output

Types Of CHF

• Left Ventricular Failure with Pulmonary Edema—Systolic heart failure

• Right Ventricular Failure—Diastolic heart failure

• Biventricular failure

• High output failure /Low output failure

Left Ventricular Failure

• Occurs when the left ventricle fails as an effective forward pump

• →back pressure of blood into the pulmonary circulation

• →pulmonary edema

• Cannot eject all of the blood delivered from the right heart.

• Left atrial pressure rises → increased pressure in the pulmonary veins and capillaries

• When pressure becomes high, the fluid portion of the blood is forced into the alveoli

decreased oxygenation capacity of the lungs

Signs And Symptoms Of Left Ventricular Failure

• Severe respiratory distress

• Evidenced by orthopnea,

• Dyspnea

• History of paroxysmal

• nocturnal dyspnea

• Severe apprehension, agitation, confusion

• Resulting from hypoxia

• Feels like he/she is

• Smothering

• Diaphoresis

• Results from sympathetic stimulation

• Pulmonary congestion

• Often present

• Rales—especially at the bases.

• Rhonchi—associated with fluid in the larger airways indicative of severe failure

• Wheezes

• Response to airway spasm

Signs And Symptoms Of Left Ventricular Failure

• Jugular Venous Distention not directly related to LVF.

• Comes from back pressure building from right heart into venous circulation

• Vital Signs

• Significant increase in sympathetic discharge to compensate.

• BP elevated

• Pulse rate elevated to compensate for decreased stroke volume.

• Respirations rapid and labored