HEART FAILURE

1. HEART FAILURE PRESENTED BY JILL KERKMAN

2. Physiology • Oxygen-poor blood flows from the body into the right atrium. • Blood flows through the right atrium into the right ventricle. • The right ventricle pumps the blood to the lungs, where the blood releases waste gases and picks up oxygen.

3. The newly oxygen-rich blood returns to the heart and enters the left atrium. • Blood flows through the left atrium into the left ventricle. • The left ventricle pumps the oxygen-rich blood to all parts of the body.

4. HEART FAILURE • Condition where the heart’s ability to pump the blood has become impaired. • The heart keeps working, but it is working less efficiently. • For individuals with heart failure, the body’s need for oxygen-rich blood is not fully met. • Heart failure usually develops slowly, often over years, as the heart gradually loses its pumping ability and works less efficiently.

5. HF Physiology • When the heart doesn’t pump as efficiently as it should, the blood slows down and less blood is pumped. • The blood returning to the heart backs up in the veins forcing fluid from the blood vessels into the tissues of the feet and legs. • When the heart’s left side, normally receiving the oxygenated blood from the lungs, isn’t pumping effectively, blood backs up into the vessels of the lungs.

6. How Common is Heart Failure? • Estimated 4.8 million Americans have Heart Failure. • 400,000 new cases are diagnosed each year. • Causes 39,000 deaths a year. • Contributing factor in another 225,000 deaths. • Death rate attributed to heart failure rose by 64% from 1970 to 1990. • Death rate from CHD dropped by 49% during the same period. • Heart failure mortality is about twice as high for African Americans as whites for all age groups. • More common among men than women.

8. Etiology of HF • CAD • MI’s • Which have scarred heart tissue • High BP • Valvular Heart Disease • Cardiomyopathy • Congenital Heart Defects • Infection of the Heart • Endocarditis, Myocarditis, etc. • Corrective Mechanisms

9. Dilated Cardiomyopathy • Involves an enlarged heart ventricle, in which the muscle thins out rather than becoming thick causing reduced systolic blood pressure. • Cause is often not known, in which it is called idiopathic dilated cardiomyopathy.

10. Hypertrophic Cardiomyopathy • The heart muscle becomes thick and contracts with difficulty. • Some research indicated that this occurs because of a genetic defect that causes a loss of power in heart muscle cells and, subsequently, diminished pumping strength. • To compensate for this power loss, the heart muscle cells grow.

11. Other Causes • Chronic alcohol abuse • Smoking • Severe emphysema • Excessive salt consumption • Hyperthyroidism • Thiamin deficiency • Pneumonia • High fever • Liver or kidney failure • High cholesterol levels • Diabetes and Obesity

12. Causes Affect the Heart By… • Reducing the strength of the heart’s muscle to contract. • Limiting the ability of the heart chambers to fill with blood. • Filling the heart’s pumping chambers with too much blood.

13. Compensating • The heart compensates to cope with and hide the effects of heart failure. • Enlargement (dilation): Allows more blood into the heart. • Thickening of muscle fibers (hypertrophy) to strengthen the heart muscle: Allows the heart to contract more forcefully and pump more blood. • More frequent contraction: Increases circulation.

15. Pathophysiology • When cardiac output is not sufficient to meet the metabolic needs of the body, compensatory mechanisms, including neurohormonal responses, become activated. • Mechanisms initially help improve contraction and maintain circulation but, if continued, lead to abnormal cardiac growth and reconfiguration (remodeling) of the heart.

16. Renin-Angiotensin-Aldosterone System • The decreased cardiac output in HF results in decreased renal blood flow. • Activates the release of renin which converts to angiotensin I, and then angiotensin II, which is a direct vasoconstrictor. • This system promotes fluid retention.

17. Adrenergic System • Decreased cardiac output causes increased sympathetic activity and increased catecholamines. • Results in vasoconstriction, leading to the shunting of blood.

18. Tachycardia • This initial compensatory response eventually becomes detrimental, as it increases myocardial oxygen demand and shortens the time for coronary perfusion. • In addition, sympathetic stimulation reduces renal blood flow and stimulates the renin-angiotensin system.

19. Heart Failure Classifications • I Normal daily activity does not initiate symptoms. • II Normal daily activities initiate onset of symptoms, but symptoms subside with rest. • III Minimal activity initiates symptoms; patients are usually symptom free at rest. • IV Any type of activity initiates symptoms and symptoms are present at rest.

20. Right Heart Failure • Ineffective right ventricular contractile function. • Pure failure of the right side of the heart can occur acutely (as in pulmonary embolus or a right ventricular infarction). • Most commonly caused by left sided failure or severe pulmonary disease.

21. Left Heart Failure • Disturbance of the contractile function of the left ventricle. • Most frequently caused by left ventricular infarction, hypertension, and aortic and/or mitral valve disease.

22. Forward Failure • Inadequate delivery of blood into the arterial system. • Occurs when systemic vascular resistance is increased, producing decreased blood flow out of the ventricles. • Results in reduced cardiac output and hypoperfusion of vital organs. • Most often occurs with aortic stenosis or systemic hypertension.

23. Backward Failure • Failure of the ventricle to empty. • Usually a result of left ventricular systolic dysfunction caused by infarction or cardiomyopathy.

24. Systolic Dysfunction • More familiar classic type of heart failure. • Due to the heart’s depressed contractility, a reduction in the force of contraction occurs. • EF usually drops below 40% (normal 50-70%). • The heart cannot pump with enough force to push a significant amount of blood into circulation. • Blood coming into the heart from the lungs may back up and cause fluid to leak into the lungs. • Known as pulmonary congestion.

25. Diastolic Dysfunction • Due to slowed or incomplete ventricular relaxation. • The heart cannot properly fill with blood because the muscle has become stiff, losing its ability to relax. • This form may lead to fluid accumulation, especially in the feet, ankles, and legs.

26. Symptoms • Dyspnea • Fatigue • Edema • Persistent Coughing • Raspy Breathing or Wheezing

27. Pharmacology • ACE Inhibitors • Prevent the production of a chemical that causes blood vessels to narrow. • Inhibits the conversion of angiotensin I to angiotensin II. • As a result, BP drops and the heart doesn’t have to work as hard to pump blood. • Side Effects • Coughing, skin rashes, fluid retention, excess K+ in the bloodstream, kidney problems, and an altered or lost sense of taste.

28. Pharmacology • Digitalis • Decreases the force of the heart’s contractions. • Also slows certain fast heart rhythms. • As a result, the heart beats less frequently but more effectively, and more blood is pumped into the arteries. • Side Effects • Nausea, vomiting, loss of appetite, diarrhea, confusion, and new heartbeat irregularities.

29. Pharmacology • Diuretics • Help the body to rid itself of extra fluid and sodium. • Commonly prescribed to reduce high blood pressure. • Side Effects • Loss of too much potassium, weakness, muscle cramps, joint pains, and impotence.

30. Pharmacology • Beta Blockers • Reduce the heart’s workload. • Work on the body’s sympathetic nervous system, which pours hormones like adrenaline into the bloodstream in response to stress. • In response to high levels of the hormones, the heart beats faster and has to work harder. • Patients with heart failure have high levels of these stress-related hormones, a sort of chronic panic mode. • By blocking that response, beta blockers make the heart beat more efficiently.

31. Pharmacology • Hydralazine • This drug widens blood vessels, easing blood flow. • Side Effects • May include headaches, rapid heartbeat, joint pain.

32. Pharmacology • Nitrates • Used mostly for chest pain, but may also help diminish heart failure symptoms. • Relax smooth muscle and widen blood vessels. • They act to lower primarily systolic blood pressure. • Side Effects • Headaches.

33. Exercise Testing • Cardiorespiratory Testing • Functional Testing • Six minute walk test • Total distance ambulated of less than 985 feet was associated with poorer short-term and long-term survival in patients having moderate to severe heart failure.

34. Aerobic Exercise Recommendations • Mode • Most common: walking and cycling • Frequency • Depending on intensity of training, 3-5 times per week has been shown to be effective in achieving the benefits of exercise testing.

35. Aerobic Exercise Recommendations • Duration • 20-45 minutes. • Continuous or interval training methods have been used to achieve training benefits. • Progress slowly to tolerate this duration without undue fatigue. • Begin with intervals of 2-5 minutes, with 1-2 minutes of rest and progress to longer exercise intervals.

36. Aerobic Exercise Recommendations • Intensity • Percent of peak VO2 • Percent of Heart Rate Reserve • RPE • Rating of perceived dyspnea • Selecting the appropriate method will depend on how an individual patient with heart failure presents clinically.

37. Resistance Training Recommendations • Shown to be safe and beneficial for Class I-III. • Free weights, pulleys, isokinetics, and weight machines. • Isometric exercise should be avoided. • Recommended techniques • Borg Scale • Acclimation Method

38. Considerations for Modifying Activities or Exercise • Slow down or stop exercising if the following symptoms develop: • Chest pain • Rapid heart rate • Unusual shortness of breath • Palpitations • Excessive swelling • Irregular or slow heart rate • Weakness, faintness, and dizziness • Leg pain or cramping

39. Heart Transplantation • Class III and IV patients are eligible. • Usually done on people under age 60. • Two year survival rate: 78% • Five years: 50-70% • 76% of transplant patients are male • 85.4% are white • Highest risk factors for death 3 or more years after transplant: • CAD • Adverse effects of immunosuppressive drugs

40. Ventricular Assist Devices • Bridge to transplantation • Permanent support • Capability to support circulation, either partially or totally, until the heart recovers or is replaced

41. Ventricular Remodeling • Batista procedure • Removing a section of healthy heart muscle. • Reshapes the heart to a normal size and form and repairs any faulty heart valves. • Effective in about 75% of cases. • If fails, patient must have immediate transplant. • New procedure and not yet widely available.

42. Dynamic Cardiomyoplasty • Detaches one end of a muscle from the back and wraps it around the ventricles of the heart. • After a few weeks, these relocated muscles are conditioned with electrical stimulation to behave and beat as if they were heart muscles. • Improves systolic pressure, limits dilation of the heart, and reduces heart muscle stress.

43. Intra-aortic Balloon Pump • Device helpful for maintaining heart function for people waiting for transplants. • May be able to use it safely for somewhat longer periods. • Average duration of 23 days in one study.

44. Total Artificial Hearts • Provide complete control of the cardiovascular system and allow total mobility. • Limited in smaller people • Device may not fit client’s body • Initially were limited to people awaiting transplantation • Being used when there are contraindications to transplantation, such as advanced age.