What is heart failure?
The left ventricle is failing to have adequate output. This can be due to a decrease in the systolic or diastolic function and can be caused by a variety of structural or functional issues. it also involves the inability to fill the chambers as well. No point deduction.
Explain the difference between preload & afterload
Preload happens during diastole when the chamber is filling and the myocardial fibers stretch before contraction. Afterload is after the ventricle has filled, the resistance that the ventricle must overcome to eject the contents from the chamber.
What are the main causes of HF
Ischemic heart disease
cardiomyopathy
hypertension
What four mechanisms often lead to HF
(1) impaired cardiac contractility. (2) ventricular outflow obstruction; pressure overload. (3) impaired ventricular filling. (4) volume overload.
Name three precipitating factors.
(1) Arrhythmias (2) Myocardial Infarction (3) infection.
- What adaptive mechanisms help the heart to compensate for overload, in efforts to maintain pumping function ?
Cardiac dilation (Frank Sterling mechanism), myocardial hypertrophy, and increased amounts of catecholamines released and renin-angiotensin-aldosterone system activation.
- Name three pathophysiological changes.
(1) ventricular dilation (2) sympathetic stimulation (3) peripheral vasoconstriction.
- What are the three clinical syndromes of HF?
LV systolic dysfunction, RV systolic dysfunction, and diastolic heart failure.
- What are the signs & symptoms of LHF?
symptoms: fatigue, exertional dyspnea, and orthopnea.
Physical signs: cardiomegaly, gallop, mitral valve regurgitation, and crackles at the lung bases.
What are the signs & symptoms of RHF?
symptoms: fatigue with breathlessness, anorexia/nausea, and fluid accumulation.
physical signs: jugular vein distention, tender hepatic enlargement, pitting edema, free abdominal fluid, and pleural transudates.
- Describe the NYHA classification system of HF.
This classification system describes the severity of the HF into four classes. Class I is the most minor, at this point the heart failure hasn’t caused many obvious limitations with exercise, fatigue, dyspnea and/or palpitations. Class II had developed into some discomfort during physical activity including fatigue, dyspnea, and/or palpitations. Class III minor physical activity gives rise to these HF symptoms. Class IV is causing these symptoms at rest and they get worse with any physical activity.
- Describe the Framingham Criteria for diagnosis of HF
A set of minor and major criteria, where the patient must meet one major and two minor criteria at a minimum to be diagnosed with HF. • Major: PND, JVD, rales, cardiomegaly, pulmonary edema, S3 gallop • Minor: ext. edema, pleural effusion, tachycardia, weight loss • One major and two minor symptoms need to be present.
- What types of diagnostic tests are done to evaluate HF?
Blood tests, chest x-ray, EKG, echocardiogram, can all be used as diagnostic tests for HF
- What are the five components of HF treatment?
(1) General measures. (2) correction of the underlying cause. (3) removal of the precipitating cause. (4) Prevention of deterioration of cardiac function. (5) control of the congestive HF state.
- What are the three types of diuretics? Explain their mechanisms.
(1) Thiazidines – work in the loop of Henle to inhibit active exchange of Cl-Na. (2) Potassium Sparing – they inhibit the reabsorption of Na+. (3) Loop diuretics – inhibit exchange of Cl, Na+ and K in the loop of Henle.
- What is the purpose of ACEI? Explain its mechanism.
ACEI is Angiotensin-converting enzyme inhibitors. Their purpose is to cause vasodilation which will lower systemic vascular resistance and venous pressure. They work by reducing the levels of catecholamines.
- What are α-adrenergic blockers? Are they effective for HF therapy?
These drugs work as arteriolar vasodilators. They are not effective for heart failure therapy.
- How are calcium channel blockers included in HF therapy?
Calcium-channel blockers should not be included in treatment for HF.
- How are nitrates effective as HF therapy?
Nitrates can help reduce the preload and they can lower venous blood pressure.
- How do beta blockers aid in management of HF?
Beta-blockers have been shown to augment cardiac output and reduce hemodynamic deterioration in patients with stable HF.
- What are cardiac glycosides? What toxic effects do they tend to have?
Digoxin, Digitoxin, and Ouabain are cardiac glycosides. Their toxicity effects can cause GI discomfort with anorexia, nausea, vomiting, pain, and/or diarrhea. The toxicity can also cause neurological effects of a headache, malaise, fatigue, drowsiness, confusion, delirium, hallucinations, and convulsions. Vision can also be affected, and gynecomastia can happen. Cardiac effects can cause arrhythmias.
- What non-pharmacological treatment is available for HF?
Revascularization, Bi-V pacemaker or ICD, or cardiac transplant.
- What is acute HF? How is this different from chronic HF?
Acute HF happens rapidly with a sudden onset of signs and symptoms of HF. Chronic HF happens slowly over time.
- Explain pulmonary edema & cardiogenic shock. Why is it important to look for signs & symptoms of both diagnoses?
Pulmonary edema signs include tachypnea, orthopnea, pulmonary crackles, and O2 saturation of under 90% on air. Cardiogenic shock will show with a systolic BP under 90 mmHg and a mean arterial pressure drop by 30 mmHg or more, urine output <0.5 mL/kg/hour, and heart rate will be over 60 bpm. Pulmonary edema is important to treat right away to get adequate breathing and oxygen saturation to the patient. Cardiogenic shock is a very serious failure of tissue perfusion and is an emergent situation. The patient needs revascularization of any occluded artery, oxygen administered, venous dilators and cardiac inotropes may be needed too.
