Lecture on pathology of heart failure

2021-08-13 06:44 PM

Grade IV: loss of physical mobility, functional symptoms of heart failure occur even at rest, even mild exercise increases symptoms

Define

Heart failure is the inability of the heart to maintain an adequate output to meet the body's metabolic needs. This is a syndrome, not a disease.

It is necessary to distinguish two types of heart failure:

Systolic heart failure: the heart loses its ability to contract normally to eject blood.

Diastolic heart failure: the heart loses its ability to relax or lose elasticity to fill the ventricles normally.

Causes: often due to hypertension, coronary artery disease, valvular heart disease... Also due to: congenital heart disease, cardiomyopathy (dilation, hypertrophy, restriction), pericardial disease, chronic heart failure, hyperthyroidism, anemia, arteriovenous fistula, beriberi…

Factors that promote heart failure

Non-compliance with diet and medication.

Myocardial ischemia or infarction.

High blood pressure.

Heart rhythm disturbances.

Infection: usually due to pneumonia, myocarditis, infective endocarditis…

Toxins (alcohol, doxorubicin).

Use salt-retaining drugs or reduce myocardial contractility (inhibitors (, calcium antagonists, non-insufficiency anti-inflammatory timeroids...).

Pulmonary embolism.

High supply status (pregnancy, hyperthyroidism, anemia, etc.).

Progression of combined pathology (kidney, lung, thyroid...).

Diagnose

Identify heart failure or asymptomatic ventricular dysfunction.

Type of heart failure (systolic or diastolic...).

Causes of heart failure.

Look for factors that promote heart failure.

Determine the prognosis

Clinical symptoms

Functions:

Shortness of breath on exertion, difficulty breathing while sitting, accompanied by cough.

Tired and weak.

Early nocturia and oliguria in severe heart failure.

Edema.

Palpitations, palpitations (due to arrhythmias).

Atypical angina or chest pain.

Entity:

Pulsed carotid pulse? Swollen neck veins? hepatic feedback - jugular vein (+).

Snout position, heart rate, heart sounds, and murmurs.

Rash in the lungs, pleural effusion.

Alternating circuit? High or low blood pressure, with changes in position?.

Edema, hepatomegaly, ascites.

Subclinical

Chest X-ray:

Big heart ball.

Pulmonary venous hypertension (due to left ventricular failure, mitral stenosis, COPD..), pulmonary artery dilation.

Pulmonary interstitial edema, alveolar pulmonary edema, pleural effusion.

Electrocardiogram: rhythm, Q wave, heart failure-T changes, ventricular- atrial hypertrophy.

Test:

Hematology: anemia aggravates heart failure.

Electrolyte: (increase in sodium is a bad prognostic factor; or increase in potassium ...).

Blood sugar; total cholesterol, LDL-C, HDL-C, triglycerides.

Renal function: bun, blood creatinine.

Liver function in the presence of elevated right ventricular pressure and chronic liver congestion.

Low blood albumin makes edema worse.

T3, T4, TSH in patients > 65 years of age with atrial fibrillation or suggestive of hyperthyroidism or unexplained heart failure.

Transthoracic echocardiography: assessment of systolic and diastolic function, valve pathology...

Other exploratory tests:

Cardiac catheterization - Coronary angiography.

Stress test.

BNP ( B – type Natriuretic Peptide) , Cytokines.

New York Heart Association (NYHA) heart failure grade

Grade I: unrestricted, normal physical activity does not cause fatigue, shortness of breath or palpitations.

Grade II: slight limitation of physical activity. For patients who are well at rest, normal physical activity causes fatigue, palpitations, shortness of breath or chest pain.

Grade III: limited physical activity. The patient is fine at rest, but light physical activity also causes fatigue, palpitations, shortness of breath, or chest pain.

Grade IV: loss of physical mobility, functional symptoms of heart failure occur even at rest, even mild exercise increases symptoms.

Heart failure treatment

Steps to treat heart failure

Treat the cause.

Exclude aggravating factors.

Treatment of heart failure.

General measures

Measures to help reduce the risk of heart damage: stop smoking, lose weight in obese people; control blood pressure, lipids, diabetes; stop drinking...

Measures to balance fluid: limit salt (<2g/day), need to weigh every day to detect excess fluid early; Limit water intake (<1.5 L/day).

Measures to improve fitness: moderate exercise, no need to limit movement.

Measures for each patient:

Control of ventricular rate in patients with atrial fibrillation and supraventricular tachycardia.

Anticoagulation in patients with atrial fibrillation or a history of embolism.

Coronary artery revascularization in patients with angina.

Drugs that affect myocardial contractility or salt retention should be avoided:

Antiarrhythmic drugs if the patient has asymptomatic arrhythmias.

Calcium inhibition.

Anti-inflammatory without timeroid impairment.

Other measures:

Influenza and pneumococcal vaccines.

Closely monitor outpatients.

Treatment of systolic heart failure

ACE inhibitors:

Start low dose and increase gradually.

Captopril: 6.25 -> 12.5mg x 3 times/day; target dose 50mg x 3.

Enalapril: 2.5mg/day; target 10mg x 2.

Lisinopril: 2.5mg/day, target 20-40mg/day.

Monitor BUN, Creatinine, blood potassium, blood pressure.

Diuretic:

Use when there are signs of fluid retention

Thiazide (mild heart failure): hydrochlorothiazide 25-100mg/day.

Furosemide (moderate to severe heart failure): 20-80mg, orally or intravenously.

Potassium-sparing diuretics: Amiloride, Triamterene.

Digoxin:

If symptoms persist, use ACE inhibitors and diuretics, atrial fibrillation.

Maintenance dose: 0.0625 - 0.25mg/day.

Reduce dose in the elderly, underweight, renal failure

Angiotensin II receptor blockers can be used for severe cough due to ACE inhibitors.

Beta-blockers:

Stabilized left ventricular failure with digoxin, ACE inhibitors, and diuretics.

Start at a very low dose and increase the dose slowly.

Carvedilol: 3.125mg x 2 times/day x 2 weeks.

Metoprolol: 12.5 - 50 mg/day.

Bisoprolol: 1.25mg/day x 1 week (2.5mg/day x 1 week…

Aldosterone Resistance:

Severe heart failure treated with digoxin, ACE inhibitors, diuretics, and beta-blockers.

The dose is 12.5-200mg/day.

Hydralazine and Nitrate:

Use in patients with intolerance to ACE inhibitors or renal failure.

Hydralazine: 10-25mg x 3 times/day; target dose 75mg x 3.

Isosorbide dinitrate 10mg x 3 times/day; target dose 120mg/day

Or Isosorbide mononitrate 40 - 80 mg/day

Antiarrhythmic drugs:

Depends on the clinical situation.

Anticoagulation: only used when atrial fibrillation has thrombosis or a history of cerebral vascular occlusion due to thrombosis.

Treatment of diastolic heart failure

Step 1: diuretic.

Step 2: Beta-blocker or ACE inhibitor.

Step 3: calcium inhibition.

Attention when using drugs to treat diastolic heart failure:

Start with a low dose.

Avoid high doses of diuretics.

Avoid excessive preload reduction.

Drug combination.

Caution when using inotropes:

Digoxin should not be used in diastolic heart failure alone except for atrial fibrillation.

Dopamine, Amrinone may be useful in the treatment of acute, severe, and short-lived diastolic heart failure, with no benefit in long-term treatment.