Heart Failure (HF) in a view

•  Dr.K.T.S
•   Coronary Artery Diseases
• on Jul, 09, 2014
•  No Comments.

Heart Failure (HF) in a View

Heart Failure (HF), often called congestive heart failure (CHF) or congestive cardiac failure (CCF), occurs when the heart is unable to provide sufficient pump action to maintain blood flow to meet the needs of the body.Heart failure means a rate of cardiac output that does not commensurate with the requirement of metabolizing tissues. In normal persons cardiac output rises by more than 500 ml/min for each 100 ml increase in minute oxygen consumption.Common causes of heart failure include myocardial infarction and other forms of ischemic heart disease (IHD), hypertension, valvular heart disease(VHD), and cardiomyopathy.Heart failure (HF) is a common, costly, disabling, and potentially deadly condition.The term heart failure is sometimes incorrectly used for other cardiac-related illnesses, such as myocardial infarction (heart attack) or cardiac arrest, which can cause heart failure but are not equivalent to heart failure.

This in lacking or inadequate in patients of heart failure either due to (1) defect in energy producing system, (2) poor energy utilization, (3) defect in break down of ATP, or (4) abnormality of excitation contraction coupling. Heart failure can be forward failure, backward failure; left heart failure, right heart failure, high output failure, Low output failure, Systolic failure, Diastolic failure. In diastolic failure, the systolic function is normal but due to impaired relaxation of myocardium, ventricular filling is reduced leading to reduced cardiac index. Diastolic dysfunction is present in hypertension, ischemic heart disease and cardio myopathy.

Types of Heart Failure

Acute Heart Failure

    Causes        1. LV myocardial dysfunction Ischemia and Infarction. Infection : Myocarditis (and cardiomyopathy) Iatrogenic : Cardiac depressant drugs.      2. Increased LV load Systolic (Pressure) overload : Hypertension, AS. Diastolic (Volume) overload : MR, AR, VSD, PDA.      3. Arrhythmias

Chronic heart failure

     Causes 1. RV myocardial dysfunction (rare) : Myocarditis, cardiomyopathy. 2. Systolic overload of RV : Preceding LVF (commonest cause), pulmonary hypertension, chronic cor pulmonale, PS. 3. Diastolic overload : Left to right shunt e.g. ASD 4. Restriction of RV : EMF, constrictive pericarditis (localized)

Refractory heart failure

            Aneurysm (ventricular)             BP raised             Carditis             Dysarrhythmia             Embolism (pulmonary)             Failure to take treatment             Gross anemia             Hidden (occult)heart disease : Aortic Stenosis, Mitral Stenosis

Diastolic heart failure

More in elderly especially those with long-standing hypertension or other hypertrophic ventricular disease Classical signs of heart failure but small heart Characteristic abnormalities of diastolic LV dysfunction on echo.

Causes of congestive heart failure in the new born

Tansposition of great vessels Hypoplastic left heart syndrome Double outlet right ventricle without pulmonary stenosis Aortic atresia and aortic arch interruption Aortic – pulmonary window, large Patent Ductus Arteriosus Tight pulmonary stenosis / atresia Clinical judgement of heart failure in border line cases is inaccurate and study of systemic venous pressure / pulmonary artery wedge pressure may be done to diagnose these patients.

Causes of High Output Failure

1. Arterio Venous fistulae Congenital, Post traumatic, Iatrogenic 2. Hepatic disease Cirrhosis, 3. Metabolic disease Beriberi, thyrotoxicosis, Cardinoid syndrome. 4. Bone disorders Pagets disease, Polyostotic fibrous dysplasia 5. Hyperkinetic heart syndrome

Factors governing cardiac function are preload and after load

Preload (wall stress during diastole or extent of stretch of resting myocardial fiber) is determined by Venous return, total blood volume, activity of atrium. After Load  (wall stress during systole or impedance to left ventricular ejection) : Determined by Peripheral vascular resistance, physical characteristics of arterial tree, blood volume arterial tree.

 Signs and Symptoms of Heart Failure

In Left sided Failure

Common respiratory signs are tachypnea (increased rate of breathing) and increased work of breathing (non-specific signs of respiratory distress). Rales or crackles, heard initially in the lung bases, and when severe, throughout the lung fields suggest the development of pulmonary edema (fluid in the alveoli). Cyanosis which suggests severe hypoxemia, is a late sign of extremely severe pulmonary edema. Additional signs indicating left ventricular failure include a laterally displaced apex beat (which occurs if the heart is enlarged) and a gallop rhythm (additional heart sounds) may be heard as a marker of increased blood flow, or increased intra-cardiac pressure. Heart murmurs may indicate the presence of valvular heart disease, either as a cause (e.g. aortic stenosis) or as a result (e.g. mitral regurgitation) of the heart failure. Backward failure of the left ventricle causes congestion of the pulmonary vasculature, and so the symptoms are predominantly respiratory in nature. Backward failure can be subdivided into failure of the left atrium, the left ventricle or both within the left circuit. The patient will have dyspnea (shortness of breath) on exertion (dyspnée d’effort) and in severe cases, dyspnea at rest. Increasing breathlessness on lying flat, called orthopnea, occurs. It is often measured in the number of pillows required to lie comfortably, and in orthopnea, the patient may resort to sleeping while sitting up. Another symptom of heart failure is paroxysmal nocturnal dyspnea a sudden nighttime attack of severe breathlessness, usually several hours after going to sleep. Easy fatigueability and exercise intolerance are also common complaints related to respiratory compromise. “Cardiac asthma” or wheezing may occur. Compromise of left ventricular forward function may result in symptoms of poor systemic circulation such as dizziness, confusion and cool extremities at rest.

In Right sided Failure

Physical examination may reveal pitting peripheral edema, ascites, and hepatomegaly. Jugular venous pressure is frequently assessed as a marker of fluid status, which can be accentuated by eliciting hepatojugular reflux. If the right ventricular pressure is increased, a parasternal heave may be present, signifying the compensatory increase in contraction strength. Backward failure of the right ventricle leads to congestion of systemic capillaries. This generates excess fluid accumulation in the body. This causes swelling under the skin (termed peripheral edema or anasarca) and usually affects the dependent parts of the body first (causing foot and ankle swelling in people who are standing up, and sacral edema in people who are predominantly lying down). Nocturia (frequent nighttime urination) may occur when fluid from the legs is returned to the bloodstream while lying down at night. In progressively severe cases, ascites (fluid accumulation in the abdominal cavity causing swelling) and hepatomegaly (enlargement of the liver) may develop. Significant liver congestion may result in impaired liver function, and jaundice and even coagulopathy (problems of decreased blood clotting) may occur.

In Biventricular Failure

Dullness of the lung fields to finger percussion and reduced breath sounds at the bases of the lung may suggest the development of a pleural effusion (fluid collection in between the lung and the chest wall). Though it can occur in isolated left- or right-sided heart failure, it is more common in biventricular failure because pleural veins drain both into the systemic and pulmonary venous system. When unilateral, effusions are often right sided.

Due to back pressure

Cerebral Headache, insomnia, sluggish mental state Pulmonary Cough, dyspnoea. Portal Anorexia, nausea, hepatic angina. Peripheral Swelling of feet, face.

Reasons Behind

(1)  Poor cardiac output Lethargy, weakness, lack or concentration, fatigue (2)  Salt and water retention Back pressure, ankle edema, nocturia. (3)  Adrenergic drive Dyspnoea, Tachycardia. (4)  Cutaneous vasoconstriction.

Sudden Cardiac Failure Occurs in

(1)   Disabling arrhythmia, (2) Rupture of valve cusp, (3) Aortic dissection, (4) Acute myocardial infarction, (5) Cardiac rupture, (6) Accelerated / malignant hypertension, (7) Fluid overload.

Signs of heart failure

Dyspnoea, cardiac cachexia Peripheral cyanosis, diaphoresis Tachycardia, pulsus alternans. Peripheral edema, ascites, JVP, tender soft hepatomegaly Narro pulse pressure Fine crepitation at lung bases, S3, cardiomegaly Pansystolic murmur of MR / TR. Signs in Infants Usual symptoms lacking but with feeding problems, failure to thrive, tachypnoea, rib retraction, grunting, nasal flairing, frequent, pulmonary infections, facial edema. Signs in Elderly Confusion, memory impairment, insomnia; dyspnoea and ankle edema can be part of ageing.  In Further Signs (5Es)         Elevated JVP         Enlarged, tender liver         Enlarged heart         Edema feet, E(A)nasarca

Clinical Features of heart failure

Alternans pulse Basal crackles Cold clammy skin Dyspnoea Elevated JVP Fast pulse Gallop rhythm Hypotension In High Output Failure there is warm flushed skin and normal to wide pulse pressure.

Diagnosis of Heart Failure

No system of diagnostic criteria has been agreed as the gold standard for heart failure.Hence,based upon the symptoms and physical signs few routine investigations such as X Ray,ECG,Echocardiography,Angiography,Cardiac scan and Monitoring are to be done to diagnose Heart failure

 

Management of Heart failure

(1)    Bed red and dietary modification (2)   ACE inhibitor (3)   Digitalis (4) Diuretic (5) Vasodilators (6) Beta blocker (7) Inotropic agents (8) Balloon counter pulsation (9) Cardiomyoplasty (10) LV assist device, cardiac transplantation.

Treatment of acute Left Ventricular failure

            Decubitus : Propped up             Dopes : Inj. Diamorphine             Deliver O₂             Diuretics (IV)             Dopamine to increase cardiac output (if necessary)             Determine cause e.g. myocardial ifarct             Diverse measures Intra-aortic balloon pump. Anti-arrhythmic therapy             Emergency cardioversion.