Heart Failure
Heart FailureClinical syndrome that develops when the heart cannot maintain adequate output, or can do so only at the expense of elevated ventricular filling pressure.
Heart Failure
Results from any structural or functional abnormality that impairs the ability of the ventricle to eject blood (Systolic Heart Failure) or to fill with blood (Diastolic Heart Failure).The prevalence of heart failure rises with age Almost all forms of heart disease can lead to heart failure.
Mechanisms of heart failure
Reduced ventricular contractility CAD (segmental dysfunction) ‘cardiomyopathy(global dysfunction)Ventricular outflow obstruction Hypertension, aortic stenosis (left heart failure) Pulmonary hypertension, pulmonary stenosis (right heart failure).Ventricular inflow obstruction Mitral stenosis,tricuspid stenosis Ventricular volume overload Ventricular septal defect.Arrhythmia Atrial fibrillation ,Tachycardia cardiomyopathy Complete heart block Bradycardia.Diastolic dysfunction Constrictive pericarditis, Restrictive cardiomyopathy Cardiac tamponade.Pathophysiology
Cardiac output is determined by preload (the volumeand pressure of blood in the ventricles at the end ofdiastole) afterload (the volume and pressure of blood in the ventricles during systole) and myocardial contractility.Fall in cardiac output. activates counterregulatory neurohumoral mechanisms , renin–angiotensin–aldosterone system leads to vasoconstriction, sodium and water retention, and sympathetic nervous system activation. Activation of the sympathetic nervous system may initially sustain cardiac output through increased myocardial contractility (inotropy)and heart rate (chronotropy). Prolonged sympathetic stimulation also causes negative effects, including cardiac myocyte apoptosis,hypertrophy and focal myocardial necrosis. Sympathetic stimulation also causesperipheral vasoconstriction and arrhythmias.The Vicious Cycle of Congestive Heart Failure
Decreased Blood Pressure and Decreased Renal perfusion
Stimulates the Release of renin, Which allows conversion of Angiotensin to Angiotensin II. Angiotensin II stimulates Aldosterone secretion which causes retention of Na+ and Water, increasing filling pressureLV Dysfunction causes Decreased cardiac output
Types of Heart Failure
-Left, right and biventricular heart failure. -Diastolic and systolic dysfunction. -High-output failure. -Acute and chronic heart failure.Causes of Low-Output Heart Failurechronic
Systolic Dysfunction Coronary Artery Disease Idiopathic dilated cardiomyopathy (DCM) Hypertension Valvular Heart Disease Diastolic Dysfunction Hypertension Coronary artery disease Hypertrophic obstructive cardiomyopathy (HCM) Restrictive cardiomyopathyAcute Decompensaated Heart Failure
Causes: Acute MI Rupture of chordae tendinae/acute mitral valve insufficiency Volume Overload Transfusions, IV fluids Worsening valvular defect Pulm.embolism MyocarditisFactors that may precipitate or aggravateheart failure in pre-existing heart disease
Myocardial ischaemia or infarction Intercurrent illness, e.g. infection Arrhythmia, e.g. atrial fibrillation Inappropriate reduction of therapy Administration of a drug with negative inotropic (β-blocker)or fluid-retaining properties (NSAIDs, corticosteroids) Pulmonary embolism Conditions associated with increased metabolic demand, e.g. pregnancy, thyrotoxicosis, anaemia IV fluid overload, e.g. post-operative IV infusionClinical Presentation of HeartFailure(Acute)
Sudden onset of dyspnoea that rapidly progresses to acute respiratory distress, orthopnoea and cough.The patient appears agitated, pale and clammy. The peripheries are cool to the touch and the pulse is rapid.The BP is usually high, The jugular venous pressure (JVP) is usually elevated. Auscultation A ‘gallop’rhythm, with a third heart sound,is heard. A new systolic murmur may signify acute mitral regurgitation or ventricular septal rupture. crepitations at the lung bases, or throughout the lungs if pulmonary oedema is severe.
Clinical Presentation of Heart Failure(Chronic)
Due to excess fluid accumulation: Dyspnea (most sensitive symptom Orthopnea, Paroxysmal Nocturnal Dyspnea (PND) Edema Hepatic congestion Ascites Due to reduction in cardiac ouput: Fatigue (especially with exertion) Weakness Poor renal perfusion leads to oliguria and uraemia Chronic heart failure is sometimes associated with marked weight loss (cardiac cachexia).Physical Examination in Heart Failure
Dyspniac Cool, pale, cyanotic extremities Have sinus tachycardia, diaphoresis and peripheral vasoconstriction Displaced Apex S3 gallop Low sensitivity, but highly specific Crackles or decreased breath sounds at bases (effusions) on lung exam Elevated jugular venous pressure Lower extremity edema Ascites Hepatomegaly SplenomegalyMeasuring Jugular Venous Pressure
ComplicationsRenal failure Hypokalaemia Hyperkalaemia Hyponatraemia Impaired liver function Thromboembolism Atrial and ventricular arrhythmias Impaired liver function
Lab Analysis in Heart Failure
CBC Since anemia can exacerbate heart failure Serum electrolytes and creatinine before starting high dose diuretics Fasting Blood glucose To evaluate for possible diabetes mellitus Thyroid function tests Since thyrotoxicosis can result in A. Fib, and hypothyroidism can results in HF. Iron studies To screen for hereditary hemochromatosis as cause of heart failure. ANA To evaluate for possible lupus Viral studies If viral mycocarditis suspected BNP brain natriuretic pepetideChest X-ray in Heart Failure
Cardiomegaly Cephalization of the pulmonary vessels Kerley B-lines Pleural effusionsCardiomegaly
Pulmonary vessel congestionPulmonary Edema due to Heart Failure
Kerley B linesFurther Cardiac Testing in Heart Failure
Exercise Testing Should be part of initial evaluation of all patients with CHF. Coronary arteriography Should be performed in patients presenting with heart failure who have angina or significant ischemia. Endomyocardial biopsy Not frequently used Really only useful in cases such as viral-induced cardiomyopathy .Cardiac Testing in Heart Failure
Electrocardiogram: May show specific cause of heart failure: Ischemic heart disease Dilated cardiomyopathy: first degree AV block, LBBB, Left anterior fascicular block Echocardiogram: Left ventricular ejection fraction Structural/valvular abnormalitiesManagement of acute HF
acute medical emergency: Sit the patient up to reduce pulmonary Congestion. Give oxygen (high-flow, high-concentration). IV frusemide 50-100 mg Administer nitrates, such as IV glyceryl trinitrate until clinical improvement occurs or systolic BP falls. Continuous monitoring of cardiac rhythm, BP . Intravenous opiates must be used sparingly in distressed patients. If these measures prove ineffective, inotropic agents may be required to augment cardiac output, particularly in hypotensive patients ( Dopamine).
Management of chronic heart failure
General measures Drug therapy Device therapy Cardiac transplantGeneral measures
EducationDiet•Good general nutrition and weight reduction for the obese•Avoidance of high-salt foods and added salt.AlcoholSmokingExercise•Regular moderate aerobic exercise within limits of symptomsVaccination•Consider influenza and pneumococcal vaccinationTreatment of the underlying cause of heart failure (CAD)Drug therapy
Loop diuretics ACE inhibitor (or ARB if not tolerated) Beta blockers Digoxin Hydralazine, Nitrate Potassium sparing diuretcs IvabradineDiuretics
Loop diuretics Furosemide, buteminide diuretics produce an increase in urinary sodium and water excretion, leading to reduction in blood and plasma volume Potassium-sparing diuretics Spironolactone, eplerenone Help enhance diuresis Maintain potassium Shown to improve survival in CHFACE Inhibitor
Improve survival in patients with all severities of heart failure.Begin therapy low and titrate up as possible:Enalapril – 2.5 mg po BIDCaptopril – 6.25 mg po TIDLisinopril – 5 mg po QDailyIf cannot tolerate, may try ARBBeta Blocker therapy
Certain Beta blockers (carvedilol, metoprolol, bisoprolol) can increase ejection fraction, improve symptoms, reduce the frequency of hospitalisation and reduce mortality. Contraindicated: Heart rate <60 bpm Symptomatic bradycardia Signs of peripheral hypoperfusion COPD, asthma PR interval > 0.24 sec, 2nd or 3rd degree block
Hydralazine plus Nitrates
Dosing: Hydralazine Started at 25 mg po TID, titrated up to 100 mg po TID Isosorbide dinitrate Started at 40 mg po TID/QID Decreased mortality, lower rates of hospitalization, and improvement in quality of life.Ivabradine
It reduces hospital admission and mortality rates in patients with heart failure due to moderate or severe left ventricular systolic impairment.Other medication in Heart Failure
Digoxin can be used to provide rate control in patients with heart failure and atrial fibrillation. In patients with severe heart failure, digoxin reduces the likelihood of hospitalisation for heart failure, Statin therapy is recommended in CHF for the secondary prevention of cardiovascular disease. Some studies have shown a possible benefit specifically in HF with statin therapyMeds to AVOID in heart failure
NSAIDS Can cause worsening of preexisting HF Thiazolidinediones Include rosiglitazone (Avandia), and pioglitazone (Actos) Cause fluid retention that can exacerbate HF Metformin People with HF who take it are at increased risk of potentially lethic lactic acidosisImplantable Cardioverter-Defibrillators for HF( ICD) -CRT
Sustained ventricular tachycardia is associated with sudden cardiac death in HF.About one-third of mortality in HF is due to sudden cardiac death.Patients with ischemic or nonischemic cardiomyopathy, NYHA class II to III HF, and LVEF ≤ 35% have a significant survival benefit from an implantable cardioverter-defibrillator (ICD) for the primary prevention of SCD.Cardiac-Resynchronization-Therapy