Dike Ojji Senior Lecturer Heart failure 1: Pathophysiology, precipitating factors and clinical presentation Dike Ojji Senior Lecturer

Congestive Heart Failure Heart (or cardiac) failure is the state in which the heart is unable to pump blood at a rate commensurate with the requirements of the tissues or can do so only from high pressures

Introduction The heart is no longer able to maintain the circulation of the tissue for normal metabolism The clinical syndrome of heart failure is the final pathway for myriad disease that affect the heart CHF is one the fastest growing epidemics in cardiology

Epidemiology HF affects over 0.2% of the world population About 5 million Americans have HF today About 500,000 diagnoses are made each year in the USA About 10/10,000 Americans older than 65years have HF Over the last decade, the rate of hospitalisation for HF has increased by 159% in the USA 3-7% of all medical admissions in SSA

Aetiology Infection (Viral) Hypertension Obesity Age Smoking Anaemia Sleep Apnoea Hypertension Cardiomyopathies (DCM) Valvular Heart Disease (RHD) Adult CHD Coronary Artery Disease Alcohol Diabetes mellitus Arrhythmias Hyperthyroidism Hypothyroidism

Pathophysiology Cardiac Abnormalities: structural & functional Structural Abnormalities: hypertrophy,necrosis, f ibrosis,dilatation,coronary artery obstruction & inflammation Functional Abnormalities: MR, Induced Atrial & Ventricular Arrhythmias Biologically Active Tissue & Circulating Substances: RAS,SNS,Vasodilators,NP,Cytokines,Vasopressin,Matrix Metalloproteinases Other Factors: Genetics, Age ,Alcohol, Tobacco, Co-existing conditions

Pathophysiology Neuro hormonal Mechanisms-RAAS,SNS Renin – Angiotensin -Aldosterone System -Impaired renal blood flow -Activation of the RAAS results in increased tone in the efferent glomerular arterioles preserving the GFR -Na retention & volume expansion -Angiotensin II stimulates production of Aldosterone & Vasopressin leading to increased volume & CO

Pathophysiology Sympathetic Nervous System Stimulation of the SNS leads to systemic vasoconstriction, increasing VR and decrease in CO CNS perfusion is maintained at the expense of systemic organs like the kidneys Down Regulation of B-Blockers Elevated plasma norepinephrine

Pathologic Progression of CV Disease Sudden Death Coronary artery disease Myocardial injury Pathologic remodeling Low ejection fraction Hypertension Death Diabetes Cardiomyopathy Pump failure Valvular disease Symptoms: Dyspnea Fatigue Edema Chronic heart failure Neurohormonal stimulation Myocardial toxicity Adapted from Cohn JN. N Engl J Med. 1996;335:490–498.

Compensatory Mechanisms: Renin- Angiotensin- Aldosterone System Beta Stimulation CO Na+ Renin + Angiotensinogen Angiotensin I ACE Angiotensin II Kaliuresis Aldosterone Secretion Fibrosis Peripheral Vasoconstriction Salt & Water Retention Plasma Volume Afterload Edema Preload Cardiac Output Cardiac Workload Heart Failure

Clinical Features Dyspnoea Orthopnoea PND Cough & Haemoptysis Oedema Muscle Fatigue Reduced Exercise Tolerance Palpitations Tachcardia Raised JVP Third or Fourth Heart Sound Hepatomegaly

Classification of HF: Comparison Between ACC/AHA HF Stage and NYHA Functional Class None NYHA Functional Class2 A At high risk for heart failure but without structural heart disease or symptoms of heart failure (eg, patients with hypertension or coronary artery disease) I Asymptomatic B Structural heart disease but without symptoms of heart failure C Structural heart disease with prior or current symptoms of heart failure II Symptomatic with moderate exertion The New York Heart Association (NYHA) classification system is based largely on the assessment of symptoms.1 The new American College of Cardiology and American Heart Association (ACC/AHA) classification guidelines were designed to compliment the NYHA classification system. These new guidelines focus more on underlying disease and the need to treat early in the disease process, even before overt symptoms of heart failure are present.2 III Symptomatic with minimal exertion IV Symptomatic at rest D Refractory heart failure requiring specialized interventions 1Hunt SA et al. J Am Coll Cardiol. 2001;38:2101–2113. 2New York Heart Association/Little Brown and Company, 1964. Adapted from: Farrell MH et al. JAMA. 2002;287:890–897. 1The Criteria Committee of the New York Heart Association. Diseases of the Heart and Blood Vessels: Nomenclature and Criteria for Diagnosis. 6th ed. Boston, Mass: Little Brown; 1964. 2Hunt SA, Baker DW, Chin MH, et al. ACC/AHA guidelines for the evaluation and management of chronic heart failure in the adult: executive summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to revise the 1995 Guidelines for the Evaluation and Management of Heart Failure). J Am Coll Cardiol 2001;38:2101-2113.

NYHA Functional Classification I: Patients with structural heart disease whose only limitations on physical activity are those that affect normal individuals II:Patients with structural heart disease who develop symptoms of heart failure with ordinary physical activity III:Patients with structural heart disease who develop symptoms of heart failure with minimal physical activity IV:Patients with structural heart disease who develop symptoms of heart failure at rest

ACC/AHA Classification Stage A: High risk with no symptoms Stage B:Structural heart disease with no symptoms Stage C:Structural heart disease with previous or current symptoms Stage D:Refractory symptoms requiring special intervention

THANK YOU VERY MUCH