Pathophysiology of heart failure ......DR MERON.pptx

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1. Moderator- Dr. M eron (MD, Pediatrician) presented By : Ahmed C-I Student Pediatrics heart failure

2. Outline Anatomy and Physiology of heart Definition of HF Types of HF Epidemiology and Etiology Pathophysiology Basic mechanisms and Pathogenesis Clinical manifestation Diagnosis Investigation Management

3. The human heart Is about 14cm tall and 9cm wide Weighs about 0.3kg in men and 0.25 kg in women Beats about 100,000 times per day Beats 2.5 billion times in an average 70 years lifetime Pumps about 2,000 gallons of blood each day Circulates blood completely 1000 times each day Pumps blood through 62,000 miles of vessels

4. Anatomy of heart overview

5. Layers of heart

6. Function of heart Transport and distribute essential substances to the tissues. Remove metabolic byproducts . Adjustment of oxygen and nutrient supply in different physiologic states. Regulation of body temperature. Humeral communication.

7. Circulatory system

8. Heart Failure A clinical and pathological syndrome that results from ventricular dysfunction, volume, or pressure overload, alone or in combination. It leads to characteristic signs and symptoms, such as poor growth, feeding difficulties, respiratory distress, exercise intolerance, and fatigue, and is associated with circulatory , neuro hormonal, and molecular abnormalities . due to insufficient or defective cardiac filling and/or impaired contraction and emptying

9. Heart failure occurs when the heart cannot deliver adequate cardiac output to meet the metabolic needs of the body. In the early stages of heart failure, various compensatory mechanisms are evoked to maintain normal metabolic function When these mechanisms become ineffective, increasingly severe clinical manifestations result Characterized by Effort Intolerance, Fluid Retention, and Reduced Activity

10. Types of heart Failure Due to loss of pumping action of the right side of the heart Blood accumulates in right atrium and blood vessel Cause edema in the feet, ankles, legs and abdomen ( peripheral edema ) Due to the failure of the pumping action of the left side of the heart Causes edema in lungs There are two types: Systolic failure: contractile problem Can’t Pump with enough force Diastolic failure: relaxation problem Can't fill with blood properly Rt. Sided Lt. Sided

11. Is the heart failure with sufficient cardiac output The falling heart evokes three major compensatory mechanism to enhance cardiac output Initially these alterations are beneficial but ultimately result in further deterioration in cardiac function If the adaptive mechanisms fail to maintain cardiac output high-output failure R esults in the development of signs and symptoms of heart failure when there is no basic abnormality in myocardial function and cardiac output is greater than normal Compensated heart failure Decompensated heart failure

12. Epidemiology HF is a burgeoning problem worldwide, with more than 20 million people affected. 8 per 1000 live born infants have significant cardiac malformation The commonest CHD are VSD (30%), PDA (12%), and ASD (7%) About 10-15 % have complex lesions with more than one cardiac abnormality

13. Risk factors for heart failure in pediatrics Maternal disorders Rubella infection Systemic lupus erythematosus (SLE) Complete heart block Diabetes mellitus Maternal drugs Warfarin therapy , anticonvelsant alcohol use Chromosomal abnormality upper respiratory tract infectins malnutrion immunosupressions

14. ETIOLOGY OF HEART FAILURE BY AGE GROUP PREMATURE NEONATE Fluid overload PDA VSD Cor pulmonale

15. FULL-TERM NEONATE Asphyxia cardiomyopathy Arteriovenous malformation (vein of Galen) Left-sided obstructive lesions (coarctation of aorta, hypo plastic left heart, critical aortic stenosis ) Transposition of great arteries Large mixing cardiac defects (single ventricle, truncus arteriosus) Viral myocarditis Anemia Supraventricular tachycardia Complete heart block

16. INFANT(<1yr)/TODDLER(1-4 yrs) Left-to-right cardiac shunts (VSD) Hemangioma (arteriovenous malformation) Anomalous left coronary artery Metabolic cardiomyopathy Acute hypertension (hemolytic uremic syndrome) Supraventricular tachycardia Kawasaki disease Postoperative repair of congenital heart disease

17. CHILD(5-12 yrs)/ADOLESCENT(12-20 yrs) Rheumatic fever Acute hypertension (glomerulonephritis) Viral myocarditis Thyrotoxicosis Hemochromatosis/ hemosiderosis Cancer therapy (radiation, doxorubicin) Sickle cell anemia

18. CHILD/ADOLESCENT… Endocarditis Cor pulmonale (cystic fibrosis) Arrhythmias Unrepaired or palliated congenital heart disease Cardiomyopathy

19. PATHOPHYSIOLOGY Of HF a pump with an output proportional to its filling volume and inversely proportional to the resistance against which it pumps. As ventricular end-diastolic volume increases, a healthy heart increases cardiac output until a maximum is reached and cardiac output can no longer be augmented (The Frank- Starling principle )

20. Frank-Starling principle &contractility Stroke Volume Is determined by 3 variables: End diastolic volume ( EDV ) = volume of blood in ventricles at end of diastole Total peripheral resistance ( TPR ) = impedance to blood flow in peripheral arteries Contractility = strength of ventricular contraction

21. Factors Affecting Cardiac Performance Preload (left ventricular diastolic volume) Afterload (impedance against which the left ventricle must eject blood) Contractility (cardiac performance independent of preload or afterload)

22. PATHOGENESIS OF HEART FAILURE In most instances patients will remain asymptomatic or minimally symptomatic following the initial decline in pumping capacity of the heart. compensatory mechanisms become activated and appear to modulate LV function within a physiological/homeostatic range, such that the functional capacity of the patient is preserved or is depressed only minimally.

23. The compensatory mechanisms that have been described 1.Activation of the adrenergic nervous systemic 2.Activation of the RAAS 3.Activation of inflammatory mediators: that are responsible for cardiac repair and remodeling Both are responsible for maintaining CO through increased retention of salt and water, peripheral arterial vasoconstriction and increased contractility

24. Symptoms and physical findings in children with HF reflect the patient's inability to adequately increase cardiac output ( eg , exercise intolerance and easy fatigue) and/or pulmonary or systemic fluid overload ( eg , shortness of breath at rest or with effort due to pulmonary interstitial edema or hepatomegaly ). Symptoms — Symptoms of HF vary with the age of the patient as follows

25. CLINICAL MANIFESTATIONS IN INFANTS WITH HF Feeding difficulties Rapid respirations Tachycardia Cardiac enlargement Gallop rhythm (S3) Hepatomegaly Peripheral edema Easy fatigability. Sweating Irritability Failure to thrive. Pulmonary rales

26. gastrointestinal symptoms(abdominal pain, nausea, vomiting, and poor appetite) failure to thrive, easy fatigability, and recurrent or chronic cough with wheezing These symptoms be mistaken for gastroenteritis, reflux, asthma, exercise intolerance, anorexia, abdominal pain, wheezing, dyspnea , edema, palpitations, chest pain, or syncope Young children   Older children  

27. Feeding difficulties & increased fatigability Is an important clue in detecting CHF in infants Often it is noticed by mother Interrupted feeding (suck- rest -suck cycles) Infant pauses frequently to rest during feedings Inability to finish the feed, taking longer to finish each feed(> 30 minutes) Forehead sweating during feeds –due to activation of sympathetic nervous system –a very useful sign Increasing symptoms during and after feedings

28. APPROACH TO HEART FAILURE 1.History In older children The usual chief compliant is shortness of breath and associated symptoms are: Orthopnea Paroxysmal nocturnal dyspnea (PND) Body swelling and fatigue Focal neurological deficit

29. In infant feeding difficulty Fast breathing Poor wait gain Irritability Weak cry and labored respiration

30. 2.Physical Examination findings depending on the cardiac output, degree of volume overload pulmonary congestion, systemic venous congestion. Tachycardia due to decreased cardiac output

31. Physical Examination cont.. General appearance Acute sick looking acute on chronic sick looking v/s Tachypnea tachycardia

32. Physical examination cont.. Paleness on dorsum of tongue and loss of tongue papillae Central cyanosis inspection Nasal flaring Intercostal and subcostal retraction Percussion Bilateral dullness Auscultation Bilateral rales Wheezing HEENT Respairatory system

33. Cardiovascular system Venous examination Raised JVP Distended neck veins Arterial examination Week and rapid pulse

34. Precordial Examination Inspection Active pericordium Shifted apical impulse Bulged pericordium Palpation Heave and thrill Auscultation Gallop rhythm Murmur

35. Ascites Tender hepatomegaly Bilateral pitting edema Abdominal Examination Musculoskeletal system

36. Bluewish discoloration of skin Paleness on the palm Decreased power of muscle Integumentary System CNS

37. Triads of H.F in children Tachypnea Cardiomegaly hepatomegaly

38. Diagnosis based on Clinical ( hx and P/E ) Radiographic ( cardiomegaly and pulmonary congestion) ECG Echocardiographic ( assess ventricular size, underlying lesion and anatomy of heart) Laboratory findings( BNP , troponine ) CBC ESR and CRP RFT LFT Dx investigation Basic investigation

39. principle of managment An understanding of the interplay of the four principal determinants of cardiac output – preload , afterload , contractility and heart rate is essential in optimizing the therapy of HF .

40. Principles Of HF Management … General Measures Treating Congestion( Diuretics) Correcting the Precipitant Factors Treatment of Underlying Cause Increase Myocardial Contractility Prevent Diseases Progression Follow up

41. References Illustrated Textbook of Paediatrics Fourth Edition Heart Diseases in Children A Pediatrician’s Guide Nelson essentials of pediatrics , seventh edition Nelson textbook of pediatrics, 21 th edition