=acquired Heart Ds , Hf.pptx

ACQUIRED HEART DISEASES

Rheumatic Fever and Rheumatic Heart Disease

Rheumatic Fever • Rare in the developed world, but remains the most important cause of heart disease in children worldwide. • Remain endemic in some parts of Asia (China, Indonesia, India, Pakistan, Bangladesh), Africa and South America. • Uncommon in Malaysia • Improvements in sanitation, reduction in overcrowded living conditions, treatment of streptococcal pharyngitis with 10-day course of antibiotics and changes in streptococcal virulence have led to its virtual disappearance in developed countries.

• Acute rheumatic fever is a short-lived, multisystem autoimmune response to a preceding infection with group A β-haemolytic streptococcus. • Mainly affects children aged 5–15 years. • Progresses to chronic rheumatic heart disease in up to 80% of cases.

• After a latent interval of 2–6 weeks following a pharyngeal or skin infection, polyarthritis, mild fever and malaise develop.

Pathogenesis RHD and valvular damage Group A Streptococcal sore throat

Produce antibody against M proteins of Streptococci Cardiac myosin and sarcolemma has structural similarity to streptococcal M protein

CD4 T-cell

Valvular damage in RHD

Acute carditis in Rheumatic fever

Antibody cross reacts with myosin and sarcolemma

Inflammation of Endocardium, Myocardium and pericardium

Erythema Marginatum

Subcutaneous Nodules

Chronic rheumatic heart disease • The most common form of long-term damage from scarring and fibrosis of the valve tissue of the heart is mitral stenosis. • If there have been repeated attacks of rheumatic fever with carditis, this may occur as early as the second decade of life, but usually symptoms do not develop until early adult life. • Although the mitral valve is the most frequently affected, aortic, tricuspid and rarely, pulmonary valve disease may occur.

Pathology (Mitral Stenosis/Regurgitation)

Progressive Fibrosis, Calcification on Mitral Valve

Fusion of the Mitral Valve Commissures and Shortening of Chordae Tendineae

Mitral Stenosis with or without Regurgitation

Increase left atria pressure, leads to pulmonary venous congestion and breathlessness

Clinical Features (Mitral Stenosis) • Symptoms • Breathlessness (Pulmonary Congestion) • Fatigue (low CO) • Oedema, Ascites (RHF) • Palpitation • Haemoptysis • Cough • Chest Pain

• Signs • Atrial Fibrillation • Mitral Facies • Auscultation- Loud S1, Mid Diastolic Murmur • Crepitation, Pulmonary Oedema

Pathology (Aortic Stenosis/Regurgitation) Progressive Fibrosis on Aortic and Tricuspid Valves

Distortion and Increase Rigidity of the Cusps

Stenosis with or without Regurgitation

Clinical Features Signs • Mild to Moderate

• Often asymptomatic • Palpitation

• Severe

• Dyspnoea • Angina

Symptoms

• Pulses

• Collapsing Pulse • Low diastolic pressure

• Murmur

• Early Diastolic Murmur (aortic regurgitation) • Systolic Murmur (aortic stenosis)

• Others

• Displaced Apex • Fourth Heart Sound • Crepitation

Rheumatic heart disease(Ix , Mx)

Rheumatic heart disease is a chronic, disabling and sometimes fatal disease. It is 100% preventable

Lab Findings • • • •

FBC : anemia , leucocytosis CRP : Elevated ESR : Increased ASO titre : >200 Todd units (peak at 3 weeks , back to normal by 6 weeks) • Anti-DNAse B test : typically remain elevated longer than ASO antibody titers • Throat culture-GAB streptococci

• ECG : prolonged PR interval , 2nd/ 3rd degree heart block , ST depression , T inversion • Echocardiograph : valvular edema , mitral regurge , LA , LV dilatation , pericardial effusion , decreased contractility

Diagnosis • Rheumatic fever is mainly a clinical dx • No single diagnostic sign or specific lab test available for diagnosis • Diagnosis based on MODIFIED JONES CRITERIA

Differential diagnosis • • • • • • •

Juvenile rheumatoid arthritis Septic arthritis Sickle cell arthropathy Kawasaki disease Myocarditis Scarlet fever Leukemia

Treatment 1. Primary prevention (eradication of streptococci) 2. Anti-inflammation (aspirin, steroid) 3. Supportive management & management of complication (surgical/medical) 4. Secondary prevention (prevent recurrent attack)

Primary prevention of rheumatic fever • Treat strep. Tonsillipharyngitis • Benzathine penicillinG 600000U IM Once OR • Penicillin V Children 250mg Oral 2-3 times daily for 10 days OR • Erythromycin 20-40 mg/kg/d 2-4 times daily Oral for 10 days

Anti-inflammation treatment • Arthritis only : Aspirin 75-100mg/kg/day , give as 4 divided doses for 6 weeks • Carditis : Prednisolone 2-2.5 mg/kg/day, give as 2 divided doses for 2 weeks

Supportive management • • • • • •

Bed rest Treatment of congestive heart failure digitalis , diuretics Treatment of chorea Diazepam , haloperidol Rest of joints & supportive splinting

Secondary prevention • Prevent recurrence • Benzathine penicillin G 1200000U every 4 weeks IM OR • Penicillin V 250mg twice daily Oral OR • Erythromycin 250mg twice daily Oral

Duration of prophylaxis Category

Duration

Rheumatic fever with carditis and residual heart disease (persistent valvular disease)

At least 10yrs since last episode and at least 40 yrs , sometimes lifelong prophylaxis

Rheumatic fever with carditis but no residual heart disease (absence of valvular disease)

10y or well into adulthood whichever is longer

Rheumatic fever without carditis

5y or until age of 21y Whichever is longer

Surgical treatment • Severe mitral/ aortic valve dysfunction that causes persistent heart failure requires corrective surgery • Commussurotomy : open a stenotic valve by scalpel incision. • Valvuloplasty : improve blood flow by passing catheter into the valve through a hole temporarily created in the septal wall. • Valve replacement by Arbor technique

Infective Endocarditis

Infective endocarditis • Often a complication of congenital or rheumatic heart disease but can also occur in children without any abnormal valves or cardiac malformations. • Risk is highest when there is a turbulent jet of blood, as with a VSD, coarctation of the aorta and PDA or if prosthetic material has been inserted at surgery. • Turbulent flow traumatizes the vascular endothelium, creating a substrate for deposition of fibrin and platelets, leading to the formation of a nonbacterial thrombotic embolus (NBTE) that is thought to be the initiating lesion for infective endocarditis. • Leading to proliferation of bacteria within the lesion.

• Includes acute and subacute bacterial endocarditis as well as nonbacterial endocarditis caused by viruses, fungi, and other microbiologic agents. • It is a significant cause of morbidity and mortality in children and adolescents despite advances in the management and prophylaxis of the disease with antimicrobial agents. • The presence of the classical peripheral stigmata of infective endocarditis should not be relied upon.

ETIOLOGY • No relationship exists between the infecting organism and the type of congenital defect, the duration of illness, or the age of the child. • Staphylococcal endocarditis is more common in patients with no underlying heart disease • Viridans group streptococcal infection is more common after dental procedures • Pseudomonas aeruginosa or Serratia marcescens is seen more frequently in intravenous drug users • Fungal organisms are encountered after open heart surgery • Coagulase-negative staphylococci are common in the presence of an indwelling central venous catheter.

Clinical Features

Osler nodes

Splinter Haemorrhages

Janeway Lesions

Infective Endocarditis Investigation and Management

Chuah Wei Hong

Roth’s Spot

Investigations • Blood cultureS • Echocardiography • Identify vegetation but not exclude

• CRP/ESR • Also in monitoring response to treatment

• Full blood count • Urine FEME • Chest X-ray

Principle of Management • Use empirical antibiotics, until culture results available • Ensure 3 blood cultures taken before antibiotic therapy • Do not wait for echocardiography

• Rx • IV high dose penicillin + aminoglycoside 6/52 • Surgical removal (infected prosthetic material)

IE Prophylaxis • Practice of good dental hygiene in all children with congenital heart disease Antibiotic prophylaxis • Required in • Oral, dental procedures • Surgery (likely to be associated with bacteraemia)

Antibiotic Prophylaxis

Antibiotic Prophylaxis

Antibiotic Prophylaxis

HEART FAILURE Lim Kok Hong

Definition • Inability of the heart to provide adequate cardiac output to meet the metabolic demand of the body.

• primary determinants of stroke volume are the afterload (pressure work), preload (volume work), and contractility (intrinsic myocardial function). • molecular/cellular level, such as upregulation or downregulation of various metabolic pathway components leading to changes in efficiency of oxygen and other substrate utilization. • neurohormones such as the renin–angiotensin system and the sympathoadrenal axis.

Heart Failure Low output Due to cardiac problem

High output no basic abnormality in myocardial function, CO is normal or increased, due to decreased in systemic O2 content or increase O2 demand

Clinical features • Varies according to age • Infancy : Symptoms : poor feeding, recurrent chest infection, failure to thrive, excessive perspiration, weak cry, irritability Signs : tachypnea, wheezing, subcostal and intercostal recession, nasal flaring, tachycardia, weak pulses, hyperactive precordium, praecordial bulge, hepatomegaly, edema generalized / usually involves eyelids, sacrum

• Children: Similar to adults Fatigue, effort intolerance, anorexia, dyspnea, cough, abdominal symptoms ( pain, nausea) , increase JVP, hepatomegaly, edema/anarsaca, gallop rhythm, systolic murmur due to valve regurgitation caused by advanced ventricular dilation

Diagnosis & Investigation • X-ray : cardiac enlargement, increase pulmonary vascularity ( left to right shunt) , perihilar pulmonary marking ( venous congestion, acute pul. Edema) • ECG : chamber hypertrophy • Echocardiography : assessment of ventricular function • Doppler : estimate Cardiac output, flow of blood, • MRI : quantifying left & right ventricular function, volume, mass and coronary artery anatomy, regurgitant fraction • ABG : arterial oxygen level, respiratory/ metabolic acidosis • Serum B-type natriuretic peptide : increased in cardiomyopathy, volume overload HF

Treatment General Measures • Oxygen supplement • Propped up position • Keep warm • Fluid restriction • Optimize calories intake • Correct anemia, electrolyte imbalance, chest infection

Pharmacological • Diuretics • Afterload reducer ( ACE inhibitors, Angiotensin II Receptor Blockers) • Digitalis glycosides ( digoxin) • α- and β-Adrenergic Agonists ( dopamine) • Phosphodiesterase Inhibitors (Milrinone)

Diuretics • Frusemide (loop diuretic) • Dose: 1 mg/kg/dose OD to QID, oral or IV • Continuous IV infusion at 0.1 – 0.5 mg/kg/hour if severe fluid overload • Use with potassium supplements (1 - 2 mmol/kg/day) or add potassium sparing diuretics. • Spironolactone (potassium sparing diuretic, modest diuretic effect) • Dose: 1 mg/kg/dose BD

Captopril • Angiotensin converting enzyme inhibitor, afterload reduction agent • Dose: 0.1 mg/kg/dose TDS, gradual increase up to 1 mg/kg/dose TDS • Monitor potassium level (risk of hyperkalaemia)

Digoxin • Role controversial • Useful in heart failure with excessive tachycardia, supraventricular tachyarrhythmias.

IV inotropic agents - i.e. Dopamine, Dobutamine, Adrenaline, Milrinone • Use in acute heart failure, cardiogenic shock, post-op low output syndrome.

Specific management • Establishment of definitive aetiology is of crucial importance • Specific treatment targeted to underlying aetiology. Examples: • Surgical/transcatheter treatment of congenital heart lesion. • Pacemaker implantation for heart block. • Control of blood pressure in post-infectious glomerulonephritis. • High dose aspirin ± steroid in acute rheumatic carditis.

References • Nelson Paedriatic 20th edi • Paediatric protocol 3rd edi • Sunflower 4th edi