CYANOTIC CONGENITAL HEART DISEASE: DR. K. L. BARIK. ASST. PROFESOR, DEPT. OF PEDIATRICS, BURDWAN MEDICAL COLLEGE.
Congenital heart diseases produce cyanosis: • Tetralogy of Fallot (TOF). • Transposition of great arteries (TGA). i) Complete TGA. ii) Corrected TGA. • Total anomalous pul. venous return (TAPVR). • Tricuspid atresia. • Ebstein’ anomaly • Single ventricle. • Double outlet rt. ventricle. • Persistent truncus arteriosus.
Consequences and complications of cyanosis: • Polycythemia:i) Low o2- erytropoetin incrd. ii) Hematocrit >65%.iii) Anemia • Cubbing: i) R –L shunt. ii) PDGF. iii) TGF-B. • Hypoxic spell : Rapid and deep breathing, inc. cyanosis, limpness- sp.posture – squatting. • CNS complication: i) Brain absess- >2yrs. Viscosity-hypoxia-microinfarct.ii) vascular stroke-<2yrs.paradoxcal emboi.& anemia. • Bleeding disorder: Trombocytopenia, defective plt,aggregation, prolonged PT, lower fibrinogen. • Depressed IQ: Chronic hypoxia and cyanosis • Scoliosis: Girls with TOF. • Hyperuricemia and gout: Older pt. with cyanotic heart disease
TETRALOGY OF FALLOT (TOF): • Most common cyanotic CHD – 10% to 17%. • 4 abnormalities originally described by Fallot- i) Large VSD. ii) RV outflow tract obstruction (pulmonic st.) iii) RVH. iv) Overriding of the aorta. • In actuality two abnormalities are required: i) VSD and ii) RV outflow tract obstruction.
TOF CONT. : • VSD of TOF- perimembranous subpulmonary. • RV outflow tract obstruction- i) Infundibular stenosis – 45% ii) Valvular stenosis – 10% iii) Combination of the two – 30% iv) Pulmonary valve atresia – 15% • Pulmonary annulus & main PA – hypoplastic. • Right sided aortic arch – 25%. • Abnormal coronary artery – 5%. Ant. decending branch from right coronary artery.
HEMODYNAMICS: • Pulmonic stenosis- concentric RV hypertrophy without enlargement – increase RV pressure. • R to L shunt – silent- insignificant pressure difference • Ejection systolic murmur – pulmonic stenosis. • Cyanosis – directly proportional to the stenosis. • Murmur – inversely proportional to stenosis. • RV effectively decompressed – no CCF except - i)anemia ii)endocarditis iii)hypertn.iv)myocard v)AR. • P2 delayed-soft-post.-only A2 – ant.- single S2 .
CLINICAL MANIFESTATIONS: HISTORY: • Symptomatic with cyanosis at birth mostly or later. • Dyspnea on exertion & exercise intolerance. • Squatting in hypoxic spell – noted commonly in TOF • Infant with acyanotic TOF - may be asymptomatic. • Severe cyanosis at birth –TOF with pulmonary atresia • Hypoxic spell- hyperpnea, irritability, crying, cyanosis, convulsion – morning after crying, feeding, defecation. Starts 2 to 4 months of age.
CLINICAL MANIFESTATIONSCONT.: PHYSICAL EXAMINATION: • Varying degree- cyanosis, tachypnea, clubbing • RV tap – lt. sternal border- parasternal impulse • Systolic thrill – at ULSB & MLSB -50%. • Ejection systolic murmur (gr. 3-5/6)-ulsb/mlsb. • Single S2 – only aortic component. • Deeply cyanotic pt.- absent or soft murmur. • In acyanotic- long syst. mur.on entire lsb -VSD&PS
INVESTIGATIONS: • ECG: i) RAD with RVH. ii) CVH may be seen in acyanotic TOF. iii) RAH is occasionally present. P pulmonale. • X-Ray Studies: i) Heart size normal/smaller than normal. ii) Decreased BVM. Black lung field- pul.atre.&TOF iii)Concave PA with upturned apex-boot-shaped heart iv) Rt. sided aortic arch – 30% cases.
INVESTIGATIONS CONT.: • ECHOCARDIOGRAPHY: 2D & Doppler. i) Large, perimembranous infundibular VSD. ii) Overriding of aorta. iii) Anatomy of RVOT, Pul.valve, PA& branch. iv) Pressure gradient across the obstruction. v) Anomalous coronary artery distribution. vi) Aortic – mitral valve continuity. vii) RV hypertrophy.
NATURAL HISTORY: • Acyanotic TOF become cyanotic. • Cyanotic pt. become more cyanotic. • Polycythemia – secondary to cyanosis. • Development of iron-deficiency anemia. • Hypoxic spell may develop in infants. • Growth retardation. • Brain abscess and CVA. • SABE –occasional complication. • Coagulopathy – late complication of cyanosis.
HYPOXIC SPELL: • Cyanotic spell/ tet spell/ hypercyanotic spell. • Young infant with TOF. • Hyperpnea, worsening cyanosis, disapp. of murmur. • Crying, feeding, defecation, ph.activity-SVR decrd. • Large R to L shunt – initiates vicious circle • Fall of Po2, increase Pco2 and fall in pH. • Hyperpnea – negative thoracic pump. • Increase venous return to RV. • Again increase R to L shunt and establish the circle.
R to L shunt due to decreased SVR. Decreased pO2& pH, increased pCO2. Increased syst. Venous return. Hyperpnea HYPOXIC SPELL CONT.:Vicious circle-
FALLOT’S PHYSIOLOGY: Conditions clinically almost identical symptoms- • Complete TGA with VSD & pulmonic stenosis. • Corrected TGA with VSD & pulmonic stenosis. • Double outlet right ventricle with VSD & pulmonic stenosis. • Tricuspid atresia with diminished pulmonary blood flow. • Single ventricle with pulmonic stenosis.
MANAGEMENT: • MEDICAL: Management of Hypoxic spell- • Treatment principles – to break the vicious circle:- • Knee – chest position, - increase SVR & decrease ven.return • Morphine sulfate, 0.2mg/kg,sub-cut/ i.m.- suppress respiratory center, decreased hyperpnea. • Oxygen – decrease hypoxia. • Sodibicarb, 1mEq/kg, iv – correct acidosis. • Vesoconstrictors – phenylephrine, 0.02mg/kg iv.- increase SVR. • Ketamine, 1-3 mg/kg iv over 60 seconds,- increase SVR and sedation. • Propranolol, 0.01- 0.25mg/kg slow iv – reduce HR.
MANAGEMENT CONT.: • MEDICAL:- • Management of complications. • Correction of anemia. • Oral propranolol, 0.5-1.5mg/kg 6hrly as prophylaxis for hypoxic spell. • Balloon dilation – RVOT & pulmonary valve. • Dental hygiene & antibiotics against SABE. • Control of infections.
MANAGEMENT CONT.: • SURGICAL:- A) Palliative Shunt procedures- to increase PBF & reduce cyanosis – • INDICATIONS:- • Neonates with TOF & pulmonary atresia. • Infants with hypoplastic pulmonary annulus. • Children with hypoplastic PAs. • Severely cyanotic infants < 3 months of age. • Medically unmanageable hypoxic spells.
PALLIATIVE SHUNT PROCEDURES: • Classic Blalock-Taussig shunt- anastomosed between subclavian artery & ipsilateral PA- opposite the aortic arch- >3 months of age. • Gore-Tex (modified Blalock-Taussig)- interposition shunt – between subclavian artery & ipsilateral PA – same side of aortic arch - <3months of age. • Waterston shunt – between ascending aorta and right PA. • Potts shunt – between descending aorta & left PA.
CONVENTIONAL REPAIR SURGERY: • Indications and Timing:- • Symptomatic infants with favorable anatomy. • Asymptomatic and minimally cyanotic pt. • Total correction in previously shunt surgery pt. after 1-2yrs. • Asymptomatic & acyanotic TOF- 1-2 yrs. • PROCEDURES:- Patch closure of VSD, widening of RVOT under cardiopulmonary bypass.
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