TETRALOGY OF FALLOT

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COMMONEST CYANOTIC CONGENITAL HEART DISEASE

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10 % OF ALL CONGENITAL HEART DISEASES

MORPHOLOGY

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FOUR MORPHOLOGICAL DEFECTS

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VENTRICULAR SEPTAL DEFECT

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RIGHT VENTRICULAR OUTFLOW TRACT OBSTRUCTION

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SUBVALVAR VALVAR SUPRAVALVAR

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OVERRIDING OF THE AORTA

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RIGHT VENTRICULAR HYPERTROPHY

MORPHOLOGY OF NORMAL HEART

MORPHOLOGY IN T.o.F

Subvalvar Obstruction

ALTERED PHYSIOLOGY

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OBSTRUCTION TO FLOW OF DEOXYGENATED BLOOD FROM THE RIGHT VENTRICLE TO THE PULMONARY ARTERY

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DECREASED OXYGENATION DUE TO POOR PERFUSION OF THE BLOOD

ALTERED PHYSIOLOGY

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SHUNTING OF DEOXYGENATED BLOOD FROM THE RIGHT VENTRICLE TO THE AORTA ACROSS THE VENTRICULAR SEPTAL DEFECT (FACILITATED BY AORTIC OVERRIDE)

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POOR SYSTEMIC OXYGENATION, LOW HEMOGLOBIN SATURATION AND CYANOSIS

CLINICAL PRESENTATION

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CYANOSIS NOT USUALLY NOTICED AT BIRTH

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CAUSES

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CHILD LESS ACTIVE IN THE INITIAL FEW MONTHS

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FOETAL HEMOGLOBIN HAS MORE AFFINITY FOR OXYGEN THAN ADULT HEMOGLOBIN

CLINICAL PRESENTATION

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CYANOSIS MANIFESTS MORE AS CHILD BECOMES MORE ACTIVE

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PHYSICAL GROWTH IS USUALLY GOOD

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MENTAL DEVELOPMENT MAY BE DELAYED IN SEVERE CASES DUE TO CHRONIC HYPOXIA OF THE BRAIN

CYANOTIC SPELLS

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TYPICAL OF FALLOT’S TETRALOGY

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USUALLY OCCURS WHEN THE CHILD CRIES OR IS VERY ACTIVE AS WHEN THE CHILD WAKES UP FROM SLEEP

CYANOTIC SPELLS

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ACTIVITY RESULTS IN

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INCREASES OXYGEN DEMAND

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DECREASES SYSTEMIC VASCULAR RESISTANCE

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INCREASES SYMPATHETIC ACTIVITY WHICH CAUSES INFUNDIBULAR SPASM, I.E., INCREASE IN THE MUSCULAR OBSTRUCTION TO THE RIGHT VENTRICULAR OUTFLOW AT THE SUBVALVAR LEVEL

DECREASED S.V.R.

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MORE SHUNTING ACROSS THE VSD – MORE DESATURATION OF SYSTEMIC BLOOD – PERIPHERAL ACIDOSIS – FUTHER SYSTEMIC VASODILATATION – FURTHER DECREASE IN SVR – VICIOUS CYCLE

SQUATTING

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TYPICAL OF FALLOT’S TETRALOGY CHILD ASSUMES SQUATTING POSTURE VERY FREQUENTLY SOME POSTURES MAY BE CALLED ‘SQUATTING EQUIVALENTS’ REASON IS THAT SQUATTING CAUSES AN INCREASE IN RESISTANCE TO SYSTEMIC FLOW – DECREASED SHUNTING ACROSS THE VSD – LESS DESATURATION OF SYSTEMIC BLOOD

NATURAL HISTORY

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WIDE SPECTRUM OF CLINICAL MANIFESTATIONS DEPENDING ON SEVERITY OF ABNORMALITIES, I.E., DEGREE OF OBSTRUCTION TO RIGHT VENTRICULAR OUTFLOW, AND SIZE OF VSD

NATURAL HISTORY

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IN SEVERE CASES, CHILD MAY HAVE REPEATED CYANOTIC SPELLS IN LESS SEVERE CASES, CHILD MAY BE FREE FROM SPELLS, BUT SEVERLY CYANOSED, WITH NORMAL PHYSICAL BY DELAYED MENTAL DEVELOPMENT IN MILD CASES, CHILD MAY GROW NORMALLY, WITH CYANOSIS BEING ONLY MINIMAL

TREATMENT OPTIONS

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ONLY SURGICAL

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PALLIATIVE SURGERY

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DEFINITIVE SURGERY

PALLIATIVE SURGERY

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AIMED TO DIVERT SYSTEMIC BLOOD INTO THE PULMONARY CIRCULATION AND THUS ENHANCE PULMONARY FLOW AND OXYGENATION STANDARD OPERATION IS THE MODIFIED BLALOCK-TAUSSIG SHUNT OR OTHER SYSTEMIC PULMONARY SHUNTS SUCH AS POTT’S SHUNT AND WATERSTON-COOLEY SHUNT

DEFINITIVE SURGERY

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RELIEF OF RIGHT VENTRICULAR OUTFLOW TRACT OBSTRUCTION SEPARATION OF SYSTEMIC AND PULMONARY CIRCULATIONS BY CLOSURE OF THE VSD

TREATMENT STRATEGIES

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PALLIATIVE SURGERY IN EARLY CHILDHOOD FOLLOWED BY DEFINITIVE SURGERY IN THE LATER YEARS, USUALLY AFTER 3 – 4 YEARS OF AGE

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DEFINITIVE SURGERY IN THE NEONATAL PERIOD OR EARLY CHILDHOOD

T.O.F IN ADULT CARDIAC SURGICAL HOSPITAL

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DELAYED DEFINITIVE REPAIR FOLLOWING SHUNT IN EARLY CHILDHOOD DELAYED PRESENTATION, FOR DEFINITIVE REPAIR RE-OPERATION FOR DELAYED COMPLICATIONS AFTER DEFINITVE REPAIR

POSTOPERATIVE NURSING ISSUES

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MOST WILL HAVE A NORMAL CIRCULATION POSTOPERATIVELY C.V.P MAY RUN HIGH DUE TO STIFF RIGHT VENTRICLE AND HIGH RVEDP GAS EXCHANGE IS USUALLY NORMAL MAY HAVE HEART BLOCKS OR BRADYARRYHTHMIAS