GOALS To define the physiology of the five most common cyanotic defects To describe the long term sequelae of the corrective procedure. To describe the PE,ECG, and CXR results for the more common defects.
INITIAL WORKUP: THE HYPEROXY TEST Give the patient as close to FiO2 of 1 for at least 5 minutes. Obtain pre and postductal ABGS What should your PaO2 be on 100% O2? Is it reasonable to expect to get 100% using a mask or hood?
CXR Mainly we are looking for situs, PBF, cardiac size and noncardiac abnormalities. Boot shaped, apple shaped, box shaped, valentine shaped, egg on its side shaped, ball on string shaped, boiled peanut shaped…el toro poo poo.
ECG Get it! If you cant read it fax it! Remember most term infants have relative RV dominance so a big LV would be unusual. Unless its a significant premie where there hasnt been time to develop the pulmonary vascular bed. In a premie, RVE is not the norm
WHAT ARE THEY? Tetralogy of Fallot d-Transposition of the great arteries Truncus arteriosus TAPVR Atresias
TETRALOGY of FALLOT See handout for basics. The primary concerns after correction are: the degree of Pulmonary insufficiency, the presence of tachydysrhymias, and residual VSDs, and the presence of significant supravalvular pulmonary stenoses. There seems to be a degree of mild learning disability post op, also ADHD.
d-TGA The most cyanotic common defect diagnosed in the nursery. The degree of saturation will depend on the degree of mixing of the 2 parallel circuits.The mixing sites are: ASD, PDA, and VSD. The more mixing, the higher the effective pulmonary blood flow
EFFECTIVE PULMONARY FLOW Blood going to the lungs which has not been to the lungs in that cardiac cycle. PGE acts to increase mixing at the great vessel level. BAS increases mixing at the atrial level We try not to increase mixing at the ventricular level.
CLINICAL Findings d-TGA Cyanosis Possibly CHF If pulmonary stenosis present, may be very blue S2 normally split in 1/3, narrow and loud in 2/3 ECG: RAD with BE. May be wnl in nursery CXR: egg on string.Narrow medias.^PBF
D-TGA cont. Cath findings: slides ECHO: classic findings are anterior great vessel gives off CAs, posterior vessel gives off two branches, may look like circle,circle
d-TGA TREATMENT PGE: usually all thats needed to improve mixing and relieve the acid base issues. At least long enough to get the patient to a center. BAS may be necessary if PGE not effective and theres a delay in correction. MUSTARD: see slide SWITCH
MUSTARD SEQUELAE Sinus node dysfunction: 10 yrs out less than 30% in dominant sinus rhythm. Atrial tachyarrhymias. Ventricular arrhymias….sudden death Coronary perfusion abnormalities RV failure
ASO: follow -up Supravalvular obstruction: most commonly PS with frequent LPA stenosis. Coronary occlusion: occurs early. Had to correct if later Neo-aortic regurg: more frequently reported. No cases requiring surgical correction but a few have required medical intervention
TAPVR Cyanosis variable and largely dependant on degree of pulmonary venous obstruction. CHF found in 41%, if early probably because of pulm vein obstruction. If later,in those without pn obs. One of the few defects which can give you a big heart and cyanosis. The other is Ebsteins.
TAPVR cont. ECG: RAD,RVE, reversal of r/s progression,RAE by 3 months Snowman on CXR ECHO: usually a smallish LA, abnormalities of venous return(difficult to find any PVs coming to LA). May find the common vein.
TAPVR The patients are not infrequently our sickest as infants. The are profoundly hypoxic and frequently acidotic. The biggest post-op issue is pulmonary vein stenosis. If thats present, pulmonary HTN is inevitable and extremely difficult to tx.
TAPVR: ECMO Because of the extreme condition many of these infant present in, some of them have been felt to have PPHN and have been submitted for ecmo. This was especially true before the availability of color doppler. This meant a number of these patients were in much better condition when they went for repair.
TRUNCUS ARTERIOSUS A SINGLE GREAT VESSEL ARISES FROM THE HEART AND GIVES OFF THE CAS,PAS AND AORTA. 19TH MOST COMMON CONGENITAL HEART DEFECT ONE OF THE LESIONS ASSOCIATED WITH RIGHT ARCH AND AORTIC OVERRIDE.
TRUNCUS cont 4 basic types based on the source of PBF. The fourth is pulmonary atresia with vsd otherwise known as pseudotruncus. 11% of cases have interrupted aortic arch The is associated DiGeorge syndrome There may be associated pulmonary stenosis
Truncus If there is no pulmonary obstruction, the dominant picture is CHF with varying degrees of cyanosis There may be significant insufficiency of the truncal valves which can have 2-5 cusps. Bounding pulses(its like a big PDA), There may be a continous murmur if the PAs are tight
TRUNCUS ECG: LVE,RVE OR BE. OCC LAE CXR: RIGHT ARCH 30%, ^PBF ECHO: USUALLY DIAGNOSTIC
TRUNCUS:Tx Decongestive tx pending surgery Surgery consists of VSD closure and a graft to the PAs. Early surgery essential.The average age of death untreated is 5 wks. Sequelae:depends on degree of truncal valve insufficiency and pulm artery obstruction