Cardiovascular Dysfunction Flashcards
Two major groups of Cardiovascular Dysfunction
Congenital Heart Disease and Acquire Heart Disorders
6 Tests for Cardiac Function
Electrocardiography echocardiography chest radiograph (x ray) cardiac catheterization excersize stress test cardiac magnetic resonance imaging (MRI)
4 uses of cardiac catherization
biopsy
hemodynamics
angiography
electrophysiology
Interventional Catheterization
A balloon catheter or other device is used to alter the cardiac anatomy to fix structural problems
complications of cardiac catheterization
hemorrhage from entry site low grade fever nausea/vomiting loss of pulse distal to catheterization site (results from clot, hematoma, or tear) transient dysrhythmias
preparation for cardiac catheterization in pediatric population
NPO 4-6 hrs before procedure entertainment for during procedure accurate weight/height developmentally appropriate explanation allergies potential sedation
postprocedural care for cardiac catheterization
check for: blood glucose level colour vital signs dressing fluid intake
two major cause of death in the first year of life
prematurity and CHD
most common congenital heart defect
ventricular septal defect - abnormal opening between the right and left ventricles
classified according to location: membranous or muscular
left to right shunt
an abnormality between the left and right ventricle cause blood to flow left to right as that is the path of least resistance (pressure and blood flow)
classification of defects
used to be cyanotic or acyanotic (changed bc children with acyanotic defects might develop cyanosis and those with cyanotic defects may appear pink and have more clinical signs of HF)
Now classified according to blood flow patterns: 4 patterns
increased pulmonary blood flow
decreased pulmonary blood flow
obstruction to blood flow out of heart
mixed blood flow (oxygenated and nonoxygenated blood mix)
right to left shunting
decreased pulmonary blood flow resulting from obstruction of pulmonary blood flow and an anatomical defect between right and left side of heart. The blockage increases the right side pressure causing it to exceed the left sided pressure and results in right to left shunting
Defects with increased pulmonary blood flow
atrial septal defect
ventricular septal defect
atrioventricular canal defect
patent ductus arteriosus
atrial septal defect
abnormal opening between the atria allowing blood from high pressure left to flow to low pressure right. 3 types of atrial defects. Pt asymptomatic but may develop HF. Treatment with path over hole, cardiac catheterization, cardiopulmonary bypass, and valve replacement
3 types of atrial septal defects
Ostium Primum (ASD1) - opening at lower end of septum; associated with mitral valve abnormalities Ostium Secundum (ASD2) - opening near center of septum sinus Venosus Defect - opening near junction of superior vena cava and right atrium; associated with partial anomalous pulmonary venous connection
ventricular septal defect
abnormal opening between the right and left ventricle. Classified as membranous or muscular. Common ventricle is when there is an absence of a septum. HF common. Pt at risk for bacterial endocarditis and pulmonary vascular obstructive disease. Tx; Placing a band around the main pulmonary artery to decrease pulmonary bloodflow, complete repair with sutures, cardiac catheterization, patch over large defects, cardiopulmonary bypass
Atrioventricular Canal Defect
Incomplete fusion of the endocardial cushions. Combined low ASD and high VSD. Allows blood to flow between all four heart chambers. Pt have moderate to severe HF, mild cyanosis, and increased risk of pulmonary vascular obstructive disease. Tx: pulmonary artery banding, surgical repair with patch
patent Ductus Arteriosus
failure of the fetal ductus arteriosus (artery connecting the aorta and pulmonary artery) to close within the first week of life. Pt asymptomatic or show signs of HF. Tx: IV admin of indomethacin (prostaglandin inhibitor) has shown effective in closing PDA - should be given via umbilical lines, thoracotomy for surgical division of patent vessel, thoracoscope inserted on left side of chest to clip ductus, coils to occlude PDA placed in pt in catheterization lab
Obstructive Defects
Coarctation of the aorta aortic stenosis valvular aortic stenosis pulmonic stenosis subvalvular aortic stenosis
coarctation of the aorta
localized narrowing near the insertion of the ductus arteriosus, which results in increased pressure proximal to the defect (head and upper extremities) and lower pressure distal to the obstruction (body and lower extremities). Pt has bounding pulse in upper extremities and weak pulse below. Cool lower extremities and low BP, signs of HF in infants. Tx: surgical repair, balloon angioplasty, stents
aortic stenosis
narrowing or stricture of the aortic valve, causing resistance to blood flow in the left ventricle, decreased cardiac output, left ventricular hypertrophy, and pulmonary vascular congestion. Prominent consequence of AS is the hypertrophy of the left ventricular wall. Valvular stenosis most common type of AS. infant S and S: faint pulse, hypotension, tachycardia, and poor feeding. Children S and S: excersize intolerance, chest pain, and dizziness
Valvular Aortic Stenosis
caused by malformed cusps that result in a bicuspid rather than a tricuspid valve or fusion of the cusps. Aortic valvotomy is performed under inflow occlusion or balloon dilation.
subvalvular aortic stenosis
stricture caused by a fibrous ring below a normal valve. Tx: incising a membrane if one exists or cutting the fibrous ring, a patch to enlarge the left ventricle outflow tract and annulus and replace the aortic valve
Supravalvular aortic stenosis
occurs infrequently
pulmonic stenosis
narrowing at the entrance of the pulmonary artery. Resistance to blood flow causes right ventricular hypertrophy and decreased pulmonary blood flow. Tx: infants - transventricular (closed) valvotomy is used. Children - pulmonary valvotomy with cardiopulmonary bypass. Nonsurgical - balloon angioplasty
pulmonary atresia
severe form of pulmonary stenosis in that there is total fusion of the commissures and no blood flow to the lungs
Decreased pulmonary Blood Flow
tetralogy of fallot
tricuspid atresia
Tetralogy of Fallot
classic form includes four defects: VSD, pulmonic stenosis, overriding aorta, and right ventricular hypertrophy. hemodynamic alterations vary widely depending on degree of PS and size of VSD and the flow resistance it creates. if the VSD is large, pressure in right and left ventricle equal so blood flow dependant on vascular resistance. Tx: palliative shunt, complete repair
Blue Spell or Tet Spells
Acute episodes of cyanosis and hypoxia. Called tet spells bc seen often in Tetralogy of Fallot
Tricuspid Atresia
Tricuspid valve fails to develop; no communication from the right atrium to the right ventricle. Blood flows through an ASD or patent foramen ovale to the left side of the heart and through a VSD to the right ventricle and out to the lungs. There is also complete mixing of oxygenated and unoxygenated blood in the left side of the heart. Tx: For the newborn whos pulmonary blood flow depends on a patent ductus arteriosus, continuous infusion of prostaglandin E until surgery, surgical tx is placement of a shunt, modified Fontan Procedure
Mixed Defects
Transposition of the great arteries OR Transposition of the great vessels
total anomalous pulmonary venous connection
truncus arteriosus
hypoplastic left heart syndrome
transposition of the great arteries/vessels
the pulmonary artery leaves the left ventricle and the aorta exits from the right ventricle, with no communication between the systemic and pulmonary circulations. Associated septal defects must be present to allow blood to enter the systemic or pulmonary circulation for mixing of blood. Most common defect associated with TGA is patent foramen ovale. Tx: IV of prostaglandin E to keep PDA or FO open, balloon atrial septostomy, arterial switch procedure, rastelli procedure
Rastelli Procedure
procedure of choice in TGA, VSD, and severe pulmonic stenosis
total anomalous pulmonary venous connection
rare defect characterized by failure of the pulmonary veins to join the left atrium, Instead, the pulmonary veins are abnormally connected to the systemic venous circuit via the right atrium or various veins draining toward the right atrium, such as the superior vena cava. The abnormal attached results in mixed blood returned to the right atrium and shunted from left to right through an ASD. TAPVS classified in 3 ways; supracardiac, cardiac, infradiaphragmatic. Tx: surgical approach varis with anatomical defect, in general the common pulmonary vein is anastomosed to the back of the left atrium, the ASD closed, and the anomalous pulmonary venous connection is ligated.
Classification of TAPVC
Supracardiac - attachment above the diaphragm, such as the SVC
Cardiac - direct attachment to the heart, such as the right atrium or coronary sinus
Infradiaphragmatic - attachment below the diaphragm, such as the inferior vena cava; most fatal form and associated with obstruction to pulmonary venous drainage and is surgical emergency
truncus arteriosus
failure of normal septation and division of the embryonic bulbar trunk into the pulmonary artery and the aorta, which results in development of a single vessel that overrides both ventricles. blood from both ventricles mixes in the common great artery, which leads to desaturation and hypoxemia. 3 types of truncus arteriosus. Tx: surgical repair involving closing the VSD so that the TA recieves the outflow from the left ventricle, excising the pulmonary arteries from the aorta and attaching them to the right ventricle by homograft. Conduit replacement needed as the child grows as they will not grow with the child