Congenital Heart Disease_ Heart Failure.ppt

Congenital Heart Disease
Most common type of heart disease
among children
a) ~ 1% of live births
b) most causes unknown
i) ~ 10% genetic
- e.g., trisomy 21 (Down syndrome)
- congenital defect in parent or sibling is greatest risk factor
Tricuspid Atresia Michael P. D'Alessandro, M.D. Peer Review Status: Internally Peer Reviewed

Types:
a) L to R shunt
b) R to L shunt
c) obstructions
1.- L to R shunts
a) ASD, VSD, PDA
i)  pulmonary blood flow (ASD)
- NO cyanosis
b)  RV pressures and Vol. (VSD,PDA)
i) hypertrophy
ii)  PVR (vasoconstriction)
- to prevent edema

c) Over time PVR  to that of SVR i) reverses shunt (cyanosis) 2.- R to L shunt a)  pulmonary blood flow i) Cyanosis “blueness” of skin b) examples: i) tetralogy of Fallot ii) great vessel transposition iii) truncus arteriosus iv) tricuspid atresia v) anomalous pulmonary venous connection

c) long standing cyanosis is associated with “clubbing” of the tips of the fingers and toes

3.- Obstructions (of flow) a) coarctation of the aorta b) valvular stenosis i) aortic ii) pulmonary c) complete obstruction is called “Atresia”

Left to Right Shunts
Most common:
a) VSD, ASD, PDA and AVSD

i) VSD most common - close spontaneously (50%) ii) ASD usually not symptomatic before 30 yrs

iii) DA remains open after birth - ~ 90% occur as isolated anomaly - reversal of flow with  PVR causes cyanosis - PGE will maintain DA cardiac defects such as obstructive disease iv) complete atrioventricular canal defect - all 4 chambers freely communicate (Down syndrome)

Right to Left Shunts
Tetralogy of Fallot
a) Most common form of cyanotic congenital heart disease
Defects:
a) VSD
b) Pulmonary artery stenosis
i) determines clinical outcome
c) aorta that overrides VSD
d) RV hypertrophy

Tetralogy of Fallot (TOF) Michael P. D'Alessandro, M.D. Peer Review Status: Internally Peer Reviewed
Clinical Presentation: a) The onset and degree of cyanosis depends on:
i) severity of the pulmonary obstruction
ii) the size of the shunt.
b) Cyanosis is usually not seen until 3- 6 months of age.
c) The cyanosis is due to right ventricle outflow obstruction causing unoxygenated blood through the VSD.

Transposition of the Great Arteries
(TGA)
a) aorta arises from RV
i) is anterior and to the right of the pulmonary artery
b) pulmonary artery arises from LV
c) total separation of pulmonary and systemic circulations
i) need a shunt to survive following birth
- VSD  stable shunt

- PDA, foramen ovale  unstable shunt (close quickly after birth)  need surgery
the aorta originates from the right ventricle, so most of the blood returning to the heart from the body is pumped back out without first going to the lungs.
the pulmonary artery originates from the left ventricle, so that most of the blood returning from the lungs goes back to the lungs again

Truncus Arteriosus
Failure of separation into aorta and
pulmonary artery
a) results in single great artery
i) receives blood from both ventricles
- early systemic cyanosis
b) accompanying VSD
c)  pulmonary blood flow
i) danger of irreversible pulmonary hypertension

Tricuspid Atresia
Clinical Presentation: a) Cyanosis is almost always present at birth and is progressive.
b) Etiology/Pathophysiology: i) Due to absence of the tricuspid valve. This leads to an interatrial right to left shunt, usually through a patent foramen ovale.

ii) It is classified by the absence of tricuspid valve, pulmonary stenosis, and VSD. iii) The most Common form is also associated With a hypoplastic right ventricle

TRICUSPID ATRESIA 1 - atrial septal defect 2 - absent tricuspid valve 3 - ventricular septal defect Blood is shunted through an atrial septal defect to the left atrium and through the ventricular septal defect to the pulmonary artery. The shaded arrows indicate mixing of the blood.

Total Anomalous Pulmonary Venous Connection (TAPVC)
No pulmonary veins directly join LA
a) drain into left innominate vein or coronary sinus
b) PV drain into RA
ASD or foramen ovale always present
a) allows PV blood to enter LA
b) R to L shunt
Volume and pressure hypertrophy of RV

1 - superior vena cava 2 - atrial septal defect 3 - left innominate vein 4 - pulmonary veins Oxygenated blood returning from the lungs is routed back into the superior vena cava, rather than the left atrium. The presence of an atrial septal defect is necessary to allow partially oxygenated blood to reach the left side of the heart. Total Anomalous Pulmonary Venous Connection (TAPVC)

Obsttructive Congenital Anomalies
Coarctation of the Aorta
Narrowing
Males 2:1 vs. female
a) females with Turners frequently have coarctation
2 types:
a) infantile (with PDA; poor outcome)
i) prior to PDA
- symptoms early in life
- cyanosis of lower body

b) adult (without PDA)
i) most children asymptomatic
until late in life
ii) hypertension in upper extremities
iii) hypotension in lower extremities
Murmurs
a) throughout systole
LV hypertrophy

1 - pinched or coarcted aorta flow patterns are normal but are reduced below the coarctation. Blood pressure is increased in vessels leaving the aorta above the coarctation. The broken white arrow indicates diminished blood flow through the aorta.

Pulmonary Stenosis and Atresia
Obstruction at pulmonary valve
May occur as isolated defect or with:
a) Tetralogy of Fallot or
b) TGA
RV hypertrophy
a) usually there is poststenotic dilation
i) “jet” streaming
Relatively frequent defect

Atresia of valve
a) no communication between RV and lungs
b) hypoplastic RV with ASD
c) flow enters lung through PDA
Aortic Stenosis and Atresia
3 types:
a) valvular
b) subvalvular
c) supravalvular
Systolic murmur
LV hypertrophy

Valvular (severe) aortic stenosis or
atresia
a) outflow obstruction
i) hypoplastic LV and ascending aorta
b) PDA MUST be present to allow blood flow to:
i) aorta
ii) coronary arteries
iii) always fatal in first week of life
- when ductus closes !!

Aortic stenosis (valvular) 1 - narrowed aortic valve Flow patterns are normal but blood flow to the aorta is reduced as indicated by the broken white arrows

Subaortic stenosis
a) thickened ring below level of cusps
Supraventricular aortic stenosis
a) inherited defect
i) mutation of elastin gene causes this defect
b) ascending aorta is dysplastic
i) greatly thickened, causing
- narrowing of lumen

Subaortic Stenosis

Heart Failure (i.e.,Congestive)
Heart cannot eject volume which is
being returned to it
a) failure to perfuse tissues effectively
b) usually slowly progressive
i) acute forms
- MI
- Volume overload
- valvular dysfunction

Compensatory mechanisms:
a) Frank-Starling mechanism
i)  stretch   contraction
b) cardiac structural changes
i) hypertrophy
c) activation of neurohumoral system
i)  sympathetic tone (NE)
-  HR
-  contractility
ii)  renin-angiotensin- aldosterone system
iii)  ANP

Most frequent causes for failure of
these compensatory mechanisms are:
a) ischemia
b) hypertension
c) whatever the reason for the failure CHF 
i)  CO (systolic failure) or,
ii)  CO (diastolic failure)

Cardiac Hypertrophy
a) cardiac myocyte is terminally differentiated cell
i) no  in cell # (i.e., hyperplasia)
ii)  load on cells causes cells to  in size (i.e., hypertrophy)
- pressure or volume overload
- trophic hormones (e.g., T 4 )
b) pressure overload
i) “concentric hypertrophy”

ii)  wall thickness iii)  cavity diameter c) volume overload i) “eccentric hypertrophy” ii) chamber dilation iii)  ventricular diameter iv) wall thickness may not change - owing to simultaneous hypertrophy d)  capillary density with hypertrophy i)  demands  ischemia !!

Left Sided Heart Failure
Most often caused by:
a) ischemic heart disease
b) hypertension
c) aortic and mitral valve disease
d) nonischemic myocardial disease
Major effect is “damming” of blood
within the lungs
LV hypertrophy and often dilation
LA secondary dilation
a) stasis, arrhythmia, thrombus

Lungs major problem
a)  pulmonary vein pressure
i) pulmonary congestion and edema
- heavy and wet
b) iron containing proteins in edema fluid and Hb from RBC
i) phagocytosed by macrophages
- converted to “Hemosiderin”
- “heart failure cells”
c) dyspnea
i) early sign

d) orthopnea
i) dyspnea on lying down and relieved by sitting upright
e) cough is common with Left sided failure
Kidneys
a)  CO
b) renin-angiotensin-aldosterone
i) retention of salt and water
- contribute to edema
- counteracted by ANP

Right Sided Heart Failure
Major cause is LEFT heart failure
Occurs as isolated failure in only few
diseases
a) chronic pulmonary hypertension
i) “ Cor Pulmonale”
Minimal pulmonary congestion
Major areas of edema are systemic,
peripheral
a) liver and portal system
i) “congestive hepatomegaly”

ii) when Left heart failure is present, hypoxic liver shows signs of “centrilobular necrosis” iii) long standing Right failure - cardiac cirrhosis iv) portal hypertension - congestive splenomegaly v) ascites vi) pleural and pericardial effusions accompany Right heart failure

Cardiac Transplantation
2 major causes:
a) DCM
b) IHD
Major success due to:
a) careful selection of patients
b) drug therapy
c) sequential biopsies
Major problems
a) stenosis (coronary arteries)
i) silent MI (no pain !)
- CHF or sudden death

b) infections c) malignancies i) lymphomas - Ebstein-Barr virus

Congenital Heart Disease_ Heart Failure.ppt

by DominicDR on Sep 03, 2010

Accessibility

Upload Details

Usage Rights

Statistics

Congenital Heart Disease_ Heart Failure.ppt Presentation Transcript