Главная страница | Контакты | Случайная страница Автомобили Астрономия Биология География Дом и сад Другие языки Другое Информатика История Культура Литература Логика Математика Медицина Металлургия Механика Образование Охрана труда Педагогика Политика Право Психология Религия Риторика Социология Спорт Строительство Технология Туризм Физика Философия Финансы Химия Черчение Экология Экономика Электроника

CONTENTS. - Anomalies of heart and large vessels development due to embriogenesis disturbances during 2-8th weeks of pregnancy

Definition:-

- Anomalies of heart and large vessels development due to embriogenesis disturbances during 2-8^th weeks of pregnancy

Epidemiology:-

- Frequency - 1%

- 50-70 % die before 1 year of age (if without surgery)

- Only ½ of cases are diagnosed in maternity house; 93% - before 1^st year

- More than 40 defects are described; 8 are most common (80%)

Most common defects:-

- Ventricular septal defect (VSD)

- Atrial septal defect (ASD)

- Patent ductus arteriosus (PDA)

- Coarctation of aorta (CA)

- Stenosis of aorta (SA)

- Transposition of magistral vessels (TMV)

- Fallot’s tetralogy (FT)

Etiology – 1:-

- Viral infections (rubella, URIs, mumps, chickenpox)

- Radioactive rays

- Drugs (thalidomide)

- Toxicosis of pregnancy

- Starving

- Polyhypovitaminosis

Etiology – 2:-

- Some diseases of pregnancy (diabetes, heart diseases)

- Chromosomal diseases (Down’s syndrome, Marfan’s syndrome, Turner’s syndrome…)

- Mother’s age over 35 years

- Maternal alcohol consumption

- Family history of a cardiac or noncardiac defect

Classification – I:-

- With left-to-right shunting (↑ pulmonary circulation)

- With right-to-left shunting (↓ pulmonary circulation)

- Without shunting

With left-to-right shunting:-

- Ventricular septal defect

- Atrial septal defect

- Patent ductus arteriosus

With right-to-left shunting:-

- Transposition of magistral vessels

- Fallot’s tetralogy

- Left heart hypoplasia

Without shunting:-

- Coarctation of aorta

- Stenosis of aorta

- Stenosis of pulmonary artery

Classification – II:-

- With increase of pulmonary circulation

- With decrease of pulmonary circulation With decrease of greater systemic circulation

- Without hemodynamic disturbances

- ___________

- With or without cyanosis

Echocardiography:-

- 3-dimensional (3D) echocardiographic images with a Doppler system with superimposing a color-coded direction and velocity of blood flow on the real-time images

Ventricular septal defect:-

- Most common: 17-30 %

- Size: 0.1 cm – 3 cm

- Localization: in membranous or muscular part

- Delayed diagnosis: first months pulmonary pressure is higher → no cardiac murmur

Ventricular septal defect:-

- Small VSD: no significant hemodynamic derangement; loud murmur; can close spontaneously (in muscle segment)

- Large VSD: progressively leads to higher pulmonary resistance → irreversible pulmonary vascular changes, so-called Eisenmenger syndrome (reversal of shunt to right-to-left shunt)

Clinics:-

- Mild defect: recurrent upper respiratory infections, effort intolerance and fatigue

- Severe defect:

- Development deficit, failure to thrive

- CHF

- Pulmonary hypertension

Clinics in early infancy:-

- Dyspnea

- Feeding difficulties

- Poor growth

- Profuse perspiration

- Recurrent pulmonary infections

- Cardiac failure

Physical exam:-

- Rough pansystolic murmur in 3-4^th intercostal space on the left border of sternum

- Accent of S2 over pulmonary artery (pulmonary hypertension)

- Left and right ventricular enlargement (palpable parasternal lift, laterally displaced apical impulse, widened heart borders)

ECG:-

- Small VSD → Normal

- Moderate VSD → signs of LV volume overload (deep Q and tall R waves with tall T waves in leads V5 and V6), LA overload (broad P wave), atrial fibrillation

- Severe VSD → right ventricular hypertrophy, with further progression - biventricular hypertrophy

Chest X-ray:-

- Small VSD → Normal

- Moderate VSD → Increased cardiac silhouette, increased pulmonary vascular markings

- Severe VSD → Markedly prominent main PA and adjacent vessels, RV hypertrophy

Medical management:-

- Increased calories of feedings

- Diuretics (furosemide 1-3 mg/kg/d)

- Captopril (0.1-0.3 mg/kg every 8 h) to reduce systemic and pulmonary afterload

- Digoxin (5-10 mcg/kg/d) - if diuresis and afterload reduction do not relieve symptoms adequately.

Surgical Care:-

- Transcatheter closure

- Surgical closure

- Indications for surgical repair:

- Uncontrolled CHF

- Large, asymptomatic defects associated with elevated PA pressure

- Pulmonary to systemic flow greater than 2:1.

- Prolapse of an aortic valve

Complications:-

- Eisenmenger complex

- Secondary aortic insufficiency

- Aortic regurgitation

- RV outflow tract obstruction

- Subaortic obstruction

- Infective endocarditis (antibiotic prophylaxis with dental or surgical procedures)

Prognosis:-

- 25 % - spontaneous closure (mostly during the first 2 years of life, can be in adults)

- 7% of infants with large defects and congestive heart failure - also spontaneous closure

- Among small defects, 80% of muscular VSDs closed and 35% of membranous

- 10 % - death during 1^st year of life

- Mean life expectancy – 40 years

Atrial septal defect:-

- Frequency: 8-15 %

- Size: small – to complete absence

- Open oval window → no clinics (30% of adults)

- Diagnosis at 1^st year – only 40% of cases

Clinics:-

- Rarely symptomatic

- Decreased exercise tolerance

- Large shunt → fatigue, dyspnea and arrhythmias

Physical exam:-

- Moderate systolic murmur in 2^nd intercostal space on the left border of sternum

- Accent of S2 over pulmonary artery (pulmonary hypertension)

- Signs of cardiac enlargement

ECG:-

- Right ventricular hypertrophy (lengthened PR interval and incomplete right bundle branch block)

- Atrial enlargement (P wave)

Chest x-ray:-

- Prominent right atrium

- Prominent main pulmonary artery

- Increased heart size and pulmonary vascularity

Complications:-

- Sinus node dysfunction

- Pulmonary venous obstruction

- Atrial fibrillation

- Pulmonary hypertension

- Pericardial effusion or post-pericardiotomy syndrome

Prognosis:-

- Poor if CHF at early age

- Mean life expectancy – 40 years

- Best time for surgery – 1^st two decades of life

- No Px for septic endocarditis

Patent ductus arteriosus:-

- Frequency: 10-25 %

- Prematures: 50-80%

- Normal finding at 1^st week of life

- Ductus between descending aorta and pulmonary artery bifurcation

Clinics:-

- Repeated respiratory infections

- Later – liver enlargement, cyanosis

- Growth retardation

- Septic endocarditis

- CHF

Physical exam:-

- Loud systolic or systolic-diastolic murmur in the 2^nd intercostal space left from sternum

- 1^st sound accent over pulmonary artery

- Murmur diminishes at deep breath-in

- Murmur disappears with pulmonary hypertension → appears again with shift reverse

Chest X-ray:-

- LV enlargement; later + RV enlargement

- Prominent pulmonary vessels

Management:-

- Can be closed with indometacin prescription (PG E2 & I2 synthesis inhibitor) – 0.1 mg/kg q8h IV first 8-14 days of life

- Surgery best after 6 months but before severe pulmonary hypertension

Prognosis:-

- Many defects will spontaneously close before 6 mo of age

- Without surgery mortality is 20%

- Mean life expectancy is 35 years

Coarctation of aorta:-

- 5-8% of all congenital heart defects

- May occur as isolated defect or in association bicuspid aortic valve, ventricular septal defect and others

Clinics:-

- Infants – CHF (acute afterload increase after ductus arteriosus closure)

- Older children – hypertension (enough time for collaterals development)

- Left ventricle overwork → increased wall stress and compensatory ventricular hypertrophy

Physical exam:-

- Blood pressure discrepancies between upper and lower extremities

- Reduced or absent lower extremity pulses

- Differential cyanosis (pink upper extremities with cyanotic lower extremities) - rare

- Murmur: nonspecific, under the left scapula

Chest X-ray:-

- Early onset of CoA: cardiomegaly, pulmonary edema, and other signs of CHF.

- Late onset of CoA: cardiomegaly, arch indentation in the area of the coarctation, and rib notching

ECG:-

- Early onset of symptoms: RV rather than LV hypertrophy and evidence of ischemia.

- Late onset of symptoms: LV hypertrophy and signs of LV ischemia or strain.

Other tests:-

- Preductal and postductal pulse oximetry readings

- Cardiac catheterization (evaluation and possible balloon aortoplasty)

Management:-

- Prostaglandin E1 (0.05-0.15 mcg/kg/min) IV to open the ductus arteriosus

- Treatment of hypertension (beta-blockers and vasodilators)

- Treatment of CHF and shock in infants

Surgery:-

- End-to-end anastomosis

- Patch aortoplasty

- Left subclavian flap aortoplasty (left subclavian artery is brought back toward the left carotid artery to enlarge an area of transverse arch hypoplasia)

Complications:-

- Hypertension

- Intracranial hemorrhage and aneurysms

- Aortic rupture or dissection

- CHF

- Recurrent coarctation after surgery

- Aortic aneurythm

- Paralysis (spinal cord ischemia)

- Cardiomyopathy

Prognosis:-

- Mean life expectancy is 35 years

- Without surgery 1-st year mortality is 25%

- Requires bacterial endocarditis prophylaxis

Transposition of magistral vessels:-

- Aorta comes from RV and pulmonary artery comes from LV → 2 separated circulations

- No disturbance of fetal circulation

- Postnatal life is only possible with blood shunts (VSD, ASD, PDA)

Clinics:-

- Early total cyanosis from birth, not responsive to oxygen

- Tachycardia, tachypnoe, decreased BP

- Developmental deficit

- CHF by 1^st-2^nd month of life

Physical exam:-

- Murmurs – due to other defects (VSD, ASD, PDA)

- Cardiac borders widening

Chest X-ray and ECG:-

- Signs of RV (or both) hypertrophy

Management:-

- Urgent surgery!

Prognosis:-

- 95% die during 1^st year of life without surgery

- Mean life expectancy is 3 months

Fallot’s tetralogy:-

- Most common among cyanotic heart defects

- Right-to-left shunt

Defects of TOF:-

- Ventricular septal defect

- Dextraposition of the aorta

- Obstruction of the right ventricular outflow tract (PA stenosis)

- Right ventricular hypertrophy

- Pentade: + Atrial septal defect

- Triade: no VSD, shunt through Open oval fenestra

Clinics:-

- 4 phases:

- “Relative stable well-being”

- “Gray attacks”

- “Blue attacks”

- “Stabilization of the condition”

“Relative stable well-being”:-

- First 4-6 weeks of life

- PDA & Physiologic polycytemia → mild clinics and mild murmur (if any)

“Gray attacks”:-

- First 2-9 months of life

- Hypoxic attacks after physical strains (feeding, anxiety) – 20-25 times per day

- No cyanosis

- No complaints between attacks

- Failure to thrive

“Gray attacks” - Hypoxic attacks:-

- Sudden dyspnoe

- Grayish skin color

- Crying

- Short-period loss of consciousness

- Short-period seizures

“Blue attacks”:-

- 9 months – 3-5 years of life or all life long

- Systemic cyanosis first at attacks, then permanent

- Drumstick fingers

- Polycytemia

- Polyhlobulinemia

- Paresis and palsies (brain hemodynamics disturbances)

“Blue attacks” - Hypoxic attacks:-

- Involuntary position (knees at chest, older – squatting down): aortic pressure is increased → better shunt to pulmonary artery

- Cyanosis and dyspnea

“Stabilization of the condition”:-

- After 3-5 years:

- Permanent cyanosis, but without attacks

- Tachypnea at rest

- Murmus is less

- ECG, X-ray, Echo - worse

Physical exam:-

- Murmur of VSD

- Decreased 2^nd sound over pulmonary artery

ECG:-

- Right ventricular hypertrophy

- Left ventricular overload and some left ventricular enlargement

- Right atrial enlargement may also be present

Chest X-ray:-

- Aneurysmally dilated central pulmonary arteries with otherwise normal peripheral pulmonary vascularity.

- Cardiomegaly results from dilation of the right ventricle, particularly its outflow tract (infundibulum)

- Appearance of “boot”

Management:-

- Attacks – position, oxygen, sedatives

- Surgery!

Prognosis:-

- Without surgery – 75% mortality before 2 years of age

CONTENTS

Page