MODULE 5 CARDIAC. CARDIAC ANATOMY CARDIAC CYCLE.

MODULE 5 CARDIAC

CARDIAC ANATOMY

CARDIAC CYCLE

TRANSITION FROM FETAL CIRC. Blood flow from placenta to fetus through

the umbilical vein to the ductus venosus and into the right atrium of the heart

No need for blood to travel to the lungs, though some does just by way of pressure gradients

Majority of blood passes through patent ductus arteriosus, the vascular channel between the pulmonary artery and the aorta

Newborn must adapt to receiving oxygen from the lungs

Transition from fetal to pulmonary circulation occurs in just a few hours

Increase in pressure in the left atrium stimulates closure of the foramen ovale

In response to higher oxygenation satruations ductous arteriosus closes within 10-15 hours after birth

Permanent closure occurs by 10-21 days after birth unless sats remain low

PEDIATRIC DIFFERENCES

More sensitive to fluid volume changes Less cardiac muscle compliance Inability to regulate stroke volume until muscle

fibers fully developed at around 5 years of age Increased metabolic rate and increased oxygen

demand Little cardiac output reserve H & H concentrations are higher as appropriate

for age necessary for oxygen transport Persistent desaturation/hypoxia can lead to

increased H & H from bone marrow response

CARDIAC ASSESSMENT

Comprehensive History Has your child ever had a change in skin

color during feeding or crying?

Does your child tire easily during physical activities?

Has anyone ever told you that your child has a heart murmur?

Does your child seem to assume a squatting position frequently?

PHYSICAL ASSESSMENT

Inspection

Palpation

Auscultation

Vital signs

INSPECTION

General appearance• Note size for age

• Activity

• Level of consciousness

• Skin color

• Muscle tone

• Nail beds

• Edema

Skin and mucous membranes

Color and skin temperature• Pink

• Pale

• Mottled

• Dusky

• Moist or dry

• Edema

Dusky skin tones

COLOR CHANGES

Mottled Skin

COLOR CHANGES

Note the pallor of extremities compared to trunk

COLOR CHANGES

Skin color; watch for changes in perfusion when crying or agitated

COLOR CHANGES

Pale or dusky undertones

COLOR CHANGES

INSPECTION

Pink mucous membranes

Nutritional status

Excessive perspiration

Neck vein distention

Retractions

PALPATION

Assess pulses for rate, rhythm, and volume• Apical

• Radial

• Brachial

• Femoral

Grading of pulses0 = absent

1 = weak, thready2 = normal3 = full4 = bounding

Capillary refill• Normal time < 2 seconds

Fontanel• Indicates fluid status

Hepatosplenomegaly

AUSCULTATION

Heart sounds are the refection of the heart’s functioning, the intensity varies with age, thickness of chest wall and cardiac output.

• S1: Closure of mitral and tricuspid valves, producing the first heart sound “lub” of “lub-dub.” This is the beginning of systole

• S2: Closure of aortic and pulmonic valves, the second heart sound “dub.” This is the beginning of diastole.

MURMURS

Innocent murmurs are those that occur in the absence of significant heart disease or structural abnormality of the heart.

Innocent murmurs are rarely heard in newborns and should be evaluated.

Approximately 30% of children beyond the neonatal period are found to have an innocent murmur.

Diastolic murmurs are always pathologic

Graded on a scale of 1-6

Clinical assessments must be correlated with murmurs

CLINICAL ASSESSMENT

Monitor vital signs• Heart rate

• Blood pressure

• Respirations

• Pulse oximetry

Interpret lab values Maintain strict intake and output

DIAGNOSTIC STUDIES

Chest X-ray

Electrocardiogram (ECG/EKG)

Echocardiogram

Cardiac catheterization

Arterial blood gases

CONGESTIVE HEART FAILURE Is the pathophysiologic state in which

the heart is unable to pump sufficient blood to meet the metabolic demand of the body. Volume overload

Pressure overload

Myocardial dysfunction: Problems with contractility

High cardiac output demand

RIGHT SIDED FAILURE

Effects of increased ventricular pressure

- Wall stress and attempts by heart to pump better

Effects of increased volume

- Dilation of the chamber

- Regurgitation back into the atrium

CLINICAL MANIFESTATIONS

Tachycardia Muscle failure – poor contractility

• Marginal B/P • Change in pulses• Diaphoresis • Poor feeding• Pale color

Hepatomegaly

LEFT SIDED FAILURE

Increased pressure in left ventricle

Increased volume in left ventricle

Increased pressure in pulmonary veins

High pulmonary artery wedge pressure

HYPOPLASTIC LEFT HEART

LILY NEWBORN PRE OP LILY ONE DAY OLD POST OP

LILY 4 YEARS OLD LILY 5 YEARS OLD

CLINICAL MANIFESTATIONS

Effects of increased pressure• Muscle failure as on the right

Effects of increased volume• Ventricular dilation and worsening of muscle

failure

Poor contractility • Marginal blood pressure

• Tachycardia

Volume and pressure overload• Backward failure

Tachypnea Increased work of breathing Moist rales Signs and symptoms of pulmonary

hypertension

Failure on either side• Poor perfusion

Capillary refill is delayed Extremities are cool

• Gallop heart sound• Tachycardia

Failure on either side• Peripheral edema• Diaphoresis• Loss of appetite

CLINICAL MANAGEMENT

Fluid restriction to help with congestion

Diuretic therapy to help manage excess body water

Nutritional support, either NGT or IV therapy

Oxygen for the heart muscle

Medication to assist with contractility• Digoxin

• Dopamine IV

Medication to aid perfusion• Captopril PO

• Milrinone IV

Treat underlying cause

MEDICATIONS-what and why? Diuretics Cardiac glycosides ACE Inhibitors/Antihypertensive agents Antibiotics Analgesics Salicylates Oxygen Gamma Globulin

CONGENITAL DEFECTS

Atrial Septal Defect Ventricular Septal Defect Patent Ductus Arteriosus Hypoplastic Left Heart Transposition of the Great Arteries Tetralogy of Fallot

ACQUIRED DEFECTS

Kawasaki Disease Acute systemic inflammatory illness Leading cause of acquired heart disease in children Usually preceded by URI

Rheumatic Heart Disease Damage occurs, usually to valves, following

rheumatic fever More prevalent in 3rd world countries Inflammatory disease affecting heart, joints, CNS Inflammatory disease that occurs after infection

with beta hemolytic strep pharyngitis

CASE STUDY

Sara is an 18-year-old first-time mom. She brings her 3-week-old baby Adam into the ER for a check because his color did not look right today. She tells you that he is a good baby, he sleeps all the time, he never wakes up to eat, she wakes him up

What else do you want to ask?

What else do you want to ask?• What was Adam’s birth weight? Mom reports 7 lbs., 9 oz.

• What is his current weight? You weigh him today at 7 lbs., 1 oz.

• How much is he eating? He eats about 3 oz. every four to six hours.

• Number of wet diapers a day? He has a wet diaper about every six hours.

• Ask mom to describe the scenario about the color changes. Mom states he was feeding today and he looked a little blue.

You ask the mom whether Adam had a murmur at birth and mom says no.

The ER doctor examines him and tells Sara he believes that Adam has a VSD

Why would his murmur be heard now at 3 weeks of age?

Why would his murmur be heard now at 3 weeks of age?

A VSD is a hole between the ventricles. At birth the pressure in both sides of the heart is equal. As the baby grows, the pressure in the left side of the heart increases, forcing blood back into the right side of the heart and backing up into the lungs, which causes respiratory distress and poor feeding. It also results in an audible murmur.

What tests would be ordered and what would be in Adam’s plan of care?

What tests would be ordered and what would be in Adam’s plan of care?

Tests:• Chest X-ray to look for cardiomegaly, pulmonary edema.• ECG for rhythm disturbances.• Echocardiogram to confirm the VSD and look for other

structural abnormalities and to determine the size of the VSD.

Adam’s plan of care will include oxygen, feeding support with smaller, more frequent feeds with a special nipple, and higher calorie formula. The food might be delivered via nasogastric feeds. Treatment will be based on the size and location of the VSD. It can be surgical or conservative

MODULE 5 WORKSHEET

Complete MODULE 5 WORKSHEET Know which medications are used for

which purpose in children with cardiovascular compromise